Race car suspension Class

[Ranger Mike]

Dr. that was a hoot...speed secrets no doubt..I have been on here for about a year and there are some absolutely top notch people on here..xxchrisxx, Danger, brewnog, turbo1, mender, russ watters..they have insight and knowledge gained over many years and have helped me with many wackey ideas i have had in my racing effort...it is a pleasure to know them and all they ask is honesty and an open mind..i sure learned some humbleness on this site..
ps if i left anyone out, i apologize..

 

[mender]

Good story and pretty typical, dr! I've had the followers tagging along a few times as well!

We run a 3 link system on asphalt road courses with similar car specs but if you have any specific questions I'll give 'em a shot.

And thanks for the pitch, Mike! Great to be here as well!

 

[the dr.]

Good story and pretty typical, dr! I've had the followers tagging along a few times as well!

We run a 3 link system on asphalt road courses with similar car specs but if you have any specific questions I'll give 'em a shot.

And thanks for the pitch, Mike! Great to be here as well!

Thanks Mender, I have only seen the car once since we got it, working 7 days a week stinks,I hope to get to spend some time with this car tween now and season start, now, we just got 6 inches of snow... I have lots of expierence with other types of rear suspensions just never run a 3 link, beat em a few times with a leaf car but... that's another story, just so you can see how I scare people at the track check out my latest blog, it has a pic of me on the top..
http://topofthebox.wordpress.com/2010/12/25/year-end-thoughts-from-the-dr/

the dr.

 

[the dr.]

I have had a chance to go over the car pretty good now and everything looks good so far, I am qwondering about panhard bar mounted on right side instead of the left... this will take some thinking... lol details later, we are looking at first practice some time in march...

the dr.

 

[mender]

Check the angle on it as well.

 

[Ranger Mike]

left side mount is the norm only because its easier to pull a chain than push it...left turns mean the panhard bar is being pulled when you turn...but...the nascar boys run the same thing on road courses so the p bar is being pulled and pushed...go for it..

ps that will really screw up the minds of the competition with this new wrinkle!

 

[mender]

Maybe you could describe the mounting location and bar length as well. What adjustments can you make?

 

[the dr.]

http://topofthebox.wordpress.com/2011/02/19/work-in-progress/
I have posted a few pic's of the track we will be running at this year, on my blog, I am still working on getting the car ready got body going on this coming week. and we have a pracitice on March 26 first race April 2 so if your in the North Georgia area feel free to stop by and say hi!

the dr.

 

[Ranger Mike]

good way to turn winter into spring...plus Daytona this weekend...looks good...bet you can't wait to get the Green flag!
Rm

 

[the dr.]

well our first practice will be this coming saturday evening, I am looking forward to it greatly! I have been overthe car with a fine tooth comb, and found a few things that make me wonder like the j-bar mounted to the right side but while kicking this around in my head this makes sense since these cars are famous for being tight and this will loosen the car up, I have toyed with air pressure and slight tuning in the past so I have decided to go with the set up that the car used last time it ran at ngs and go from there my driver has very limiteed time in a race car much less a 3 link so this coming saturday is going to be a real learning esperience.
anyone got any pointers I can pass along to my driver? he is a pretty sharp guy who has learned tons in the off season and is a quick learner... I just need to guide him in the right direction...

the dr.

 

[Ranger Mike]

on 3 link rear suspension this is what i got as good set up:
top link or third link/toque link should be mounted 12 to 13 " above center line of axle housing and 1 to 3 inch behind vertical center line of axle housing. it also should be mounted at center of weight mass of the car...i.e. if car has 60 inch rear track and 53 % left side weight
60 x .53= 31.8" so center of mass and top link mount location is 31.8 inch to left of the center of the RIGHT rear tire.
Angel the top link down hill about 20 degrees..and usual adjustment is between 15 to 25 degrees..btw on asphalt we run 3 to 7 degrees...

adding more down hill angle will tighten up the car under power off the corners,,,,but the hook up does not last as long and by using a lesser angel the car will hook up more smoothly but not as quickly.

you may want to add a shock damper to the 3rd link mount. this will control rear end looseness and wheel hop under braking..the axle damper should mounted 5 degrees up hill. Never mount it level or down hill. If the rear end loosens persist at corner entry use more axle damper up hill angle adding no more than 2 degrees at a time. max 7 degrees up hill angle on dirt. if axle hop and loosens still is there we have to look at brake caliper mounting..
if rear is too tight at corner entry decrease down hill angle...

lower trailing arms usually mount 3 to 5 inch below axle center line. the most common center to center length for

lower trailing arms is 20 inches.

lower trailing arms normally ,mount 5 degrees uphill. uphill angle gives better forward bite. both links with same angle create slight roll over steer. you can change wheel base to control rear steer by shortening or lengthening one of the

lower trailing arms . Many dirt cars run 20.25 inch right

lower trailing arm 1/4 inch longer than left side , to increase roll over steer.


What shocks are you running on the car?

what is length of the track and what is the angle of the banking in the turns?

hope this helps

 

[the dr.]

Ranger Mike, thanks for the help, we didn't get to try any of it out last night since it came a torrential downpour here but we are going to have a practice Tuesday night and first race this coming Saturday...
question what effect does shortening the 3rd link have? it is 29.75 now and We can't run anykind of dampers at all no busciut bars although I do have a iron in the fire that may find away around that...lol everything else is pretty on track with what you have sugested... I did change the lower bar angel to your suggestions since it seemed more inline with my thoughts... only changed it 3 degrees... but we will see and I want to thank alll of you here for your input...
again its a standing invite to each of you if your in the NW Ga. area on Saturday night holler at me We got a place for you on our trailer! but one little bit of warning... we may put you to work...lol and we pay with hot dogs!

the dr.

 

[Ranger Mike]

Thanks Dr.
In the case of the 3rd link, length does matter..kind of...if you draw a line through the mounting points on the lower links it points to the front of the car, if you draw a line through the 3rd link, it also points to the front of the car..where they cross is the rear instant center (IC). and this point is where they all act as a torque arm. Modified 3link have a shorter 3rd link and a cushioned type of 3rd link to cushion the forces being fed to the rear tires under acceleration. These are spring loaded torque links or rubber biscuit bars. Its about the angle of the 3rd link. If the instant center is moving around a lot under acceleration, you have a very squirrelly car. Th ultimate 3rd link depends on its length. Longer length is ' better' only because the mount point will be lower in the chassis and the reaction to the chassis under acceleration will be more gradual and make the car more drivable than if you have a higher mounting point.

Summary from this and above post- the more the instant center moves around, the more the rear steer changes and goes from rear understeer to rear over steer and you got a hand full of car...during rear chassis movement in the corner. An IC that moves least and is located as low as possible in the chassis will provide best force to the tires as you will get.BTW, we ran a third link that was almost at the rear motor mount point, on out asphalt super late model. Biscuit bars and spring load torque links are Band-Aids to try to cure bad engineering of mount points.
Thanks for the invite and get that Checker in the first race, amigo!
RM

 

[the dr.]

Ranger Mike, we have 26 7/8" lower arms, with a 29" 3rd link, car has bilstien shocks it is long wheel base car... 107" wheel base, tonight we go for our first race last tuesday we went for practice, and driver was just getting used to it and improved DRAMATICALLY! shaving off 2 seconds during the night, had J bolt at rear end work loose and it took us a while to find it so we loaded, and watched... like I told driver "better to park it and check it than to race it and wreck it" . so we are looking forward to tonight.I played with air pressure a little and found that 9lbs worked real good on right rear. NGS is a 3rd mile very high bank red clay track track record for late model is 12.89 and in Mod Hobby we were in the low 15's so I was very happy. looking for major improvements tonight. I want to thank you for all the info you have provided it has really improved my understanding of the 3 link. and with that I feel comfortable in making changes and tuning... we have to weigh 2900lbs and tuesday night we crossed the scales at 2900 exactly.. so I am going to add a little lead today to make sure we will cross the scales at weight... Car has lot's of roll over in the turns but driver says it feels good and car is fast comes off turns really good and picks up fast without all the fishtailing we had issues with on the leaf spring car...we have 2.5 inches of stagger and I have tires to add some if needed latertonight depending on track.. track has new clay and it is worked in really well, I am off to the shop to get car loaded and get ready for tonight... hope everyone has a great weekend... and thanks again for your help...
the dr.

 

[Ranger Mike]

still snowing up here in yankee land

get that checker , Doc!

 

[the dr.]

well here is an update, we have had 2 races and have had to start in the back on both of them we have an 10th and a 8th, this weekend driver finally learned how to get the car in the corner but i have a question... on the rear shocks we use the rubber rings to show travel. our right side,we are getting 4 or 4 1/2" of travel, on left side its only 2 1/2 " of travel.now I am wondering should I make an adjustment to even it out some and if so what should I change? the car was really good last night and we had an awesome run but I see more in the car and I don't want to chase the car all year I would like to get ahold of it now... our rules say that the 3rd link has to be a solid par no spring loaded or buscuit bars, well we have been racing against a lot of cars that have been running them, this week they announced it was going to be policed strictly this next week so we are already 2 races ahead of some of these guys... it did seem kind of twitchy coming off the corner a couple times but I think that may of been driver error... so I really want to thank you for your help and I hope to be posting a victory lane pic here soon...
the dr.

 

[Ranger Mike]

What stagger you running?

loose on corner exit - look at stagger..is she is loose coming off the turn, reduce the stagger.add cross weight..see set up below. Normally we soften the right rear spring or stiffen the left rear spring but shock travel indicates that we don't need this. if you had run a spring 3rd link we would soften it.What number shocks are you running on the car? i assume you got 7 inch travel on the fronts and 9 inch travels on the rear corners..
What is setting of rear panhard bar?

did you get chance to do tire temperatures?
did you scale the car? set up i use as base line for dirt car is 53 to 55% left side, 55 to 56% rear and 49 to 51 % cross weight

 

[fstock34]

i have a question about a car I am trying to build it is a street stock built out of a 1985 monte carlo and as far as sprung and unsprung weight would it be benefical for me to add weight in the form of heavy gussets to the rear axle housing( on the lower sides of the axle tubes not the topside) to get rear weight percentage and beef the strenth? As well add a few pounds of reinforment to the left rear trailing arm (by melting led into the hollow bottom side on the lower third of the arm toward the rear end housing only leaving the other 2/3rds empty) to add more rear percentage and some left side?? My tracks rule book allows alteration to those items to add strentgth. While i do know that would be adding unsprung weight i also know that the chassis is built very well and with a 56% maximum left side percentage rule a 3000 pound minimum weight rule and a 5 inch ride height rule. a lot of teams in this divison have been forced to set their cars up having weight on the right side of the car to meet those requirements and i think that adding weight right on the rear housing and the trailing arm would help my cars set up quite a bit (this weight would lower than the frame rails by quite a bit as well back as far as it could be before running into polar moment issues). From what i read on this forum earlier this should help add rear grip off the corner being that the track surface is 2 season old with no large bumps to make the tires jump by making the role center higher am i correct or did i read things wrong?? Any thought from the fellow racers on here would be greatly appreciated because this will be my first year in this divison moving up from factory stock to street stock and the set up and things like that are much more complicated for this car than my factory stock was. Hope you all have a happy holiday weekend and i look forward to hearing from you guys.

 

[Ranger Mike]

Welcome..You have been doing your home work well and have a pretty good grasp of getting the handling under control.
Unsprung weight is bad only because you can not control it..as good as.."sprung weight" as far as that can be controlled.
In these " stock"series racers, there is a lot of room to gain competitive advantage, you just got to know where and how...

I am for beefing up the trailing arms. I am not a big fan of doing the melting lead thing as it is a real pain and will not reinforce the chassis member ( welding gussets is the way to go). What do the rules say about adding weight? When do you have to scale the car? Do you have to scale after each race? Or are the top three scaled after the main event? Exactly how much weight are we talking about?
Do you have the battery relocated? What do the rules say about the springs and sway bars?

 

[mender]

The mid 80's metric chassis (Monte Carlo) has a poor camber curve and that either needs to be corrected if allowed within the rules or compensated for with the right suspension combo.

Adding unsprung weight in the amount needed to positively change the weight distribution will complicate your set-up and be more and more of a handicap as the track gets bumpy (it will!). I'd recommend doing only the amount needed for strength and concentrating on tuning the suspension. There are a lot of little things that are legal that when done properly can make more of a difference than a couple % weight change.

Without having the rules it's difficult to advise you; do you have a link?

 

[fstock34]

Thanks guys for your quick responses it is greatly appreciated. For some reason the website won't allow me to link the rule book so i copy pasted it below. I am in a hurry right now but later tonight or tomorrow i will create another post with some other questions i would like to pick your brains about. Thanks again.

YEAR, MAKE, AND MODEL MUST BE DECLARED BEFORE CAR WILL BE ALLOWED TO COMPETE. IT IS THE DRIVER'S RESPONSIBILITY TO UPDATE THIS INFORMATION, AS NECESSARY. SUSPENSION AND STEERING COMPONENTS MUST BE IDENTICAL AND FUNCTION AS THOSE AVAILABLE ON STANDARD PRODUCTION VEHICLE OF THE SAME YEAR, MAKE AND MODEL. THE ONLY SUBSTITUTION AND MODIFICATIONS ARE THOSE MANDATED AND DETAILED IN THE FOLLOWING RULEBOOK. ABSOLUTELY NO SPECIAL OR NON-PRODUCTION OTHER SUSPENSION OR STEERING COMPONENTS EXCEPT FOR THOSE ALLOWED IN THE RULEBOOK.

BODIES

1. Must be 1955 to present American made cars with minimum wheelbase of 100”.

2. No trucks, sport utility vehicles, station wagons, or front wheel drives.

3. All bodies must utilize a full factory stock steel hood, steel roof, and steel trunk lid. All three pieces must be from the same year, make, and model vehicle. Internal support structure may be removed but all factory window channels and drip edges must remain intact on roof panels. Internal support structure only may be removed from hood and trunk lid. Perimeter edges on side of hood may not be removed. Factory front and rear roof pillars must remain stock to top of front fender and top of rear quarter panels.

4. Body sides including front fenders, doors, and rear quarter panels may be fabricated using minimum 22 gauge steel but must retain original factory appearance and body liner. Body sides may not be any lower than original rocker panels. Doors must be welded or bolted shut. All sheet metal must maintain 5 inch ground clearance.

5. Gutting of bodies allowed. All flammable material must be removed along with all glass, chrome, and plastic.

6. All cars must have full stock front firewall, in the original location of chassis being used. Stock floor pan must be maintained to rear of driver’s seat, across entire width of interior. All holes in front and rear firewall, and floor pan, must be covered with minimum 22 gauge steel. Rear firewall MUST be steel. Modified or sectioned firewalls will be subject to a 50 pound minimum weight penalty.

7. Aftermarket stock appearing rubber or plastic nose and tail pieces may be used, but must match body being used. All cars using such nose and tail pieces must have (2) tow hooks in both the front and rear for towing purposes. Hooks must be fabricated from solid steel or chain. Cables will not be allowed. Slits may be cut in nose and tail piece so that hooks or chains may be tucked in until needed, but must be accessible at all times without the need for hood or deck removal.

8. Cars must have complete wire screen or lexan windshield, supported inside at center by (3) vertical steel bars, minimum 1 inch by 1/8 inch, not less than 4 inches apart. No part of the front windshield opening or rear window opening may be obstructed. NO rear windshields.

9. Hood scoops allowed up to 4 inch maximum height, measured at any point. Hood scoops may be aftermarket or factory items. Single hood scoop only. Opening may face forward or be located at rear of hood.

10. Maximum 6 inch height, clear lexan spoilers allowed. No lettering on lexan spoilers. No side pieces allowed on lexan spoilers. May use factory OEM spoiler for body being used. Maximum 4 inch tall aluminum or steel spoilers with no side pieces are also permitted. One spoiler only allowed and must attach to rear of trunk lid.

FRAMES and SUSPENSION

1. All cars may replace frame rail from centerline of rear axle, to rear bumper mounts, utilizing 2 x 3 inch box tubing. All cars must retain unaltered front crossmember and spring mount location. Coil spring cars must retain original cross member and spring mount location. Uni-body cars must connect front and rear sub frames with minimum 2 x 3 inch box tubing. Uni-body leaf spring cars may replace rear frame rails entirely with 2 x 3 inch box tubing and may connect to rear of original unaltered front sub frame. Leaf spring mounting points on cars with fabricated rear frame sections must be in OEM location and must mirror one another from side to side. Any leaf spring lowering blocks used must be the same dimension on both sides. Rear crossmember on coil spring cars must be in stock location and must remain unaltered from stock except for upper control arm mounting brackets which may be improved. Frames on coil spring cars must remain stock from front bumper mounting surface to rear axle centerline except for additional bracing.

2. All cars must retain minimum of 5 inch ride height at all times, with driver buckled in seat.

3. Front spring pockets must remain stock and in stock location. Front crossmember must not be altered in any way.

4. The rear shackle attaching points must be within factory tolerances of stock location.

5. Wheelbase may not be shortened.

6. No rod ends allowed on any suspension part, except for shocks and sway bar links.

7. Aftermarket sway bar and sway bar links allowed. Sway bar must fasten to lower control arm.

8. Front lower control arms and steering components must be from make and model of chassis being used. All suspension components must remain stock unaltered. Stock steel OEM passenger car spindles only. NO corvette spindles. All casting numbers and other identification marks must remain on spindles.

9. All suspension components (except otherwise noted) must mount in stock location for year, make, and model of chassis being used. Front upper and lower control arm mounting points on frame, may NOT be altered or relocated in any way. Gussets may be added to suspension pieces for strengthening purposes only.

10. Shocks may be mounted in any location. Only steel shocks permitted, one per wheel.

11. Stock type ball joints only. Screw in lower ball joints are permitted. Ball joint and tie rod ends with interchangeable studs are not permitted. No Howe precision ball joints or tie rod ends permitted.

12. Stock type steel springs only although spring rates may be altered. Springs must be in stock location.

13. Aftermarket steel tubular upper control arms are permitted but they must mount to stock frame mounts without modifications. Control arms must bolt directly to factory mounting holes and retain factory type ball joint. Strut cars may use aftermarket strut mounting plate, but must mount in stock location utilizing stock holes.

14. Urethane, rubber, or metal suspension bushings, may be used.

15. Rear suspension upper control arm or torque arm mounting holes, may be moved on frame only.

16. Lower control arm mounting holes, may be moved on rear end housing only.

17. One external weight jacking device allowed per wheel.

18. Rear upper control arms or torque arms must be for year, make, and model of chassis being used. These parts must not be altered in any way except for bushings. Lower control arms may be fabricated from rectangular or round tubing, but must be dimensionally identical to stock components that they are replacing with respect to center to center distance of mounting holes. NO tolerance will be given from stock dimensions.

19. No aluminum suspension components.

20. No panhard bars allowed except for factory torque arm cars. No rear sway bars allowed.

21. Suspension must be stock configuration and design for year, make, and model of vehicle being used.

ROLL BARS

1. Minimum 1 ½” x .120” or 1 ¾” x .095” round steel seamless (or DOM) tubing mandatory.

2. All cars are required to have a rear vertical hoop behind and above the drivers’ head connected to left and right front roll bar legs by a roof hoop.

3. The front roll bar legs must follow the contour of the windshield post and cowl.

4.. Maximum distance from the windshield to the rear of roll bar should be no more than 4 inches.

5. A diagonal bar from the top left to the bottom right must support the rear vertical hoop. 6. A roll bar must connect the left and right of the rear vertical hoop at seat height and across the floor pan at the bottom.

7. An additional bar must be installed at dashboard level, extended from the left front roll bar leg to the right front roll bar leg.

8. A minimum of three door bars on the left side and 2 door bars on the right side must be used. Door bars must be convex in shape and extend into the door panels. Door bars must be attached to each other and the frame with vertical bars.

9. Minimum 1/8” x 1 ½” gussets must be welded into all main cage joints and driver’s door bars.

10. Racing seat MANDATORY.

11. Minimum 1” diameter steel tubing welded directly into the cage must support driver’s seat. 3” lap belts and 3” shoulder harnesses are mandatory. Crotch belts are recommended. All belts and harnesses must be securely fastened to the cage (harnesses must be attached below shoulder level).

12. All belts must be dated and no more than 5 years old. All belts must be un-frayed and in good appearance. Roll bars in the drivers’ area must be padded.

13. Headrests and drop-down window nets are mandatory.

14. A radiator hoop may be utilized in front of the cage with a maximum of 2 upright supports.

15. Rear cage supports may extend to the rear of the frame, no uprights allowed. All main hoops must attach to the original frame.

16. Plating of driver side door bars HIGHLY RECOMMENDED.

RUB RAILS/ BUMPERS

1. Rub rails allowed.

2. The top of the rub rail is to be no higher than the top of the tires, and no lower than hub center height.

3. Rub rails must be made of tubing maximum 1 ¾” O.D. and will be 2” maximum to the inside of the rail to body.

4. One single rub rail per side.

5. Ends must not be exposed to the outside of the body skin.

6. Bumpers must be securely safety chained to each frame rail to prevent them from dropping onto the raceway.

7. A flat piece of metal must be welded or bolted from the outside edge of bumper flush to rear quarter panel and front fender if not using rubber nose.

8. Tow hooks required on both frame rails, front and rear.

9. No sharp edges or cut-off ends.

10. Front and rear bumpers may be fabricated but must not extend any further from body than stock bumper and must fit under stock or replacement nose and tail pieces. Fabricated bumpers may not be any wider than sheet metal in front and rear, and must be capped to eliminate any sharp edges.

WEIGHTS and PERCENTAGES

1. All coil spring cars must weigh 3000 pounds, with driver-after the race.

2. All leaf spring cars with stock rear frame sections must weigh 3100 pounds, with driver-after the race. This type of car is one using frame connectors to join front and rear stock frame sections and may not have any other fabricated frame rail except for rearward of rear axle centerline.

3. All leaf spring cars with fabricated frame rails from front clip back, or cars with altered wheelbase, must weigh 3200 pounds, with driver-after the race.

4. Coil spring cars may have a maximum of 57% left side weight. Leaf spring cars may have a maximum of 56% left side weight.

5. Leaf spring cars may have a maximum of 48% rear weight. No rear percentage limit on any coil spring cars.

6. All cars with engines having 10:1 compression ratio must add 100 pounds to base weight and have 1% less left side weight. 10:1 coil spring cars are allowed 56% left side weight. 10:1 leaf spring leaf spring cars are allowed 55% left side weight.

7. All cars with fiberglass or aluminum aftermarket bodies, must add 100 pounds.

8. All weights and percentages will be measured with driver buckled in seat.

9. Riverhead Charger cars are allowed to compete, but must maintain 5 inch frame height, weight a minimum of 3350 pounds and have a maximum of 54% left side weight. Riverhead Charger cars must adhere to all other Charger rules, with the exception of rear windshields-which will be allowed.

10. Frame height will be measured at lowest part of frame, including any bolt on lead.

BRAKES

1. Four wheel stock hydraulic brakes in working order mandatory.

2. No brake adjusting devices within driver's reach. No adjustable proportioning valves allowed.

3. Aftermarket master cylinders permitted.

4. No aluminum brake rotors allowed. OEM calipers only for year, make, and model of chassis being used.

5. May install rear disc brakes utilizing stock parts and an aftermarket bracket.

ENGINE

All engines must be sealed within 3 races from start of season. Cubic inches, compression, carburetor, and engine components will be checked and verified. Seal will not guarantee that engine will not be rechecked additionally, at anytime during season. It is the driver's responsibility to have engine sealed. Tech sessions will be scheduled before the season begins and during the season, as necessary. All seals will be installed at track or at scheduled sessions only. A small fee for seals and drilled bolts will apply.

1. Any overhead valve V-8 American manufactured production engine permitted.

2. Stock stroke and stock bore (+0.60 max.)

3. Engine must be in stock location, with solid type motor mounts utilizing stock holes in both block and frame. Engine must be centered in chassis and may not be lowered in chassis, tilted, or moved toward firewall.

4. Engine must be of same manufacture as car used. GM in GM, Ford in Ford, Mopar in Mopar.

5. Maximum compression ratio of 9.0:1.

6. No porting, polishing, or alterations of any kind permitted.

7. Chevy engines must have a maximum stroke of 3.480 and a maximum bore of 4.060.

8. Maximum displacement of 360 cubic inches (+.030 overbore on Mopar) on all engines. 9. Edelbrock Performer PN# 2101 or 2116 and unaltered Holley R4412, 500 cfm, carburetor mounted on a 1” adapter plate. *Check with tech inspector for part # of intake manifold for different manufactured engines*

10. Mechanical throttle linkage with toe strap and double throttle return springs required.

11. Stock production, cast iron heads (no bow tie or bowtie vortec heads). World Product #4266 and #4267, Engine Quest: CH 350C, CC 170BA, CC 170 BA2, CC 167 CS2, CC 167 CS, CC 167 ES2, CC 167 ES and Dart: 100-210-70, 100-210-10, 100-242-66, 100-243-65, 100-263-64, 100-243-70, Pro topline 2236494906, and World Products #5303B for Fords are allowed (part numbers must be visible).

12. Dish or flat top pistons only.

13. Any flat tappet or hydraulic roller camshaft allowed.

14. Stock dimension magnetic flat tappet lifters or hydraulic roller lifters for engine used mandatory. If hydraulic roller lifters are being used, the valve springs may not exceed 1.300 inches in diameter. Retro-fit hydraulic roller lifters are permitted. No modification or shimming of hydraulic roller lifters is allowed.

15. Roller rockers allowed, no shaft style rockers (unless factory issued) or stud girdles.

16. Stock single point distributor or stock electronic ignition only.

17. No MSD boxes.

18. Stock unaltered standard or automatic transmissions mandatory.

19. Stock type steel flywheel, clutch, and pressure plate ONLY. Minimum weight of flywheel will be 15 pounds. Minimum weight of pressure plate will be 13 pounds. Minimum weight of clutch disc will be 3 pounds.

20. Blow proof steel bell housing mandatory for standard transmissions.

21. Automatic transmissions must use working stock torque converter only. Must be minimum of 12 inches in diameter, measured at the main body of converter, not at mounting flange. Absolutely no lock up or direct drive automatic transmissions.

22. All cars must be able to move under their own power, and be self-starting.

23. Headers allowed.

24. All cars must have 2 Dynomax #24222 mufflers. System must be securely fastened and leak free.

25. One radiator in front of engine only.

26. All cars must carry a securely fastened and leak-proof 1-gallon overflow tank. NO ANTI-FREEZE!

27. GM #602 Crate engine will be permitted with box stock #4412 2 barrel Holley carb. Crate motors are subject to tech inspection, regardless of seals.

REARS

1. Stock rears for year, make, and model. Mounting brackets may be moved on rear end housing.

2. May use Ford 9 inch rear (non-floater).

3. All rears must be locked.

4. Magnetic steel spool, mini-spool, or welded spiders only.

5. No lockers or ratchet type rears allowed.

6. No fabricated rear end housings. Center section and housing must be OEM production items.

WHEELS AND TIRES

1. 8” steel racing wheels mandatory.

2. 1-inch steel lug nuts with proper taper are mandatory.

3. Different offsets allowed.

4. ¼” spacers permitted.

5. Track tire only.

GAS TANKS

1. Encased fuel cell mandatory. 22 gallon maximum capacity.

2. Fuel cell must be securely fastened to rear frame.

3. Fuel shut off valve must be in plain view and within drivers reach, painted fluorescent red or orange and clearly marked “ON” and “OFF”.

4. Stock mechanical fuel pumps only, no electric fuel pumps.

5. Bottom of fuel cell may not be lower than 10” to the ground with driver.

6. Must have a minimum of a 1-inch by 1 inch X-brace under fuel cell.

7. Tip over valve is mandatory, Flapper under gas cap is recommended.

BATTERY

1. Battery may be located in the drivers’ compartment and enclosed in a spill-proof container securely fastened to the floor.

2. All batteries must have a spill or splash cover.

3. Battery shut off switch is mandatory. MUST BE IN PLAIN VIEW, painted fluorescent yellow or orange and clearly marked “ON” and “OFF”.

DRIVESHAFT

1. Magnetic steel drive shafts only.

2. Drive shaft should be painted white or yellow for visibility if lost on racetrack.

3. All cars must use a steel retaining hoop at the front and the rear of drive shaft.

GENERAL

1. No rear view mirrors, radios, or any other form of driver/crew communication.

2. Driver MUST monitor one way track scanner and obey and respond to race director’s instructions.

 

[Ranger Mike]

excellent...as crew chiefs dream...ok, i think we have some room to improve the chassis set up dramatically..and LEGALLY- let's start with the front..you can run aftermarket sway bar and this is a plus..
you can run screw in lower ball joints, you can run tube upper A-arms and as long as you got a " stock " spindle, you can run a different spindle..all of which can adjust the roll center and greatly assist the camber curve which is pretty bad.
If you have the time and the determination. you need to send me the details of your set=up but this will require you to measure many things on the car..reply back if you have a mind to do this..

 

[fstock34]

Ranger mike i definitely have the time and determination to do anything that will help. The factory stock i had was built by me from the ground up and we were protested throughout my last full season in 2009. Reason being while everyone else was buying tires every 2-3 races we bought three tires all season long the left front was 3 season's old and pulled out of a scrap tire pile. We couldn't afford tires that often so every week we cleaned the tires with a heat gun and wire wheeled them with mineral spirits (that what hoosier told us to do). Then based on what the car was doing during the last say 5 laps of the feature we adjusted the set-up to compensate for the tire-wear. Instead of tires we changed shocks we changed springs we made sway bar adjustments stuff like that so i don't mind doing work at all. We had an engine detonate during practice of race two so we missed a few weeks that year which probibly cost us a championship but of all the races we ran that year we finished no worse than third and no worse than second throughout the last 7 events and also received the trophy for fastest lap of the season furthuring baffling furious drivers who couldn't understand tires arent everything. We also ran the same tires the following season for the first three events and won another feature before we sold the car. Most basic things i understand its just the things that you couldn't do in the factory stock were allowed to do now and these new things I am lost on lol. Ranger mike in reference to the things you asked about i have these items so far.

1. As of right now we have a 1 and 1/4 stock monte carlo sway bar.
2. stock ball joints in the lower a arms. (in the thriller we experimented with taller lowers it made the car terrible however we changed back to stock lower's and reamed the upper ball joint hole about 1/4 inch to seat the upper joint farther down into the spindle and the car was 2 tenths faster and stuck amazingly in the corner.)
3.We have tubular upper a frames from left hander. We have a set where the ball joint is in stock location and stock mounting holes and also a set where the ball joint is relocated for caster purposes (left hander is only company that makes this a-arm to my knowledge) and the mounting holes are slotted for further caster adjustment.
4. 86 monte carlo spindles however we also have a set of impala spindles on the shelf.
5. also for rear "control arms" if you read the rule book about it references the rear trailing arms as "control arms" and the rule book clearly states you can have tubular "upper control arms" so we purchased these as well.

I am definitely willing to do anything that will help ill message you anything you need or if you want private message me a number and a time when your not busy and available to talk racing i could probibly explain clearer about the car. Any information is greatly appreciated its so hard to find racers willing to share it. When i had the thriller if a driver or crew member who was running around in the back getting lapped came up to me and asked me to look at their notes or what they could do to improve their cars i always tried to help them out a little bit so I am glad to see there are still people out there like me and I am not totally nuts for doing it lol. thanks again in advance for your help

 

[mender]

Let's start with a question: why are the Impala spindles still on the shelf? Get 'em on the car!

You've already proven that the car wants a better camber curve. It'll take some work but once you get the front end geometry fixed you'll be faster and go through even fewer tires. You'll find you can back down on the spring, shock and bar rates which will also add stick. It may take a bit to get used to a softer set-up but it will be faster.

Measure your present camber curve for a baseline then switch and remeasure. You'll have to redo the bumpsteer as well.

I haven't read these articles but you might find something of worth:
http://www.ansearch.co.nz/search?search=metric+chassis+setup&cc=com

 

[fstock34]

lol the impala spindles are still on the shelf because were building the car now and were starting by putting the rear end in so we can roll it across the shop and get it on the lift lol. I def agree with the soft springs in the factory stock we ran lf-800 rf-900 lr 225-175 rr-200-125 depending on what the car wanted which was much much softer than everyone else. But as far as the front end is concerned I've heard that at some point you can go to low and that's bad as well...but how low is that?

 

[mender]

It's too low when the suspension bottoms, the geometry starts to go away or the driver can't keep up with the car - soft requires a smoother driver that plans his/her driving a little in advance.

With bad geometry, high spring/bar rates are needed to keep the car in its very narrow sweet spot. Once the front end is sorted, the rates can be lower and the car is much less fussy about set-up.

What's your track shape? Length? How much banking are you running on? Dirt or asphalt?

 

[Ranger Mike]

good points, Mender...for those who are reading along with us, stock cars have tall ride height clearance to clear road hazards we find dead in the middle of the road..or road conditions. We want to reduce ride height to lower center of gravity, and reduce amount of air going under the car. Early Nascar racers went to soft springs to lower the car as low as possible ..they added stiffer sway bars ( anti roll bar) to assist the softer springs during corner weight transfer) ..it all goes back to the round track axiom - Low, Left and Light.
Ref- change out the spindles- this should lower the front Roll Center and you have just proved the benefit of lowering the ft RC when you lowered the top ball joints by 1/4 inch.

I attached the set up sheet so please fill in A thru L and email the data to me. I will input and send it back to you via email.
When we benchmark a race car we do this to record vital data that may be lost when we get in a wreck. I always taped poster boards togeather to make a huge sheet of white cardboard that was placed under the cars front wheels on the garage floor. You have to use plumb bobs to get some readings. Try to measure as accurate as possible.



I have a more advanced software program that has a third dimension but this program will be the easiest to use and give us the biggest bang for the dollar.




One more thing to consider - Buy a set of digital wheel scales( or borrow a set) We always used an old set of tires and wheels for the set up procedure. We painted these red. stored them and we made sure to air them up to proper Psi each time we used them. We also got a set of weights ( tractor weights in our case, but bags of salt, grain , the fat girl friend ( make sure to scale her if she looks like she been watching too much TV eating candy). These are common sense steps to keep measurement consistent. Make sure tires are at proper setting, full tank of fuel, driver weight in car, all chassis setting proper.

 

[mender]

Just have to mention that the tire pressures should be the same as when hot, and you should know how much weight difference different tire stagger makes and how much to adjust the weight jack to compensate. This can save your day when you end up cutting some tires and have to use odd sizes.

 

[Ranger Mike]

mender has good points..this is for the"advanced chassis setup " course..ha ha ..this is prob way to much detailed info but here goes,,,

once you have bench marked the car, you should scale it and measure impact of adding air pressure to the applicable tire relative to scale weight. Also find out how much weight change happens when you turn the jack bolt, or sway bar link. Ackerman will effect this too. Once you have it bench marked, place the car on level floor and cut ride height blocks for each corner and make sure you paint set up marks on the frame at each location. this is a good pit side shortcut when you have to make major component swaps after a wreck and this will get you close to the original set up when you do not have scales available.
(btw - we use roll off ramps which are simple wood platforms of same height as the scales. the car is rolled off the scales and you can jump on t he car to work the suspension until it " settles" and roll the car back on the scales). Other scale tips are to disconnect the sway bars during the process.

 

[mender]

Mike, I think we could fill quite a few pages just with tips!

 

[Ranger Mike]

Mender..i hear you..only prob is this forum would not appreciate it unless...we could state the tip relative to physics and application there of..we " old timers" got a wealth of info that will disappear when we take the ultimate dirt nap...maybe..ifin there is enuff interest, and we had some formal schooling help from the advisors..we could document these speed secrets relative to the particular principle of physics that it applies to?

 

[mender]

Good points; I agree with you regarding the intent to keep things "sciency".

Maybe we could get an indication from one of the admins?

 

[mender]

No comments?

Well, since this thread has a rather remarkable 245 views per post, one might assume that it's in the right place and the people who frequent this forum are interested in the topic and that it's safe to proceed!

 

[Ranger Mike]

fstock34 and the Dr. ...would you like to share your chassis set up information with the public? I will contact ADMIN regarding recommendation on this subject..mean time, can all those racers, Engineers, old hands that have contributed to this thread, please give us input.

Prankster16a ..want to help?
My thought is that we have two project cars available - fstock34 and the Dr. One is a dirt car and the other is an asphalt car. I think the folks at the software program I use would be receptive to assisting with the tech data regarding the math used. The purpose of this endeavor would be to demonstrate the use of Physics when applied to race car set up.
xxChrisxx please let us know..Dr. Dodge? Turbo-1? Brewnog? Input?

 

[Ranger Mike]

ok guys
step up and give me yer opinion