Automotive Race car suspension Class

AI Thread Summary
The discussion emphasizes the importance of understanding race car suspension dynamics to improve handling and performance. Key issues include the car's tendency to push while entering corners and being loose upon exit, which can be addressed by adjusting downforce and the third link location. The roll center and instant center are critical factors in suspension design, affecting tire loading and grip during cornering. The conversation also highlights the significance of software tools like Suspension Analyzer for optimizing suspension geometry. Overall, proper suspension setup is essential for maximizing tire contact and achieving competitive performance on the track.
  • #1,601
Ranger Mike said:
We found out the top link mounting point on the rear end was same setting as from the Port City factory. We are running 58% left side weight so the distance from right rear tire centerline to tip link mount was off 6". since we can only use solid links , no springer top link or spring trailing arms, the mount location is vital to good tire hook up. As found distance from rt rear CL was 32" on 66" rear track width. So 58% left side weight means the mount point is 66 x .58 = 38.25" and changing it means both rear tires are loading the same.
Hi Ranger Mike,
I stumbled across this website, and from what I've been able to soak up so far from your posts has helped me out tremendously, and I appreciate your input. I have a question concerning the correct top link mounting point as illustrated in your post above. I hope that it's not a stupid one, but I'm kind of perplexed as to how you would go about changing the mounting point for the top link on your rear end. In your illustration, it appears that the link is not connected to the center of the rear end. Maybe I'm interpreting that wrong, but could you explain how you would make the top link mount from the chassis to the rear end a straight line without shifting the entire rear-end housing over to the left? (or is that what you need to do?)
 
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  • #1,602
Outlaw, This is what we did , probally different rear than yours but hopfully it may help.
 

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  • #1,603
I sincerely thank you both..please let me work up a teaching point from you racers but you both are sure as hell going to the winners circle soon!
do not forget the card board box...for the trophy!
rm
 
  • #1,604
Thank you Racerman,,exactly what I was talking about! 3rd link properly connected. Good job!

Why is top link mount so critical?

The top link is the rear end link that pulls the race car. This is why the spring type top links have a compression spring to lessen the rear end loading when you get back on the gas at corner exit. This top link directs all rear end force to the chassis. The rear tires grip the track and try to pull the rear end to the rear as the trailing arms on the bottom push the car to the front and try to climb up under the car.

Why location matters- In road course car set ups you want everything set up 50/50 % weight bias, so all front tires scale close to equal and the rear end tires scale equal.

Not so on left turn racers where you want a left side weight bias. When in a turn you want the left side weight rolling over to the right side to assist the car with better traction (tire grip).

Correct location of the 3rd link mounting is a real help so the tires are pulling on the third link equally otherwise when you step on the gas, one tire will bite more than the other and shoot you toward the outside of the track or the inside.

Think of a shipping pallet on the garage floor. You hook a chain on the pallet , not at the center but a foot to the right of center. Now pull the chain, The pallet will cock to the right.

The pallet example is a way to show that you must hook up a locked rear end so both tires bite the same. The pallet example above shows that the right side moves first because there is less weight on that side. Remember down force! We do not really cock the rear end but what really happens is more force is added to the side of the car the link is closest to. In this case we have more force added to the left rear tire ( same as adding a lot more wedge) so we create an off corner PUSH condition.

If you run a 10 year old chassis check the 3rd link mount. When it left the chassis factory back in the day the car was set up with about 52% left side weight. Today you may be running 58% left side weight. This means you can be 2 to 3 inches off the correct location. It is so easy to cure and eliminates one huge rear end traction problem, so fix the 3rd link mount. So screw the chassis builders old specs. They are no longer valid as the chassis has been hacked on so much over the years.

So you need to mount the top link as my post 81 on page 3, post 253 on page 8, post 707 page 21 show.
 
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  • #1,605
3rd link mounting 253 8
3rd link mounting 707 21
3rd link mounting 81 3
3rd link mounting 1603 46
3rd link spring rate 261 17
4 link I C 301 16
4 link rear suspension 132 9
Ackermann 646 33
Aero Burnulli effect 574 29
Anti Dive 403 21
Anti Dive 492 25
Anti Squat 314 16
Anti Squat 327 17
ARB (sway bar) front 357 18
ARB (sway bar) front 358 18
ARB (sway bar) rear 521 27
Benchmark the car 285 15
Big Bar Soft Spring 1118 56
Big Bar Soft Spring 362 19
Big Bar Soft Spring 381 20
Big Bar Soft Spring 568 29
Bump steer 13 1
bump steer 643 36
bump stops 220 11
Camber build 663 37
Caster 319 16
Center of Gravity 563 29
Chevelle rear end 830 42
design suspension from scratch 388 12
design suspension from scratch 566 19
Eccentric 229 12
Front RC location 251 9
Front RC location 691 24
Fuel Cell location 272 14
Fuel Cell location 505 26
Gas shock tuning 217 11
Heat cycle machine 572 29
Hotchkiss suspension 353 18
jacking effect 229 13
jacking effect 691 35
jacking effect 811 41
jacking effect 879 44
Lead - front end geometry 1369 69
leaf spring 789 40
leaf spring 1322 67
Light is right 560 28
Metric clip street stock rear end 301 16
Metric clip street stock rear arb 521 27
Metric clip street stock 830 42
Metric clip street stock 832 42
Metric clip street stock rear steer 858 43
Metric clip street stock 1264 64
Metric Spindle swap 284 15
Metric Spindle swap 809 41
Motion rate - rear 308 16
Myth of Weight Transfer 228 12
Myth of Weight Transfer 676 34
Myth of Weight Transfer 811 41
Myth of Weight Transfer 676 34
Myth of Weight Transfer 228 12
Myth of Weight Transfer 676 38
Myth of Weight Transfer 470 24
Panhard bar 246 13
Penske shocks 217 11
Polar moment 562 29
progressive spring 216 11
Race Line 667 38
RC Height 229 12
rear end camber 1326 67
Rear end Instant Center 301 16
Rear roll steer video 1200 60
Rear roll steer video 858 43
rear steer 116 8
rear steer 81 5
Ride height 552 28
Roll center & offset 229 8
Roll center distribution 229 8
Scrub radius 325 17
Shocks (dampers) 703 40
Spindle Angle 325 17
Spindle Angle 332 17
spring rate calculations 19 2
spring rate calculations 589 30
Spring rate vs wheel rate 17 2
Squaring the car 270 14
Squaring the car 479 24
Stagger 36 3
Stagger calc 36 2
Stagger tape 426 27
Street Stock 1314 66
Street Stock 1264 64
Street Stock 830 42
Street Stock 832 42
Stringing the car 269 14
Stringing the car 293 15
Tire down force 62 4
Tire temp readings 468 24
Track width 255 13
Track width 264 14
Track width 322 17
Track width 505 26
Upper A-arm angle 312 16
Wheelbase 264 14
 
  • #1,606
Thank You RaceMan! That picture is very helpful.
 
  • #1,607
Ranger Mike said:
3rd link mounting 253 8
3rd link mounting 707 21
3rd link mounting 81 3
3rd link mounting 1603 46
3rd link spring rate 261 17
4 link I C 301 16
4 link rear suspension 132 9
Ackermann 646 33
Aero Burnulli effect 574 29
Anti Dive 403 21
Anti Dive 492 25
Anti Squat 314 16
Anti Squat 327 17
ARB (sway bar) front 357 18
ARB (sway bar) front 358 18
ARB (sway bar) rear 521 27
Benchmark the car 285 15
Big Bar Soft Spring 1118 56
Big Bar Soft Spring 362 19
Big Bar Soft Spring 381 20
Big Bar Soft Spring 568 29
Bump steer 13 1
bump steer 643 36
bump stops 220 11
Camber build 663 37
Caster 319 16
Center of Gravity 563 29
Chevelle rear end 830 42
design suspension from scratch 388 12
design suspension from scratch 566 19
Eccentric 229 12
Front RC location 251 9
Front RC location 691 24
Fuel Cell location 272 14
Fuel Cell location 505 26
Gas shock tuning 217 11
Heat cycle machine 572 29
Hotchkiss suspension 353 18
jacking effect 229 13
jacking effect 691 35
jacking effect 811 41
jacking effect 879 44
Lead - front end geometry 1369 69
leaf spring 789 40
leaf spring 1322 67
Light is right 560 28
Metric clip street stock rear end 301 16
Metric clip street stock rear arb 521 27
Metric clip street stock 830 42
Metric clip street stock 832 42
Metric clip street stock rear steer 858 43
Metric clip street stock 1264 64
Metric Spindle swap 284 15
Metric Spindle swap 809 41
Motion rate - rear 308 16
Myth of Weight Transfer 228 12
Myth of Weight Transfer 676 34
Myth of Weight Transfer 811 41
Myth of Weight Transfer 676 34
Myth of Weight Transfer 228 12
Myth of Weight Transfer 676 38
Myth of Weight Transfer 470 24
Panhard bar 246 13
Penske shocks 217 11
Polar moment 562 29
progressive spring 216 11
Race Line 667 38
RC Height 229 12
rear end camber 1326 67
Rear end Instant Center 301 16
Rear roll steer video 1200 60
Rear roll steer video 858 43
rear steer 116 8
rear steer 81 5
Ride height 552 28
Roll center & offset 229 8
Roll center distribution 229 8
Scrub radius 325 17
Shocks (dampers) 703 40
Spindle Angle 325 17
Spindle Angle 332 17
spring rate calculations 19 2
spring rate calculations 589 30
Spring rate vs wheel rate 17 2
Squaring the car 270 14
Squaring the car 479 24
Stagger 36 3
Stagger calc 36 2
Stagger tape 426 27
Street Stock 1314 66
Street Stock 1264 64
Street Stock 830 42
Street Stock 832 42
Stringing the car 269 14
Stringing the car 293 15
Tire down force 62 4
Tire temp readings 468 24
Track width 255 13
Track width 264 14
Track width 322 17
Track width 505 26
Upper A-arm angle 312 16
Wheelbase 264 14
Thanks RM for all the information you provide and the reference guide to various topics. Being new to this forum, this information helps me quickly find information and hopefully, will keep me from asking the same question twice...LOL. THanks Again!
 
  • #1,608
@Ranger Mike
I've looked( and probally missed it lol) but could you tell me your thoughts on a panharb bar running from left rear just inside the wheel and about 2 inches infront of the axel housing to the right side chassis about 10 inches in front of the axel . So roughly 8 inches forward on the right as compared to parallel to the rear. I have seen this on a few pavement oval track cars and have thought it may give added bite on throttle.
Thanks !!
 
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  • #1,609
Ranger Mike said:
Thank you Racerman,,exactly what I was talking about! 3rd link properly connected. Good job!

Why is top link mount so critical?

The top link is the rear end link that pulls the race car. This is why the spring type top links have a compression spring to lessen the rear end loading when you get back on the gas at corner exit. This top link directs all rear end force to the chassis. The rear tires grip the track and try to pull the rear end to the rear as the trailing arms on the bottom push the car to the front and try to climb up under the car.

Why location matters- In road course car set ups you want everything set up 50/50 % weight bias, so all front tires scale close to equal and the rear end tires scale equal.

Not so on left turn racers where you want a left side weight bias. When in a turn you want the left side weight rolling over to the right side to assist the car with better traction (tire grip).

Imagine a you have a log chain and a 5 foot x 5 foot x 4 foot box. You want to pull a 2800 pound box and inside a spare engine located to the left side and a few old tires filling up the other side.

You want to find the center of mass so the box will slide straight and not pull to one side. If you use the centerline of the box and hook the chain at 2 ½ foot. The box will not slide straight as you pull it. You have not pulled the box on its Center of Mass. If the top link is offset to the right of the center of mass, the right rear tire will be loaded more and the left rear tire will be loaded less. We have a push or understeer situation just like when you have too soft a right rear spring. Right rear has too much traction. This is why you have a mystery induced push on corner exit. You are not loading the tires equally when you step on the gas coming out of the turn.

So you need to mount the top link as my post 81 on page 3, post 253 on page 8, post 707 page 21 show.
 
  • #1,610
Hi RM
I like your analogy with the box. Wouldn't that be similar to the rear pusing that box. If the right rear tire was loaded heavy and have more traction. Wouldn't it turn the box to the left and vice versa for the left tire?
 
  • #1,611
RAceman
A level panhard bar ( same mounting height on both sides) means force is vectored laterally to the tires. Any angle up hill to the right rear will cause upward force on both tires and unload both tires. Now you have to compensate with spring change. A 1/2 inch height change from level can make significant handling changes.
 
  • #1,612
ufo
top link is a pull bar
 
  • #1,613
Ranger Mike said:
RAceman
A level panhard bar ( same mounting height on both sides) means force is vectored laterally to the tires. Any angle up hill to the right rear will cause upward force on both tires and unload both tires. Now you have to compensate with spring change. A 1/2 inch height change from level can make significant handling changes.
@Ranger Mike ,
What I was refering to is acually being forward on the right side compared to parallel with the rear on both sides. Most of the panhard setups we have run are infront of the rear equallyon both sides and some of the new cars have the right side chassis mount ahead of the left rear mount that is on the axel housing by 8 to 12 inches and they run it with a j-bar.

Thanks !!
 
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  • #1,614
When the panhard bar or J-bar is parallel with the rear axle center line, cornering force goes laterally and is the best vector to transmit this force. Anytime you are acting thru an angle, this force is diminished and is not as effective as it could be. Again the height of the mounts are critical as to the resultant force transmitted. A difference of heights can help or hurt rear traction.

I can think of one advantage to use this angled set up. Look at the attached drawing. Think of the wood box and the chain discussed above. The body will be pulling on the J bar when cornering as momentum causes body roll. The tires are sticking on the track anchoring the car. When the J bar is parallel, the force is directed straight to the tires.
J Bar mounted at an angle -
What happens to the rear end when the J bar pulls on the rear end mounting bracket attached to the left side of the rear end housing? It will pull the rear end into rear over steer. If you have made provisions to accentuate this (slotted the mounting brackets or put a spring on the trailing arm) , your right side wheelbase will lengthen and the left wheelbase will shorten up. You will be able to maintain tire contact better than the other racers going into the turn before backing off.
Remember 1/2 inch of oversteer will change the performance noticeably. A 1 inch change will be a definite edge and is totally legal!
 

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  • #1,615
Insane video on the induced rear roll over steer. note the left rear tire moves to the front in body roll.

 
  • #1,616
If the Rules say it, you know what you can't do! But EVERYTHING ELSE is open..if you dont do it , some other racer will or already has it.
 
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  • #1,617
Ranger Mike said:
If the Rules say it, you know what you can't do! But EVERYTHING ELSE is open..if you dont do it , some other racer will or already has it.
Spot on !
I read the rules to see what they do not say, not what they do say.
 
  • #1,618
my point is..ifin you can pick up 1/10 of a second with Roll center change, 1/10 on rear roll steer, 1/10 on better forward bite, 1/10 on better deeper braking, 1/10 on heat cycling tires (first 10 laps only), you go a 1/2 second per lap on the other racers. Do not waste $$$ on 50 extra horsepower the spec tires will never be able to handle. Put it to better use handling. Let the also rans worry about correct spring rate tweaking, shock adjustments, stagger, wedge. If you need to change this at the track, you are not competitive. These are bandaids.
If your track rules put the fast qualifiers on the tail, set the car up to race on the outside groove.
 
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  • #1,619
750,000 views..Thank you , Racers!!
 
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  • #1,620


race car class - racing is dangerous
a new race concept means thinking outside the box, like changing steering ratio and ..well this video on Big Daddy Don Garlits goes personal. All racers I think have this in the back of their mind .. every green flag or green light .. nuff said...
 
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  • #1,621
Evening Ranger Mike. I'm using a triangulated 4 link on the rear of my vintage modified. Can you explain to me how changing the bar angles will affect the handling?
 

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  • #1,622
This set up has advantage of more lateral support for the rear end. You have vectors acting to each chassis mounting point as well as the Panhard bar. I suspect the pivoting in rear roll over steer will be quicker as the forces are acting at an angle to the lateral forces and not at 90 degrees as the traditional 4 link does.
The upper links can be adjusted same as the traditional upper links are.
see post 132 on page 4 for details on 4 link
 

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  • #1,623
Thank you sir! I will read up on it. I'm happy with the setup so far but I'm working to optimize it
 
  • #1,624
the upper link settings are a given as much has been written on this. You have jack up the car, wheels off, set the rear end at track level ( read up on this in my earlier posts) measure both side wheel bases at track level, then at max roll so right side is in compression and left side in droop, then you can see if the rear end remains neutral, or goes into roll over steer or under steer. Until you do this you won't know what is going on when cornering
 
  • #1,625
Ranger Mike said:
the upper link settings are a given as much has been written on this. You have jack up the car, wheels off, set the rear end at track level ( read up on this in my earlier posts) measure both side wheel bases at track level, then at max roll so right side is in compression and left side in droop, then you can see if the rear end remains neutral, or goes into roll over steer or under steer. Until you do this you won't know what is going on when cornering
That makes sense. Eliminating the panhard bar saved me about 23 lbs of weight in the correct spot
 
  • #1,626
Vintageracer13 said:
That makes sense. Eliminating the panhard bar saved me about 23 lbs of weight in the correct spot
 
  • #1,627
here is the situation. you eliminate the panhard bar and this will lower your rear RC. Forget about tuning with the rear RC. REAR ROLL CENTER. Everything is centered about this point. Effectively you still have a 4 link suspension but now without a solid anchor to take care of the rear weight momentum going to the outside (panhard bar). Lateral momentum ( sometime called weight transfer..arrrrrrr) thru the RC motion gets you to mid corner without spinning out or heading to the guard rail. Now the chassis is set and ready to come back to neutral. All Roll over steer does lets you run in the turn deeper before getting off the go pedal. Then you tune with the upper links for forward bite. RC tuning is critical on any track. Must have. The virtue of the panhard bar is you can raise it to loosen the car or lower it to tighten the car very quick and easy, loosen tow bolts , tape measure it and retighten, Me, I like vectors working at 90 degrees so i can deal with it easier. You go using angular vectors and things get complicated and at a race track in the heat of the moment..i do not need this. I leave finesse to the Formula One boys that got lots of extra help, worthless as they may be. Put the panhard bar back on. 23 # is 3 gallon of fuel. You should be racing with fuel cell anyway for safety.
 
  • #1,628
Hi Vintage 13! How can you have two points of lateral control, on the center of the rear, one on a arc and one in a straighjt line perpendicular to the bottom of the frame, and not have a bind when it goes into roll, or straight up and down movment?
 
  • #1,629
Is there any interest in exploring more performance when your class rules dictate 500 cfm 2 bbl carb only? Should we dig into this and see if we can make some more horsepower?? Pls reply and i will proceed.
 
  • #1,630
UFO said:
Hi Vintage 13! How can you have two points of lateral control, on the center of the rear, one on a arc and one in a straighjt line perpendicular to the bottom of the frame, and not have a bind when it goes into roll, or straight up and down movment?
I don't have a good enough understanding of why it works but it does. The car I copied has won every feature but 2 this year and won the championship last year. The car rolls the center very well and also doesn't have a panhard bar. With this setup I feel the panhard would cause a bind. To me it essentially the same as the A or G body GM suspension that is used in street stock racing. I would love to see it modeled in a software program to see how it actually works
 
  • #1,631
V-13 sorry I thought you had a panhard bar. what is the octagon bar on the right side in your pic . With a closer look I see it is not connected to the frame. Your bottom rods mounted so close at the bottom of the rear is almost triangulated. That would give you a very low roll center, for the rear, that would travel close to a straight line perpendiclar to the mount points on the bottom of the frame. It will move slightly to the right if you have left rear leed and the opposite with right leed. The roll center hight should be at the heims on the rear.
 
  • #1,632
Hi RM if you were to set up brake floaters on a 3 link would you set the bar toe angles the same as the trailing links or square to the axle?
 
  • #1,633
Brake floaters remove brake forces from other suspension movements and direct the braking force to be used to tune the chassis setup with the radius rods. These radius rods can be level or angled up or angled down. IF angled up, the result adds down force on the tire contact patch. If angled down the force lifts up the tire on braking. If kept level or straight no force impacts the tire. Generally, the side which has the most up angle will have the most downward force and add tire bite on that side. Too much rt side rear uphill angle will make the car hard to turn because the rt rear has too much bite under braking. Too much left rear will make the car loose because the left rear has too much bite and the car wants to pivot around that tire during braking. A good starting point is left rear level and rt rear 10 to 15 degrees up hill. This keeps the rear end tight under braking. Much info in Steve Smith book IMCA Modified Racing Technology on this matter.
 
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  • #1,634
i was meaning top view looking down on the bars. Thank you
 
  • #1,635
square to the axel. force vectors work most effective at 90 degrees
 
  • #1,636
UFO said:
V-13 sorry I thought you had a panhard bar. what is the octagon bar on the right side in your pic . With a closer look I see it is not connected to the frame. Your bottom rods mounted so close at the bottom of the rear is almost triangulated. That would give you a very low roll center, for the rear, that would travel close to a straight line perpendiclar to the mount points on the bottom of the frame. It will move slightly to the right if you have left rear leed and the opposite with right leed. The roll center hight should be at the heims on the rear.
The bar you see is a toe bar to keep the axle tube straight
 
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  • #1,637
Hi Ranger Mike,
In thinking about all the variables when making a change to a suspension component, we have had discussions around the topic of for every action; there is an opposite reaction.

My question is softening or stiffening opposite corners when making a spring change. In my case, I am softening the RF spring on our Asphalt Midget but am afraid if I do so the weight transfer increase will help but now will struggle in getting the weight to transfer back to the LR thus decreasing my forward drive off the corner.
Is my thinking correct that I should look at making two changes (one RF and LR) in proportion to each other?
 
  • #1,638
Wedge or cross weight
Do not make the number one mistake all weekend warriors make. That mistake is changing too many things on the racecar at one time.
Regarding the spring change. This proves to be the exception because you never just change one spring. You MUST change the spring/shock combination together. When you soften the right front spring you will take bite (load ) off the left and RIGHT rear. The softer spring will download the right front and cause the car to pivot MORE around this tire. To have to spring kick the load back to the rear for more bite you must change the shock absorber (damper) with the correct rate. If you had a front shock that was more of a tie down rating the downforce (weight transfer I hate that term) would stay up front longer and cause loose off the turn conditions. You want to have the “weight “ kick back” mid turn to load the left and right rear tires properly.
Cross Weight or Wedge - We use wedge ( cross weight) to increase tire load on the left rear tire. This increases tire bite off the corner. Let us say the local racers all run about an inch wedge. At the track, we place a socket on the jack and jack under the rear end housing to lift both rear tires. The right rear should lift up the 1 inch just as the left rear tire shows daylight under the contact patch. This is the wedge or cross weight we attained with the jack screws we have on the car. In the turn, the body will roll over and the wedge drives the left rear to wedge the tires to keep contact. The % cross weight on street stock is usually 1 to 2 % total weight , Late models with slicks run 2% typically. The ideal situation is to have no cross weight and very good spring shock packages to tune the car.
Rule of thumb - every inch of wedge is 1% Cross weight.When wedge goes past the normal amount ( and inch more than what the normal amount is) then make a left rear spring change. Then reduce the wedge to under the normal amount and adjust at the track as required. Cross weight is adjustable because the local track will change due to temperature, amount of rain washing off the oil and rubber, etc… You need to have a way to dial the chassis in for new conditions and not use it up for basic chassis setup.

The best tool you have to chassis tune a racecar is a notebook and a tire pyrometer. Learn how to read tire temperatures and adjust.
 
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  • #1,639
I update the index periodically. Post numbers are correct the page number prob not. See page 1
 
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  • #1,640
What is the correct length a panhard should be . How far in front of the right rear axel tube center line should it be ? Asphalt late model on 8 inch tires perimeter chassis.
 
  • #1,641
Is this thread still going? It's a bloody teenager!!

Surely it sets the record for longest active single-topic* thread.

*ruling out anthology threads, such as jokes and animal pics, etc.
 
  • #1,642
I am proud to say I am contacted often by PM for advice setting up their race cars. For obvious reason they wish to do this privately. Results are excellent most of the time. Thank you DaveC ...btw most racers start racing when they are teenage. I was racing before I had a driver license!
 
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  • #1,643
SDavem- Panhard bar roll center is the center of the bar and is the easiest to tune due to both side mounting point adjustments. You have a small 8 inch tire so traction is going to be everything. The rear roll center is very important here. You need a lower roll center to improve bite. Roll center should be between the bottom of the ring gear (assume Ford 9") and just below the rear axle tube. 10 to 11 1/2 inch is ball park. How much wedge or cross weight % do you have? From your description you have a short panhard bar that will place the rear roll center at a diagonal to the front end.

Note- If your front roll center is located at the center point of front tread width. If it is offset 3 inch to the right side, I try to make the rear roll center offset three inch to the right. If you have the fronmt RC other than described, you must add more spring rate to one side just to compensate the car handling. I personally do not like this as the roll center will not be in line and this adds complexity to the spring tuning. I like a very long panhard bar mounted at the rear of the housing. Longer levers throw much less chassis bind in the setup. Can you relocate? What is the mounting point location of top link relative to the track width? What % left side weight do you have? Photo from Steve Smith book Paved Track Stock Car Technology
 

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  • #1,644
I've been following along here for a few years, absolutely top notch discussion. Retired from racing 20 odd years ago...... missed it terribly.
So back at it again. Used to do everything with plumb bob, chalk lines and a angle finder.
And a few beers
Bought the program Mike recommended And redesigning a old car with it.
Many many questions to follow.
 
  • #1,645
Zippi
i guess it never get out of your blood once you get in it. so ask away...
i would say this forum is for the racers who wish to learn so if you want to share the build, great, if you want to private message me i have had hundreds of these so can do that too.
welcome back racer!
rm
 
  • #1,646
Thanks Mike! I'll PM you as to rules and the location of where we run. We showed up last year with the car, and the old timers recognized us right away. Got warned about rule interpretation pretty quick LOL
 
  • #1,647
Welcome to PF.

Zippi said:
Thanks Mike! I'll PM you as to rules and the location of where we run. We showed up last year with the car, and the old timers recognized us right away. Got warned about rule interpretation pretty quick LOL
We prefer that discussions be held in the open forums instead of in PM conversations. But I guess if you're going to be asking for advice for how to get around the track rules, a PM conversation might be the best choice...
 
  • #1,648
I recommend that this forum is for learning and teaching.
Zip..you are not known nor is your new car and team and this is good. Your location is not known also, I am sure the thousands of tracks out there have similar chassis set ups and the same monkey see monkey do mentality applies.

Any getting around sanctioning rules would be ... cheating!!! And we all know this does not happen in racing...AKA Smokey says if it ain't in the rules, it is allowed. Perish the thought!

As your local competitors are highly unlikely to monitor this forum and not know you my bet is you pretty safe.
We are not re-inventing the wheel here.

Having been on here for ten plus years, I highly respect and value Mr. Berkemans input so if at all possible, an open discussion is much appreciated. But my private PM is open as long as we understand the situation. OK?
 
  • #1,649
Ranger Mike said:
We are not re-inventing the wheel here.
I see what you did there... :wink:
 
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  • #1,650
Fair enough to both of you, i like your pun there Mike! However i just wanted to give some background info so the discussion could be narrowed down. Im good with a public discussion. Im interested on the page 12 discussion about your equal length upper and lower control arms. We're able to do this on the new design, no one around here has done it, i was wondering what your thoughts would be on a flat bumpy track? A track similar track to Mount Lawn Speedway. Chevelle clip, 3 point rear ,
 

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