- #1
toyotadude
- 18
- 0
Herro guys, I'm trying to build a motor for shop class (from scratch really, new manifolds, ect ), I'm only 15 so please take it easy on me
Anyways, I've been trying to calculate my ideal runner length/diameter and stufflets for the intake manifold design. I've got a question about that, however. The motor is a 2.0 liter Camry motor (lol), twin T3/T4 turbos (I'm adamant about that). There will be obviously a rather large amount of turbo lag (which I like), but to calculate intake manifold diameters, you need to know where you'd like your "peak torque". Ideally, I'd like my peak torque about where I peak out my boost (~25psi, all out on these two smaller turbos), but I've noticed in some cases peak torque is reached later after peak boost... any idea why?
I assumed that the T3/T4 may lag up until ~5k RPM and possibly hit full boost in 5.5-7k RPM... (maybe? ), and because at max boost generally where I'd get most volumetric efficiency... that's where I'd get peak torque? (assuming the rest of my engine is build for high(er) RPM powa)
One thing just struck me though, seeing that ~25psi I'd be absolutely stringing out the T3/T4's, in THEORY if I didn't have a intercooler large enough to cool it, my actual peak torque COULD go down in the rev range because of higher intake temperatures, and thus according to the ideal gas formula modified to get lbs/min of air... I could be getting less pounds o' air at higher revs if I can't keep it cool, thus actually "downing" of peak torque o.o
And now another question xD, assuming that all that is done ^, I need to calculate the VE to find out the diameter of my runner length (according to Vizard's formula from this one book :P), but because it IS turbocharged, VE would be over 100% (or I hope it is, lol). But how exactly can one calculate that?
Assuming I took off a few psi for turbulence and blockage o' flow from the intercooler at max boost, would the VE increase in porportion to the amount of pressure over atmospheric pressure there is in the intake manifold? Or am I dreaming? xD
Anyways, I've been trying to calculate my ideal runner length/diameter and stufflets for the intake manifold design. I've got a question about that, however. The motor is a 2.0 liter Camry motor (lol), twin T3/T4 turbos (I'm adamant about that). There will be obviously a rather large amount of turbo lag (which I like), but to calculate intake manifold diameters, you need to know where you'd like your "peak torque". Ideally, I'd like my peak torque about where I peak out my boost (~25psi, all out on these two smaller turbos), but I've noticed in some cases peak torque is reached later after peak boost... any idea why?
I assumed that the T3/T4 may lag up until ~5k RPM and possibly hit full boost in 5.5-7k RPM... (maybe? ), and because at max boost generally where I'd get most volumetric efficiency... that's where I'd get peak torque? (assuming the rest of my engine is build for high(er) RPM powa)
One thing just struck me though, seeing that ~25psi I'd be absolutely stringing out the T3/T4's, in THEORY if I didn't have a intercooler large enough to cool it, my actual peak torque COULD go down in the rev range because of higher intake temperatures, and thus according to the ideal gas formula modified to get lbs/min of air... I could be getting less pounds o' air at higher revs if I can't keep it cool, thus actually "downing" of peak torque o.o
And now another question xD, assuming that all that is done ^, I need to calculate the VE to find out the diameter of my runner length (according to Vizard's formula from this one book :P), but because it IS turbocharged, VE would be over 100% (or I hope it is, lol). But how exactly can one calculate that?
Assuming I took off a few psi for turbulence and blockage o' flow from the intercooler at max boost, would the VE increase in porportion to the amount of pressure over atmospheric pressure there is in the intake manifold? Or am I dreaming? xD