Front to rear rake measurements at frame rail?

[imported_mega]

anyone have the stock front to rear rake measurements at the frame rails near the jack pads?

I think I've got a bit too much squat in the rear, car needs more turn in bite, and never gets loose on exit. Already have the front full soft and rear full stiff on coilover damping

Current weights with me in the car

FL 972 FR 903 51.9 %
RL 894 RR 846 48.1 %
51.6 % 48.4 %
Total 3615 pounds

[Phloozy]

These are my rough measurements for floor to jack pads
4 5/8" in the rear
4 1/8" in the front

[bbnks2]

Originally Posted by Phloozy

These are my rough measurements for floor to jack pads
4 5/8" in the rear
4 1/8" in the front

That's to the actual black plastic? Those jack points tend to get messed up from jacks/stands. Would be better to measure to the actual bottom of the side skirt fore/aft of the front/rear points.

Rake will be more impactful at higher speeds. The bigger impact for lower speed will be toe. Reduce rear toe-in and increase front toe-out. If you don't already have front toe-out that change alone to a small amount of toe-out will significantly change how the car initially turns in. Once you dial in over 3.0* of camber up front the car actually starts to toe-out under braking compression naturally aiding in turn-in. So more camber in the 3.0 range is good. Not necessarily because you need that much camber but because of how the geometry changes dynamically with the static alignment change.

From what I understand, keeping the front-end higher (less rake and closer to stock ride height) would be a positive thing for reducing understeer. Will be interesting to see what YOUR measurements are to see if you are lowered a lot or not.

I don't know what stock is but keep in mind tire diameters. A 1M for instance comes with 265/35r19 wheels out back and sits much higher overall closer to 5.5" but it's all from the tires and the controls arms sit pretty much the same as my car does. On 24.7" diameter tires I am at ~4 4/8" / 4 7/8"-5.0" ride height to the bottom of the skirt. Around 3/8" total rake. If I wanted to increase rake from here to aid in rotation I would RAISE the rear not lower the front.

[Phloozy]

Originally Posted by bbnks2

That's to the actual black plastic? Those jack points tend to get messed up from jacks/stands. Would be better to measure to the actual bottom of the side skirt fore/aft of the front/rear points.

Rake will be more impactful at higher speeds. The bigger impact for lower speed will be toe. Reduce rear toe-in and increase front toe-out. If you don't already have front toe-out that change alone to a small amount of toe-out will significantly change how the car initially turns in. Once you dial in over 3.0* of camber up front the car actually starts to toe-out under braking compression naturally aiding in turn-in. So more camber in the 3.0 range is good. Not necessarily because you need that much camber but because of how the geometry changes dynamically with the static alignment change.

From what I understand, keeping the front-end higher (less rake and closer to stock ride height) would be a positive thing for reducing understeer. Will be interesting to see what YOUR measurements are to see if you are lowered a lot or not.

I don't know what stock is but keep in mind tire diameters. A 1M for instance comes with 265/35r19 wheels out back and sits much higher overall closer to 5.5" but it's all from the tires and the controls arms sit pretty much the same as my car does. On 24.7" diameter tires I am at ~4 4/8" / 4 7/8"-5.0" ride height to the bottom of the skirt. Around 3/8" total rake. If I wanted to increase rake from here to aid in rotation I would RAISE the rear not lower the front.

Yeah, I only had the jack pad measurements on hand because I was asked them at one point :P As for your comment on less rake being better to reduce understeer I'm not sure i understand how that would work.

[bbnks2]

Originally Posted by Phloozy

Yeah, I only had the jack pad measurements on hand because I was asked them at one point :P As for your comment on less rake being better to reduce understeer I'm not sure i understand how that would work.

By keeping the front-end closer to stock geometry. Most people add rake by lowering the front... like pretty much every lowering springs out there for these cars. Many of them end up producing 1" or more of rake to eliminate "wheel gap" for looks.

[Phloozy]

Originally Posted by bbnks2

By keeping the front-end closer to stock geometry. Most people add rake by lowering the front... like pretty much every lowering springs out there for these cars. Many of them end up producing 1" or more of rake to eliminate "wheel gap" for looks.

Oh ok ya that will be bad, its why measuring to to fender is not the best idea. My rear LOOKS lower because the wheels tuck even though there is rake.

[bbnks2]

Originally Posted by imported_mega

anyone have the stock front to rear rake measurements at the frame rails near the jack pads?

Other than rake and toe... maybe look at the rebound settings too? IDK what adjustments you have available to you but you might want to run LESS rear rebound to get the front to dive quicker and give the front tires more bite.

[bbnks2]

Originally Posted by Phloozy

Oh ok ya that will be bad, its why measuring to to fender is not the best idea. My rear LOOKS lower because the wheels tuck even though there is rake.

Looks damn good... And yeah even with 1/2" of rake the front will look like it's sitting 1/2" higher like the car has negative rake but reality is the opposite.

I think he asked for stock ride height numbers. You're lowered, right? Looks to be about 1" lowered. Could be the wheels/tires though like I mentioned. I know a stock car has around 1/2" of rake.

[Phloozy]

Originally Posted by bbnks2

Looks damn good... And yeah even with 1/2" of rake the front will look like it's sitting 1/2" higher like the car has negative rake but reality is the opposite.

I think he asked for stock ride height numbers. You're lowered, right? Looks to be about 1" lowered. Could be the wheels/tires though like I mentioned. I know a stock car has around 1/2" of rake.

Oh ya im very lowered haha sorry i must have missed that

[imported_mega]

my car is lowered too, more than I like.. I plan on raising the rear to get back to stock rake f/r ratio