Short story: Could someone with a completely stock 88, measure from the middle of the wheel to the top of the fender opening (bottom edge of fender over wheel) on the front and rear. Also measure from the fender opening (in line with the middle of the wheel) to the ground on the front and rear.

Long story: An engineer I work with used to design suspensions systems and has an interest in racing. He/we are going to do some serious suspension analysis including potentially moving some mounting points on my Formula. Since my car is already modified he wants some baseline measurements to compare too. Since my car is a track only car, the benefit to most others may be limited but if things work out to be worthwhile to change I may do a build thread with some track results for the fun of it.

never mind but, do you want the factory tire measurements?

[This message has been edited by Indiana_resto_guy (edited 09-11-2009).]

I know on my car and one other I just did suspension on from the ground to the center of the wheel opening they were 27-3/4 in the front and 28 to 28-1/4 in the rear
the car I just did for someone that races autocross I lowered 3/4 in the front and 1-1/4 in the rear with coil overs and polly.
I do not know the distance from the center of the wheel to the fender lip. but I got you 1/2 way
D.

I really need to get a tape measure and keep it here at work. Folks are always asking for measurements, and my car (a stock 88) sits out in the parking lot, and all my tape measures are at home.
Maybe I'll go buy one at lunch time.

Yes I want them with the factory size tires front and rear. Also forgot to add that the car needs to be as level as possible and not parked on a hill or anything.

The distance half way helps but we are taking this exercise to the extreme here for several reasons. From the ground up will include the flat part of the tire at which point air pressure will come into play. By measuring from the fender down to the axle center line, we can then change the tire pressure in our program. We also will be referencing all measurements off the frame so we need the relationship of the suspension to the frame. We will be using a total station to measure the centers of the bolts, pivot points, axle center, frame etc. We need to have the distance between the fender and the middle of the wheel, (as close as possible as everything else will be measured to .001") as that is a reference line for where to start from as the OE specs. My car has cut springs, slotted strut mount holes, poly bushings, less weight and different frame stresses (roll cage) which will all come into play here. One thing we are looking at is, it may have been better to keep the full length springs and then raise the roll center instead of just lowering the cg for the whole car. It is an experiment/exercise/possible expansion to other vehicles and my car is the one we have the most control over in being able to make changes to and be able to test vs asking someone to start cutting up their car and not have too much pre-change data on. If some of that did not make sense just remember I am the driver. He is the guy with the specialized knowledge.

Pluses for the help so far.

I'm no suspension expert but I want to ask a question.

You mention it might have been better to raise the roll center rather than lower the CG. I'm guessing this was to allow greater suspension travel in off camber corners and maintain tire contact patch?

That is one of the things we are looking at. Our initial findings were that the outside suspension is moving about 3 degrees total and the car is starting out around -2.5 degrees. Therefore in the hardest part of a turn the camber is going positive.

This is an old photo with Monroe struts before I switched to Koni's in the rear. The camber change is not nearly as bad with the Koni's but it is still there. Look at the difference between the front and rear wheel angles.

I have a bone stock 88. The distance is about 18 feet. The wheel is off the car on the other side of the garage.



Please forgive me, I couldnt resist the urge. I hope you get it worked out.

On my completely original 88GT with original tires the measurements are:

Front - Ground to lip = 27 1/2", centre of wheel to lip = 15 1/2"
Rear - Ground to lip = 26 7/8" , Centre of wheel to lip - 15 1/8"

Anything else?

On my stock 88 coupe, the measurements are (with no one in the car, and a full tank of gas):

Front - Ground to lip = 27", center of wheel to lip = 15 1/8"
Rear - Ground to lip = 27 1/4" , center of wheel to lip - 15 1/2"

This is on the driver's side. The passenger side is about 1/4" lower. That's to be expected, since most of the engine weight is on that side.
My wheels are not stock, but the outside tire diameter is. I used a wheel size calculator to figure out my tire size on the new wheels. My speedometer is dead on, according to my GPS.

Perfect. As things progress we will hopefully have something worth passing on.

Thank you.

quote Originally posted by Super Duty Critter: I'm no suspension expert but I want to ask a question. You mention it might have been better to raise the roll center rather than lower the CG. I'm guessing this was to allow greater suspension travel in off camber corners and maintain tire contact patch?

The distance between the roll axis and centroid axis at each end of the car determines the roll moment and the rate at which loading of each contact patch changes with lateral G.