In much need of suspension help!

Ok guys, I have collected all the data, taken video, have racepak data, now I need a expert to help sort it out. Running a 88 notch with a 547 and a glide on a 10.5 tire, local heads up deal. Car runs mid 9's @ 144 in 8300da with a 1.39 60 on a good track. Motor made peak hp at 7000 and peak tq at 5300, crossing the line at 6750 currently. Just made the switch to a glide this year and I believe I need more gear, running 3.73 now and going to go to a 4.10 to help the car leave harder. Afco da in back, strange single's in the front, not sure of spring rates, I bought the car with them, the back I am pretty sure are stock. Team z parts in rear, with relocated uppers. Trans has a 1.80 straight cut and a ptc converter. Hoosier slicks running around 12psi. The instant center calculations are not to good, I plotted them on induction motorsports and came up with IC length 26.017. IC height 7.83, AS 138.437. Need to move IC out I am thinking and get AS down and also keep stock mounting locations to meet rules. Where and what do I do first? I someone to give me some direction so I can figure this out and keep beating the chevy guys.

pictures? weights? video?

We'll get you figured out.

Weighs 3110 with driver. What is the best way to put up video? On the racepak I can leave on the converter with hardly any spinning. Car has 5" of travel with limiters if needed and I think they are. Rear suspension hardly moves, tried some different shock settings, but the best I could do was a 1.38.
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what is your rear upper set at?

converter stall? fallback on the shift?

Rear upper, do you mean length, if so that would be 6 7/8". The converter stalls right at 5400.

where do you shift and whats the rpm fall back to?

I have been shifting right at 7000, falls back to 5750. Might be some more in changing shift point, haven't got that far yet with this motor.

also cam? compression? cyl head?

I'm leaning towards a gear swap, keep it in the powerband where its happy.

Cam is fairly serious, don't have cam card in front of me, but it is a hair over .800 with .275 duration at .050, 14.1 comp. and full out p-51's.

I don't have my sliderule in front of me, a 4.11-4.30 gear will do it wonders, let it 60' good, shift it 7100 or so...let it cross 7300ish.............converter is fairly snug, but not by much..............tighter converter with steeper gear the car go boogity boogity..............

you stated the uppers were relocated. How? Did you lower the front mounting point?

Thats what I was kinda thinking a gear change could help richter, but I am thinking the suspension will need work to get it to the ground. Thanks for your opinion, makes spending money on gears a little easier, any guesses how much it might gain?
Larry the uppers are relocated with the team z setup, it moves the rear of the upper bar up some.

wouldn't that shorten the ic distance the same way lowering the front point would?

Yes on the calculator is does shorten the ic and add antisquat.

video-use photobucket. it is the easiest.

Scale the car. knowing the weights of the corners at race weight is very important with stock suspension stuff. Dave Z will say the same thing.

Your 60' can be a lot better even with the setup you currently have. I have seen those upper relocation kits from Dave but have never used them. We use stock mounting points for our 1.19-1.21 60's.

Stock mounting points is okay, as long as the ride height is correct.......im back to stock points now as well.


Can you post up the height measurements of your control arm points + lengths?
Are the lower rear end brackets adjustable?

Trying to get video up, but new camera is being a pain!! The rear brackets are not adjustable at this point.
Here is some more info in the mean time.
Corner weights are as follows, this is with the c6 before the glide, so they are close, but the glide is lighter of course and I added 60lbs to the back of car in front of cell to make up the difference plus extra to meet class weight of 3100.
LF 881 RF 837
LR 672 RR 696
I have tried to different ride heights for the car, I had the car setup with the front end high so the headers will clear, which you will see in the video if I can make it work right.
I use the calculator for the both to see the difference, even though I only ran the car with the front end setup high.

Front end high setup
upper arm length 6.85 lower arm length 17.4
upper rear height 17 lower rear height 9.6
upper front height 15.1 lower front height 8.750
cg height guess around 22 wheelbase 101.2

ic length 32.382 ic height 8.0118 anti-squat 113.901

front end set down to normal
arms are the same length obivously so I will just give height changes

upper rear height 17.125 lower rear height 9.350
upper front height 14.850 lower front height 8.350

ic length 28.309 ic height 7.723 anti-squat 138.042

I will note that the rear sits a little lower than most I've seen, around 16 3/8" to fender lip. The springs have seem to sagged over the last few years.

I realize this will take some work from someone to help me on, but I really don't have anyone local and need to learn what I am doing. If someone on here has the knowledge and is willing to help me out and it works I would gladly pay them something for their time.

I would do it for free if you were close to north Texas.

What angle are your lower control arms? I don't know if I missed it but what is the front height at?

lower front height 8.750" with front end high and 8.350" with front end normal.
Maybe I will need to travel, I have to get this thing to leave hard.

How low is the car??? 8.35" on the lower front arm is very, very low!! Don't see this working to good? Can you raise the backend up 1"?

Raising the back is a good starting point.

Do most of the classes that run the Fox body cars and keep the rear suspension's "factory points" do so because most rules dictate it? Or is it because it's just way too hard to put/fit big upper (and/or lower) control arm chassis brackets under the car (with a decent number of holes in them) to make I/C adjustment much easier?

If the rules allowed it (and there was enough room under the car) seems to me that adding new top & bottom control arm chassis brackets with even a modest number of additional holes would really open up the I/C adjustment window on these cars without having to raise/lower them.

DILLIGASDAVE wrote:Do most of the classes that run the Fox body cars and keep the rear suspension's "factory points" do so because most rules dictate it? Or is it because it's just way too hard to put/fit big upper (and/or lower) control arm chassis brackets under the car (with a decent number of holes in them) to make I/C adjustment much easier?

If the rules allowed it (and there was enough room under the car) seems to me that adding new top & bottom control arm chassis brackets with even a modest number of additional holes would really open up the I/C adjustment window on these cars without having to raise/lower them.

Rasing and lowering is pretty easy but I guess I see where you are coming from, Dave.

Our car uses the stock mounting points but we do have the rear pushed an inch further back than stock so both the uppers and lowers are longer. The lower picture(current setup) has the rear raised 1" and the front lowered 1" from the upper picture. We moved the IC to just under my feet and it was under our butt with the nitrous motor. Car weighs the same and the front to rear bias is the same as the nitrous combo. The best it ever did with a big plate shot was 1.19 before and now has been 1.24 with the turbo setup still leaving kinda soft. Our car is lower than most when we go to the track and actually guys have accused us of moving the mounting points on the car to get it that way but we haven't.

Well, I have been working like crazy the last few days, finally got some time to try lifting the rear 1" and take some measurements. Here is what I came up with.

IC length 39.79 IC height 8.868 Anti-squat 102.515

This put the lower front arm at 9.125". I am thinking I am goint to have to move some mounting points, what do you guys think?