drag racing suspension

[rw95gt]

What should I upgrade next to improve my cars suspension for the track? I run big and littles at the track and a 28" stiff wall slick. I have a tru trac in the rear and moser axles. I run a bmr upper control arm mount and use the lower mounting hole to improve instant center. I also run a jpc double adjustible upper control arm and stock lowers. Also im using a dss aluminum driveshaft. I still run the front sway bar.

The best 60ft to date is a 1.48 with 12 psi no nitrous and a 1.35 with 10 psi and a 100 shot spraying on green.

So what should i do next? I was thinking cj springs but i dont want my car to sit higher then stock. I am also thinking about a rear anti roll bar and just cutting my stock rear springs to lower the rear about a half inch to help weight transfer. I would like to see 1.3 short times with out nitrous.

 

[Proto]

The 2010 cj's have an "improved stance" verses the rake that the 08 cj's have. LCA relocation brackets, CHE preferably, to add some downward bite off the line.

Caleb and taylor over at Fastlane would def be the guys to talk to

 

[Steve@BAS]

You should also get a set of LCAs. Bobs & Revans have them on sale for the Christmas season!

 

[AlanSVT]

Hey not sure if it would help. But I can show you a set of Bobs LCA in person. I havent installed mine yet.

 

[AlanSVT]

Also, quality is really nice.

 

[Sharad]

Yep, LCAs, adjustable shocks & struts, springs, solid ARB, front swaybar eliminator. Although I must say, 1.35 on spray is good stuff.

What is your launch RPM on boost only and on spray? What does the car do when you launch on boost only? Any video?

 

[IronTerp]

I don't know Randall......you've done incredibly well with the mods done to your car. Like the fellas above said, there is some more bolt on tweaking that you can do to your GT500, but ultimately at what level do you want to take the car??? To get your 60' significantly below 1.35 is going to take a different approach with the car which may not be where you want to take it.......

 

[rw95gt]

I have been busy the past few weeks but after studying video of my car at the track i think im going to try a set of lakewood 90/10s. My rear does all the right things but my nose doesnt stay up long enough. I think the weight tranafer help will make the car more consistant and maybe lower my shory times. I dont want to run poly lowers because they fail on cars that are drag raced. Also going to remove the front sway bar again to allow more front suspension movement.

 

[white88lx]

shocks and struts would probably be the best choice imo

 

[stkjock]

Springs and adj shocks

 

[Coonsnake]

1.35 with a stick and street car is awesome, imo i wouldnt change anything. Change up to much and your daily will ride like a drag car.

 

[UnleashedBeast]

The 2010 cj's have an "improved stance" verses the rake that the 08 cj's have.

From what I have read, the new CJ springs M-5300-R are not suitable for a street car. They lower the car too low to clear simple speed bumps and inclines. Everyone on different forums that have tried them on street/strip cars, removed them in short time, and sold them.

rw95gt,

I decided to give adjustable Strange shocks a try. Bang for the buck, they are a bit cheaper than the Tokico, but with a little more flexibility so I have read.

I too have heard wonders about the CJ springs, but I just do not like the extreme rake they give the GT500. I decided to experiment.

My thoughts, use the CJ front springs, they are actually "SFF Yellow Tag" GT premium front springs (I have two pair, willing to sell you a pair). In the rear, try some QA1 2.5" rear coils. You have two choices.

1. Use their 14-150 spring, but this will give you the same rake like the CJ rears unless you cut a coil off. *Not fond of cutting coils*

2. Use their 12-150 spring with an adjustable perch. The 12" spring alone may lower the car too much in the rear, hence the adjustable perch.

*QA1's above are 150 pound/inch springs* For comparison sake, the CJ rear springs are 14" free height and 142 pound/inch rated. The coil design of the rear Ford CJ spring suggest that they are not linear. They look like a progressive rate design to me.

I can tell you that the Steeda competition springs in the rear of my car are 12" tall free height, linear 185 pound/inch rate. It lowers the rear of my car perfectly even at only 12" due to the higher rate. Perfect for corner carving, not so much for drag racing.

If QA1 had a 12.5-150, it would be perfect for a 28" rear drag radial setup.

 

[Robertt305]

Don't touch the car it's setup perfect as is !!

Your 60ft is amazing.... My best is a 1.55

 

[UnleashedBeast]

Update,

The Cobra Jet "SFF" yellow label springs lowered the front of my car exactly the same as my previous Steeda Competition lowering springs.

Cobra Jet springs - 14.69 free height @ 136.5 lb/in
Steeda Comp Springs - 12" free height @ 225 lb/in

The car's front ride height with Steeda Comp springs was 27 1/4" driver & 27 1/2" passenger

The car's front ride height with Cobra Jet front springs is 27 1/2" driver and passenger

Rear springs, now that I know the Cobra Jet springs lower the car the same as the Steeda springs, I'm convinced that the QA1 12-150 springs will lower the rear just right with no rake. A spring perch may not be required to clear the 28" drag radials.

Currently, the car is still using the Steeda rear springs, and the car is 28 1/4" ride height on both sides.

Steeda rear springs - 12" free height @ 185 lb/in
QA1 rear springs - 12" free height @ 150 lb/in

My guess, the car will sit ~ 1/4" lower in the rear with the QA1 springs.

Just thought I would share the information.

 

[Sharad]

I have been busy the past few weeks but after studying video of my car at the track i think im going to try a set of lakewood 90/10s. My rear does all the right things but my nose doesnt stay up long enough. I think the weight tranafer help will make the car more consistant and maybe lower my shory times. I dont want to run poly lowers because they fail on cars that are drag raced. Also going to remove the front sway bar again to allow more front suspension movement.

I prefer spherical bearings on my control arms, but fwiw, UPR's 2010GT runs 9.90s on poly lowers and it has a lot of passes on it.

 

[UnleashedBeast]

UPDATE:

QA1 12-150 springs lowered my car an additional 1/2" in the rear. Ride height has been reduced from 28 1/4" (Steeda Comp spring) down to 27 3/4" (QA1 12-150 springs)

Next update will be if 28" M&H drag radials clear. 325/50/15

If I experience rubbing issues, I will have a local friend here mill some aluminum spring perches from 1/4" to 1/2" tall.

 

[Proto]

Unleashedbeast is on it!!

 

[UnleashedBeast]

Unleashedbeast is on it!!

Gotta kill some of that horrid Cobra Jet spring rake. It doesn't look good at all while driving on the street.

 

[Robertt305]

Pics of before and after !!!

 

[acobra03]

Any updates?