Suspension Guys, I Need Advice!

[JLear]

I have a '14 GT that I've been modding and taking to the track and up until this point I've never really had 60' issues. I have BMR adjustable upper and mount, lower control arms with relocation brackets, and adjustable panhard. The driveshaft is a DSS with the pinion angle correctly set.

When the car was n/a and had a 4c it would get consistent low to mid 1.6 60's and I thought that was about where it should be for the power I had. Now that I have removed the stall and added a TVS and the hp and tq have went up the car will not hook for crap. I first thought maybe my tires were the issue so I purchased some Et Street Pro's and that didn't help, so then I moved the control arms from the top to middle hole and that didn't help much if any. Yesterday at the track I dropped the air all the way to 14lbs and it semi hooked but still spun on the 1-2 shift, I don't think it's recommended to run a radial that low on air and I seemed to be the only one on sticky tires having traction issues so I'm ruling out track prep as a possible issue. At 17-18lbs I had several attempted passes that it just sat still and spun on the hit.

My car is lowered with Ford Racing K springs and I'm thinking maybe they're too stiff to allow the proper weight transfer. I just wanted to get the opinions of guys that know alot more than me before I start buying stuff that is not going to help. This is a street car and I'm not looking for 1.3 60's, but I think a mid 1.5 should be realistic. These mid to upper 1.6's and sometimes a 1.7 just aren't cutting it! LoL

Thanks in advance!

 

[rcm90]

I'm going to say the springs are not helping you at all. I'd move to BMR drag springs or cj springs. Stock shocks/struts? Do you have any videos of the car so we can see what it's doing?

 

[JLear]

I'm going to say the springs are not helping you at all. I'd move to BMR drag springs or cj springs. Stock shocks/struts? Do you have any videos of the car so we can see what it's doing?

I was actually looking at the cobra jet springs but really like the look of the car with the K springs. I guess I need to decide whether the look is more important than performance. Do you happen to know if the cobra jet springs will return the car to the stock height or do they lower it some? All shocks/struts are stock and the only video I have is when it actually hooked somewhat decent. For every full pass I've made there's probably two that I never got took off lol.

 

[JLear]

Here's a launch pic from yesterday, not alot of lift/squat going on..

 

[KrisR]

Are you still using 3.15s?

 

[skwerl]

These cars are pretty nose heavy, especially with a blower. What have you done as far as weight reduction/redistribution? A hundred pounds off the nose will make a huge difference in weight transfer.

 

[JLear]

Are you still using 3.15s?

Yes, stock gears.

These cars are pretty nose heavy, especially with a blower. What have you done as far as weight reduction/redistribution? A hundred pounds off the nose will make a huge difference in weight transfer.

No weight reduction other than removed the spare. A buddy was there yesterday in his paxton coyote with the same suspension as me with the exception of he has bmr springs. We run similar times and his is hooking hard. That's what leads me to believe my springs may be too stiff.

 

[skwerl]

My Bullitt rode great with the CJ/Bullitt springs but I never could pull better than about a 1.54 even with stupid horsepower.

 

[KrisR]

Do you have the front sway bar still in place?

 

[DiMora]

What are you running for shocks and struts?

 

[JLear]

Do you have the front sway bar still in place?

Yes.

What are you running for shocks and struts?

Stock at the moment, I have some qa1 rears that I can borrow if the experts do not think it's a spring issue lol.

 

[skwerl]

Unhooking or removing the front sway bar will help tremendously with weight transfer. That alone will be worth a tenth.

 

[rcm90]

I was actually looking at the cobra jet springs but really like the look of the car with the K springs. I guess I need to decide whether the look is more important than performance. Do you happen to know if the cobra jet springs will return the car to the stock height or do they lower it some? All shocks/struts are stock and the only video I have is when it actually hooked somewhat decent. For every full pass I've made there's probably two that I never got took off lol.

Unhook the front sway for the track. Like Brian said moving weight off the nose will help, but it should still leave plenty hard as is. Those springs are doing you no favors. I have 2013 cj springs, the lowering ones. It transfers weight like crazy. I'd plot your suspension to check what a/s and I/c is. There is a great thread in the drag racing section about it.

The front end came up then dropped down about 4' out of the hole. That can cause the rear to unload and blow the tires off. That's normally a shock problem, but I'm sure a proper spring will fix that for the most part.

FWIW here is how my car sits.

 

[KrisR]

Like the others said, try disconnecting the front sway bar next time, I'm guessing it will help. You can just unbolt the endlinks as an experiment, and pull the whole thing out if it helps.

 

[fdjizm]

What front struts? they seem like they are not letting the front up.
When I go to the track I set my front struts at 0-1 clicks which is full loose.
I've played around with it before and loose was the best performing.

Lil bit of track porn...

Notice the gap at the rear tire, the car is not so much squatting as it's transferring weight.
The front tires have no weight on them and even leave the floor about 1/4".
My setup is not done or perfected yet, just an example.. best 60' was 1.64.

 

[JLear]

Thanks for the responses guys. I will definitely try somethig with the swaybar and also call Kelly to get his opinion on rear springs. All shocks/struts are currently stock.

 

[JLear]

Unhook the front sway for the track. Like Brian said moving weight off the nose will help, but it should still leave plenty hard as is. Those springs are doing you no favors. I have 2013 cj springs, the lowering ones. It transfers weight like crazy. I'd plot your suspension to check what a/s and I/c is. There is a great thread in the drag racing section about it.

The front end came up then dropped down about 4' out of the hole. That can cause the rear to unload and blow the tires off. That's normally a shock problem, but I'm sure a proper spring will fix that for the most part.

FWIW here is how my car sits.

I read a few pages of that thread and I must admit that I'm sure that's some good info but it's way over my head lol. I will probably try the swaybar delete and some different rear springs and see if that gets me where I want to be. Your car looks sick btw!

 

[BMR Tech]

Hold on before making changes.

Is the car spinning? The video did not appear to show much of any spin - and the photo you posted above of the launch, if perfect, assuming you dont blow the tires off.

 

[BMR Tech]

Okay, nevermind.....I just saw you say it doesnt hook (but did for that video)

I don't think the springs are the best choice, BUT, I don't think they are hurting your car at this time (I offer the best drag springs on the planet, so take that for what it's worth)

Many times when I have customers who are experiencing the issues you are, it is a tire issue, track issue, or driving issue.

Next time you go to the track, I recommend removing the front sway bar.....putting the tires at 16.5PSI before the burnout. For the burnout, burn them for 4-5 seconds then roll out and listen for the tires grabbing.

A set of rear shocks, like the Vikings....and the proper LCA/UCA angles will work just fine with those spring you have. I've got way too many customers with identical combos to yours, going 1.4X sixties.

 

[badnews]

I'm guessing similar times, since the 60 ft did not improve?

I agree with Kelly, confirm the basics before changing a lot of stuff for potentially not the result you want.