fasttagurl

iTrader: (12)

Pushing 700hp NA, I am having trouble getting my tires to hook up, the issue is not the tires, they are Hoosier drag slicks, 28X10.5X15. On each launch and at 3 different tracks, it has blown the tires off and still ran a 10.30.

I have a race I want to attend in 3 weeks, so I will not have time or funds to purchase my much-needed upgraded suspension (can you say Afco's?), so how can I get my current mediocre suspension to hook for me for this one race? I run the KYB single adjustable shocks with stock springs, the ones I believe have 1-8 settings? I know, an upgrade is much needed.

How can I get these to work for the one race?

Michelle

Bitemark46

Michelle, whats the car doing? Any vids? Does the tire go up in smoke right off the hit or does it hook then go into spin? I think those KYB's are rebound (extension) adjustable only. So you may need a double adjustable shock to hold the hit.

What psi are the tires?
Whats your whole suspension consist of?
Whats the ride height?
Ever plotted your suspension? If so, what are your values?

I'd be glad to help as much as I can.

fasttagurl

iTrader: (12)

Yes, Redgar posted some vids from the shootout last week; the car on each launch looks like it wants to pick up the nose more, but it just "hops" then continues the pass. And from my 60" times down to a 1.50s instead of 1.30s, something is off. It looks like it blows them off right from the launch.

http://www.challengevideos.com/video...Stephen+Wells+

http://www.challengevideos.com/video....+Mike+Sheads+

We've tried PSI everywhere from 15 on up, but nothing worked. Suspension set-up consists of Spohn torque arm, stock shocks, KYB springs, BMR lower control arms, drag-launch bar in rear from Madman, no front sway bar, and I believe that's it. Needs an Afco drag shock set-up and coilovers really bad. I believe it's at stock ride height with stock springs, correct? It's a drag-car only, so we don't want it low like a show car, etc. Never plotted the suspension-may need to be my winter project!

Bitemark46

Sorry but I'm a little confused. So are the shocks stock and he springs KYB or vice versa?

The "hop" is basically your front struts running out of extension and with nothing to keep pushing the nose up the front comes down. This could be from the setting on them (if adjustable) is too loose. Try and stiffen them up to slow the rise. The other reason could be from the stock height. The lower the nose is the farther down the piston in the strut goes towards the bottom and thus increases strut travel. So you probably only have around 2-3" of useable strut travel. General rule of thumb is that 5" is adequate.

Since you are running stock front springs and struts I'd say thats your problem. Your springs are too stiff. You need more extension and you need to control the rate of it with the adjustable struts.

You mentioned you've tried 15psi and up. Thats a lot of air. Try going down to 11-12psi hot and see what it does.

Your BMR control arms... does it have the adjustable holes in them? Do you have them in the lowest hole?

Lastly, if you don't have time to buy parts before the race then I would try and adjust the rear ride height to get the lower control arm as parallel as possible (i.e. cutting the springs). Maybe if you have a friend with a spare set you can cut if you don't want to cut yours. If your tires won't rub by cutting the springs you will lower the rear of the car (i.e. move weight to the rear). This also affects your instant center and antisquat values.

Hope this helps.

-Mark

Bitemark46

Oh, one more thing...I think your mid 1.3's vs your now 1.5's was due to track surface. Your car will go 1.3's again but the way your cars sits now the track surface has to set on kill...hence maybe why the other tracks you were going 1.5 60'.

z28bryan

iTrader: (7)

I'm pretty sure KYB AGX shocks adjust both compression and rebound with 1 ****

therealcreeper

iTrader: (37)

didn't really read much but yeah, the KYB's adjust bump and rebound together

one thing you might want to try is throwing on some worn out stock shocks for now. they make pretty good drag shocks because they really don't do much of anything, so the car can transfer weight better.

Bitemark46

Ok. So if you have it on full stiff on extension then the compression is on full stiff? I gotcha. One would really need 2 independent adjustments.

z28bryan

iTrader: (7)

You sure that's a good idea? Lots of people say to get better dampened shocks to get rid of wheel hop. And wheel hop conditions = bad

therealcreeper

iTrader: (37)

It's a complicated issue. Drag shocks work by offering very little damping, very much how worn out stock shocks function. You need the weight to transfer pretty quickly, and a worn shock will do a good job of that. I think some people have better luck with good rebound damping in the rear to keep it "down" and not springing back up but it takes a lot of trial and error to get right.

Of course you can overtransfer weight, or underdampen, etc. so it really takes a lot of testing and tuning to get right, sort of contradictory to what is being asked for in this thread

MADMAN

iTrader: (4)

Michelle just call us tomorrow.