majohns

i want to put an eibach sportline kit on my car. i know that's allot of drop. my question is if i put that kit on can i add drag shocks to it and get the lowered car plus get the weight transfer of the drag shocks? or, will there not be enough suspension travel for it to work? thanks

Jazzer The Cat

I am not a drag guy, but your proposed idea will not work as intended Short/stiff springs are just not what you want up front and don't see drag struts compensating for it well.

My recommendation is to ALWAYS build ones car to meet the ULTIMATE goals and allow what be for everything else. My car is 100% focused on taking corners and I live with the noise and relatively rough ride I get on the street.

Jazzer

majohns

that's kinda what i thought. my last car was lowered and it handled like a dream, but when i went to the strip it wouldn't hook and i didn't go enough to compensate the expense on wheels and slicks. i just thought i would ask.

Jazzer The Cat

Now.... not "hooking" is not entirely a suspension thing, in fact, it is mostly tires. Wheel hop is addressed by suspension and better weight transfer to apply as much downforce as you have to the rear wheels.

Do you have wheel hop or spin and what tires are you running on the 1/4 mile?

Jazzer

majohns

i have not ran this car. i ran my last car many times no wheel hop. but i would run pretty good street tire at 15psi no water box and it would boil the tires it 1st, 2nd, spin in 3rd, and chirp 4th. i think mainly due to the 2in. drop and not having much weight transfer. i know it will spin with street tires but my car now does not spin near as much at stock height.

my last car:



new car:



big height difference!

Jazzer The Cat

You're getting more into 1/4 mile knowledge and just not going to be of any real help I am gonna ask you to do some reasearch to further answer your questions, because I am a much more twisted-dood

Jazzer

Norm Peterson

By itself, a 2" drop doesn't affect your rearward load transfer as much as people tend to think. From your description of how easily you get/got wheelspin, the difference of 50 - 75 lbs rear axle load due to the difference in CG height isn't going to be nearly enough to matter one way or the other.

What lowering does affect is the rear suspension geometry - think 'instant center', 'anti-squat', and how fast the geometric load transfer happens. The geometric part of load transfer is much faster than waiting for the rear of the car to squat or rise, and can be enough to stop borderline cases of wheelspin before they get started. Without knowing where the geometry was in you old car or where it is now with the new one, it isn't possible for me to tell you what to expect.

Not getting wheel hop can come from having tires that simply aren't grippy enough or from having swapped at least the rear axle LCAs out for aftermarket pieces with much firmer bushings (poly) or rod ends.


Presumably, front drag shocks are going to let the nose rise faster, which as Jazzer mentioned already is somewhat at odds with the notion of using stiff front springs. All they'd do here would be to let the nose rise up to the lower height it'd ever go to, a little faster. The downstream effect on CG height also rising is still not going to be much of what you want unless you've got the power and the grip to pull the front wheels.

Rear drag shocks.shock tuning can briefly help plant the rear tires on launch and again briefly on the upshifts. These, at least, would work about the same whether you're lowered or not.


Norm

majohns

ok correct me if i am wrong... i need rear drag shocks, and front drag shocks are pointless. its kinda confusing to me, because suspension is more complicated than i tend to get into. let me put it this way... i want to install the eibach sportline kit and it still be able to hook (for the most part) i know slicks are the only way to really make it hook. but as far as street tires go what would i need to do to make my car hook as much as possible with a 2in. drop? thank you for hanging in there with me.

Norm Peterson

Not all street tires are equally grippy (and NT555's aren't the grippiest street tire either). DR's are variously grippy, but have their own set of disadvantages in daily driving (rain, tread life, loss of grip due to the heat cycles accululated just puttering around town, etc.). You need to do more of your own research on this, with your price range in mind (it can get pretty easy to spend somebody else's money ).

You'll benefit from LCA relocating brackets, particularly given the rather extreme drop that you're pretty insistent on going with. But I think you'll have to experiment to find out which holes work the best. At 1.75" drop, you'll probably end up dropping the axle ends of the LCAs by somewhere between 2" and 2.5". That's what a few rough guesses and an anti-squat spreadsheet seem to be telling me, anyway.

You should also benefit from LCAs with firmer bushings. I don't get the idea that hard cornering is your game at all, so the disadvantages of poly that can show up when you're autocrossing or running out on a road course aren't likely to bother you much. The ride WILL get somewhat stiffer going over one-wheel bumps.

I'm getting to shocks later here, because I believe that you need to fix the geometry before you start tinkering with how fast either end of the car moves up and down on its suspension. Once the car stops moving vertically, there isn't a shock in the world that will make any difference either way (shocks need have their internal piston to be moving in the tube in order to put up any resistance whatsoever). And with 100% antisquat (which you can achieve with the right hole location in relo brackets), the rear suspension won't even be trying to move. Won't particularly squat or separate.

But ideally, the rear drag shocks would be adjustable at least for 'bump'.

I won't go so far as to say that front drag shocks won't give you any benefit at all, just that the stiffer sportlines will throw part (maybe a lot) of it away. If I was as serious about drag-racing as I am about cornering, I wouldn't even be thinking of Sportlines or anything that stiff and that low. But this has to be your compromise, not mine.


Norm

majohns

ok so i would probably be better of with the prokit instead of the sportline? but i would benefit from rear control arms regardless of which route i go?