Hi Guys

I have recently fitted H&R Springs to my 996tt. The car feels horrible now. Its very unstable at high speed and my rear tires are wearing badly on the inside.

Any advice on which bump steer correction kit to get??

Any advice at all will be greatly appreciated

Thx!

 

dropping the car w/out dogbones/sways/alignment etc will not get it done. springs alone? not so good. as you've found.

 

What does one need to do with the dogbones??

 

have them installed and re-align the car. very important.. or the car sags.. resulting in, well...

* gt2/x73 alignment spec(s)

 

Any advice on which dogbones to go with?

 

any name brand specific to 96t. check out vivid, maybe eibach makes em. i can't even remember what mine are lol..

but i've had two tt's with h&r sport spring setup. currently w/ MO30 shocks and gt3 sways and the car wants for nothing

try that and the springs will redeem themselves and you'll have incredible handling and ( ahem ) *normal* inside tire wear. you'll shred your tires at the very least w/out these adjustment(s).

the caveat being springs will never feel cushy on a purely *street* car or as a DD! *most* everything is a trade off, on some level, when it comes to mods

 

Forget dog bones. Everyone loves to sell you those. Your camber is not the issue but rather you have too much toe if you are wearing the inside 1" or so of the rears. Get adjustable rear toe arms with bump steer. Tarret makes good stuff. If you wanna get the best, have someone get you the front and rear PMNA 997 Cup toe arms.

 

... and there ya have it. what do i know lol

 

I don't know what it is about dog bones that everyone loves to sell you on those. I've been down that road before, had them on my car and ended up replacing them withe the OEM parts. All they do is add noise and make it a further pain in the *** to set up since you are throwing another adjustment variable in there. Interestingly the OEM dog bones are the same parts that are used on GT2s, GT3s, and also Cups. I think it's safe to say they will work on a TT. Everyone has it in their head that camber kills tires when in fact too much toes does. Even lowered you should have no issues getting -2.0 degrees or so camber with the stock upper arms. That will not kill your tires. Camber wear will show up as wear more across the whole tread of the tire while too much toe will show up as the inner tire wear that most guys see. Lock down your rear toe setting with solid thrust arm bushing along with adjustable toe arms and you will see your tire wear drastically improve.. 0.15' per side (0.30' total) toe works great in the rear. Throw a GT3 rear bar on there and your got a good street package..

 

john you race your car. i think ( possibly ) for a lowered street setup, drop link/bones whatever might be fine. i have no experience with your level of fine tuning your car, and would ordinarily defer to your expertise, but what you suggest *might* be excessive for what the OP is attempting to achieve. presumably, a better tracking street setup that doesn't kill his tires prematurely, or so low it sags, or hits the stops. hence my suggestion, as a cure for that. not that they were the end all/be all. hell, that would open the door to the old "springs vs coilovers" fruitless and circular debate lol

again, they seem to work just fine for me. additionally, they must make them for a reason!? but again, you're far more "expert" than i, admittedly.

add: i did mention that the gt3 sways were critical to achieving a good mid level compromise setup. i give ya that

 

Spring only are the worst way to lower a car. The stock shock aren't designed to deal with them. Coil overs are the preferred method. Depending on how far you lower it you may or may not need dog bones, but you will need adjustable rear toe links at a minimum (camber and toe in the rear of a 996 move inversely to each other). Also check your sway bar drop links. Once again depending on how much you lower it, the stock links my let the sway bar rub against the frame. Adjustable drop links can solve this, but be fore warned they are noisy.

 

Understood. I just threw my $0.02 in there because of all the mistakes I've made along the way and what I've found that works and doesn't. For someone with lowering springs with a budget and a goal of a street set up that doesn't destroy the tires, I would not waste money on dog bones. I believe money will be much better spend on rear adjustable toe arms (with or without bump steer depending on the amount of lowering. While there I'd swap in solid thrust arm bushings (the OEM ones are super squishy) which are cheap at $200 and call it a day. Basically $400-$600 in parts. That's about the price of a set of dog bones. As you know, the rear GT3 bar is nice and an effective tuning tool and adjustable drop links are nice but those items won't effect tire wear. Just to give you an idea, the only suspension component on my car that is stock are the rear doggones. There is just no reason to change them unless for some reason you want to run with super low camber in the rear.

 

my car has seen many track days as evidenced by the peeled paint on my calipers lol. sadly, they were not peeled by me, but rather by a previous owner who had the advice and input of some known and reputable tuner/track rats here in socal. even including some custom brake cooling ducting that looks like sh*t, but presumably works better than stock as well. i got it as i now have it ( mostly ) and have never found it to be lacking in the handling dept, in any way at all. really. but even then, i don't track as such. i just tear up canyons.

however, if i had it to do all over again, i'd most certainly defer to your expertise and take your advice on the subject. you clearly know the cars. cheers

 

The stock rear upper arms are sold on the cup cars,yes but they have adjustable lower control arms and toe arms so they can take out camber if needed. They also have heim joints pressed in the dog bones.. They also are track cars that go around turn just as much as they go straight very unlike their street counter parts. Every pro team cup car I have seen is all the same. they use rsr sub frame, has no eccentric adjustment and they use every link with heim's and adjustment.

OP, ERP sells a bumpsteer kit for the front and you can use dog bones if you want to just make them all (4) the same lenght. start with 5mm longer then stock, that should put you mid stroke of the lca eccentric. You will need adjustable toe arms for sure though.

 

http://www.brrperformance.com/blog/w...3/IMG_4518.jpg

http://www.brrperformance.com/blog/w...3/IMG_4418.jpg


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