Hi everyone! My '03 6TT has 67k miles and the stock suspension has started to show some signs of suspension wear (more specifically, I feel some lateral movement when going over midcorner bumps, not just vertical movement, and when I turn into a corner, I feel like the front end of the car is "skating" for a split second before the car changes direction) and I'm thinking about replacement parts.

My current plan is to get Bilstein B8 dampers and H&R sport springs, and replace the 4-5yr old PSS tires with RE71R tires. The car currently has 225/40/19 and 305/30/19 size PSS, and I'm planning to go to 245/35/19 and 305/30/19 RE17R. The wheels are Forgestar F14, 8.5" wide in front and 11" wide in the rear. (I still need to find the offsets)

The car is a weekend canyon fun runs car but is 100% street usage because I have a spec Miata for the track.

5 questions for the group:

• Are there any other wear and tear items that are "must replace" (e.g. camber plates for the front, drop links for the sway bars, rear toe locking plate kit)? I'm trying to keep the parts list down to a minimum to keep costs down
• Will I need other parts to get the alignment correct (e.g. rear adjustable toe control arm)? I believe the H&R sport spring lowering mild enough to avoid those.
• Will I have rubbing issues? I can't find anyone posting about this exact combination of tires and suspension, but it "should" be ok given that others have run these tire sizes with lowered cars
• Should I go ahead and use the "X73" alignment that is apparently already input into all of the alignment machines?
• Should I look into transmission and engine mounts to have an "X73-like" setup?

Thanks for your help!!

 

I'd go for the H&R coilovers or PSS10 over sport springs because they have the dual springs and will ride better. Your thrust arm bushings could be worn, some solid bushings can tighten things up and can help with tire wear. You will need adjustable toe arms in the rear for the lower stance to bring the alignment back into spec. Engine mounts will stop the uneasy feeling of the engine moving around while cornering. I'd leave out the mounts for later to do the suspension better if you are on a budget. Replace your trans mount if the rubber is worn out. Just a normal street alignment is fine, more aggressive will wear on your tires. 305's should fit, if they don't rolling the fenders is an easy fix.

 

i have no experience with 19's beyond trying them years ago on a previous 996tt and swapping out the 19's; first for 9x12x18's then 8.5x12's and i prefer the narrower tire for tight cornering..

i've kept this setup now for years, only improvement now would be coilovers and i dont need em. but i think 19's are LOUSY for canyon carving, myself. so, with h&r sports and b8's i think you be much happier with the overall plant and ride quality if you went with a gt2 sized wheel and tire setup.

also, i would suspect you make have a worn trans mont and that would definitely contribute to "lateral slop" on corners. you can feel it for sure. once you replace those items? it should be VERY taut.

if you dont know WHEN the MM's and the t-mount were changed? ( if ever?? ) i would swap them out. i run the oem 997 t-mount with wevo semi-solids and run h&r ( reds ) sports with MO30 bilsteins ( essentially the same as b8's ) the ride and stance with a oem gt2 alignment ( start there OR x73 align #'s though the x73 "drop" is only -20MM while the H&R reds will drop about an inch?..) and tweak to taste from there.

so i'd do everything you mention except i'd definitely ditch the 19's. you'd have the stance you want from the suspension upgrades ( and lowering ) and the gt2 sizes and "plant" make for better suited and "factory proven" handling & ride than ANY 19 combo. for canyons, that is

lastly, you "might" want to consider some TS adjustable toe links if you DO opt for a more traditionally proper gt2 setup, as there is a definite tendency for WOT squat on lowered TT's that will contribute significantlly to increased and uneven inner tire wear. mostly on the right, if running oem awd. oh, yeah, then there's the rear fender roll, lol. NBD and it'll save some rub, but it all comes down the the conditions and how hard you push in your canyons.

I'm sure others will bring their advice as well. GL with the new parts.

 

Thanks everyone for the advice so far. Please keep it coming!

Regarding the GT2 tire sizes, it seems the choice gets very limited. There are no "modern" tires other than the Falken RT615k (eg can't get RE71R, Rival,zII or other similar tires).

For the coilovers, I am a bit concerned that I'm paying extra for adjustability that I won't be using. are there any concrete advantages other than comfortable ride?

 

No input on the dampers and springs but I would do new upper strut mounts and bearings, tie rod ends, and lower control arms when you do the other work. These are the items that cause much of the noise that come up in the posts. They are likely well worn and could used replaced. Changing them when do the suspension work won't add a bunch of time but will save you a lot of time if you had to go in and do it as a separate job.

 

For a tight street car thisbisnwhat I'd suggest.
powerflex poly bushings for lca and thrust bushing
ts adjustable toe links
h&r street or pss10 coilovers
replace struts mounts if needed
eibach sway bars with hd links
poly engine mounts
window weld trans mount

set the ride height medium, not super lower. Run a gt2 alignment.

as for 18s vs 19s. That's debate will go back and forth forever. On a street car, 245/305 19s I think is really the best option. Ride great, look nice, and way more tire selection. If it's a straight track car, 18s are best.

 

19's VS 18's a a purely aesthetic argument/discussion. 18's are *best* period if performance and handling are taken into account, and that would end that equation/debate. the fact is, "19's" are a "compromise" and any "perceived" advantage to running 19's would be mitigated by properly lowering the car as planned. filling the wheel well with the larger 19" wheel does nothing to improve anything, other than perhaps "looks".

all that said, buying new wheels and tires might not be in the "budget"? but if you are SERIOUS about canyon carving? 18's is the way to stay, though most anyone headed into a canyon on 19's will still undoubtedly make it down the other side of the mountain lol

 

If your still running original engine mounts, that's the first thing I'd replace, even if it's just putting in a fresh set, inexpensive OEM mounts.

Same for transmission mount.

As for the suspension setups, I'll leave it to those with more experience with this particular car, but I will say that often mystical properties are given to coilover setups, when their primary advantage is really adjustability. Hugely important on a track car when your tuning for different tracks and racing setups, corner balancing the car with required ballast, etc., but not so much of a huge advantage on a street car.

No doubt high end Moton, JRZ, etc. setups are superb engineering and can bring a level of tuning and control way beyond a standard shock/spring setup, but even so, the right springs with matching shocks (H&R springs + B8's for example?) can be a fantastic street setup if it's the right combo.

 

 

I disagree with 02996x50 about 19s. Properly setup and sizes, they don't give anything away to an 18 on the street. Tons more tire option like stated as well. Re-71r are a great street and auto x tire. Stickies 200tw tire currently available. They do wear fast though. I would not recommend and r comp for street use. Bad in the rain, wear super fast, and sand blast the hell out of your car

 

 

Don’t waste your money on dogbones. If someone tries to convince you that you need them on a street car, run...

 

 

when i picked up my car it had PSS10's and about 50K total miles on it. It was an '01


Within the first 2 months I replaced Motor Mounts, Trans Mount, and Front Strut Top Mounts....all were pretty shot.

Curious, I read little about the rear strut top mounts going bad, is there a reason for this?

 

You just need the rear toe links to get back into alignment, not sure which ones are dog bones.