murrayg

After enjoying my 944 for 2 years, I finally made it to the track. VERY COOL!!! You really can’t appreciate these cars if you don’t. http://www.atlanticmotorsportpark.com/ .

OK, now the slippery slope!! The car is an early 85 with the following:

Front – 250 lbs springs 1.5 inch lower, Koni sport adj inserts, 26mm sway bar, delrin bushings, boxed steel arms, 225-50-15 AVS tires.

Rear – 18mm swar bar, delrin SB bushings and “rod end” SB drop links, lowered to match the front (car level), 225-50-15 AVS tires …….and everything else stock.

It’s no surprise the car has moderate understeer. My “winter project” is to focus on the rear suspension as the front is not too bad. My first thought is 28mm T bars with Koni sports. However, I keep hearing about the shocks with “helper” springs, or kind of “coil overs” with the stock T bars. I checked into this and $1400 a set is WAY over what I can spend. What are my options WRT rear suspension without spending tons of money. Oh ya, I’m not looking for a race car here, I drive this thing every day (7 months a year).

As always,
Thanks!!
Gord.

tifosiman

With 250lbs on the front and stock rate on the rear the understeer should be more than moderate. You definetly want to bring up the rear rate.

I would suggest going for the larger Tbars. It is more work at first but honestly with rear coilovers in "helper" configuration you will need to touch the Tbars anyway to correct the ride height. If you aren't planning on changing spring rates later and want to leave it alone, I would just go for the larger Tbars and be done (especially for a car that will be primarily a street car). If you like messing around with rates and like a lot of adjustability, then rear coil-overs in helper format or as standalones (sans Tbars) is the way to go.

Hope that makes sense. Good luck!

MAGK944

I just got another set of these with 600# hypercoils from Jay at Ground Control for my street car. I have a similar set-up to you except with Bilstein struts and 250# 1in lower Welt Springs up front. 30mm front and 18mm rear sways. Rear has been lowered 1in to match the front.

To do anything you will have to get at those torsion bars, even if fitting helper springs, so why not go full coilover instead. Less hassle, more control. These are $649 a set complete with koni inserts, springs and bottom mounts. Speak to Jay at GC, he was very helpful.

Potomac-Greg

Upgrading t-bars is technically the best approach. But it's a labor intensive job that either requires you to have a lot of skill or a lot of money. I went with helpers and used the rear eccentric adjustment to get the height as low as possible. Not a perfect solution, but something I could manage on my own. I have 400# springs up front and 250# plus t-bars in the back. Handling is just about neutral, maybe a bit understeery, but that's probably a good setup for where I am in my track learning curve.

PS: I run a stock sway bar on 20 year old bushings (a decision made because I am cheap), and I think that's been a major positive on handling. With firm springs and soft sway bar (probably not doing much at all) I get good turn-in. If I ever upgrade sways, it will be in the back. Maybe reduce your front sway to OEM?

Z-man

First off, you can upgrade the tires a wee bit - if you swap out your wheels for 8Jx16's at all four corners, you can run 245-45/16 sized tires. While this won't really change the understeer/oversteer attitude of your car, it will give you more grip all around, which should allow you to bring up your speed before your terminal understeer kicks in.

That said, here's my setup: 400lb coil overs front, 31mm hollow torsion bar out back. M030 front sway, 22mm Weltmeister rear sway, and a bunch of other goodies... (See my website for the low-down) I feel this setup is perfect for the stuff that I do on the track. However, it is a bit too stiff for the street. Also: I run in the advanced run groups, so it may not be the best upgrade for you.

I feel that going with an upgraded torsion bar is a simpler setup vs. using helper springs in the back, unless you do away completely with the torsion bars and convert to a full coil-over suspension in the back. With helper springs, you've got two components you need to adjust when dialing in your suspension - that can complicate things greatly.

Both upgrading the torsion bars and getting coil overs installed are expensive. (BTW: if you go with the coil-over route, they still have to get to your torsion bars, since they would need to be re-indexed. So why not just sway them out??) Count on at least $1000.00 if you want to firm up your rear suspension -- and that's on the cheap!

Ok - all that being said, I suggest the following: besides upgrading your wheels, I would consider upgrading your sway bars first. The 968 M030 19mm 3-way adjustable sway bar will help balance out the car a bit. Also: if your rear shocks are original, if you swap those out with a fresh set of Koni yellows, they will help make the rear end more compliant, and they should help dial out the understeer - albeit marginally.

The beauty of these upgrades (245 tires, 19mm rear sway, and Koni yellows out back) are:
1. You will notice a difference - it will help dial out the understeer.
2. These upgrades are far less expensive than upgrading your torsion bars and/or installing coil overs in the back.
3. When you do upgrade your suspension to something firmer, these components should still work. (The Koni rear shocks work well with my 31mm torsion bar).
4. Your car won't be a pain to drive on the street. (IE: Your dentist won't be putting in new fillings every couple of months...)

Sorry for the long post -- hope this helps,
-Z

MAGK944

Here is a good reference for understeer/oversteer corrections. http://www.tech-session.com/kb/index.php?article=22

Your main issue is that your front is much stiffer than stock while your rear is still stock. The stock set-up has understeer dialed-in and by increasing the front spring #'s you have dialed in even more understeer. You can dial this out in vaious ways, see the above link^. But IMO it's best to get the rear spring rate to match the front, then fine tune with the other options.

M758

Do t-bars.
Rear coilover are cool and all, but done right are is the same work as t-bars or even more. If you need spring rates greater than what 30 mm solid bars can get you then you will be forced to go with rear coil overs, but otherwise do the tbars. The nice thing about t-bars is once in they are done and never need to be touched. You can still tweak ride height with spring plate and t-bars just do their thing.

28's are probably a good match for 250's

V2Rocket

i have a similar setup, 25.5 bar up front, 18 in back with 200# springs on the front..mine is pretty neutral handling though. the best solution would be to upgrade your t-bars but as a short term a larger rear swaybar could help too

Papamurphdog

+1 on t-bars. 30mm will stiffen the rear. Make sure the rake is neutral or positive 1 degree. Fat sway bars and solid monts for same will help keep the car flatter too. That will all help turn in. Of course you also need to make sure the front has about 2 degrees negative camber and proper caster, toe, etc,. but tires will suffer with a lot of street miles. You don't have to go super stiff to have fun on the track. If you went with 45 or 40 profle tires that would help stiffen the ride a bit too. I have 40's on the back and 35's in the front on 17" wheels. The sligtly smaller front tire diameter seems to help turn in also. Just my two cents

StoogeMoe

I am running nearly the same setup as you. 250lb springs up front and almost the same sway bar sizes. I put in a 28mm torsion bar in the rear, and I can tell you that the balance is perfect. You may have to adjust your sway bars to get a neutral balance, but it can be done. Not only is this a great track setup, but is still tolerable on the street.

Yeah, installing the t-bar wasn't that fun, but chalk it up as a learning experience.

I think you are past the slippery slope at this point. There's no turning around now. You should have gotten into drugs instead. It would have been cheaper and they have rehab for that.

Z-man

I think that would be too stiff for the 250-lb springs that are up front on Gord's car. I run a 30mm effective (31mm hollow) torsion bar, and I have 400 lb springs up front. My car is neutral with a slight oversteer attitude.

250lb front springs with 30mm rear torsion bars will give the OP a car that is very biased towards oversteer. Too much oversteer.

-Z-man.

tifosiman

Yeah, I'm thinking 28mm is a better match. Just my humble opinion.

(BTW, I'm suprised no one has made any "stiff rear" jokes yet! Come on, it's Friday!! ).

theiceman

i was gonna say just shove a broom handle up there , that'l stiffen her up !!

Tom R.

just as long as it is technically correct - correct?

I have a hard time stiffening my front and you want me to make jokes about some guy wanting something stiff and rear end in the same sentance.

murrayg there is someone selling a set of koni rears for cheap in the members only for sale section. may be worth the $18 to become a member.

Potomac-Greg

"If the stiff front continues for more than four hours, please see your doctor."