Issues with stock 911 suspension?

Bullet Bob · 03-21-2006, 03:18 PM

I recently bought an '88 Carrera and at around 85 mph it begins to feel a bit squirrely (while passing on country roads). Some time ago I had a Nissan 300ZX twin turbo and I remember it feeling firmly planted up to 120mph on the same type of road.

My 911 has a chin spoiler and whale tail and everything else is bone stock. Are there things that need to be done to stiffen up the suspension (stiffer torsion bars, sport shocks), or is this just typical or the 911? At the lower speeds it feels great around corners. I could live with a stiffer suspension, but a bone jarring ride would not be good. I do not want to make this a race car.

I have posted questions regarding upgrades in the past and my 'to do' list includes:

Turbo tie rods
Strut tower brace
lower by 12mm

Will these help alleviate the problem, or do I just need to get used to it?

Thanks,
Bob

cbeers · 03-21-2006, 03:23 PM

Not right at all!

Mine is solid well into triple digit speeds, no tail.

How do your spring plate bushings look?
How are your tires?
Air pressures?
Shocks?
You mention new tie rods, are yours shot?

give us more of a description of 'squirrely'

By the way, pictures of any new ride are mandatory

McMinville, I grew up at the base of Mt. Hood, outside Sandy on Hwy 26........

-Chris

dd74 · 03-21-2006, 03:32 PM

Yep - mine's solid as well into triples.

To put on your to-do list: replace all bushings; lower to appropriate level, turbo tie rods, align, corner balance, then if you have any $$ left over, go for a strut brace.

Obtain a good basic well-operating suspension before add-ons like strut braces.

Bullet Bob · 03-21-2006, 03:37 PM

Bullet Bob · 03-21-2006, 03:39 PM

Bullet Bob · 03-21-2006, 03:44 PM

The car is in great condition, though it has 170k miles. The tires are Bridgestone Potenza 195 65 R15 (front) and 215 60 R15 (rear) and the tread is 90%. Shocks seem to be okay but it is hard to tell. I haven't checked the tire pressures but I would assume they are around 30 psi.

Squirrely... It feels like there is a delayed steering response and then the car darts in that direction. With the ZX, the steering response was immediate and very precise. This feels a bit more imprecise and it gets the heart rate up... makes me go for the brake pedal. I want to root this out and fix it. Any thoughts?

Thanks,
Bob

dd74 · 03-21-2006, 03:46 PM

Sweet car. I don't know about the shifter and boot, though.

Bullet Bob · 03-21-2006, 03:47 PM

yeah, it is on the 'to do' list as well :-)

dd74 · 03-21-2006, 03:52 PM

Quote:

Originally posted by Bullet Bob
The tires are Bridgestone Potenza 195 65 R15 (front) and 215 60 R15 (rear)

This denotes 15-inch rims. All late Carreras I know of from '88 had 16-inch rims.

Bullet Bob · 03-21-2006, 03:56 PM

would 16" rims with 45 or 50 series tires make much of a difference?

anthony · 03-21-2006, 04:22 PM

I'm not sure how much of a difference but 16" wheel with a lower profile (stiffer sidewall) performance tire would have to make some difference in turn-in. Which Potenzas are those?

I'd look at shocks first. How old are they? Then I'd look at the condition of the a-arm bushings and tie-rods.

My SC is all stock (87K miles) with new Koni reds and it feels very planted and stable at speed.

diy83sc · 03-21-2006, 04:45 PM

Nice Carrera! Looks like it's wearing 7 and 8" wheels. I have the same mounted with Potenza S03 225/50 front and rear although a better combo might be 215/55 on the front. Before you invest in 16" fuch$, you may want to consider tires first.

I'd start with front and rear tire pressures of 29/34 respectively. How I "test" my rear swing plate bushings is to, on an open highway with little traffic, find a cruising speed then hit and release the accelerator quickly and see if you get significant side to side to side sway. It *may* indicated soft or worn bushings.

Weaver · 03-21-2006, 05:02 PM

With 170K miles, I would say atleast the rear shocks are shot. Obviously if you are going to change them, do all four. Torsion bar bushings were shot on my '88 at 70K miles! You might want to look at those.

65/60 series tyres would not be my choice, too tall for me. People say they give a good, smooth ride, but thats a tall side wall for cornering.

Bullet Bob · 05:13 PM

Incidentally, I have a set of 16" Fuchs on my 914-6 restoration project. They are 16x7 & 16x8 and they have new tires on them (225 50 ZR 16). Maybe I will throw those on this weekend to see if there is much of a difference. The wheels need to be restored because they look terrible. Is there an easy way to verify that the shocks are bad?

What is the cost to have fuchs polished and painted?
Is there an easy way to verify that the bushings are worn out (visual check)? Are Delrin bushings the best replacement?

dd74 · 03-21-2006, 05:56 PM

Quote:

Originally posted by Bullet Bob
Are Delrin bushings the best replacement?

Go with Elephant Racing bushings. Plastic just don't work well compared to Elephant's products. At least IMO.

ianc · 03-21-2006, 06:12 PM

You might also want to throw those turbo tie rods on there ASAP.

My front end was feeling sort of sloppy, as in the response wasn't tight or immediate. I swapped out the OEM's for the TTR's this past weekend, and the difference is clear on a 130K car.

If your shocks are original, changing them for Bilstein Sports or HD's will make a huge difference as well. These cars are too stiff for the bounce test to work well, so I would just change them out. HTH,

ianc

kqw · 03-21-2006, 06:39 PM

Does the car feel kind of wiggley rather than darty? I agree with the folks here. Rear shocks going bad or are bad.

Sooooo, replace the rear shocks and get a good alignment. Isn't it amazing that just when tax returns are on the way, a 911 smells it and gets to take it's bite out of it????

Evans, Marv · 03-21-2006, 07:30 PM

I would think at 170K miles, you should take a hard look at both bushings & shocks - expecially if the ones on there are original or close to it. The rubber in the tie rods could also be old enough to have developed some play. TTRs are a good idea anyway. You (& the rest of us too who buy older, pretty high mileage cars) have to realize the car is used, so it would be normal to go through some of the suspension & running gear. By the way, did you have a PPI done on it before you bought it? If so, did your mechanic say anything at the time?
Good luck & welcome.

ZOA NOM · ZOA NOM's Garage

Ball joints.

kqw · 07:52 PM

Quote:

Originally posted by Bullet Bob
The car is in great condition, though it has 170k miles. The tires are Bridgestone Potenza 195 65 R15 (front) and 215 60 R15 (rear) and the tread is 90%. Shocks seem to be okay but it is hard to tell. I haven't checked the tire pressures but I would assume they are around 30 psi........

You're kidding....Did the PO get rid of the wheels that came with the car? Probably......

Stock tires for your car should be 205-55-16 front and 225-50-16's in the rear, on 16x6 and 7 wheels ......and...

Your tire pressue is off a bit. I'm sure others will chime in but, I run 33psi front and 37psi in the rear However...that pressure is on the wheel and tire size mentioned.