Ed Hughes

Didn't catch the part about reluctance to do the thru-body mod...

Joseph: I JUST finished putting 22/29's on my '84 with Sport Bilsteins all around. IMO, it is not too rough for the street. In fact, I was surprized at how mild it is. I do like a taut suspension, but the biggest change I see with the stiffer bars is when you go over seams in the pavement, you can "feel" them. Over train tracks and stuff, it feels fine. I don't want to try the pothole test.

I'm planning on a front sway quite soon. I notice a little oversteer on the street in hard turns, I hope to have it out for a trackday in the next couple of weeks to test there with the MPSC's on.

Joseph Mills

Ed-
I should hit I-35 and come down and beg a ride in your car to see what 22/29's ride like. I do not want to go with too high a spring rate. BTDT.

Those MPSC's sound like some sweet tires. I don't know what you've used in the past but the feedback I hear is that the SC's are about as good as anything out there AND provide 40+ heat cycles.

I really like the 205/225 15" Kumho 710's I run in AX, but they have a way too short a lifespan for track.

Maybe someday I'll own a 3rd set of fuchs. Now that's sick.

Joseph
88 Carrera
AXhound

69 911E -
75 914-4 -

Ed Hughes

The MPSC's are nice on a car with a little weight guys with 2200lb cars have trouble getting heat in them. Mine's closer to 2700, so it hasn't been an issue. If it's too cold at a DE, I'd probably keep my street tires on. They do wear very well too. Toyo RA-1's are also popular around here.

Luke

Put some spacers up front .... hehe

achris

I just picked up the car back. My mechanic needed 2 days to reset ride height to 25,5"/25" (fender lip to ground). The problem is, that after each change, you must drive the car for a few blocks, and then check ride height again. As the factory manuals describe, you have to bounce once the rear downwards and measure, do the same but upwards and measure again, set to the middle for both front and rear and then check again fender lip height or better torsion bar center height on all four corners. Slight differences 5-8mm are allowed, but I needed to have it perfect. Unfortunately no weight scales available around here.

In fact I use fender lip height just as an indication. Further we measure the difference between center front torsion bar to ground, and center rear torsion bar to ground. Considering the factory specs, this difference should be 124mm.

I also installed new front brake calipers and added a fan and thermostat (BMW part opening at 91 degrees C, 196 F) to my oil cooler. The fan was not included in Euro cars without cat.

My prvious alignment settings, after resetting ride height, checked out to be :
front camber : -1
rear camber : -1,5
caster : 6,12
front toe : toe out 10' each side (total 20')
rear toe : left toe in 10' , right was 0.

This time I was present and checked everything out very carefully myself. The new settings are :
front camber : -0,5
rear camber : -1,5
caster : 6,12
front toe : toe in 8' each side (total toe in 16')
rear toe : toe in 17' each side

By setting the rear height back to normal, decreasing front camber and setting both front and rear toe settings to toe-in, I hope to decrease the oversteering.

I will let you know about the results, if I get a chanche to get out of the city for a fast ride tonight.

If I should report about my previous '83 SC, which I tested with 19/24, 19/26, 21/26, 21/27 and finally 22/28 bars, I would say don't bother, 22/28 is the best combination for 50/50 street and track.

Saturday is track day in Serres, around 600 Km out of Athens. This will be the final test for my setup.

Chris
'88 Carrera

Joseph Mills

Chris-
Sounds like you did it right this time. Expert alignment IS labor intensive and it's nice the guy let you monitor all the adjustments. I'm lucky myself in that I have an AX friend that let's me use all his alignment equipment plus scales for corner balancing. It takes me a long time but I know it's as correct as can be.

I'll take into consideration your T-bar recommendation since I'm starting the process of shocks & T-bars myself. I'm just still up in the air as to what sizes I want. No one local I can find that has 22mm F T-bars installed that I can get a ride with. I may have to travel to Dallas to find a ride.

You might document your tire pressures before you try it out tonight.

I look forward to your results.

Joseph
88 Carrera
AXhound

69 911E -
75 914-4 -

achris

YES !!!

It is now midnight, and I just came back from a 1 hour ride at the coast with a big smile in my face. Perfect ! The car handles now much more neutral, and initial oversteering is gone. THIS IS IT.

Josef, no reason to be afraid of the 22mm bars, just go for the best, the Sanders hollow ones. 29mm are the right ones for the rear. Grease them well and change the rear bushings with new ones from Neatrix. Glue the bushes on the arms and cover them with some talk powder for easier installation.

For the tire pressures I used your advice and went from 29/36 to 28/38.

Thank you all for your support. I will report about the track day (which is in 2 days !) next week.

Chris
88 Carrera

Joseph Mills

That's really good news Chris. Makes all the frustrations worth it when it comes out right doesn't it.

If you could borrow or rent a pyrometer for your track day, you could really dial in and optimize your tire pressures.

I will go with your recommendation of the Sanders T-bars once I decide on the sizes.

Good luck with your track day and let us know what you make of it's new handling traits at speed.

Joseph
88 Carrera
AXhound

69 911E -
75 914-4 -

Ed Hughes

I'd go with the Elephant Racing bushings...they are a little more pricey, but worth it, IMO. Many others have posted their thumbs up too. Heck, why not the monoballs too? I did all of that before I put the new t-bars on last week, and that is still the best upgrade I've done to date.

2002M3Drew

Not intended as a criticism, but I'm curious as to why you went with essentially a DE torsion bar combo, but stayed so conservative on alignment? 0.5 deg per side of front camber (I assume you meant per side and not total camber) is way tame for track use. (I just added a Wevo setup to mine so that I could get camber up to close to 2 degrees negative per side.) The same with going with negative toe in the front (slight toe out in front gives much crisper turn-in.) I know from doing upgrades to mine how critical alignment is to the end result.

It sounds like the rear toe (the 0 side) was probably your culprit in the "evil handling." Regardless, glad you are happy with your end result!

achris

To answer your question 2002M3Drew, I changed the alignment settings to decrease oversteering. Yes, it is -0.5 deg per side front camber.

Regarding the 'evil handling', I believe it was caused by the f/r height settings. After the installation of all new suspension components, the rear settled down by 1" after some driving. This must have been the main reason for the oversteering. That's what the guy at the alignment shop said.

After the height was set back to 25" rear (25,5" front), a more 'conservative' alignment followed, in order to decrease the oversteering. Next thing was the first track day, where everything was well. If the problem was really caused by wrong height in the back, then I should be able to increase f/r camber again.

achris

On Saturday morning it was track day for the Porsche Club Hellas in Serres. My car handled like a dream. My best lap for the 3,2 kilometers was 1min 45sec, just 4-5 sec behind most of the 996 turbos, and in front of some normal 996/997 carreras ! Best lap of the day was done in 1min 25sec by a 993GT2 racecar with something like 600hp.

The next investment will be for new semi slick road/track tires. My normal tires lasted only 4-5 rounds before starting to get too hot. Handling was neutral, provided that I kept the gas pedal steady during cornering. By too high a cornering speed, the car was starting to slide on all four wheels. I could control it by carefully decreasing speed.

Oversteering happened only if I pushed the gas pedal to the floor during cornering in third, mostly at the exit of a long turn.

I believe that the wrong rear ride height was the main reason for my initial problem. Thank you all for your help and support.

Chris
'88 Carrera

Joseph Mills

Chris,

Congratulations on your track times!

Sounds like quite an improvement in handling. Good deal!

And it appears, from your initial track impression, that you have managed to attain a suspension setting that provides very controllable oversteer. Sounds like a sweet balance to me.

You might consider not making any further suspension changes at this time. Since you don't have any glaringly deficient issues to address, why not give yourself a chance for more seat time to become better acquainted with your new suspension setup. And at this point, you may be better served by making only one change at a time.

Ultimately, the track tires you select will have an impact on your suspension tuning. Some competition tires prefer more camber, some prefer less. Anyway, once you've made your selection, if you elect to use a pyrometer, you can determine how well you are working the tire by monitoring the temps across it's tread and that will indicate whether you can use more or less camber.

Good luck!

Joseph
88 Carrera
AXhound

achris

Enjoy my video from the track day :

Video_track_day



Chris
'88 Carrera

Peter Zimmermann

This thread really shows how different setups work for different drivers. Drew is absolutely correct in mentioning both camber and toe at the front of the car. Neither issue induces oversteer, a little more negative camber, up to -1.2/side, would actually reduce oversteer by making the front stick better, and a small amount of toe-out, say +1/32/side, will make the car turn in better. Also, I'm completely mystified by the tire pressures, I've found that every 911 that I've driven in competition a good starting point was 34F/36R, then re-set as necessary hot until you find what works. The pressure gain is what's important to know, as well as the temp differential between the inner third of the contact patch and the outer third. Only when that is known can you hope to improve the car.
Pete