Rude Handling Problem

Al Cody · 02-15-2002, 07:24 PM

I've discovered a rude handling quirk in my 924S. A road test I read about the 944 mentioned it also. You may have discovered this one yourself. The 924S/944 tends to go from understeer to over steer when the throttle is lifted in a turn. I discovered this the hard way shifting from 3rd to 4th in a fast downhill sweeper. My car did a really big lurch, then sorted itself out when I got the gas pedal back on the floor.

What is the soultion to this handling problem. I have new shocks, tires, suspension bushings and a 14mm rear sway bar. I am suspecting an 18 mm bar in the rear is the way to go. I need some expert experience here. Now that I've discovered this glitch its really bugging me!

Thanks for the help!

Al Cody · 02-16-2002, 09:07 AM

The 924S, it is the same as the pre 85.5 944, except for the non-flared fenders, of course. Is this only my car? Has anyone else experienced this with their 944? It'd help to know other 944 owners experiences. Some of you guys auto-x and race with highly tuned suspensions. What works? Or is this just 944 and that how it is?

Thanks!

Bob's944 · Bob's944's Garage

Not sure what kind of experience you have, but with rear wheel drive cars when you're driving at the limit in the corners, the rear end will move out under throttle and will tuck in under decelleration. Basically you steer the front of the car with the steering wheel, and the back of the car with the throttle. Sounds to me like you should have shifted to 4th before the sweeper so that you could have remained under throttle throughout the entire sweeper.

Dantilla · 02-16-2002, 09:19 AM

That's not a handling problem. It's another tool to put in your bag of tricks when driving at the limit. The 911 guys steer more with their right foot than with the steering wheel.

Al Cody · 02-16-2002, 09:35 AM

Yes, I agree. It is very stable under steady throttle. At the time I was do field research on 911SC accleration vs 924S acceleration. We were pushing it pretty hard and down hill too, so gravity would bring out all the worst in our cars. The 911 may have had the same problem as we both gave it up about the same time, we were hitting 100mph. Results : I had about a car length on him by this time and I gave away a car length at the stop light. I am pleased with that part.
I have read some pretty good threads on over steer and understeer. I think if I stiffen up the rear it creates a more oversteer which should help my case. It can be sorted out. I just need to know which way to go so I don't make it worse. Thanks for the reply.

seb928s · 02-16-2002, 11:50 AM

When I was driving my 951 when it still was working in turns I would has the gas on so the rear-end of the car pushed me around the turn better. I love oversteer these cars have some oversteer if you use gas in the turns otherwise it's more understeer. The 951 is a great first car for me. Now I think the 951 is really easy to drive. I'm used to the little tricks it throws at me. I spinned the car 270 degrees in about 10 feet of room without hitting anything I just tap the brakes and hit the gas when I was in the spin. It happened one night driving to get gas it was wet and I was just driving on a stright road and I guess I hit a oil slick because it was not that far from the light.

yOnKiNaToR · 02-16-2002, 05:12 PM

i agree..is is not a quirk to have neutral handling. on my 924S, i have pretty neutral handling and if i want to get the back end around faster or drift, i can use e-brake, severe weight transfer to the front, and/or i just slam the gas in 2nd or 3rd and i can get the tires to loose traction and get some oversteer. very well balanced car.

geoffbaltz · geoffbaltz's Garage

What is it that Ahmet says?

It's all the driver....

-g

gixer02 · 02-16-2002, 08:21 PM

It IS all the driver... once the car is set into a balanced mode and accelerating through a corner, snapping off the the throttle will cause trailing throttle oversteer. (back end slides out) That is taken directly out of the "Porsche High Performance Driving Handbook" by Vic Elford. I finished reading it about 10 min before reading this post. Basically letting off the throttle shifts the weight unloading the rear tires resulting in oversteer. It's not the car at all. (but maybe this symptom is more noticable in the 944 family because of 50/50 weight distribution) I suggest the book- it's an informative and enjoyable read. Vic Elford is a world renowned racer.

Pat

Al Cody · 02-17-2002, 08:25 PM

I've been thinking of getting the Porsche High Performance Driving Book for a while. I thought it was going to be most relevant to the 911 series, so I've been putting it off. Guess I'll get that order in and see what I can learn. I raced GP motorcycles for 10 years and this is my first sports car. I am really enjoying it and on a steep learning curve in the handling department. Cars are a whole different ball game.

Motorcycles will get pretty unhinged if you get off the gas in a big way. The Porsche is extremely satisfying to get it right in a series of turns. Thanks for the input. It helps to know what your experiences are. I'll read the book and stop worrying about my car for a while.

944pete · 944pete's Garage

In the latest issue of 911/Porsche world magazine there is a good article on braking into and out of corners. It explains the physics of weight transfer pretty well. What you're describing doesn't sound so much like a handling quirk but maybe entering the corner too fast and getting on and off the brake too abruptly. Check out that article and also Bob Bondurant's book on High Performance Driving.

Pete

Al Cody · 02-18-2002, 09:18 PM

No brakes, I just shifted gears. 3rd to 4th. The brief interuption to power caused the unloading of the suspension. Plus we were going down hill which further unloaded the suspension and agrivated the situation. I'll check out the article, thanks!

gixer02 · 02-18-2002, 10:41 PM

yea, just reading a bunch of articles/books has made me a better driver....(not at all close to being an expert though

) Here's alot of good reading http://www.esbconsult.com.au/ogden/locost/phors/phors.htm I can't wait until this spring when I get a chance to attend some drivers ed and autox events for the first time. Cheers

Pat

Dantilla · 02-19-2002, 09:05 AM

Last night I was driving my wife's Jeep- yes, Jeep wrangler- Lift kit and tall tires- around a one-eighty corner on the way home on wet pavement. Jeep had a bit of understeer going on, so I lifted, got a bit of oversteer to rotate, roll on the throttle to complete the turn with understeer, all pretty much sub-consciencely. After completing the turn, thought of this post- Welcome to the laws of physics!