dsrufer

Rennlisters:


I'm running an '87 911 Carrera for PCA DEs. When I stand on the stock brake calipers with track pads, the rear of the car gets a little squirrelly. The car has a front chin spoiler and wing. It's been said by guys at the track to get a bigger wing to apply more down-force on the rear of the car. Recent feedback said otherwise. So I'm left no exactly knowing which way to turn.

For consideration, I'm looking at the Getty Design RS 3.9 "SC" wing.

Outside of that, the car is so well balanced at the track (bump steer kit, camber plates, lowered, etc.).

Thank you very much for any guidance and suggestions.

Dan

wildcat077

I've added a 3.8 RSR wing to my 89 to complement my fiberglass bumpers and hood and i can't really say that i notice a difference except maybe for the weight loss ... perhaps your car is in need of a good corner balance to distribute the weight a bit better under braking !

Should you be dead set on a 3.8 RS wing,they come up regularly on the Pelican classifieds in the 350-500 dollar range.

Cheers
Phil

KaiB

Perhaps you could stop "standing" on your brakes.

I also agree on the setup and corner balance statement.

PelicanParts.com

Very well may be an alignment or suspension issue before lack of rear downforce. This occurs braking in a straight line? If yes, must be a bit of a handful when trail-braking?

Are you running adjustable shocks?
Mark/Pelican Parts

ricster

Lower to euro ride height, corner balance and align and make sure all the suspension components are all up to date. The rear wing wont help anything in this situation

Ed Hughes

Down force is the last thing you should be looking at. I'd go through brakes and corner balance first.

JCP911S

+++

All cars experience weight transfer under braking. Porsches a bit less so, due to rear engine, and certainly, stiffer suspension will reduce weight transfer.

Porsche used smaller rear calipers for this very reason... so make sure your brakes are up to spec and that the friction material on your pads is the same front to rear. Also check for flat-spots on your rear tires... if they flat-spot once, they're shot... they'll find that same flat-spot, and lock up every time.

But ultimately all non-ABS cars will tend to lock their rear brakes in threshold braking situations.

The solution is relatively simple... learn how to control your car. It's called driving.

redridge

+1 on looking elsewhere besides a wing... but you mention it already has one. Anyway, check 4 wheel alignment. suspension, balancing... as mentioned previously.

theiceman

I concur with all statements above .. rear wing is for high speed stability . When you "stand" on the brakes to reduce your speed drastically downforce becomes far less a factor as it is gone once you "stand" on your brakes..

look elsewhere my friend..... im thinking your nose is diving too much and lightening the back end due to weight transfer. just a theory though ..

race911

Doesn't that cause us the most cause for concern--that this level of "expertise" is out there circulating with us?

Anyway, there's no such thing as downforce on a production based car until you're out on the pointy edge of development. Reducing lift, sure.

And as mentioned repeatedly above, working to ensure your existing mechanical bits are up to even as-new stock spec will take care of your problems until you're within the last second of what the car's capable of doing.

Amber Gramps

"Guys at the track" = ricers

JCP911S

Off topic, but must be fun hanging out in your garage...

race911

???

JCP911S

Nice car collection.

race911

Oh. Well, basically nothing is in running form right now. And even if they were, the only one with under 125K on it is the wrecked hulk of the RSA that's sitting outside the warehouse for the past 10 years with a clean title showing 42K miles!