tj90

Hes not joking. Thats me in his avatar taking his car out for a spin around balboa park! Damn fine handling car ZP!

Edward

Count me in for total turd status.

Edward

Martin S.

the instability you are feeling in a standard 993, no aerokit, is probably due to the fact that the car is getting light at speed. The 993 moveable spoiler has the equivalent aerodynamic efficiency of the old Duck Tail...note that with the Duck Tail on the older 911 cars according to Frere in The 911 Story, the tail does not eliminate lift, but it does reduce it.

If you want to eliminate lift, according to the factory, you need a 993RS aerokit which has 0, that's right folks, 0 lift at the rear at 170 mph...no downforce, but 0 lift. There will be about 35 lbs of lift on the front

If you want downforce, you need the 993RS Club Sport Aero kit. It will provide 160 Lbs of downforce to the rear at 170 mph....with 9 degrees of down angle on the rear wing...and as with the 993RS, about 35 Lbs lift in the front.

So don't worry about the rear tray...it is on there to reduce noise I have heard/read...and besides, how many speed runs is a sane person going to do in the US? We have no autobahn, autostrada type roads.

GabiOsz

If you are worried about it leave it on, if not take it off!

I have had mine off for ages and noticed no ill effects at all, I'm happy to leave it off and have done 165mph with no issues in terms of stability.

LAT

Martin, what does the Tequipment Aerokit I provide in downforce, you know the biplane fixed wings.

Bull

BTW, I'm not doubting that with a stock suspension, etc., that you felt "instability" with your car. Nor do i doubt that I would feel instability with the car....on the same day under the same conditions. I do doubt strongly that either one of us could tell if the tray was on or off in a blind test, same day, same conditions.

I know where SD is very well. We used to race inboard hydroplanes on Mission Bay, which will cause you to learn about aerodynamics fairly quickly!

Stay cool.....just leave the tray off!

TB993tt

How fast are you going to go ?
MOD500 and I did 193mph with no undertray, Leon S did 198mph in his Ruf (don't know whether he has his on or off) all accounts were that the 993s moved around in a somewhat frightening manner at these speeds - no chance that an undertray would make a difference to that - here are the lateral Gs at v high speed:

Flying Finn

I've done 150+ mph (few times, when my car was stock, with or without tray & when modified) and I can steer with one hand and eat pop corn with other hand while reading threads about this stupid issue.

Thaddeus

This thread is funny. Nothing like dropping in on "old" issues that have been endlessly re-hashed.

If you guys want to have some fun, go to the 944 forums and post a question about how hard it would be to turbocharge an NA car, or go to the 928 forum and post a question about the viability of replacing the timing belt with a chain. Bring lots of popcorn....

ZombiePorsche44

I agree that the tray is a small part but that was my experience that day, it is conditional on wind direction and many other factors that cannot be easily re-created.
Most of all I think my suspension sucks and the US ride height exacerbates the lift problem any time I'm over 150mph. I would guess with a stiff headwind I might experience a lift problem at a lower speed and might not even notice it with a stiff tailwind.

I do however love how brave/crazy most of the 993 drivers here are (including me), pushing their cars to uber fast triple digit speeds on public roads......are we nuts or what?

OT:
Bull,
I grew up on Mission Bay (south mission beach) and have run everything from my Sanger 17' SK with a small block ford, to an SST-140, to my Nacra 5.3 catamaran.

Many years ago when I worked at San Diego Boat Mart we campaigned a Glastron/Carlson CV-20 unlimited outboard with a full race prepared Johnson O/B putting out around 375hp to the prop. We did very well that year, winning almost all of our class races, but that was probably due to the fact Bill Muncey was our driver.

My family & I have belonged to Mission Bay Boat & Ski Club for over 40 years and participate in the Unlimited Hydros every year including last month.

Last weekend we had the Ski racers here with the new generation of 13-14 year olds doing laps at around 100mph, you gotta love the feeling of indestructability youngsters have.

I'm glad you have enjoyed our waters here and if you're ever in town let me know and we'll do a little boating.

ZP44

ZombiePorsche44

I would expect nothing less from the "King of Cool"..................

ZP44

Mark in Baltimore

Naaah, we just missin' that ol' mlincoln lovin'...

Bull

Excellent! Will do when I get back there. Used to have a Gf in San Diego and it was a second home 15 years ago.

The water days were long ago after returning from an all expense paid trip to SE Asia. I was living in Seattle, and we mostly ran 5 Liter Hydros, highly modified with Chevys on Methanol...until we got hold of a Gurney/Weslake Eagle 289....Ron Jones hulls. When I want to feel really old, I remember that Chip Hannauer was in school, running a 145 Cu. In. Class boat with his Father! ....or working on Jim Clapps crew with the early Chopper engines.

THEN, we were nuts!

Back to the topic at hand.......should we do a poll on how many Db quieter the top speed runs are with the tray on vs. off?????

Joe S.

I don't know the answer to your question, but I have this aerokit, Pss9's, RS ride height, no engine tray and zero stability issues...

LAT

I have the Aerokit 1A on my cab with M030 set at Euro ride height, no tray and zero stability issues...just wondering is all..