jeanmarcboilard

Does anybody have any factual data or numbers on the extra downforces created by the GT2 front vent and the GT2 rear wing compared to the regular Turbo or Turbo with aerokit?
Thanks

T10Chris

If I'm remembering right, I've read somewhere that standard 996 Turbo has approximately 9 kg of rear downforce at 190 mph and around 18 kg of lift on the front end at same speed. Not sure what the GT2 specs are, but I think its front end is either aero neutral or small downforce amount of downforce.

jeanmarcboilard

Thanks for the reply.

Berra

GT2 numbers are +2kg front/+9kg rear downforce.

This is I believe, at 125 mph!

jeanmarcboilard

Thanks, I'm trying to find out if a functioning gt2 front bumper conversion would be a good match with an aerokit rear wing.
Right now I have a nonfunctioning gt2 front bumper and aero wing and it's awful. I'm sure the conversion would definitely help but I'd like to know if it would be equal to having the front aero lip.

gophaster

I had researched this a bit a while back because I was considering switching to a GT2 rear decklid/wing. I wasn't able to find very much detailed info. In the end I decided against it because it looked like a pretty involved job to make a GT2 front bumper fully functional on 996TT.

My understanding is that the TT rear tail does increase downforce and the TT front end was designed to produce minimal lift while retaining the lowest possible drag coeffcient. The GT2 rear wing further increases the downforce and the GT2 front end also provides an increase in downforce as well as better airflow through the radiator.

I'm guessing that a non-functional GT2 front bumper would not be optimal because the air is not being routed correctly like below...









There was effort put into the design of both the stock TT setup and the GT2 setup (I would imagine the Aero kit as well) so it would likely be best to treat the front and rear components as a package in order to not alter the balance of the car.

April 2000 Car & Driver Magazine - First Drive 996 Turbo

"Porsche has worked hard on the aerodynamics to produce a lift coefficient of minus 0.01 at the rear (slight downforce). In combination with the new 911's more predictable dynamics, the Turbo tracks dead straight above 150 mph and doesn't need as many corrections or quite the intense alertness of the previous model (also an all-wheel-drive car), let alone the wayward early cars."


Swan, Tony (May 2001). "2002 Porsche 911 GT2 - A Hardcore 911 Turbo". Car and Driver.
"Despite a 10-millimeter reduction in ride height from the 911 Turbo, the drag coefficient is slightly higher — 0.34 Cd vs. the Turbo's 0.33 — due to the fixed rear wing."


2002 Porsche GT2 Press Release
"Because the 911 GT2 is capable of extremely high racetrack speeds, Porsche
refined the aerodynamic characteristics to produce greater downforce, even
sacrificing a lower coefficient of drag (Cd) to do so. "

Berra

It is said that you can't drive a aero package Turbo without the front lip, but would be good to know the numbers.

It's funny how Porsche sold it for a good amount of money, but never said anything about numbers.

jeanmarcboilard

Thanks guys, all good stuff.

Fishey

Turbo Technical introduction.

jeanmarcboilard

I saw those numbers for the regular turbo. Lots of work goes in to make sure it's just right and optimized. Some of the stuff that gets slapped on the front or back is really detrimental to that balance.

Freddie Two Bs

Why bother for 9kg?...?

jeanmarcboilard

I was told by someone else that the aero kit rear wing created an extra 110kg of downforce! I think there's a balance to be found. 9kg pushes down a bit, better than 9kg of lift right? Too much downforce would have other unwanted effects.

Fishey

Just lowering the car has a major effect on Aero.

gophaster

BINGO!! From the info that we have:

Stock TT: Wing creates downforce, Front has minimal lift
GT2: Wing creates a bit more downforce, Front creates some downforce

I would guess that Aero kit would sit somewhere in between and the wing also create slightly more downforce than stock TT and front splitter would also slightly increase downforce or perhaps eliminate lift.

If you could get your GT2 front bumper functional plus the Aero Kit wing I would think you should be fine.

Berra

Yeah aero wing and GT2 front should work.