Decision making process --

winning races = no change
not winning races = change

We were winning and then added more HP/Torque - - along came wide body
with same WT/HP and we could not win - - - so we are now looking at wider
track and more tire.

We found by racing at Willow Springs with some really nice C32 cars that
in the turns wide body wins - they could carry 10MPH more in the sweepers.

Regards,

 

JR, 306 to the wheels, but my last NASA dyno cert was two years ago. GTS wants this done yearly, ST each 3 years, I believe.

I run 2627# for GTS4 and don't have two maps and a secret switch between them...

 

When I converted my 1983 NASA GTS3 911 from a narrow body to a wide-body it completely transformed the car. It was worth something like 2 seconds at MSR, immediately, right out of the box. It's a no brainer, make the change.

 

Just two more data points for you, both bob turgeon and i went wide-body in our 993s at the same time. same cars, same weights, same stock engines (at that time at least... both of us later built the engines, but we ran for a season or two in NASA and PCA with stock 993 engines). Only significant changes were aero, widebody flares, and fat tires (and moving suspension mounting points outward on the front subframe). Our builds have been documented in the forum. Our cars were significantly faster (and I mean several seconds) at every track (didn't matter if it was lightning or WGI)... wasn't even close anywhere. I am sure bob has data files to show the exact differences just on those variables listed.

 

Going widebody has a greater benefit than just fitting wider tires. The wider track reduces the lateral load transfer. So even if you kept the same size tires you run now your cornering capability will increase.

 

You don't know until you try..... High Plains is calling, Kai.
Can you hear the sweet serenade.... high plains ....high plains ....HIGH PLAINS

BTW - the good news is I've decided to remove the spark plugs from cylinder #3..... the bad news is I'll now be running at 2100# as the car is now a 3.17 liter.

 

Let's face it Porsche did not build wide bodied race cars to make them go slower, widen that b*tch up.
Phil

 

Go wide! Or buy Yonkers old car off me...

 

Mark....out now, but will email later.

 

I'm not 100 percent sold on wider is better...in all cases

I run 245f/275r tires...r6

Tried and successfully stuffed a 315r tire in the back...at Sebring the car was a bit slower same day / same pro driver. Tires were same diameter.

The lost time on data was mostly acceleration based. The heavier rear tire / rim made the car lose acceleration

But who knows...i think a lot of the cars out there have giant ironing boards on the back slowing them down

 

As Glen has said the wide body setup does a lot for gaining turn in grip and better lateral stability. Cornering makes up more time than the drag brought on. Added aero (splitter/wing) does more to slow the top end speed than the wider fenders. I have run spacers on my NB tire/wheel setup and the car is faster than the original NB setup so the track width is a big benefit. The front running NASA GTS Bimmers/racers are going to be faster by a good margin at a National event or if you venture into region where they have developed both car and racer. I would widen the track even if you run spacers on the rear and use your existing tire/wheel package. To properly widen the front your existing wheels should work since you are moving the wheel carriers out on the front using the 30mm holes provided on the chassis. The wheel offset is pretty close to the same and a 5mm spacer can be used to get it back to where you were with little affect on the steering. It is much easier to move the front setup on the 964 than on the 2wd 993 chassis with the brake booster in the way. If you want more infor ping Geoffrey he has a ton of knowledge on the setup.

 

I am curious, why nobody mentioned the weight?
Going wider is also an opportunity to use FG or CF and drastically lower the weight of the car or balance the load if you want to stay in the same class (adding some weight lower or toward the front for a 911).

 

Kai, do it. Night and day re. corner entry speed.

 

Wider worked for Wessiach, hey ....

 

Kai-
If you want to be successful in a GT 3 or 4, you gotta do it.
We used Getty design bodywork for the silver car and it went together very well, although that was many years ago. Expect that the project will be more $$ignificant than originally expected.