jrgordonsenior

http://www.nasagts.com/

IcemanG17

are there any modification factors like PT has.....for stuff like sequential transmission or real automatics like I have? I know there is a bunch of +/- factors in PT and ST..but I don't see any for GTS? I'm hoping I can get a - for the old fashioned automatic.... maybe -.2?

bobt993

Brian, GTS is simple. Build your car to the max. Do aero, gearing then Dyno/wght. Tube frame moves you and so does 4wd. Your likely going to class into GTS3 or 4 depending on the weight of the car. I like the development of the car being added. Just tweaking air ducts, wings, splitter etc makes enough of a difference to stay at the front. Some cars favor the longer HP tracks while some are stronger on the tighter tracks with shorter straights. This makes the competition a ton of fun. You may have an advantage one weekend only to be chasing at the next track.

magnetic1

No more 4WD "penalty". Only thing is tube frame stuff, slicks and some high dollar stuff.

claykos

I was told that the ex GMG world challenge car taht won GTS5 at Nats pulled a hair over 450 rwhp...That motor is basically a 2010 3.8 motor with headers and a killer map from PMNA.

A real unrestricted 4.0 RSR type motor should pull a good bit more than that I would say. I know the 2-ring 3.8 RSR engines built up using ~2005 type rsr components make somewhere in the 480-500 rwhp range.

IcemanG17

I would LOVE to do this......a real ground up race 928....moton shocks, Doc Brown 6.4L stroker...serious aero and seriously light..basically a clone of Mark Andersons POC GT1 racer....but my budget isn't anywhere near that

So I am on the other side...trying to make the car as fast as possible for as little investment as possible....I never thought my 203whp 3100lb automatic 928 on tiny tires would be as fast as it is.... with a few mods and better driving it will get there!!

jrgordonsenior

James S. commented on another thread that they got 410 rwhp on their Mustang dyno and he was surprised by the 450 reading at Miller on the Dynojet 244. I went from 270 to 282 on that same Dynojet and wasn't happy. Dynos are great for tuning, not so great for compliance policing.....

The 4.0's are built by Loren @ 911 Design and I'm sure he can tweak them up or down as needed. He'll have to next year to stay in POC's GT2 class which had the same basic parameters as NASA's GTS5 (6.5-9). We raised the minimum 1/2 point to 7 for 2011....

jrgordonsenior

You're at 15.27 with the class minimum at 14.5 which leaves you lots of room to lose more weight, add some hp, or a combination of both. I agree that car would be hard to beat in GTS2 racing against Spec Boxsters and GTI's.....

magnetic1

No one out west races GTS2 w/ BMW M3s?

disasterman

In the midwest & great lakes regions all of the M3's are GTS3 and there are a lot of them.

IcemanG17

JR
The problem is the motor makes way more torque than HP...241torque and 203hp ends up at 222 power factor...so that puts my weight up to 3219....

However that dyno pull was odd..the car typically makes 200whp-230 torque....which would put my weight at 3117.5 which is right about where it is now..... with my best times at Thunderhill on the bypass at 2:06.9 I should be competitive for the podium....and I do think there is a few more seconds in the car with some aero and improved driving...

The fastest local car is about 2:05's on the bypass.....

disasterman

That is an awful lot of weight to lug around and stop. A lot of that weight is located in the wrong place, above the beltline. A light car with equal pwr to weight is going to have an inherent advantage.

North Coast Cab

Not necessarily true. A track with long fast straightaways will give the higher HP car a chance to gain momentum and ultimately pass i.e. Mid O or Road America. The light car should brake better and be faster in the turns and of course just do all their passing there.
GTS is an awesome class and as the development continues it is great to see the lower HP cars turning some very fast laps.
Also, it seems like the West Coast has a lot of GTS4/5/U cars while the East Coast has mostly GTS1-3 cars.

mark kibort

and the old RSR motors from a few years ago, made over 450rwhp unrestricted. they were supposted to be very close to the cup motors with the motorsport upgrades for WCGT.

Here is a 05 and 06 cup dyno run as well as a koni GS 997 running over 350rwhp out of the 3.6 liter

mark kibort

the ONLY reason a high HP car will have any advantage is IF it has a better HP to drag ratio at the higher speeds, otherwise, same HP to weight will accelerate the same at any vehicle speed. This might be what you are saying, but typically, a higher HP car will be a bigger car, so the drag factors might wash. this is why you typically see SpeedTouring cars running near the same times as the top T1 cars at tracks LIKE RoadAmerica. (ie 2:26ish) even with the touring cars having less HP to weight. brakiing and handling is still 2 out of the 3 factors in racing IMHO.