Scca Gt2 Hp ?
07-29-2018, 04:12 PM
#1
Scca Gt2 Hp ?
I'm trying to get an idea of how much horse power I need to shoot for to run scca gt2 next season? anyone willing to disclose or is this a big a secret? thanks!
07-29-2018, 04:45 PM
#2
Gt2 is not a hp/weight formula. You need to build the motor to gt2 rules. Iirc, There are restrictor sizes for different motors like ls6 oem stock vs. Ls6 with a max valve lift etc. And a c5 running an ls3. So check the gcr which is online. Ping oli on this forum. He is less about secrets and more about close fun racing. He is in that class and can tell you much more.
07-29-2018, 06:40 PM
#3
Pro
It is kind of a HP to weight formula in that you pick the engine and weight from a chart in the rule book. See page 345.
https://dk1xgl0d43mu1.cloudfront.net...pdf?1530669060
I think a LS6 (with a stock intake and throttle body) built to the limit of the rules or LS2/L76 (with a 75mm flat plate restrictor) built to the limit of the rules will make about 450 rear wheel horsepower depending on the dyno. It’s all very confusing as you also have to read the STO section of the rulebook to see what exactly you are allowed to do engine-wise (cam .600”, compression 12:1, ported heads with 1% weight penalty, etc...). I have no idea what kind of power a restricted LS3 or LS7 will make.
https://dk1xgl0d43mu1.cloudfront.net...pdf?1530669060
I think a LS6 (with a stock intake and throttle body) built to the limit of the rules or LS2/L76 (with a 75mm flat plate restrictor) built to the limit of the rules will make about 450 rear wheel horsepower depending on the dyno. It’s all very confusing as you also have to read the STO section of the rulebook to see what exactly you are allowed to do engine-wise (cam .600”, compression 12:1, ported heads with 1% weight penalty, etc...). I have no idea what kind of power a restricted LS3 or LS7 will make.
Last edited by clubracer23; 07-29-2018 at 06:44 PM.
07-29-2018, 07:20 PM
#4
Gt2 is not a hp/weight formula. You need to build the motor to gt2 rules. Iirc, There are restrictor sizes for different motors like ls6 oem stock vs. Ls6 with a max valve lift etc. And a c5 running an ls3. So check the gcr which is online. Ping oli on this forum. He is less about secrets and more about close fun racing. He is in that class and can tell you much more.
07-29-2018, 07:24 PM
#5
It is kind of a HP to weight formula in that you pick the engine and weight from a chart in the rule book. See page 345.
https://dk1xgl0d43mu1.cloudfront.net...pdf?1530669060
I think a LS6 (with a stock intake and throttle body) built to the limit of the rules or LS2/L76 (with a 75mm flat plate restrictor) built to the limit of the rules will make about 450 rear wheel horsepower depending on the dyno. It’s all very confusing as you also have to read the STO section of the rulebook to see what exactly you are allowed to do engine-wise (cam .600”, compression 12:1, ported heads with 1% weight penalty, etc...). I have no idea what kind of power a restricted LS3 or LS7 will make.
https://dk1xgl0d43mu1.cloudfront.net...pdf?1530669060
I think a LS6 (with a stock intake and throttle body) built to the limit of the rules or LS2/L76 (with a 75mm flat plate restrictor) built to the limit of the rules will make about 450 rear wheel horsepower depending on the dyno. It’s all very confusing as you also have to read the STO section of the rulebook to see what exactly you are allowed to do engine-wise (cam .600”, compression 12:1, ported heads with 1% weight penalty, etc...). I have no idea what kind of power a restricted LS3 or LS7 will make.
07-30-2018, 02:47 PM
#7
You will not make 500-550 rwhp with these rules and restrictor plates. All dynos not being exactly equal, you should be in the 450-480 range. LS3 isn't the way to go as you have to weigh 250 pounds more and run a smaller restrictor. Not going to make up for that with .060" larger piston diameter.
07-30-2018, 05:30 PM
#10
Pro
07-30-2018, 05:36 PM
#11
A built ls7 could do 500-550 through a 65mm sir. My ls7 (rip) was stock other then headers and heads done (stock cam, intake, throttle body etc) made 470whp. We detuned it to 400whp for Nasa st2. I would like to build an all forged ls3 this go round.
07-30-2018, 05:58 PM
#12
Le Mans Master
You will not make 500-550 rwhp with these rules and restrictor plates. All dynos not being exactly equal, you should be in the 450-480 range. LS3 isn't the way to go as you have to weigh 250 pounds more and run a smaller restrictor. Not going to make up for that with .060" larger piston diameter.
I tend to agree with this statement.
I have been racing GT2 since around 2013. Right now the LS3 option does not seem to be the most successful Corvette variant to choose from.
07-30-2018, 06:01 PM
#13
Pro
It seems that SCCA thinks a “OEM” LS7 (3325 lbs.) makes more power than a “built” LS7 with a 65mm flat plate restrictor (3200lbs.).
FWIW I have a SCCA GT2 Corvette and am trying to figure this out for myself. For now I have decided to go with a built L76 with a 75mm flat plate restrictor at 3030 lbs. (including a 1% weight penalty for ported heads).
FWIW I have a SCCA GT2 Corvette and am trying to figure this out for myself. For now I have decided to go with a built L76 with a 75mm flat plate restrictor at 3030 lbs. (including a 1% weight penalty for ported heads).
Last edited by clubracer23; 07-30-2018 at 06:05 PM.
07-30-2018, 06:12 PM
#14
My ls7 let go in a pretty spectacular/horrifying way at lime rock. Long story short, it took my car with it. So I’m starting the long process of a complete rebuild of car and want to be able to run in both classes/sanctioning bodies. I took this photo laying on my back looking through where the oil pan should be....
Last edited by mp4659; 07-30-2018 at 06:14 PM.
07-30-2018, 06:25 PM
#15
Pro
07-30-2018, 08:20 PM
#17
My ls7 let go in a pretty spectacular/horrifying way at lime rock. Long story short, it took my car with it. So I’m starting the long process of a complete rebuild of car and want to be able to run in both classes/sanctioning bodies. I took this photo laying on my back looking through where the oil pan should be....
07-30-2018, 09:07 PM
#18
Burning Brakes
You’re a glutten for punishment Mike.... Look at those crazy SCCA rules. Keep it simple with NASA and power to weight. You’ll be like Adrian last season changing body kits between events. Even he just gave up and just runs the car in SCCA trim and leaves some on the table when he runs with NASA.
07-30-2018, 09:24 PM
#19
You’re a glutten for punishment Mike.... Look at those crazy SCCA rules. Keep it simple with NASA and power to weight. You’ll be like Adrian last season changing body kits between events. Even he just gave up and just runs the car in SCCA trim and leaves some on the table when he runs with NASA.
Last edited by mp4659; 07-30-2018 at 09:24 PM.
07-30-2018, 09:26 PM
#20
im not really sure how that acp wing is gt2 legal but im not complaining....from what i could tell max wing length is 68'' and 10.75 cord, with a footnote allowing the apr gtc500.