997.1 GT3 NASA TT3
#1
Drifting
Thread Starter
997.1 GT3 NASA TT3
Has anyone run a 997.1 GT3 in NASA time trials? The current classing for GT3 is TT1, TT2 or TT3 based on power to weight and +/- based on tires and a few factors.
I'm hoping to fit my car in to TT3 which is 10:1 power (whp) to weight (with driver). If you take peak hp at 8500, 8000, 7500, 7000 and average the 4 it should be about 360 rwhp. Stock weight for a US sunroof car is around 3,250 with a full tank of gas. I have a OEM club sport back half cage (40 lbs) but lighter Recaros and I weigh about 155 so I should be about 3400.
3400/360= 9.44 but using factory aero you get to add back .4 so 9.84 which is really close to 10:1. Anyone been able to limit power a bit or add a little weight to sneak in to TT3 at 10:1?
I'm hoping to fit my car in to TT3 which is 10:1 power (whp) to weight (with driver). If you take peak hp at 8500, 8000, 7500, 7000 and average the 4 it should be about 360 rwhp. Stock weight for a US sunroof car is around 3,250 with a full tank of gas. I have a OEM club sport back half cage (40 lbs) but lighter Recaros and I weigh about 155 so I should be about 3400.
3400/360= 9.44 but using factory aero you get to add back .4 so 9.84 which is really close to 10:1. Anyone been able to limit power a bit or add a little weight to sneak in to TT3 at 10:1?
#2
Rennlist Member
Weigh and dyno your car. I think it may weigh less and make more power than that. Mine does on both. Maybe could get a tune that dials it back...
#3
Drifting
Thread Starter
You may be right though may need to detune a little bit.
#4
Rennlist Member
3040 w a half tank so about 3230 with me and gear on
Id have to pull a dyno grap. HP was flat at about 7500 to redline tho.
Id have to pull a dyno grap. HP was flat at about 7500 to redline tho.
#5
Drifting
Thread Starter
#6
Race Car
The weight is with driver, I'm pretty skinny though. What did your car weigh without you in it? Also the power isn't just peak, it's at redline then subtract, 500 rpm, 1000 rpm, 1500 rpm and average the 4 I believe.
You may be right though may need to detune a little bit.
You may be right though may need to detune a little bit.
So your car is going to make it's peak around 7400-7600 meaning you'll get at least one measurment after peak power as well. In the end the power is pretty flat at the top of the curve in our cars. My average number was almost the same as my peak number. I'd expect yours to be more like 370 if I was taking a stab at it. not a huge difference but that much further away from the 10:1 goal.
Bottom line our cars fit well in the old rule set at 9:0 :1 with factory aero. They just aren't a great fit at 10:1 esp since it's not easy for us to be able to tune the car differently to adjust power values.
Just bolt on slicks and bigger wings and take as much weight as possible out of the car and try for TT2 instead. You can do every trick in the book and still not be at at the 8:1 for TT2.
#7
Drifting
Thread Starter
The power average is not based on redline. It's peak power on the graph, then measurements every 500 rpm up to 1500 rpm away from peak power but this includes both sides of the graph away from peak power.
So your car is going to make it's peak around 7400-7600 meaning you'll get at least one measurment after peak power as well. In the end the power is pretty flat at the top of the curve in our cars. My average number was almost the same as my peak number. I'd expect yours to be more like 370 if I was taking a stab at it. not a huge difference but that much further away from the 10:1 goal.
Bottom line our cars fit well in the old rule set at 9:0 :1 with factory aero. They just aren't a great fit at 10:1 esp since it's not easy for us to be able to tune the car differently to adjust power values.
Just bolt on slicks and bigger wings and take as much weight as possible out of the car and try for TT2 instead. You can do every trick in the book and still not be at at the 8:1 for TT2.
So your car is going to make it's peak around 7400-7600 meaning you'll get at least one measurment after peak power as well. In the end the power is pretty flat at the top of the curve in our cars. My average number was almost the same as my peak number. I'd expect yours to be more like 370 if I was taking a stab at it. not a huge difference but that much further away from the 10:1 goal.
Bottom line our cars fit well in the old rule set at 9:0 :1 with factory aero. They just aren't a great fit at 10:1 esp since it's not easy for us to be able to tune the car differently to adjust power values.
Just bolt on slicks and bigger wings and take as much weight as possible out of the car and try for TT2 instead. You can do every trick in the book and still not be at at the 8:1 for TT2.
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#8
Rennlist Member
At your weight, it looks like you escape the rear engine penalty.
If you run 275 or less tires, you get 0.3 back. BFG's run very wide in the 275/35/18 size, and may work for you.
However, you'll want to have a little cushion for dyno variability - the penaties for going over are pretty harsh, and ramp up quickly.
If you run 275 or less tires, you get 0.3 back. BFG's run very wide in the 275/35/18 size, and may work for you.
However, you'll want to have a little cushion for dyno variability - the penaties for going over are pretty harsh, and ramp up quickly.
#9
Drifting
Thread Starter
At your weight, it looks like you escape the rear engine penalty.
If you run 275 or less tires, you get 0.3 back. BFG's run very wide in the 275/35/18 size, and may work for you.
However, you'll want to have a little cushion for dyno variability - the penaties for going over are pretty harsh, and ramp up quickly.
If you run 275 or less tires, you get 0.3 back. BFG's run very wide in the 275/35/18 size, and may work for you.
However, you'll want to have a little cushion for dyno variability - the penaties for going over are pretty harsh, and ramp up quickly.
#14
Rennlist Member