So where did all the money go? Right to the rear wheels!
NSX Dyno Day, July 25, 2001
Rob pulling my car around to the dyno stall. "Last door on the left."
I arrived at S&S Performance at 9am on a beautiful, sunny Wednesday. The high temps and humidity of the past few weeks were finally gone, and he comfortable 70s were here! Rob pulled my car into position on the Dynojet and started lashing it in place with tie down straps. The front was no problem, but as the rear frame loops are too high (the straps would come across the exhaust) so they had to attach onto the lower control arms. They used straps instead of hooks and were very gentle, and as they have done a ton of Corvettes, they knew no damage would occur.
Scott doing to ever critical alignment phase of the parking procedure.
I filled out the obligatory release form, and went out to assist Scott in setting up the car. There were a few issues to take care of, 1) As I had a fresh (cold) bottle of N2O in the trunk, it was at 900# pressure. I had them put their 110vac bottle heater on and get it warming up to 1000#+. 2) We had to remove the front coil cover to tap an RPM signal for the dyno. 3) The dyno oxygen sensor needed to be attached to the exhaust. Once these little details were taken care of we were ready to go!
No frills here at S&S, nothing but horsepower.
As they didn't want the responsibility of revving the car to 8000rpm with nitrous (obvious big block guys-theyve never seen, or heard a car go to 8000rpm apparently), they let me man the controls for the tests. We did 5 runs, #1 was a quick test to see if the sensors were all indicating correctly. Its here that I found that TCS needed to be OFF for dyno runs. That's a helpful safety tip. I wanted to do two runs each with and without nitrous. #2 was the first full pass without N2O. I slowly came up to 4000rpm in 1st, 2nd and 3rd, then in 4th I pressed the throttle down and let her fly. At 8000 I let off the gas and let the drag of the dyno slow the car down, as using brakes are a big no no. The numbers were 247.5hp, 189.1fp torque. #3 got us to a best of 259.3hp and 196.8fp torque. Not bad for a car that comes with 270 crank horse power. The car gets to a little over 140mph at the top of 4th gear.
Rob looking for a usable tie down point.
Now for a couple runs with the N2O. The pressure gauge was reading just under 1100#, so we were good to go. #4 was the first run on the bottle, and at 4000rpm in 4th with the throttle down I hit the left button on the Momo wheel and it started to accelerate. As I don't have a purge, there was a bit of lag before the extra power kicked in. This run netted us 314.5hp and 256.8fp torque. I let the wheels come to a stop, and Scott said You don't have a purge, do you?. Everyones a smart guy.
All strapped down and ready to roll, air sensor in place, N2O bottle OPEN.
Run #5 should be the best, and it was: 315.2hp at 253.7fp. So the N2O nets an extra 55.9hp at the wheels, and 56.9 more ft-lb of torque. Scott said that those numbers were a little low for a 70hp shot of juice. I'm sure he could fix it for me, as they have a couple cars on the bottle there that produce over 1500hp. Ill keep what I've got for now, thanks.
Scott getting an RPM pickup point off the front coil.
RM Racing has a dyno sheet for their NSX which has been modified very similarly to mine. There numbers came in at 252.8hp (compared to my 259.3hp) and 312hp (compared to my 315.2hp). Not too far off if you ask me. As long as my car rates a little better than theirs, I'm happy.
Yes, it shows 315.2hp
Using the 20% hp loss motor to rear wheel rule, that puts my car around 378hp, maybe a little more. I did notice that the car didn't rev anywhere near as quickly on the dyno as it does on the street (due to the rotating mass of the dyno? strap tightness?) and wonder if that effects the actual rear wheel horsepower. Hmmm. The NSX sure acts faster than the numbers would indicate. I've tested against a number of high hp street cars and have come out on top nearly every time. The combination of car weight, gears and long legs make this a potent street car, and an amazing track car. As long as I can keep whipping C5s and supercharged small blocks on the street, what do I care?
Scott the magician at work. He builds HUGE race cars in the 1000+hp realm.
Total cost for the 5 Dyno runs and weighing the car was $115. You couldn't have asked for a more professional and knowledgeable group of performance junkies. Hats off to S&S.