Stock '01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

[treynor]

Stock \'01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

This was on my bone-stock '01 RT/10 with 1,000 miles on the clock. Test conditions: 55 def F, barametric pressure 30.0. Runs performed in 4th gear with fan pointed at undercarriage of car for cooling. Correction factor 4.5%, corrected RWHP 408, corrected torque 442 ft/lbs.

So much for the rumors of losing HP to the '00 - '01 cam change!

Dyno graph of corrected HP / torque to follow shortly.

 

[treynor]

Re: Stock \'01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

First off, here's the dyno graph of the corrected (SAE) HP and Torque curves:

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The first dyno run produced 429 RWHP with a virtually straight HP curve. By the end of the run, the coolant temp had risen from 190F to about 220F. I let it cool down to 200F, and then did a second run. This run was identical to the first up to the point where the car made 400 HP, at which point the HP curve abruptly flattened as though it had been planed off. Coolant temp rose to about 225F. At that point, we rolled out a fan and pointed it at the front of the car (from underneath, the dyno is raised) to help keep the car cool. With the temps back down to 190F, we did a third run, the one recorded above. Interestingly, the third run shows substantially more midrange torque than the first run, no doubt a function of the cooler air reaching the air intake. Lesson: make sure you use a fan during dyno runs to (a) keep the engine cool, and (b) keep the intake air at close to ambient.

Next up: K&N air filters and Hennessey smooth tubes, and another dyno run...

 

[Kid97GTS]

Re: Stock \'01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

Nice numbers. But, aren't the CORRECTED numbers the only ones that really matter? Otherwise, it's kinda like apples to oranges given the huge effect that temps and pressure can have on power numbers. That said, Venom Lover's ~420-425 hp (Corrected) on a stock 97 GTS and another 422 hp number on a 97 with smooth tubes and filters only still look substantially bigger than the new numbers coming out on the '01 cars. Anyone know why?

 

[Tom Welch]

Re: Stock \'01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

Use either number but, stick with the number that you use for all of your future testing.

Most dyno shops that use the dynojet machines print only the corrected numbers(they also have the correction factor printed on them) so the corrected number would be the one to use for all comparisons across the board.

At a recent dyno day that our club sponsored, where 22 vipers ran on the dyno the average hp number(corrected) for a bone stock car was 406 rwhp, with minor mods like removing the rear exhaust and installing tubes and filters a few cars pulled numbers into the teens and one made 425. These were of course gen 2 cars ranging from 96 to 00 models.

Just some FYI,

tom
Http://btrviper.com

 

[Supercharged Vipermad]

Re: Stock \'01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

You're quite correct about using corrected numbers as a valid means of comparison. I posted both sets of numbers (and a corrected chart) because I wasn't sure what sort of numbers people normally used on the board; now that I've seen everyone quotes corrected numbers, I'll only post those going forward.

I have three possible explanations for the apparent horsepower difference between some '96-'97 cars and the '00-'01 cars: mileage. My car had an even 1,000 miles on the clock when I dyno'd it; I would not be at all surprised if it picks up another 10-15 HP over the next 10,000 miles just from continued engine break-in. Car & Driver sees this effect all the time when they retest cars at the end of 30,000 mile long-term reviews. The other possible explanations are (a) dyno conditions -- for example, a fan pointed directly at the air intake will get more, cooler air to the engine than will my approach (fan underneath the car blowing air up / through the radiator to keep the engine cool), and (b) individual variances -- we're talking about 2-3% differences in power here, which could be explained by CA oxygenated gas or production line variances.

That all said, the main reason for me getting the first dyno run done was to provide a baseline by which to measure all future modifications. As long as I dyno the car the same way each time, I should have numbers which are comparable. Next up: K&N filters & smooth tubes, followed by another dyno run. Should have that done within the next couple weeks.

 

[treynor]

Re: Stock \'01 RT/10: 427 RWHP, 463 ft/lbs uncorrected

Dave,
430 HP isn't surprising. I got 415 with K&Ns, smooth tubes, and stock exhaust -- see my recent "surprise, surprise" post. You have 15 HP more with a Borla exhaust (+10 HP) and a much more fully broken in engine (+10-15HP), but minus the smooth tubes (-5 HP). If you were to now add headers, you'd pick up another 13-25 HP, taking you to the usual 450 +/-5 for BPU Vipers.

As for not using a fan -- I can get one good run in without a fan, and then my coolant temp spikes. Again, my engine's still quite green (1150 miles) and is making more heat & less power than it will at 10,000 miles.

I *just* finished installing my VEC-1, and I'm too tired to go out this evening and get it calibrated, but once I do I'll be back on the dyno pronto.