BDrool Posted August 19, 2009 Report Share Posted August 19, 2009 Just had my GT500 dyno'ed. There are 2 sheets one for SAE smoothing and another for uncorrected smoothing. Didn't have much time to get a good explanation on the difference. Maybe one of the experts here can explain. The other sheet is on the next post due to size. BTW, the alt. was 4300' +/-. This was the first 2010 GT500 they did and they were speechless on the result numbers. Link to comment Share on other sites More sharing options...
BDrool Posted August 19, 2009 Author Report Share Posted August 19, 2009 The other sheet... Link to comment Share on other sites More sharing options...
ingram4868 Posted August 19, 2009 Report Share Posted August 19, 2009 I'm not proficient with dyno readings but I thought the 07-09 were baselined somewhere around 448HP. If you add in the FRPP CAI and tune that puts them about the same. I'm curious what our TS experts say. Link to comment Share on other sites More sharing options...
F150 Duke Posted August 19, 2009 Report Share Posted August 19, 2009 Once again very consistent RWHP numbers. Assuming 15% drivetrain loss, you're looking at 560HP at the flywheel. Link to comment Share on other sites More sharing options...
BDrool Posted August 19, 2009 Author Report Share Posted August 19, 2009 Actually, 15% would put it right at 540 by my calculation if you read the SAE chart. 15% would be 71.229, that on the 474.86 is 546.09. I know the altitude plays a big part but I don't know how much on forced induction. Link to comment Share on other sites More sharing options...
machinehead Posted August 19, 2009 Report Share Posted August 19, 2009 Actually, 15% would put it right at 540 by my calculation if you read the SAE chart. 15% would be 71.229, that on the 474.86 is 546.09. I know the altitude plays a big part but I don't know how much on forced induction. BDrool - I'm not an expert on HP by any means but I think you're looking at it backwards. If it were 560 at the flywheel and there was a 15% loss (15% of 560) that would tell you that RWHP would be about 476 (560 less 15%, or 84, equals 476). At least that's how I've understood it. I'd be the first to admit...I could be wrong Link to comment Share on other sites More sharing options...
BDrool Posted August 19, 2009 Author Report Share Posted August 19, 2009 Machinehead, thanks for the input. That does make sense and sounds better. Anybody an expert on this? Link to comment Share on other sites More sharing options...
azza Posted August 19, 2009 Report Share Posted August 19, 2009 BDrool - I'm not an expert on HP by any means but I think you're looking at it backwards. If it were 560 at the flywheel and there was a 15% loss (15% of 560) that would tell you that RWHP would be about 476 (560 less 15%, or 84, equals 476). At least that's how I've understood it. I'd be the first to admit...I could be wrong That is consistent with how I read it. A quick way to do it is divide the dyno result by 0.85 which gets you to 558. Interesting that the Correction was upwards due to the altitude. Something I have not seen that often. Link to comment Share on other sites More sharing options...
F150 Duke Posted August 20, 2009 Report Share Posted August 20, 2009 I'm definitely not an "expert" but I've been too and run my truck on several dynos ('05 F150 AF1 air intake, maggie cat back exhaust, and custom tune - 386 flywheel hp (stock was 300)). Machinehead and I are right though. Flywheel HP is what the manuf states as horsepower. So when Ford says 540HP, they are saying the engine produces 540 HP at the flywheel. However, there is loss in the drivetrain so only a percentage (usually 85%) sees it's way back to the rear wheels. Thus the RWHP designation. The dyno chart is only able to tell us RWHP or the amount of power that made it to the dyno through the rear wheels. Thus we use the 15% loss to calculate out what he could approximately be making at the flywheel or what Ford would report to us as horsepower. Thus it looks like the GT500 is putting out slightly more then the 540 horse power quoted. It's nothing drastic, but it's 20 HP more which you could easily feel. I've always been told that your seat of the pants cannot feel a change in HP unless it's greater than 10. The corrected amount for higher alititude doesn't suprise me with it's result but rather that I haven't seen it before. The higher the altitude, the thiner the air. Thus it's harder for engines to make more power the thiner the air is. So where he's driving he's actually seeing less HP or power out of his GT500 due to altitude. But what the chart is saying is that his vehicle would have made 476 or so rear wheel power or HP if it was at a lower altitude. Pretty slick conversion and I have not seen a dyno do that before. But then again, I've never been near a dyno at a higher elevation. Link to comment Share on other sites More sharing options...
Wilson Posted August 20, 2009 Report Share Posted August 20, 2009 those numbers are pretty in line w/ mine. I was 483rwhp and 463rwtq would be curious to see your AFR Link to comment Share on other sites More sharing options...
Baby Gorilla Posted August 20, 2009 Report Share Posted August 20, 2009 The higher the altitude, the thiner the air. Thus it's harder for engines to make more power the thiner the air is. Seems right to me. Less oxygen at higher altitudes. Oxygen is really what's being combusted. Link to comment Share on other sites More sharing options...
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