Ok, since Chet keeps insisting on posting his road dyno numbers , here a comparison of how some of the more popular road dynos compare to a real Mustang dyno (thanks to RS motors for the dyno numbers). Also, after the dyno day on the 25th of October, we should be able to see how they compare to MAP's Dynojet. Let me preface this thread with this: All dyno numbers are just numbers. They will be different for every car and all weather conditions. These road dynos vary even more then a shop dyno typically will, as I do not run any corrections for intake temps or pressure. I'll post IAT's with the graphs, as those typically make the largest effect on WHP and WTQ. Subaru's typically have IAT's about 5-10 degrees warmer then ambient outside temp. My graphs come from Airboy's Interpolation Excel sheet, and DataLogLab. In all cases, the road dyno's were corrected for tire size and total weight of the car (or as close as I could guess). It appears like the excel dyno is the most repeatable and consistent. I have found this to be true with multiple other cars, as well. I should also note, not all of the logs are full pulls from 2k-redline, so the numbers tend to get a tad skewed towards redline as the road dyno interpolates between points to put numbers down (Ryan's DLL road dyno is the most noticeable). Without any further ado.. Scuba Steve: IAT's were around 90. Excel Dyno: DLL Dyno: RS Mustang Dyno: 253 WTQ 259 WHP Shibbs: IAT's were around 80. Excel Dyno: DLL Dyno: RS's Mustang Dyno: Ryan: IAT's around 70. Excel Dyno: DLL Dyno: RS's Mustang Dyno: So -- what do we get out of all of this? Well, it's been said that the excel dyno reads close to a dynodynamics dyno. Dynodynamics dynos typically read slightly higher then Mustang dyno's. From looking at the numbers above, it appears this is close. The DLL numbers look to be around 15% higher then the excel dyno, and I would venture to guess would be closer to Dynojet dyno numbers. However, there are some exceptions to the rule. Shibbs's car, for example, is very similar on all of the dynos. I should also note that loading a car on the dyno is often different then loading a car on the street. My understanding is that the mustang dyno does the best at loading AWD vehicles, but there will always be some differences between how a car behaves on a dyno vs on the street.
Thanks Nate...but you didn't post up a picture of the butt dyno...why? :biggrin: I agree, numbers are just numbers. It's a great way to see a change in power when your adding modifications or changing your tune. Otherwise they really don't matter much. side note- I love the way my car feels, the fact that I can feel the power all the way to redline makes me satisfied. Thanks again for the great tune and the excellent service you've provided many of MNSubaru members.... and Chet *THUD*:squint:
I find it interesting that Scuba Steve's Excel and DLL dyno's and Ryan's DLL dyno plots of HP rose in HP until redline. I normally see the HP peak nad then fall off slightly before redline. Any reason for this? I ask because peak numbers mean very little to me. I am more interested in how the response is and how they play out in the overall curve.
That particular road dyno plot outlining my car stops at 5800 or so. I bet it would start to fall off. On the RS Dyno plot it HP starts to drop at 6300 and tapers off to about 245 HP at 6950.
Wow. I never even looked at the road dyno after we did my car, Nate. My car is crazy consistent tho! hahaha
Yeah, I made a mention of that in my original post. The road dynos, evidently especially the DLL one, can get skewed at the top end, especially if the log doesn't go all the way to redline. With that said, Dave's (Scuba Steve) car's dyno is very close to holding a straight HP curve at redline, as his turbo is still holding around 18-19 PSI at redline. Ryan's, on the other hand, should be decreasing after about 6000. You can see this happen on the excel dyno and RS's dyno, but the DLL dyno is a little "off."
Gotcha. I was just wondering because some looked normal and others looked like they were from a honda,lol.
Whats thud ??? I just wanted to see how far off they were, you can't always believe what you see in random forums so I wanted to see local dynos for the comparisons. Thank you Nate. Side note I am seeing 22.2 psi in 4th from a 60 roll ... can we fix this?
I'll do new ones today, my computer died cause of the cold last night. I never got a good run, do you want my MAF info?
He's talking about turbo efficiency when frum rolling at 22 psi on td04... Nice data Nate. MAP dynojet plots on the way?
Tom your RS dyno was 249whp and 347wtq? If so your road dyno wasn't that far off ... Sheen I wasn't doing frumrolls I was just checking high boost in 3rd-5th. I like to check where that stuff is periodically.
Yeah. I don't know what is more goofy -- my torque curve or my hp curve (which looks more like a torque curve, lol).
Were you are were you not the one saying YESTERDAY you dont do that anymore? I hope you get another ticket, this one for over 100 (instant arrest)
Whatever Erik I was checking high boost pressure I would go to 70 and see what I got, and yeah the TD04 spools full boost by then ...
i wanna ride in your car tom and feel that punch of torque. do you make passengers wear HANS devices????:laugh:
no leak my friend just a much better running car now!! although i didn't have time to install the gmbcs
yeah but i woke up real late and it was cold as **** outside so i was like no thank you lol road dyno still turned out pretty good :biggrin:
Thought I'd share from the NA side of the Subaru world. Old dyno on LSE's Dyno Dymanics: (stock engine, I-Speed RS reflash) DLL average run. I ran 6 runs, 3 each direction to get a feel for plotted range. A couple runs were very close to each other and where middle of the pack in terms of range. All runs were pulls from just over 1k rpm and 100% throttle before 1.5k to redline. I did some small correction to the numbers to match LSE's run for peak toque. LSE did seem to run a little high. This was to compare curves more easily. I have a +4% correction for this. This is the 4th run: (stock engine, I-Speed RS reflash, throttle body spacer, intake manifold spacer) The curves aren't quite directly comparable due to the changes, but for the most part, they compare pretty well. The intake manifold spacer bumped up low end noticably and top end is a hair more mild which shows up pretty good in the road dyno and is expected when lengthening the intake runners. The tool seems to work pretty well. I'm still fond of multiple runs and averaging though. You kind of have to expect some fluctuation.
