Over the past year and a half, we’ve subjected Project TT to numerous modifications and a few runs on the dyno. The intent was to document as best we could, changes in power as a result of the modifications installed. In a perfect world, we would have dynoed the car stock, then again when we added a chip, again when we added an exhaust and so on. Unfortunately, this isn’t a perfect world. We’ve encountered several setbacks along the way and circumstances beyond our control have precluded us from being able to achieve this. Before we move on to the modifications covered in this installment, let’s recap some of our previous installments to illustrate our point.

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It's not really boosting to 23psi - it's peaking there - which is where you get the big torque spike down low. Stock the car would put down 150whp on this dyno. So i've gotten over 30whp and considerably more torque to the wheels with just those mods. That's right in line with my expectations.

Modified by joe@vwvortex at 3:17 PM 3/26/2007

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Audi 225

Stock : 179.71 awhp
195.50 awtq

After GIAC, Forge 007 and K&N Drop In :

219.66 awhp
276.06 awtq

Best 1/4 : 14.00 @ 92mph
Spiking @ 25lbs.

Got an exhaust now and havent dyno'd it yet.. hopefully a couple of more ponnies.

Thats all the mods.

Folks - ALL dyno's are different. Mustang dyno's read low. Dynojets read higher. Stock TT 225's on Dynojets can put down 200whp in FWD mode. If I wanted higher numbers it would matter to me and I'd go to a dyno jet and put down about 240whp. I want to see what the differences in mods are. This has shown that. When your car puts down 150whp stock and gains over 30whp - that puts me in the 275-280 hp range which is what is typical for these types of mods. I'm also running 91 octane.

Here's a dyno from GIACUSA.com for the TT. Done on a Mustang Dyno with 91 octane. Notice the numbers.

This is Nathans dyno comparing his modified TT in 91 octane mode vs. 100 octane mode. Notice the baseline numbers.

Both these dyno's are very similar to what my car puts down. THAT is why I'm very happy with the numbers I'm putting down. 182/214 for Project TT vs. GIAC at 182/216 and Nathan's dyno of 182/212 on 91 octane. Nathans had similar mods to my car. It's never been about the numbers - only about the delta.

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Thanks!

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Many thanks.

another great write up

great mods and great results

I really don't know all the technical reasons - but Mustang dyno's are load based dyno's. They put a load on the car during the run, which dynojets don't. This results in lower numbers overall. There's alot more to it technically - but that's the readers digest condensed version.

Dyno's are only good for tuning cars and determining the changes that modifications make - not for determining how much hp your car makes.

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The most frustrating thing though is how different dyno's can be. Having seen a number of different dyno's plots and even knowing differences between dyno's it was hard to tell what my baseline should be.

When I originally dyno'd on a dynojet in fwd mode - the numbers were low - but we really didn't know how low they were. Not until we were able to dyno another stock TT 225 on that same dyno under similar conditions did I even know how low my first dyno was. This lead to the discovery of the high rpm boost leak.

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