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Paul Workman · 02-13-2012

Shrek,

Asside from a (low?) 309 hp baseline, 30 hp gain seems about right compared to the results others have had for the same mods, as well as what Marc H's web site data suggests. That's a good thing, but it tends to support (in my mind anyway) that the baseline number may be even more indicative of something else that "ain't quaht raht" here.

For example, here is a bone stock 90 (except for a Borla cat-back exhaust) that pulled 339 rwhp - pretty close to what yours makes after headers, etc. THIS is what makes me wonder if there is a gremlin that needs to be rooted out in the base case, as your car responded very much in line with what others experience for the same mods.

Note: On the dyno runs (below) the A/F ratio was getting too lean - turned out the secondary fuel pump was not working - so the operator was cutting it off at around 6k rpm. And, note it was stock except for a Borla cat-back. (The resonator tubes diameter were something like 1-3/4": no resonance, but also "a bit" restrictive too.)

Shrek, I hope you don't think I'm being a "Debby Downer" or throwing cold water on your improvements. It is because the improvement value is typical that it brings attention to the fact the baseline and end results are not what is also typical, and there may be a reason - maybe even a simple fix - for it.

For example, Dom discovered the secondary throttle plates in his TB weren't opening fully when the accellerator was floored. A simple adjustment and voila! Same thing happened on my wife's C3.

I'm just sayin, 20+ hp is 20+ hp. And, hell...guys spend $300-$400 to pick up 5 hp from porting the TB! So, I'll shut up about it now, but I just thought it might be worth a look. Could be dyno error too, for that matter.

Good luck!

P.

PS: I just noticed something... The new torque number is higher than my baseline number, but the hp is not. Is the torque/power curve dropping off suddenly above 6000 rpm or was the run cut off prematurely? Any chance we could see the dyno sheets - before and after??? That might be the answer to this question. If it is, then we'll know.

02-13-2012	#18
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,466	Re: Dyno Pull yesterday (OBX Headers) Shrek, Asside from a (low?) 309 hp baseline, 30 hp gain seems about right compared to the results others have had for the same mods, as well as what Marc H's web site data suggests. That's a good thing, but it tends to support (in my mind anyway) that the baseline number may be even more indicative of something else that "ain't quaht raht" here. For example, here is a bone stock 90 (except for a Borla cat-back exhaust) that pulled 339 rwhp - pretty close to what yours makes after headers, etc. THIS is what makes me wonder if there is a gremlin that needs to be rooted out in the base case, as your car responded very much in line with what others experience for the same mods. Note: On the dyno runs (below) the A/F ratio was getting too lean - turned out the secondary fuel pump was not working - so the operator was cutting it off at around 6k rpm. And, note it was stock except for a Borla cat-back. (The resonator tubes diameter were something like 1-3/4": no resonance, but also "a bit" restrictive too.) Shrek, I hope you don't think I'm being a "Debby Downer" or throwing cold water on your improvements. It is because the improvement value is typical that it brings attention to the fact the baseline and end results are not what is also typical, and there may be a reason - maybe even a simple fix - for it. For example, Dom discovered the secondary throttle plates in his TB weren't opening fully when the accellerator was floored. A simple adjustment and voila! Same thing happened on my wife's C3. I'm just sayin, 20+ hp is 20+ hp. And, hell...guys spend $300-$400 to pick up 5 hp from porting the TB! So, I'll shut up about it now, but I just thought it might be worth a look. Could be dyno error too, for that matter. Good luck! P. PS: I just noticed something... The new torque number is higher than my baseline number, but the hp is not. Is the torque/power curve dropping off suddenly above 6000 rpm or was the run cut off prematurely? Any chance we could see the dyno sheets - before and after??? That might be the answer to this question. If it is, then we'll know. Last edited by Paul Workman; 02-13-2012 at 07:54 AM.