C4 Dyno - with/without Steve W. Chip
#1
Three Wheelin'
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![](http://i593.photobucket.com/albums/tt17/rn_durham/C4/C4_dyno.jpg)
This was fun. My first time experience with a dyno pull. Standing behind the car at 6500rpm will definitely make you hold your breath. Plus I never get to watch my spoiler in action. Anyhoo-
100% stock engine, stock exhaust, fairly recent valve adjust, plugs, dizzy rotors/caps, 78k miles, very good leakdown number:
At the wheels
226.1 @ 5957 /.91 = 248 flywheel
207.7 @ 5064 /.91 = 228 flywheel
Same engine, 90 seconds earlier after installing the Steve Wong / 911chips.com 93 octane chip:
At the wheels
232.6 @ 6302 /.91 = 255.6
213.5 @ 4870 /.91 = 234.6
+6.5rwhp
+5.8rwtq
Pretty much exactly as advertised.
Assuming that I actually make the stock flywheel numbers, that gives a 9% drivetrain loss. This is an AWD Mustang dyno. The plot above is scaled to their correction guesstimate. I had three pulls, first two with chip, third pull without. The first two were within 1hp. All were done in 3rd gear.
After driving on the chip for the past couple weeks I can say that the <4500rpm torque increase is absolutely noticeable. The small peak increase really doesn't reflect the change in acceleration. Idle feels a bit smoother but the real change is mid-range. In all, I'm a happy camper. Steve was fantastic on customer service to boot.
Additionally, the dyno folks at ESP in Sterling, MA, took their time and seemed excited to toss something a little different up on the rollers. A couple enthusiastic VW/tuner guys hung around to watch the pulls. All were just friendly car guys.
#2
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A mere 6 hp improvement and now you need to use 93 octane, please!
Did you miss reading this:
https://rennlist.com/forums/964-foru...ip-advice.html
Did you miss reading this:
https://rennlist.com/forums/964-foru...ip-advice.html
#4
Three Wheelin'
Thread Starter
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^ Next on the list! Finally
I experimented with some leather repair/color restoration on my cashmere hides and it looks like I can bring them back to new and swap them onto the 12-way power frames. Will have a fun thread on that coming up. How does your new engine feel compared to the old?
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#5
Race Car
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oh man - the 'new' engine is just unreal...Steve W did a fantastic job on the heads. We went with 993 valves, better guides, ti retainers and better springs - so -effectively a stock OEM setup, but just done better...so as far as HP increase, I get only what a good broken-in bottom end with a new top end can give. But all said and done, it went from being a nightmare to being like a new car...awesome...
NOW - I have to pull apart and rebuild the 4WD system I think - I broke something at the track - and my shop can't tell me what it is - in fact they say it's not broken (and it drives fine, so maybe they are right), but I can feel something wrong in there somewhere - so I may go lookin - which is when you go from "exploratory' to "oh crap now I gotta rebuild that too" and then fix change and renew x y and z while in there...lol....but all good.
if you are ever passing through on 95 give a shout...
NOW - I have to pull apart and rebuild the 4WD system I think - I broke something at the track - and my shop can't tell me what it is - in fact they say it's not broken (and it drives fine, so maybe they are right), but I can feel something wrong in there somewhere - so I may go lookin - which is when you go from "exploratory' to "oh crap now I gotta rebuild that too" and then fix change and renew x y and z while in there...lol....but all good.
if you are ever passing through on 95 give a shout...
#6
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Thanks for posting the #'s!
Like you, I'm also impressed with my SW chip (93, primary bp, cat bp).
I've thoroughly enjoyed the rock solid idle and improved sub 4,000 RPM response for the past couple of years.
Recently I installed a cat bypass and I must say that REALLY woke up the car. Even more power and response, but further down the power band.
That it sounds even more mean, is just a bonus!
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#8
Racer
Join Date: Feb 2011
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I bet! Wow.
Thanks for posting the #'s!
Like you, I'm also impressed with my SW chip (93, primary bp, cat bp).
I've thoroughly enjoyed the rock solid idle and improved sub 4,000 RPM response for the past couple of years.
Recently I installed a cat bypass and I must say that REALLY woke up the car. Even more power and response, but further down the power band.
That it sounds even more mean, is just a bonus!
Thanks for posting the #'s!
Like you, I'm also impressed with my SW chip (93, primary bp, cat bp).
I've thoroughly enjoyed the rock solid idle and improved sub 4,000 RPM response for the past couple of years.
Recently I installed a cat bypass and I must say that REALLY woke up the car. Even more power and response, but further down the power band.
That it sounds even more mean, is just a bonus!
I can attest to Steve's skills and knowledge. He supplied my old '86 3.2 Carrera with a chip as well and it really improves drivability,.. at the least.
Congrat Nick, now just couple this to a cat by-pass and a cup pipe and you will see even better #s.