Has anyone upgraded their pulley on their 2011 Whipple-charged GT's?

[NightriderWRX]

Well I got tuned today by Ben at PUR-Performance in St. Charles, MO. yesterday. The car put down 553rwhp on the stock 624hp whipple supercharger. Which I guess would be pretty accurate with the around 20% drivetrain loss would put the car around 663.6 crank horsepower; if my math is correct .20 X 553whp = 110.6 (difference) + 553 = 663.6bhp so all in all if the proclaimed 624 crank horsepower from the whipple to a stock motor (no bolt-ons) would put the estimated whp to 499.2 ((i'm sure my math is probably off; but then again it's 3:30am and I'm sitting here pondering what's next. My goal is to achieve 600rwhp; but the question is; have I maxed the safe zone on my block yet. I know that there are some companies making well over 600rwhp; but are their dynos/numbers different, as well as other contributing factors.

My mods for my 2011 5.0 GT included are:

Kooks 3/4" Long Tube Headers + off road x-pipe
Magnaflow Competition Style axleback
Whipple 123mm Cold Air Intake
L&M Billet Dual 66mm Throttle Body
SCT Handheld Tuner
MCleod RST Street Twin Disk Clutch Kit + Steel Flywheel

So in reality the question is has anyone upgraded their pulley yet and if so what did you go with. I have a couple options to go I guess; upgrade pulley + E85 will def. get me past my 600rwhp goal; however would it be safe. My thoughts are well E85 burns cooler than regular pump gas; therefore it should be able to run more boost... <- Sorry coming from a Subaru (night and day i know)... any help would be great!

 

[whoareyou]

Get in contact with Lethal Performance. They have been doing a lot of upgrades to their stock block Whipple charged 5.0. Most recently they upgraded to a 2.9L charger.

 

[GetBlown2k3]

I would put the pulley at the bottom of the list at this point. How much boost were you seeing on the dyno? I know that Lethal is running about 10psi on their Whipple, and several other people are running 10psi on their blowers (including VMPs 5.0 with the TVS).

Not to knock your tuner at all, but sometimes if the tuner doesnt know all of the little in's and out's of how to get every bit of power from the 5.0 motor with the VVT, you might not be taking full advantage of your mods. For example; when I had my 03 Cobra, I took it to a "well known" shop in the Northern Va area for dyno tuning after my KB 2.2 install (wont mention names b/c they are on svtp) and the car dynoed at 553rwhp. I just felt that the car had more in it, so the next day I left the car with the tuning God who goes by the name of Hermann, and the car made 608rwhp. Both numbers were in the same climate, both Dynojets, and both STD numbers.

It could also be the dyno that reads low. Was it a Mustang Dyno, Dynojet or Dynodynamics? If I were you I'd take it to the track and see what kind of times and trap speed you can lay down. If you are trapping 134mph or something, I'll bet my house that it's the dyno reading low.

 

[28]

Also did you get a mild or aggresive tune? It could very well be your mech gave it a mild(safe) tune.. I think the 5.0's are proving durable up to the 600rwhp mark so far as proven by shops everywhere.. I still don't think anyone has actually thrown a rod yet as far as I know even folks that have gone to aftermarket pieces just did it for piece of mind or compression changes. Not for replacing damaged parts..