hate to say this but no it doesnt. stock C5's dyno in the 320-330 range.

 

it's hard to troubleshoot things over the internet
it'd help to see some more data - boost, a/f, dyno charts, or even some pictures etc

what correction was the dyno using if any? what were the weather conditions from the NA to SC dynos? Did the shop do any sort of change in calibration?

 

best thing, the suggestions you guys are making are well over a couple grand in parts alone (exhaust, injectors, utec....). if he couldnt afford to do that last week, i doubt he's going to do it now.

if he just got rid of the underdriven crank pulley, that would be the best starting point.

 

Are you sure about that? This stock c5 put down 298whp.

http://www.dragtimes.com/Chevrolet-C...lip-11833.html

It's kinda hard to find stock c5 dynos, but here's a few in this link.

http://forums.corvetteforum.com/phot...59848/cat/1130

 

UR does claim to make a stock diameter pulley though

http://www.unorthodoxracing.com/Merc...de=350zultraSc

 

to answer your questions...

it is a stock diameter ur pulley...so it cant be that...

i am using utec not ss box

im peaking boost around 6.5 but averaging around 5.5

and its a non rev up

i saw the charts and my injectors are running max load starting at around 6000

 

+1
in a race though, it might at best be close or the C5 probably has the edge from having more low end tq and weighing less overall

 

how much does a compression test usually cost?

 

not a whole lot
most of the labor is taking the intake manifold off

 

if compression is low how do you fix a problem like that

 

if you are using the utech then what kind of fuel system do you have? you obviously are not using the vortech supplied aux pump and fmu. the s/s box triggers the aux pump to turn on and off under boost conditions.if you are maxing out those injectors at 6000rpm on a 3.33 pulley you definatly are having fueling issues. that is why you are not making any power . you need to show us a dyno chart to see your power curve and A/F ratios. it may look right at the lower rpms but flat line up top due to the injectors running out of fuel. your tuner may be trying to compensate with the injector duty cycle due to there not being enough fuel pressure. do you have a fuel pressure gage installed?

 

you can do a leak down test if compression appears to be bad. If that's bad, then you know the engine has a problem

pretty much either live with it or get an engine rebuild are the only real options

 

i am using the vortech fmu and inline pump..it take a constant 12v charge I called vortech to double check and then i had my shop finish up hooking up that part...the fuel is not the problem

 

What kind of dyno did you use?

Did you use the same dyno for both your N/A and F/I dynos?

A 50hp gain for 5.5psi isnt too shabby really. On the other hand my car went from 267whp n/a to 366whp with the 3.33 pulley on the same dyno with the out of the box tune.

 

that goes to show how variable dynos are. 366 whp with a 3.33 is pretty much outside the standard deviation.

stewie, not sure how you are triggering the vortech aux fuel pump. sounds like your tuner doesnt know how its controlling it either.

why not use the SS box and simplify everything. guarantee you wont make less power.

 

how tight is the serp belt? I know when I had my vortech it needed to be so tight it sounded like a guitar string

 

also post your timing map as well, When i was tuning my vortech with the UTEC I gained 40 whp just by adjusting the timing.

I think my timing at peak boost at redline was around 14.5

This was with a 2.87 pulley

 

you probably have some sort of boost leak somewhere. also you need some injectors.

 

Does the Utec have a way to turn on and off the Aux. fuel pump supplied by Vortech ? If so.....is it hooked up right and turning on when getting into boost ?

If your injectors are maxed out at 5-6psi , I doubt that the aux. pump is coming on or the FMU isnt working right .

You for sure have a boost leak or your belt is slipping badly . You should be seeing 7 to 9 psi with the 3.33 pulley .

Take the car back to where you had it installed and have them fix it . If you did the install , take it to an onstaller and have them go over the car to check it out .

 

ya same dyno...

how can you tell if belt is slipping? i watched it run and it looks fine

and how can i check for a boost leak?

and i called vortech and they said that all the aux fuel pump needs is a constant 12v charge that the ss box did nothing besides give it that constant 12v when the car was turned on