I had a chance to put my vette up on the dyno today. I've got a fast 78, longtube headers, x-pipe with cats, and B&B bullet exhaust. My #'s after two pulls were 323 hp and 327 tq. Is this normal for a 98 C5 with the above mods? I was expecting a little bit better #'s than this. The car hasn't had a tune yet for the mentioned mods (I was going to wait until after I installed my heads and cam later this summer to get a custom tune). Any ideas?
Here's the graph:

 

A4 or M6?

 

It's a M6

 

The numbers are low but you need to tune that car ASAP.

 

A manual and on a dynojet??? Something is wrong, very wrong there...

 

yeah my 00' m6 formula dynoed higher than that stock. something is up

 

tune it, im sure there is another 20rwhp or more sitting in there

 

Yeah that does seem low... my formula with the LS1 intake and MAC's (ORY) UD Pulley, P&P TB, LID, and a Magnaflow catback Dyno'ed 348hp 357tq to the rear a few weeks ago, Before getting it tuned it but down 337hp and 349tq. So yeah tuning will help.

 

As stated, low. I would check the tune just to be safe.

 

i agree that don't seem right

 

My 98 m6 camaro did 326/336 with long tubes, ls6 mani, ported tb and exhaust

 

I dont think that low really.. A 98 ls1 has the worst heads, add on top of that the car is going to be outa tune and i dont think thats really that far off.. get it tuned and i bet you would see 345-350 rwhp 360-365 rwtq.

 

The 98 Heads are no different than the 99+ flow wise, Just the 97-98 are not the center bolt style

 

The car has a little over 100k miles also. Could the tune be that far off? Could something else be wrong? The car runs pretty strong as is and doesn't burn oil, and still gets 18-20 mpg in town and 29-30 mpg on the highway. Not sure where to begin looking for potential problems. Any ideas?

 

looks a lil'bit rich up top... Maybe some knock pulling timing

 

Just as a comparsion my vette with a intake and cat back pulled ~325 on a dynojet, no tune. I would tune it since you added the fast 78 and headers, there is prob another 15-20 rwhp on the tabe with a tune