My friend has a impala ss with intake and exhaust. He put down 265rwhp before the tune which I expected, but he says after the shop was done with his tune it was 296rwhp This really sounds like a chapter in the BS book. You think the dyno guy just inflated the numbers? It doesn't seem like a top notch place to his description.

 

woops: fwhp

 

Thats easy, tell him you want to see the dyno graph.

 

But couldn't the dyno guy just make the dyno ready 10% higher so it would be on the graph. I'm going to look at it next time I see him though.

 

was it dynoed on the same dyno...same day?

30hp from a tune...seems a bit much. but i wouldn't say unheard of.

if it was different dynos or even different days...its very possible.

and were those corrected?

 

I could see intake + exhaust + tune netting 30whp compared to a stock LS4. Was the "before" run with the mods? How long had he had the mods? Maybe the car hadn't adjusted to them yet.

 

He had the intake and exhaust for over 3000 miles. The dyno was same day. Before and after tune finished. He said the tuner was having a hard time at first so maybe when he got mad he just pressed the inflate numbers button.

 

Sounds like the tuner didn't know what he was doing. Your friend should take his car to someone that's tuned a few hundred LSx engines before.