Exhaust need a retune?

[Aaronp]

Hello,
I have a ls1 running with a aftermarket EMU master ECU, I had it tuned about a year ago when the car was running a EXTREMELY restrictive exhaust I have since had a twin stainless mandrel bent put on the car. Last weekend a local garage had a dyno day so I put the car on and it's picked up about 35hp with the exhaust change does the car need to have a retune or will the current tune be sufficient. I will include the dyno sheet for info
Cheers
A

Edited by Aaronp on Wednesday 12th July 19:29

[stevieturbo]

Any engine should always be tuned correctly...

If it was tuned correctly before and you've made substantial changes...then it probably does need re-tuned again.

But there is no info on that graph or post to suggest how the car is running at present and whether it is a problem that needs looked at.

[227bhp]

To be sure it needs a dyno session with more equipment attached to measure AFR and listen for det, it may be ok....
A lot of engines make very good power, just before they collapse.

[Aaronp]

Cool i will get it booked it

[GreenV8S]

I suppose it saved them some time for something they were doing on the cheap, but I wouldn't have recommended doing a power run without monitoring equipment on an engine that was in an unknown state of tune, and I'm surprised they did it. If you'd had monitoring equipment, you'd know now how well it was mapped.