Mike A.

Does the stock ECM on an HP525 need to be re-calibrated after the engine is punched out to 540cid? Thanks!

F-2 Speedy

iTrader: (6)

If your referring to the 525 EFI, I would, you should increase the injector size for the larger displacement also, what else did you do besides bore it ? I think a remap is in order

Griff

Yes

BUP

iTrader: (9)

Yes as well

Mike A.

We changed rockers to 1.8. Everything else stayed same. I pulled motor to fix issues from blown head gasket. Damage not catastrophic.

HP at 5300 was 620 on dyno with stock ECM cal. That said, what are potential issues if we leave ECM as is? Thanks?

MDGperformance

What were the afr ratios on the dyno if you make the engine bigger you will need more fuel to keep it in the same safety zone as the stock engine,lean is mean but you up your risks of a meltdown

F-2 Speedy

iTrader: (6)

If you lean out a hole, your not gonna be a happy camper, thats a good number for those heads, a little fatter as far as fuel goes would be piece of mind, do you have the arf #'s........

jdf4068

lean means boom

twinscrews

Call Eddie at Young Performance. He has two of my 525's, he can tell you exactly what you need to do.

Young Performance

The PCM 555 has a cubic inch "compensator". It's basically a matter of telling it that the engine is a 540 instead of a 502. There are other gains to be had with timing, etc. What type of AFR's did it have on the dyno? If you don't know, you would be wise to find out.
Eddie