Running in engine on previous map with Vcam turned off ?

Hi Folks, just a quick one,

Recently had the engine rebuilt with a new block and installed V-Cam. So the only thing that’s changed is the piston diameter from 87mm back to 86mm and the intake cam. Previously had tomei 260 9.15mm lift cams, the Vcam is 264 8.7mm lift.

would it be safe to run it in on the current map if left the VVT turned off, kept an eye on AFRs, set rev limit and pulled boost ?

Really wanted to have it out for a big show this weekend but tuner hasn’t got time to do it anymore.

Thanks

It's a bit difficult to answer those questions as there are so many variables that could affect the outcome. I wouldn't want to say "sure no worries, go for it" and you end up damaging your rebuilt engine.

Is your show a "Show and shine" or you want to drift or drag or circuit race? What ECU are you running? How good was the tune before you rebuilt the engine? Finally, just to make sure I understand, your engine was previously tuned without the VCAM setup?

If you stay off boost, drive it gently, your close loop fuel control is enabled and there's enough room in the trim for the ECU to adjust, I would say go for it, but again, there are many variables that we can't have access over a forum in the internet...

It’s just a show and shine so I’ll be driving it like a granny for the first few hundred miles with break in oil.

It was tuned without Vcam before by a shop that does the majority of RBs and drift cars in the county. Just without Vcam (I think it’s the first one in Ireland) but I can leave it off for the time being.

I agree with Frank:

"If you stay off boost, drive it gently, your close loop fuel control is enabled and there's enough room in the trim for the ECU to adjust, I would say go for it, but again, there are many variables that we can't have access over a forum in the internet..."