brent_si

I just had a professional machine shop do je pistons to my b16. The rest of the motor was just rebuilt with stock parts at the same time. The compression is either 8.5:1 or 9:1 do I need to get my ecu tuned before I run it? Or can I use the stock ecu safely for a while?

brent_si

This is without turbo. Getting turbo rebuilt.

93egSLEEPER

its fine to drive untuned... will probably run kinda rough

brent_si

Even if the only thing on the motor is the pistons it will still run rough? Literally everything else is totally stock except intake and exhaust?

93egSLEEPER

it will run a bit rough because of the compression change. that happened to my when i went from a JDM B16 (10.4:1 CR) to a gsr w/ ls pistons (about 9.3:1 CR). air/fuel ratios were a bit messed up til it was tuned.

brent_si

Damn The only ecu's I have are the one with the turbo tuning and stock. And its my only car...

93egSLEEPER

it will be fine to drive on with a stock basemap... just it wont have the "tuned performace" like im sure you are used to.

blaze the chemi

If you still have your P2T ECU stick that thing in. It'll be somewhat bogged down and it might throw a code, but until you have reinstalled the turbo and larger injectors, it's the best thing you can do.

I'd even drive to your tuner with the wastegate spring out and stock injectors in on the stock ecu, then place everything in for the tune itself. That way there would be no way to accidentally blow anything up.

robfrmny21

do not hit vtec with it and your good, you just want to break the rings in, when you get your turbo you will need to retune it cuz your gonna turn the boost up

brent_si

So I can't hit vtec in it? This makes no sense other people said that I could drive it with no problem with the lower compression pistons on stock ecu. While I break in the motor it will have only a cai, exhaust, and pistons. All I want to know is will it be ok to run on stock ecu with just that stuff?

Frozen E

It'll be fine to drive. I've got about 5,000 miles on my built B16 with 9:1 compression running NA.
Turbo took a **** and just been too lazy to do anything else with it. Put stock injectors, ECU and a regular header on it. Been fine for a while now.

brent_si

Finally a straight answer from someone with expierence! Thanks. How does it run?

brent_si

Would 320cc injectors be ok to run on my car on like 7psi? Or should I go bigger?

93egSLEEPER

im running 440cc injectors with my LSV at 9psi

brent_si

Any opinions on what oil I should use to break the rings in???