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RB25 resize injectors

Posted: Thu Nov 30, 2017 5:05 am
by fikemoo
Hi guys been a while since I've posted on here but I'm having a few issues with a friends car. He's had abit of a winter project and the car is off to be mapped on the 14th of December by a nistune tuner here in the uk. And I said I'd be able to do the basics like change the size of the injectors and change the maf so he can just plod it along to the tuner and let him do the real business. But I got a phone call today and the car is driving like rubbish. It only really revs ip to around 3000/4000 and is running as rich as anything. As I said all I did was remove the previous persons map from ecu and put a v3 z32 rb25 base map and changed the maf and resized the injectors from standard to 666. Have I done something wrong

Thanks mike

Re: RB25 resize injectors

Posted: Thu Nov 30, 2017 9:10 am
by Matt
Can you post the tune file you used? Have you tried lowering TIM until fueling is around 14.7:1 at cruise (and trims on cruise around 0%)?

Re: RB25 resize injectors

Posted: Fri Dec 01, 2017 4:36 am
by fikemoo
The car wont even drive it's running that badly. I used just the base map you guys provide and changed the injector size and the maf to a z32. It's running crazily rich

Thanks mike

Re: RB25 resize injectors

Posted: Fri Dec 01, 2017 5:15 am
by fikemoo
here is the map that is currently on the car (attached) i have had to put it back to the standard r33 maf as we think there could possibly be an issue with the z32 maf, but if you could check to see if i have done anything wrong

Re: RB25 resize injectors

Posted: Fri Dec 01, 2017 11:18 am
by Matt
K seems in the right place after the injector resize

Is the Z32 MAF genuine (see the main forum section with post on Z32 MAFs)

Should be 0.4V at power on and around 1.1V around idle also

Re: RB25 resize injectors

Posted: Tue Dec 05, 2017 6:59 am
by fikemoo
Hello matt a new update on this something I forgot to mention is the guy purchased the maf second hand and it had been installed in a 4" alluminium tube. Would the 1" difference in tube size make that much of a difference to cause the problems

Thanks mike

Re: RB25 resize injectors

Posted: Tue Dec 05, 2017 2:37 pm
by Matt
Yes it would if the internals were removed and put into 1" large tube. The VQ maps are calibrated for tube size :wink:

Re: RB25 resize injectors

Posted: Tue Dec 05, 2017 10:41 pm
by fikemoo
Right ok that makes sense. I just wasn't sure how much it would effect the car. So what can I do. I obviously was just trying to get the car to a mapper as my knowledge isn't that great

Thanks for all the help

Mike