new issue....

[der affe]

OK so have the new cat on the car and they fixed the shitty install job

http://www.r3vlimited.com/board/showthread.php?t=112567

i haven't had a cat on the car for about 2 years since the last time i went through emissions.

the new problem is the car pings until around 2000 rpm when accelerating in 1st 2nd and 3rd gears. it has never done this before. i always run 91 (we don't have 92 or higher in AZ). WTF?

can i retard the initial timing in the dist? to help this out until i can make another cat bypass section?

any suggestions?

thanks,
Greg

[ethree]

Why would the cat cause detonation?

[der affe]

i don't really know....more back pressure????? although that really doesn't make any sense, E30's run with them all the time. maybe my cat by pass was loud enough that i couldn't hear it before. i am open to suggestions though.

[ethree]

I had a bad tank of gas a while ago which made my car detonate a bit under load so I used some of that octane booster crap which helped quite a bit until I put the next tank of my usual chevron 91. It's a thought.

I was more just curious as to what led you to believe the cat was related? Anything other than timing?

[der affe]

I had a bad tank of gas a while ago which made my car detonate a bit under load so I used some of that octane booster crap which helped quite a bit until I put the next tank of my usual chevron 91. It's a thought.

I was more just curious as to what led you to believe the cat was related? Anything other than timing?

that is the only thing i have changed, the mileage has dropped too

[der affe]

bump, anyone?

[jlevie]

A stock M20B25 won't ping with 87octane gas. Only if the engine has a chip should you need higher than 87. Has a chip been installed?

[der affe]

here's a quick list of the specs. rember it is a 2.7 STROKER , not a 2.7 ETA

http://www.r3vlimited.com/board/showthread.php?t=112567

from my understanding the 325I has higher static compression so you need to run the 91 octane.

if i could i would run the lower octain for the burn travel and lower gas $$$

[ethree]

Mine is a chipped m20b27 I should have stated that in my earlier post.

Did you do a full rebuild when you built your stroker?

[der affe]

oooopppps the link in the earlier post didn't take.....now it makes more sense.

i bought it with the motor already installed, but he showed me recepts for a full rebuild