vtec timing with boost

a while back, a friend of mine put a turbo on his b16a. He had killer torque, but lost his top end vtec. Another friend said it was because of the timing. He went into a deep explanation about “blow by” but he lost me somewhere.

anyway, keeping that in the back of my mind, i did some looking around before i put a turbo on my b16. Some searches on this board and on h-t gave me some different answers. my friend and some ppl hear said that the timing should be retarded a few degrees. But on the other hand, some people here said that advancing the timing would make it more aggresive.

My big question here for all you boost barons, is simply this- what do i have to do with the timing? do i advance or retard? and how much would be optimal for a daily driving on the street? i hope to have a t3/to4b pushing 6-7 psi.

many a-thanks and domo arigato :bow: any help will be very appriciated


i know that quite a few of you out there have a boosted b16. Come on, help a gen 2 brother out! please?.. :slight_smile:

DEFINATELY DO NOT ADVANCE the timing, expecially with a high revving B16. On NA cars, advancing a couple degrees is okay, but higher Octane gas is recommended. Personnally, my timing is retarded 4 degrees for 8-10 psi. We only have 91 Octane here, so if you can get 93 on a regular basis, 2 degrees should be okay.
As for the power falling off on the top end, typically retarded timing will mostly affect the low range power/responsiveness. What kind of cams was he running? The B16 cams are really weak-especially AUTO B16 cams. Most likely it’s his FUEL affecting his top end. Is he using anything to tune it, AFC, SMC, FMU?

thx for the response. so 2 degrees…

as for my friend, he has gone a different route with his car. He was running stock b16 cams and fuel was controled by a fmu, 12:1 if i remember right. I have just b16 cams, but now im thinking about getting something else. Would gsr cams do alright? I read a post on H-T where a lot of guys were talking about it. some perfered the gsr cams over itr.