I got blox b cams in my h22 and the vtec transition is crazy harsh. Its got a nice even tone until vtec hits and with a snap of a finger at 5000rpm its crazy loud and raspy and obnoxious and just doesnt feel right. My tuner says the transition isnt right either. Anyone have any ideas what could be goin on?
A pinch in the exhaust?
A loose timing belt? (my timing belt is kinda flappy when its runnin)

 

What's the whole setup?
I'd fix your timing belt then.
Can you post up your dyno?

 

x2. VTEC maybe engaging at the wrong time thats the reason we ask to see the graph

 

I dont have the graph right off hand but the numbers were wack. 190whp and crazy low tourqe numbers.

setup is:
jdm h22
blox b cams springs and retainers
camp1320 tri-y header
2.5" exhaust (3" straight back next week)
stock bottom
68mm tb port matched plenum

Btw, after the tune and after eveyone was very dissapionted with the numbers we noticed a pinch in the exhaust that decreased from 2.5" to about a 1.5" maybe smaller

 

ok so fix what you know is broken.

 

He's going to get a 3" ran next week. Fixing it wouldn't be worth the time.

 

I am with a straight 3" but I was just wondering if this could be why vtec isn't right or if anyone had any other posibilities of why it would do this

 

Install the 3inch exhaut and dyno again

 

will do. Hopefully that solves the problem. I've seen these same setups make over 220 to the wheels so we'll see what happens

 

can you see a chart of it at all? When VTEC engages does it dip or is it flat

 

To be honest I can't find the graph so that sucks.
Lets say it did dip when vtec engages, what would you suspect then?

 

that its set to low, raise it up a tad and see what happens

 

5000 rpm shouldnt be to low should it or I guess maybe it depends on the cam?

 

It can depend on many thigns. My tuner said he thought my 3" exhaust helped him turn vtec on at 4400 which he says usually you would see a power dip as described

 

Could you name a few of the things it could depend on?
that makes me feel alot better about the 3" exhaust solvin the problem for the most part.

 

I'm going to quess that the IM, cams and header make the most difference. But even the small thinks like intake length have a big effect.

 

Sorry I'm a little confused about this statement. Are you saying the three things you mentioned could not be right?

 

address all the problems you stated above first. if you still question its transition, its probibly time to move your engagement point up. if the "b" cams have a conservative primary lobe with a aggressive vtec, you might need to bring your engagement point up higher. all considering your air fuel and timing are correct.

 

Thanks man. Thats what I was lookin for. All these things you just described have been runnin through my head but I never really got it out bc of uncertainty due to lack of knowledge about the situation

 

I beleive your timing is gonna be off if your timimg belt is flappy and also the vtec should be set at 5300rpm's or higher.

 

Cool man. Yea I feel that way to. Thanks for the input