so i built a 95 gsr short block and have a ctr top end, with a 95 gsr vtec solenoid.. vtec comes in about 5500 rpms but cracks really weak and seems to take about 5 seconds to enguage. i hear it and feel it just a little bit, not like firends cars i have been in. also i have the stock ls manifold all the way back to the stock muffler, could this be causing 2 much back pressure and and hindering the vtec?

 

What ecu or tune are you running? Vtec shouldn't 'crack, kick, snap' or whatever kids are calling it these days. It should be a smooth transition. If vtec kicks when it engages, that means you have a dip in power right before, that is a bad thing.

 

VTEC shouldn't 'crack hard' it should be smooth.

 

vtec shouldn't "crack hard" it should be a nice little smooth transition. If you want vtec to "crack hard" then buy a vtec controller and make it kick in at 6500rpm

 

well i guess its working fine then, stock p72 obd1 no tuning, ok well then cool i guess i just expected a bit more for a 11.0 to 1 gsr engine... maybe new cams and a header and exhaust are in order. thanks guys. very helpful

 

what cams are you running? if you have a ctr head then you need to upgrade your ecu....

 

why would i need to upgrade the ecu? it doe not knock, runs fine, has a hard time getting about 8k rpms tho... maybe thats the problem.

 

well obviously your running ctr cams with gsr ecu. the point is that a gsr ecu does not send out enough fuel for your ctr cams..therefore even with the ctr cams your ecu is only running it to gsr specs..i have 01 itr cams in my gsr head with gsr valvetrain and just running a gsr ecu my car felt like crap..but when i got a p28 and chipped it with an ITR basemap "basically an itr ecu" my car was running to its potential...in other words its like running a ls ecu on a gsr motor...

 

ding ding ding! Tuning is everything brother and the correct ecu setup could be causing exactly what your talking about

And for the love of God please learn that vtec should NOT crack hella hard homey..that is all gl OP

 

What intake manifold? The stock P72 ECU opens the intake air bypass valve in the stock GS-R intake manifold at 5750, but VTEC activates way down around 4400 rpm.

 

Yeah I would have to say buy an aftermarket intake mani, that alone made my vtak feel 10 times stronger and you could actually hear it.

 

for the how many times now...how do you hear vtec? LOL

 

mmmmmmmmmMMMMMBAAAAAAAAAAAAAAAAAAAAAAH

 

what most people think is vtec is actually the secondary valves in the intake manifold opening up. you put an intake on it and you can hear a difference in sound.

 

so the louder the stronger huh? Hmm maybe i should just hook up my vtec to an amp....i might be 100 times faster...ahahaha

 

^^^^^^^^^^^ that is what im thinking!!!! first you need to get a tune and get rid of the p72 because vtec is at 4400 rpm and then opens the secondaries at 5750 rpm but since you have a LS intake there is no air bypass valve so it not running to the full power of the ctr cams the ecu thinks you are still a stock gsr

 

not an ls intake manifold you clown. you cant put an LS IM on a gsr head.
im sure he means an "LS exhaust manifold down to his exhaust" jsut like he said.

 

oh my bad lol!!!!!!!! i thought he had a ctr head thats why i thought he maybe put a ls mani but still he needs a tune on a p28 or something else

 

sorry for my honda ignorance... i have a 650 hp 68 cuda, i know about that one. but im learning.
every "fast" vtec car i have been in "cracked" vtec hard, the fastest one was a 92 hatch with a bone stock h22. cracked hard and pulled hella hard. anyhoooooo i do have a ctr head, but it still does not have a ls intake. its a b16 intake. with a cheapie short ram... can i chip the p72? would that be of any use? what about a cheapie ebay header? better than ls manifold?

 

sounds like u need to read this articale. Read the whole thing or it would make any sense. VTECwas not developedas an instant power gainer like Nitrous it doesnt swich on the power. VTEC was ment to take and help the motor produce a more ever power band across the low rpm up through the high rpm.

http://www.team-integra.net/sections...p?ArticleID=45

 

i understand how vtec works, thanks.... but what im wondering is if doing any of the header stuff or chiping would help out much, the stock ls manifold seems pretty restrictive. also the rev limiter at 8200 not cool. so would going with a cheapie header and chiping the ecu help much or are those just a waste of money?

 

signature worthy!!!!!!! ha

 

I'm surprised no one picked up on this yet, A GSR block with a B16/ITR head will have a lower CR than a stock GSR. Your CR is now, lower than 10:1 it's more like 9.7:1, assuming no milling or decking took place. That can also be a reason why your car is running like crap.

 

lmfao!!!!

 

nah it was decked and milled and all then went a bit too far so i had to add a shim, never do them at seperate times, or if you do please remember what you took off your head!!!! oops. another mistake.