TypeR_Turbo

We ran a fully built LS/Vtec on C16 race gas which made 455whp @ 17psi of boost. But if you look at the dyno sheet the Vtec was switching on and off after 5700rpm all the way to 7500rpm. On our datalogging with Hondata it was switching back and forth from low map to high map. But on 15psi it was running fine and staying in Vtec. Any help would be greatly appreciated would like to dyno again at 20-22psi of boost but must fix problem first!!

I will post dyno sheet in a day or two.

nsxmatt

Check your oil level and maybe even the screen for debris.

TypeR_Turbo

Here is the dyno sheet! And the oil level was topped up and oil pressure was good. Oil pressure was just about 35-40psi through VTEC.

toolowsol

My engine is around 70psi in vtec

TypeR_Turbo

we are running a type R oil pump with a PRO DRIVE oil pump gear. Oil pressure before VTEC is 75psi and then when it hit's VTEC it drops to about 35-40.

11psiTurboSI

weird ... cuz I run 75psi when vtec engages too! You shouldn't be losing oil pressure in vtec

TypeR_Turbo

are these hybrid ls/vtec's or full vtec motor?

donkiman

your oil sensor in the back of your block is what lets your computer know that you have sufficient oil to run vtec. if you do not have sufficient oil, even though vtec is hooked up, your computer will not let it engage. this does not solve your problem and u prolly already know this but its all i can say.

fipracing_com

Did you do any headwork? From the sound of it, its almost like you are missing some oil control orifices that go in the head, esp the ones the go under the Cam caps by the camshaft pulleys, also their is one that goes into the block on the back that controls oil flow to the head.
http://www.acuraparts247.com/s...ch=no
Parts 9, and 10

Also in the VTEC Head http://www.acuraparts247.com/s...ch=no

Parts 3 and 4

http://www.acuraparts247.com/s...ch=no
Part 15,

that is the pressure switch, this will cut vtec off if the oil pressure drops.

Did you remember to plug the Oil hole on the bottom side of the head look here
http://www.c-speedracing.com/h...0.jpg

TypeR_Turbo

we have done quite a few of these swaps and all those pieces are in. And of course the head is plugged for LS/Vtec or else there would be oil all over the place.

Blaze45

Well we know why your in and out of VTEC, your oil pressure is wack.... Figure out what the heck the issue and fix it. You should be at 75psi when you get into vtec, and it should stay there, maybe even rise a bit....

Good luck figuring it out,

Blaze

Civic_95_Si

Do you have a bigger dyno sheet. That ones a little hard to read.

m R g S r

Common, 35-40psi? That's the reason VTEC is going in and out, there isn't enough oil pressure to keep it activated.
Soo. . 455whp without VTEC, not bad. . .

TypeR_Turbo

cool well i'll try and figure something out thanks guys. once we get the problem fixed i will let you know what our big dyno numbers will be.