SOHC_MShue

So I tuned a boosted z6 today and we weren't making the top end power we expected. We checked over every single thing we could think of and still nothing would help the top end. It had a pretty large turbo and torque would peak and then just fall on its face. We even tried running the dumptube differently. Finally we tried testing to see if vtec was actually physically engaging. We ran a wire directly from the battery to the vtec solenoid while the car was idling. The solenoid clicked, but there was no change in the way the car idled. AFR's didn't change at all, idle didn't become lumpyier(if thats even a word..), tone didn't change, nothing. So we figured well theres our problem.

For the heck since i can never hear vtec engage on my y8block/z6head setup i ran a wire in the same way. Still just like the other car no change in anything. The question is on a z6 should you hear a tone change? I've never once heard one in mine. I could hear it for sure when i had the y8 head...oh and i even have a zex 59300 cam so the vtec lobes are even more agressive than stock.

liam821

First off, correct me if im wrong, but to use the vtec solenoid, you connect ground, not power, to activate it.

Vtec in a sohc is only on the intake cam, not the exhaust, and by forcing it on should not only give you a CEL but it should effect idle.

Id check all the wiring...

liam

FactionR

you shouldnt really "hear" it like a DOHC VTEC because its only the intake valves opening higher/longer, not the exhaust valves.

also in theory VTEC will not engauge at idle, not enough oil pressure/flow to lock the pins in place.

SOHC_MShue

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by liam821 &raquo;</TD></TR><TR><TD CLASS="quote">First off, correct me if im wrong, but to use the vtec solenoid, you connect ground, not power, to activate it.

Vtec in a sohc is only on the intake cam, not the exhaust, and by forcing it on should not only give you a CEL but it should effect idle.

Id check all the wiring...

liam</TD></TR></TABLE>
well when i connect power it clicks like its engaging. Yea i thought for sure it would effect idle..but on both cars it didn't. The higher cam profile would have to effect something. I even tried giving it about 3k rpms or so and it would have oil pressure and still no change.

JDMCRX

iTrader: (2)

My car with the open dump u feel vtec more then hear it lol .