i have a turbo h22a, and i've dyno'ed the car. the graph shows a significant dip at 5200.

i tapped the oil line for the turbo from the oil pressure sensor. some people have said that vtec won't turn on because of a drop in oil pressure from the T fitting. is this true and is there a way around it?

thanks!

-ray

 

You may just be low on oil. I always knew when my oil level was geting low, cause I could feel the VTEC wasn't engaging. Topped it up and it was fine!

 

VTEC takes a lot of Oil and pressure. Tap off of somewhere else. Are you throwing any check engine lights? what electronics? VAFC? The VTEC valve train is noted as having something like 64 different leaks. May run the risk of starving the turbo also.

 

throw a check valve and gauge at the vtec solenoid, if you dont have 70 psi at VTEC point - no VTEC, also need min coolant temp and ........forgot, help pls!

 

i have the aem EMS...i'll check so see the pressure tomorrow morning. before i had the EMS, i only had a FMU and a in-line fuel pump. even then, i had no pull at VTEC, so i'm assuming that's it. but i'll check the pressure....

thanks guys! but any other ideas or places i should check too?

-ray

 

That's pretty bad if my *guess* is correct... you no longer have an ECU that won't activate VTEC if there is insufficient oil pressure, you actually have insufficient oil pressure to activate VTEC.



I looked at a turbo 94 LS that doesn't produce past 30 psig of oil pressure due to the flow through the turbo and oil lines. I'll update tomorrow what a .060" restrictor does to the oil pressure.

 

engine oil, i have plenty of....but oil pressure...i'm gonna do some datalogging today and see what pressure i have at VTEC, or at any time

thanks!

-ray

 

i just learned that the AEM EMS doesn't monitor the engine oil pressure. and after turning off VTEC, the car pulls. something i never felt for the 6 months i've had my turbo. and yes, it was almost as good as sex

does anyone know how to check oil pressure? and if there's a different place i tap the oil instead of straight from the sensor?

-ray

 

good question

 

right now, it looks like either:
1)VTEC not engaging due to lack of oil pressure
2)Fuel map is set so that VTEC is running lean
3)Fuel map is set so that VTEC is running rich

because the car feels like crap when VTEC hits and there are occasional times where the check engine light would flash on. by the way, does the EMS use CEL?

this is a noob question, but what exactly does VTEC do? i know it switches to difference cam lobes, but does it allow more fuel and air to burn so the car can run faster? in the same A/F ratio? rather than the other lobes that make the car run more efficient?

if what i'm saying is true, and it's dumping the same ratio, but at different cam lobes, shouldn't the A/F without VTEC be the same as with VTEC? and if i'm completely wrong is it MORE fuel at VTEC or LESS fuel at VTEC?

thanks!

-ray

 

VTEC requires 70PSI (think thats the #) to lock up the "power" profile lifters, maybe your VTEC solenoid is defective. with trying to be an ******* you should really have someone look at it for. AEM I think can also be programmed to use the MIL/CEL light as a shift light doe sit always come on at certain RPM???? check for code. as for your AF ;
there are a 1000different AFs in your computer. they are based on things such as TPS, MAP - engine load and rpm. lets say you are cruising in vtec at 7000rpm and 20%TPS with 0PSI boost that is a stoicher (is that a word) AF than 7000RPM with with 100%TPS and 20PSI boost, thats why you have fuel maps. I hope you dont have just a WOT fuel map.

 

on h22's you can take out the set screw on the side of the head. but i reccomend off the block. put a t on your sender unit.. any whoo..if your running a h22 on a p13. good luck youll never get it tuned right.I MEAN NEVER. p13's are the worst
ecu for boost. before i had hondata went to 4 diffrent tuners and they all iched their head.. it would burn so rich when vtec kicked in even with the vafc leaned all the way out..problems,problems,problems.i wish i would have never turboed mine.

 

@ching chong

what are you talking about? p13... he's running the AEM EMS, a great system, if you know how to tune it

 

oh sorry,great

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rtype11 &raquo;</TD></TR><TR><TD CLASS="quote">VTEC requires 70PSI (think thats the #) to lock up the "power" profile lifters, maybe your VTEC solenoid is defective. with trying to be an ******* you should really have someone look at it for. AEM I think can also be programmed to use the MIL/CEL light as a shift light doe sit always come on at certain RPM???? check for code. as for your AF ;
there are a 1000different AFs in your computer. they are based on things such as TPS, MAP - engine load and rpm. lets say you are cruising in vtec at 7000rpm and 20%TPS with 0PSI boost that is a stoicher (is that a word) AF than 7000RPM with with 100%TPS and 20PSI boost, thats why you have fuel maps. I hope you dont have just a WOT fuel map.</TD></TR></TABLE>


Did whoever tuned your car first tune the low cam, then the high cam...? If not, your problem may reside there... They should've first tuned the low cam, then tuned the high cam, examine their curves, find where they cross and make that rpm your VTEC engagment point...

 

ok, aftering talking to a friend about it and also considering all the above posts....

ever since i installed my turbo, VTEC never worked. even with the stock ECU (for approx 6 months). and just like you explained, it would go through the RPMs, but it won't produce the extra power at VTEC.

my engine oil light on the dash turns off after the engine is started so it sounds like it works. other than oil level, does that also check for pressure too? if it does, i don't think it's the sensor or a pressure issue.

but regardless, i will check the oil pressure sensor for physical damage. also, where exactly is the VTEC solenoid and/or sensor? i can't find it in the Helms manual.

-ray

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cowboy &raquo;</TD></TR><TR><TD CLASS="quote">i have a turbo h22a, and i've dyno'ed the car. the graph shows a significant dip at 5200.
</TD></TR></TABLE>

this tells me you have vtec working, b/c this is sign of the vtec crossover. i dip in power followed by more gain in hp... if vtec didn't engage then you would see a smooth hp curve without any sudden dips in dyno curve

 

The oil pressure light on the dash only comes on below 5psi anyway, its like a really too late if that come son when your driving.

The VTEC oil pressure sensor is something different to the oil pressure switch

Where is you oil line coming from?

 

the oil light comes on when the key is in on position, then turns off when engine starts. i believe that's normal

the oil light never comes on whether i'm in boost or vac.

my oil line for the turbo comes from the oil pressure sensor behind the block & below the oil filter

-ray

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaxSterling &raquo;</TD></TR><TR><TD CLASS="quote">

this tells me you have vtec working, b/c this is sign of the vtec crossover. i dip in power followed by more gain in hp... if vtec didn't engage then you would see a smooth hp curve without any sudden dips in dyno curve</TD></TR></TABLE>

i don't have a dip in my dyno graph around where vtec suppose to engage, does it mean my vtec is not working? by the way, i'm using the vafc hack for fuel management.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4U2NV &raquo;</TD></TR><TR><TD CLASS="quote">

They should've first tuned the low cam, then tuned the high cam, examine their curves, find where they cross and make that rpm your VTEC engagment point... </TD></TR></TABLE>


Did you know that ALL dyno graphs cross at 5252rpm. Doesn't matter what power you are making, it how the hp is calculated from the torque is why it always crosses there

 

bump, I'd like to know if anyone else has got some light on this.

 

i don't really have much to offer on y vtec is not engaging, other than that oil pressure and coolant temp are 2 big factors...i jsut finished putting a turbo on my eg with a gsr and it seems that my oil pressure does not get as high as when i was na...used to run about 75-80psi on my gauge and now it runs like 50-60 psi...oil feed is t'd off the oil pressure sender...still tuning the car so i don't know if vtec is engaging, but the times that i have gotten the revs up high enough the apex vafcII light changed color indicating vtec...will get back with info...right now wastegate has a 10 psi spring in it and i don't wanna boost that high...so i can't even get on the throttle without boost rocketting up to 10 psi...

sorry i can't really help much...good luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dbang003 &raquo;</TD></TR><TR><TD CLASS="quote">i don't really have much to offer on y vtec is not engaging, other than that oil pressure and coolant temp are 2 big factors...i jsut finished putting a turbo on my eg with a gsr and it seems that my oil pressure does not get as high as when i was na...used to run about 75-80psi on my gauge and now it runs like 50-60 psi...oil feed is t'd off the oil pressure sender...still tuning the car so i don't know if vtec is engaging, but the times that i have gotten the revs up high enough the apex vafcII light changed color indicating vtec...will get back with info...right now wastegate has a 10 psi spring in it and i don't wanna boost that high...so i can't even get on the throttle without boost rocketting up to 10 psi...

sorry i can't really help much...good luck</TD></TR></TABLE>


It takes at least 55psi of oil pressure to activate VTEC...