1988 SC Blow off Valve Addon What one/how to - Toyota Nation Forum : Toyota Car and Truck Forums

4-AGZE · 02-11-2005, 08:35 PM

Im looking to put on a new blow off valve on my 1988 MKI AW11 MR2. The stock one is letting the pressure off too early, and not letting enough build up in the first place. With the engine parts allready on it, i should be boosting over 14, yet am only reading 10 on the meter.

What most concerns me about replacing the stock blow off valve is that it ISNT just a blow off valve, its a ABV (air bypass valve), bypassing air away from the SC when it isnt spinning. I want to know how i can retain the feature of not having the sc allways on, and also put in a new BOV.

Thanks

***MR2Jedi*** · 02-11-2005, 08:42 PM

you'll have to be a paid subscriber to put a picture there. as far as your supercharger. i thought when the engine was running, the supercharger was running too. driven by a belt from the crank..?

4-AGZE · 02-14-2005, 11:43 PM

No, the supercharger isnt allways running, its controlled by an electronic clutch only engaging at 25% throttle and higher.

Does ANYONE know how to/what to do....

***MR2Jedi*** · 02-14-2005, 11:53 PM

hhhmm? I didn't know that. thanks for setting me straight.. I've been unsuccessfully trying to put a pic on here too...

projektfushun · 02-17-2005, 03:03 AM

I also want to know how to add a BOV to mu supercharged mr2. How would it be done? I love th sound of a BOV and i want it in da MR2 but i don't know how. I heard it's doable.

projektfushun · 02-17-2005, 03:20 AM

also for my stock mr2 supercharger is it a centrifugal-style supercharger? Im learning more and more and just wanna get things stright

***MR2Jedi*** · 02-17-2005, 08:53 PM

just replace your stock bypass valve with an aftermarket BOV. u may need an adapter.. nothin' to it...

projektfushun · 02-18-2005, 12:23 AM

will i lose horsepower or anything if i do ass the BOV and where do i look for a BOV to fit my ride?

***MR2Jedi*** · 02-18-2005, 12:37 AM

I wouldn't say that BOV's are for HP gains, but to release unused turbo boost when you let off the gas. your stock bypass probably works better and is more reliable that an aftermarket one. i have a TurboXS BOV on my MR2 T. and i really like it but some times I find it annoying. especailly on a date. I have been thinking about switching back to my stock one and venting it to atmosphere..I dunna no...

projektfushun · 02-18-2005, 01:29 AM

hmm i like it cuz of the sound, so i have a supercharger and i remove the ABV and connect the BOv in place of where the ABV was? Im new to this i want to mod this to werk. I been looking @ BOV's online and i noticed they have 3 openingz, 2 big ones and a lil tip @ da top?

***MR2Jedi*** · 02-18-2005, 09:23 AM

there are all kinds/shapes/sizes/loudness/colors.. HKS, TurboXS,APEXi,and the list goes on. the BOV is installed on hot pipe between turbo/supercharger and intercooler.

toyotaspeed90 · 02-18-2005, 04:12 PM

wow... some misinformation here

14psi is pretty hard to hit....especially on a stock s/c pulley that was meant for 7psi... people who do the abv bypass mod and have the nevo pulley are still barely registering over 12psi.... depends on what you've done to yours that makes you think you should be that high... most manufacturer's aren't correct....

the s/c is a roots blower

the s/c turns on and off via an electromagnetic clutch.... the ecu controls it (unless like me you're using an aftermarket ecu and have it on a switch)

nobody that i've seen on mr2oc have added a bov.....

***MR2Jedi*** · 02-18-2005, 04:39 PM

I have no expereince with SC's. But don't see any reason offhand that they couldn't use a BOV. given the fact that U don't know anyone thats using BOV there must be some reason for that? just for my own education...thnx

4-AGZE · 02-22-2005, 01:44 AM

You're absolutely right about the operation of the electro-magnetic clutch, I definently made a mistake saying it was controlled by throttle position.

I have the cusco pulley, which at the time of purchase was reputed to be the highest-boosting pulley around at 14 psi.

I phrased my querry incorrectly saying that i wanted a new BOV, really all i want is to have the pressure not be released so early. If thats with a new blow off valve, thats great, if its with a roll of duct tape, thats great too, i care far more about the performance than the appearance and sound.

feral4.mr2 · 03-21-2005, 12:41 AM

a BOV does not work on a 4agze system. the s/c is on the vacum side of your throttle body. so if you put a BOV where the ABV is you will be sucking unfiltered air into your engine, not venting boost air out.
4-agze, what size crank pulley do you have thats spose to push over 14psi?