b.o.v. problem???

mastergrader007 · 05-12-2008, 12:27 AM

Hi,
I just bought an 88 supra turbo from a friend with the JDM 7mgte engine. it is all stock and running strong. my question is, i had shimmed the wastegate and than realized i couldnt hear the b.o.v. when i shifted gears. this made me nervous so i took out the shims but i still can't hear it let the pressure go. is this normal?? i have never owned a turbo before and im a little nervous. also, how far should the needle go on the boost gauge?? as in PSI? just wanna make sure everything is working proper.. thanks

OH, forgot to mention, my gauge goes from -2 up to +4 mmhg (whatever that means)! and my boost is half way between 0 and +4 at best
please help me!!!

mastergrader007 · 05-12-2008, 04:05 PM

Hello,
Just wondering if anyone here uses this site??? where is everyone??? i have a problem and im looking for some help here please

Bill UK · 05-12-2008, 07:49 PM

First of all you shouldn’t hear the Bov vent, the supra is fitted with a recirculating Bov and doesn’t vent to atmosphere, to test the stock Bov;remove it from the car and blow down the main large ? hole, you shouldn’t be able to feel any air passing through to the other large ? hole. (You will need to establish if you have a stock Bov first)
Not sure of the stock psi mine goes to the max on the stock gauge, and 10 psi on my extra boost gauge. The only mods are shimmed wastegate (3 washers) and front cat removed. If I remove the second cat the boost goes up to 14 psi and I hits fuel cut-out.

mastergrader007 · 05-12-2008, 10:09 PM

thank you very much for your help. i was beginning to think that this forum was a ghost town or something. lol. yes its a stock bov and i guess i can re-shim my wastegate then! awesome. thanks again

Blake

ps. i just bought this supra and there is no exhaust on it yet. would this cause a lack of boost pressure??

edmonton · 06-29-2008, 05:02 PM

Quote:

Originally Posted by Bill UK

First of all you shouldn’t hear the Bov vent, the supra is fitted with a recirculating Bov and doesn’t vent to atmosphere, to test the stock Bov;remove it from the car and blow down the main large ? hole, you shouldn’t be able to feel any air passing through to the other large ? hole. (You will need to establish if you have a stock Bov first)
Not sure of the stock psi mine goes to the max on the stock gauge, and 10 psi on my extra boost gauge. The only mods are shimmed wastegate (3 washers) and front cat removed. If I remove the second cat the boost goes up to 14 psi and I hits fuel cut-out.

is it possible to buy an aftermarket bov that vents to atmosphere then maybe just plug the hole where the stock bov recirculates too?

SideWinderGX · 06-30-2008, 02:59 AM

Quote:

Originally Posted by edmonton

is it possible to buy an aftermarket bov that vents to atmosphere then maybe just plug the hole where the stock bov recirculates too?

While this would technically work, the supra meters *all* the air that enters the engine. When air is released when you shift and vented to the atmosphere, the engine thinks its still in the engine...which will cause it to run very rich. the car will still run, but not as well.

edmonton · 06-30-2008, 05:51 AM

Quote:

Originally Posted by SideWinderGX

While this would technically work, the supra meters *all* the air that enters the engine. When air is released when you shift and vented to the atmosphere, the engine thinks its still in the engine...which will cause it to run very rich. the car will still run, but not as well.

then would you have to buy a computer to tune the air/fuel mixture or is the vented air so small it doesn't matter? what have other people done that added after market blow off valves? thanks

dupra87 · 10-20-2009, 03:06 AM

i have just done the same thing. but i bought a cheap one. bad choice. spend the money and get a good one. my car dies if i dont have the pressure all the way on. its like i dont even have it. so in short dont be cheap buy a nice one

cre · 10-20-2009, 03:30 AM

Some people suck it up that a BOV is going to screw up their performance between shifts, others buys a piggyback that will allow them to tune for it and others buy a BPV or a BOV with a BPV attachment (BPV = bypass valve, these are the ones which, like the stocker, dump back into the intake).

05-12-2008, 12:27 AM	#1
mastergrader007 3" Exhaust Join Date: May 2008 Location: Ontario, Canada Posts: 79	b.o.v. problem??? Hi, I just bought an 88 supra turbo from a friend with the JDM 7mgte engine. it is all stock and running strong. my question is, i had shimmed the wastegate and than realized i couldnt hear the b.o.v. when i shifted gears. this made me nervous so i took out the shims but i still can't hear it let the pressure go. is this normal?? i have never owned a turbo before and im a little nervous. also, how far should the needle go on the boost gauge?? as in PSI? just wanna make sure everything is working proper.. thanks OH, forgot to mention, my gauge goes from -2 up to +4 mmhg (whatever that means)! and my boost is half way between 0 and +4 at best please help me!!! Last edited by mastergrader007; 05-12-2008 at 01:36 AM.

05-12-2008, 04:05 PM	#2
mastergrader007 3" Exhaust Join Date: May 2008 Location: Ontario, Canada Posts: 79	anybody use this site? Hello, Just wondering if anyone here uses this site??? where is everyone??? i have a problem and im looking for some help here please

05-12-2008, 10:09 PM	#4
mastergrader007 3" Exhaust Join Date: May 2008 Location: Ontario, Canada Posts: 79	thank you thank you very much for your help. i was beginning to think that this forum was a ghost town or something. lol. yes its a stock bov and i guess i can re-shim my wastegate then! awesome. thanks again Blake ps. i just bought this supra and there is no exhaust on it yet. would this cause a lack of boost pressure??

10-20-2009, 03:06 AM	#8
dupra87 Intake Join Date: Sep 2009 Location: fl Posts: 35	reply i have just done the same thing. but i bought a cheap one. bad choice. spend the money and get a good one. my car dies if i dont have the pressure all the way on. its like i dont even have it. so in short dont be cheap buy a nice one

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05-12-2008, 07:49 PM	#3
Bill UK AEM EMS Join Date: Jul 2006 Location: UK Posts: 891	First of all you shouldn’t hear the Bov vent, the supra is fitted with a recirculating Bov and doesn’t vent to atmosphere, to test the stock Bov;remove it from the car and blow down the main large ? hole, you shouldn’t be able to feel any air passing through to the other large ? hole. (You will need to establish if you have a stock Bov first) Not sure of the stock psi mine goes to the max on the stock gauge, and 10 psi on my extra boost gauge. The only mods are shimmed wastegate (3 washers) and front cat removed. If I remove the second cat the boost goes up to 14 psi and I hits fuel cut-out.

10-20-2009, 03:30 AM	#9
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Some people suck it up that a BOV is going to screw up their performance between shifts, others buys a piggyback that will allow them to tune for it and others buy a BPV or a BOV with a BPV attachment (BPV = bypass valve, these are the ones which, like the stocker, dump back into the intake).