Control Overboosting with BOV??
02-02-12 | 08:30 AM
#26
‘88 GTU
Joined: Jun 2008
Posts: 249
Likes: 4
From: Denver CO
Technically no, because you haven't gotten rid of the main cat. Freeing up the exhaust flow is the main reason for over boosting. In my personal opinion, you should not have an FCD on this set-up. Fuel cut is there to in a way protect your engine, by cutting fuel to the rear rotor. Some people say that fuel-cut can cause an engine to blow as well though so if you're constantly hitting fuel cut this all needs to be addressed. Regardless, I believe you should remove the FCD until your adding more fuel to the set-up and have a way to monitor it. Also, take your stock turbo out and port out that waste-gate to control boost pressures.
Once again my opinion: Remove FCD immediately, Upon removing the main cat, remove the turbo and port the waste gate to control boost pressure. Re-install Turbo and install cat deletion pipe. Also as an extra safety precaution, it would be a good idea to runner a larger fuel pump because this is by far the weakest link in the fuel system. FD fuel pumps go for around 50$ on here, drop right in, and do the job nicely.
No engine blow!
Once again my opinion: Remove FCD immediately, Upon removing the main cat, remove the turbo and port the waste gate to control boost pressure. Re-install Turbo and install cat deletion pipe. Also as an extra safety precaution, it would be a good idea to runner a larger fuel pump because this is by far the weakest link in the fuel system. FD fuel pumps go for around 50$ on here, drop right in, and do the job nicely.
No engine blow!
Good info there thank you! I'm going to be running a downpipe from RX7store there is no cat I got this car with no engine,I'm installing a JDM replacement thats why I needed to know, do you have a link to the --HOW TO-- on porting the waste gate? I'm not running a boost controller I plan on leaving it up to the turbo.. so I will have the basic mods like I listed then adding some porting to the waste gate and a Walbro 255 hot wired. Sound good? also will have a nice boost gauge and Wideband
I could be wrong though.
02-03-12 | 06:25 AM
#29
Rotard o_O
Joined: Jan 2012
Posts: 34
Likes: 0
From: Jupiter, FL
Then I'm told to get Rtek along with injectors but not sure what size and if its only the secondaries that I need to change? anyone maybe a link to the right size and app for my 88?
02-03-12 | 08:04 AM
#30
Full Member
Joined: Jun 2011
Posts: 149
Likes: 0
From: -
That how to does not mention anything about changing the spring? anyways I just want the car to have bpu's with out turning the boost up no boost controller just stuff to monitor it.. so it will get like I said before boost gauge/AEM wide band, intake,exhaust including downpipe, a hot wired walbro 255, I'm still told even after the turbo is ported it still has the chance to boost creep but not as bad as if it was the stock porting.
Then I'm told to get Rtek along with injectors but not sure what size and if its only the secondaries that I need to change? anyone maybe a link to the right size and app for my 88?
Then I'm told to get Rtek along with injectors but not sure what size and if its only the secondaries that I need to change? anyone maybe a link to the right size and app for my 88?
02-03-12 | 08:22 AM
#31
‘88 GTU
Joined: Jun 2008
Posts: 249
Likes: 4
From: Denver CO
We've had a few discussions on this wastegate malarky over on the MRC site, its worth reading through this thread i've found for you.
02-03-12 | 09:42 AM
#32
Rotard o_O
Joined: Jan 2012
Posts: 34
Likes: 0
From: Jupiter, FL
Depends on what Rtek you will get. http://digitaltuning.com/?pid=rtek7_techinfo
02-03-12 | 12:42 PM
#33
Theoretical Tinkerer
iTrader: (41)
Joined: Oct 2003
Posts: 1,590
Likes: 47
From: Norcal/Bay Area, CA
For a stock turbo up to about 10 psi, I'd say the stock 550's are fine assuming everything else is in good shape. If you want to push it to about 12psi where the stock turbo maxes out, I'd suggest 720 secondaries and an Rtek 1.7.
You can play with the FC fuel calculator to get ideas of injector sizes.
02-03-12 | 01:27 PM
#34
Rotard o_O
Joined: Jan 2012
Posts: 34
Likes: 0
From: Jupiter, FL
You don't need to upgrade the wastegate actuator spring if you're using an external boost controller. If you did upgrade the spring, you wouldn't need a boost controller.
For a stock turbo up to about 10 psi, I'd say the stock 550's are fine assuming everything else is in good shape. If you want to push it to about 12psi where the stock turbo maxes out, I'd suggest 720 secondaries and an Rtek 1.7.
You can play with the FC fuel calculator to get ideas of injector sizes.
For a stock turbo up to about 10 psi, I'd say the stock 550's are fine assuming everything else is in good shape. If you want to push it to about 12psi where the stock turbo maxes out, I'd suggest 720 secondaries and an Rtek 1.7.
You can play with the FC fuel calculator to get ideas of injector sizes.
03-06-12 | 09:45 PM
#36
The adjustment on a BOV is for how responsive it is to opening. It won't open unless it sees a pressure differential on its diaphragm(the reference port). Some of the poorly designed valves begin to leak at higher boost levels, but that won't stop boost creep. The old greddy type-s may have had a provision for being used as a pop-off valve.
uh oh... hmmmmmm this is kind of interesting and i'm wondering if this may be my issue ..
I dropped in a motor into my car . full long block , and i replaced any sketchy hose beforehand . as well as tie wrapped them so they wouldn't fall off .. now I'm having a little issue .
My car wont boost over 6.5 psi (45kps) is power FC speak . now I'm looking for any and all possibilities .. first I'm thinking boost leak .. But whats strange is it makes the 6 psi instantly asoon as I open the throttle its like something is acting as a waste gate or maybe something is opening up after that and just dumping the boost pressure or well it was pointed out to me that thats what the car seems like its dooing .. the car has the stock twins its an FD lol I know itsi n the wrong section but the question is is kind of related . and it has nothing after hte downpipe compleeetely open exhaust .. so if anything ti should be over boosting .. but yet its not..
Then I thought about something when I first installed my greddy elbow ( I bought it used and it came with mr greddy BOV Type-S . and started the car the screw was all the way out and even at idle you could feel that it was releasing air more air when the car was accelerated and let off ofcourse but still some air was bypassing so I tightened the screw and no more air at idle ..
NOW after this issue I'm thinking could the greddy type-S ... be the cause of my boost leak after 6psi??? if I didn't adjust hte bov enough . the stock FD is supposed to boost 10 psi , my power FC has hte boost set at 10 PSI .. so for all intensive purposes lacking another type of boost leak .. could it be that hte BOV is acting as a control and keeping my psi at 6.5?
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