WTF cant boost past 25 psi HELP
mods list
2003 evo 8 5 speed
revolver cams
pro street cam gears
supertech dual valve springs, seats, retainers
gates timeing belt
full 3'' tbe no cat
works o2 housing
b/r ported 10.5 hotside
b/r ported stack exhaust manifold
forge waste gate red spring
hks RS intake
nisei upper and lower icp
hyperflow fmic
aps bov
forge unos mbc heavy spring
b/r ported throttle body
b/r ported stock intake manifold
coolingmist meth kit with veri cool and pda
walbro 255 fuel pump
arp head studs
exedy twin HD
tuning
stock ecu
evoscan
ecuflash
innovate wideband
defi boost gauge
defi egt gauge tap at second runner on manifold
defi water temp
defi oil pressure
jdm map sensor to log boost
laptop for loging
jestr for the tunes
there you have it. almost every single mod i have.
i always run 93 oct at 23.5 spike psi
i USED to run 100 oct at 27 too 28 psi maby 2 times a munth
munths later i got meth. i never touch'd any settings on anything..and when i started to tune for meth boost would not go past 25 psi. and here i am today.
2003 evo 8 5 speed
revolver cams
pro street cam gears
supertech dual valve springs, seats, retainers
gates timeing belt
full 3'' tbe no cat
works o2 housing
b/r ported 10.5 hotside
b/r ported stack exhaust manifold
forge waste gate red spring
hks RS intake
nisei upper and lower icp
hyperflow fmic
aps bov
forge unos mbc heavy spring
b/r ported throttle body
b/r ported stock intake manifold
coolingmist meth kit with veri cool and pda
walbro 255 fuel pump
arp head studs
exedy twin HD
tuning
stock ecu
evoscan
ecuflash
innovate wideband
defi boost gauge
defi egt gauge tap at second runner on manifold
defi water temp
defi oil pressure
jdm map sensor to log boost
laptop for loging
jestr for the tunes
there you have it. almost every single mod i have.
i always run 93 oct at 23.5 spike psi
i USED to run 100 oct at 27 too 28 psi maby 2 times a munth
munths later i got meth. i never touch'd any settings on anything..and when i started to tune for meth boost would not go past 25 psi. and here i am today.
I can't figure it out. I played with the waste gate more and the mbc. Did a boost leak test 836 times. I have no idea.
Could it be the jdm map sensor?? Probly the dumb question of the munth but whatelse do I got
Could it be the jdm map sensor?? Probly the dumb question of the munth but whatelse do I got
i dont get it. its fine now. boosting 28 psi. wtf is up with this thing.
last nite at the track it was not boosting for **** 25psi.
today i take it for a ride and im getting 28+ psi. i dont get it.
last nite at the track it was not boosting for **** 25psi.
today i take it for a ride and im getting 28+ psi. i dont get it.
Does the APS BOV vent to atmosphere or does it recirculate? Have you tried another, proven good DV that is recirculating type, but of a different brand?
I don´t see a heavy duty WGA listed in your mods. Are you still on the stock WGA?
Where are you getting the boost reference from? Are you taking it off the compressor housing discharge nipple or a "T" from the intake/BOV line?
Did you completely eliminate the factory vacuum lines and restrictors, plug off the open ports and leave the BCS electrical harness plugged in?
Are you running 4mm vacuum hose directly from either a "T" sourced from the BOV/intake manifold line, or directly from the comp hsg discharge nipple to the bottom port on your MBC? And then another, second 4mm hose directly from the side port on your MBC, to the port on your WGA. All hoses should be tightly secured with zip ties.
When you say that your WGA is adjusted fully tight, what do you mean exactly? Maybe you should go back to step one: That is, Turn your MBC to full soft, loosen the turnbuckle by rotating it counterclockwise until it just freely slips on and off the peg on the flapper valve and take your car for a WOT run in 4th gear. Your Base WG pressure shoukld be about 11 PSI.
From this base WG setting, shorten the actuator rod two complete 360* turns. Take it for another WOT run. Boost should be up around the 13-15 PSI range. Then give the turnbuckle another 2 full turns and retest(be sure to let it cool down before messing with it). You should now be up around 17 PSI. From this point only increase by 1 turn increments till you finally arrive at a preload of about 21-22 PSI. From that point on up, then start using your MBC to dial in the last few pounds of boost.
If you are running a stock WGA then I wouldn´t trymore than 22 PSI preload as the stock one gets iffy above 21 PSI. You need a Heavy Duty WGA if you´re gonna be running Alky and 28 PSI. The stock WGA just doesn´t cut it. If you are using the stock WGA, then that could be your problem.
I don´t see a heavy duty WGA listed in your mods. Are you still on the stock WGA?
Where are you getting the boost reference from? Are you taking it off the compressor housing discharge nipple or a "T" from the intake/BOV line?
Did you completely eliminate the factory vacuum lines and restrictors, plug off the open ports and leave the BCS electrical harness plugged in?
Are you running 4mm vacuum hose directly from either a "T" sourced from the BOV/intake manifold line, or directly from the comp hsg discharge nipple to the bottom port on your MBC? And then another, second 4mm hose directly from the side port on your MBC, to the port on your WGA. All hoses should be tightly secured with zip ties.
When you say that your WGA is adjusted fully tight, what do you mean exactly? Maybe you should go back to step one: That is, Turn your MBC to full soft, loosen the turnbuckle by rotating it counterclockwise until it just freely slips on and off the peg on the flapper valve and take your car for a WOT run in 4th gear. Your Base WG pressure shoukld be about 11 PSI.
From this base WG setting, shorten the actuator rod two complete 360* turns. Take it for another WOT run. Boost should be up around the 13-15 PSI range. Then give the turnbuckle another 2 full turns and retest(be sure to let it cool down before messing with it). You should now be up around 17 PSI. From this point only increase by 1 turn increments till you finally arrive at a preload of about 21-22 PSI. From that point on up, then start using your MBC to dial in the last few pounds of boost.
If you are running a stock WGA then I wouldn´t trymore than 22 PSI preload as the stock one gets iffy above 21 PSI. You need a Heavy Duty WGA if you´re gonna be running Alky and 28 PSI. The stock WGA just doesn´t cut it. If you are using the stock WGA, then that could be your problem.
Does the APS BOV vent to atmosphere or does it recirculate? Have you tried another, proven good DV that is recirculating type, but of a different brand?
no i have not
I don´t see a heavy duty WGA listed in your mods. Are you still on the stock WGA?
yes its in there forge waste gate with red spring
Where are you getting the boost reference from? Are you taking it off the compressor housing discharge nipple or a "T" from the intake/BOV line?
i tapped the fpr for boost reading
Did you completely eliminate the factory vacuum lines and restrictors, plug off the open ports and leave the BCS electrical harness plugged in?
yes
Are you running 4mm vacuum hose directly from either a "T" sourced from the BOV/intake manifold line, or directly from the comp hsg discharge nipple to the bottom port on your MBC? And then another, second 4mm hose directly from the side port on your MBC, to the port on your WGA. All hoses should be tightly secured with zip ties.
im running the waste gate to the side of the mbc and the turbo comp line to the bottom
When you say that your WGA is adjusted fully tight, what do you mean exactly? Maybe you should go back to step one: That is, Turn your MBC to full soft, loosen the turnbuckle by rotating it counterclockwise until it just freely slips on and off the peg on the flapper valve and take your car for a WOT run in 4th gear. Your Base WG pressure shoukld be about 11 PSI.
its a forege waste gate. with a so called red 19 to 24 psi pring. its full tight. meaning i had to pull it up to get it on the waste gate flapper. i hit 18psi..
From this base WG setting, shorten the actuator rod two complete 360* turns. Take it for another WOT run. Boost should be up around the 13-15 PSI range. Then give the turnbuckle another 2 full turns and retest(be sure to let it cool down before messing with it). You should now be up around 17 PSI. From this point only increase by 1 turn increments till you finally arrive at a preload of about 21-22 PSI. From that point on up, then start using your MBC to dial in the last few pounds of boost.
i used my mbc once the waste gate would not run more boost. at that point the car was fine. but then went back to doing this again..
If you are running a stock WGA then I wouldn´t trymore than 22 PSI preload as the stock one gets iffy above 21 PSI. You need a Heavy Duty WGA if you´re gonna be running Alky and 28 PSI. The stock WGA just doesn´t cut it. If you are using the stock WGA, then that could be your problem.
no i have not
I don´t see a heavy duty WGA listed in your mods. Are you still on the stock WGA?
yes its in there forge waste gate with red spring
Where are you getting the boost reference from? Are you taking it off the compressor housing discharge nipple or a "T" from the intake/BOV line?
i tapped the fpr for boost reading
Did you completely eliminate the factory vacuum lines and restrictors, plug off the open ports and leave the BCS electrical harness plugged in?
yes
Are you running 4mm vacuum hose directly from either a "T" sourced from the BOV/intake manifold line, or directly from the comp hsg discharge nipple to the bottom port on your MBC? And then another, second 4mm hose directly from the side port on your MBC, to the port on your WGA. All hoses should be tightly secured with zip ties.
im running the waste gate to the side of the mbc and the turbo comp line to the bottom
When you say that your WGA is adjusted fully tight, what do you mean exactly? Maybe you should go back to step one: That is, Turn your MBC to full soft, loosen the turnbuckle by rotating it counterclockwise until it just freely slips on and off the peg on the flapper valve and take your car for a WOT run in 4th gear. Your Base WG pressure shoukld be about 11 PSI.
its a forege waste gate. with a so called red 19 to 24 psi pring. its full tight. meaning i had to pull it up to get it on the waste gate flapper. i hit 18psi..
From this base WG setting, shorten the actuator rod two complete 360* turns. Take it for another WOT run. Boost should be up around the 13-15 PSI range. Then give the turnbuckle another 2 full turns and retest(be sure to let it cool down before messing with it). You should now be up around 17 PSI. From this point only increase by 1 turn increments till you finally arrive at a preload of about 21-22 PSI. From that point on up, then start using your MBC to dial in the last few pounds of boost.
i used my mbc once the waste gate would not run more boost. at that point the car was fine. but then went back to doing this again..
If you are running a stock WGA then I wouldn´t trymore than 22 PSI preload as the stock one gets iffy above 21 PSI. You need a Heavy Duty WGA if you´re gonna be running Alky and 28 PSI. The stock WGA just doesn´t cut it. If you are using the stock WGA, then that could be your problem.
i replyed to each one of your ideas and info.
its odd. if i do a 3rd gear pull only like as if im logging the car i hit 28psi strong.
if im at the track or do a 1 2 3 4 gear pull i peak at 25 psi. i cant get it to boost any higher.
then ill go do a log again in 3rd gear and ill hit 28 psi no problem.
this is my problem now. normal or no????????
ok i spoke to someone on this. seems its normal. it makes sence to me so my problem is normal. thanks all and thanks for sparky getting me to get the car to boost right when it was wrong to begin with.
That "someone" must be a smart guy!!! 
This is simply a matter of boost taper. You hit peak boost at lower rpms in the 3500-4000rpm area. You never get below 5500rpm in a drag run. From 4000-5500rpm, you obviously taper to 25 or so. The stock turbo isn't going to sustain a flat 28psi all the way to 5500rpm and beyond...
This is simply a matter of boost taper. You hit peak boost at lower rpms in the 3500-4000rpm area. You never get below 5500rpm in a drag run. From 4000-5500rpm, you obviously taper to 25 or so. The stock turbo isn't going to sustain a flat 28psi all the way to 5500rpm and beyond...
That "someone" must be a smart guy!!!
This is simply a matter of boost taper. You hit peak boost at lower rpms in the 3500-4000rpm area. You never get below 5500rpm in a drag run. From 4000-5500rpm, you obviously taper to 25 or so. The stock turbo isn't going to sustain a flat 28psi all the way to 5500rpm and beyond...
This is simply a matter of boost taper. You hit peak boost at lower rpms in the 3500-4000rpm area. You never get below 5500rpm in a drag run. From 4000-5500rpm, you obviously taper to 25 or so. The stock turbo isn't going to sustain a flat 28psi all the way to 5500rpm and beyond...
lol
thanks
see i know it tappers down a bit but i thought it would still spike to your boost level and then tapper. since its at higher rpm i thought since your WOT in ev ery gear running the ***** off the car i thought it would just tapper faster up top since the turbo cant keep up. but still hit that peak boost level. owell
another funny thing was last night i did 12.2 with a 1.65 60 foot at 110mph.
my best run months ago was 12.1 at 116 mph with a 1.79 60 foot. odd. owell turbo kit is on the way. i was just hoping to get a good few runs in and then do the upgrade kit and see my differences. thanks again
That "someone" must be a smart guy!!!
This is simply a matter of boost taper. You hit peak boost at lower rpms in the 3500-4000rpm area. You never get below 5500rpm in a drag run. From 4000-5500rpm, you obviously taper to 25 or so. The stock turbo isn't going to sustain a flat 28psi all the way to 5500rpm and beyond...
This is simply a matter of boost taper. You hit peak boost at lower rpms in the 3500-4000rpm area. You never get below 5500rpm in a drag run. From 4000-5500rpm, you obviously taper to 25 or so. The stock turbo isn't going to sustain a flat 28psi all the way to 5500rpm and beyond...
Do you mean that the turnbuckle won't turn in any further because it is bottoming out on the actuator rod? This can happen with the Forge WGA's for the VIII in certain applications. Remember that it does double duty on both the 9.8 as well as the dimensionally distinct 10.5 turbine housings.
For this reason, the actuator rod has an extra long threaded end section on it. If the tip of the rod bottoms out inside the turnbuckle, then the solution is to cut about 1/4-3/8" off the end of it. This should in most cases allow the actuator rod to thread deeper into the turnbuckle, affording a few more PSI of preload.
If indeed you've tightened the turnbuckle down as far as it will go, then talk to Mike at Forge and ask him what he thinks. This might very well be a possible solution allowing a bit more preload to be extracted from the beast.
EDIT: Any of you kids at home trying this just be extra cautious when cutting length off the threaded end of the actuator rod. Remember, this is only needed if you are unable to raise preload further because of actuator rod bottoming out inside the turnbuckle.
Last edited by sparky; May 30, 2007 at 03:47 AM.
Probably Warr's interpretation is right on! However, there remains a seed of doubt in my mind: I just wonder when you say that you have your Forge WGA maxed as tight as it will go, whether or not I'm understanding what you're saying.
Do you mean that the turnbuckle won't turn in any further because it is bottoming out on the actuator rod? This can happen with the Forge WGA's for the VIII in certain applications. Remember that it does double duty on both the 9.8 as well as the dimensionally distinct 10.5 turbine housings.
For this reason, the actuator rod has an extra long threaded end section on it. If the tip of the rod bottoms out inside the turnbuckle, then the solution is to cut about 1/4-3/8" off the end of it. This should in most cases allow the actuator rod to thread deeper into the turnbuckle, allowing for a few more PSI of preload.
If indeed you've tightened the turnbuckle down as far as it will go, then talk to Mike at Forge and ask him what he thinks. This might very well be a possible solution allowing a bit more preload to be extracted from the beast.
EDIT: Any of you kids at home trying this just be extra cautious when cutting length off the threaded end of the actuator rod. Remember, this is only needed if you are unable to raise preload further because of actuator rod bottoming out inside the turnbuckle.
Do you mean that the turnbuckle won't turn in any further because it is bottoming out on the actuator rod? This can happen with the Forge WGA's for the VIII in certain applications. Remember that it does double duty on both the 9.8 as well as the dimensionally distinct 10.5 turbine housings.
For this reason, the actuator rod has an extra long threaded end section on it. If the tip of the rod bottoms out inside the turnbuckle, then the solution is to cut about 1/4-3/8" off the end of it. This should in most cases allow the actuator rod to thread deeper into the turnbuckle, allowing for a few more PSI of preload.
If indeed you've tightened the turnbuckle down as far as it will go, then talk to Mike at Forge and ask him what he thinks. This might very well be a possible solution allowing a bit more preload to be extracted from the beast.
EDIT: Any of you kids at home trying this just be extra cautious when cutting length off the threaded end of the actuator rod. Remember, this is only needed if you are unable to raise preload further because of actuator rod bottoming out inside the turnbuckle.
yes the ajuster (turnbuckle) is bottoning out. i guess i need to cut threads off. that is what i ben saying. its max boost right now on just the waste gate is 18psi. it has the red spring inside the waste gate. from my understanding the red spring is a 19 to 24 psi spring. witch i think is a load of bull now. i have no boost leak and everything else is fine.
If you're gonna attempt this, then I would suggest that you first remove the entire WGA assembly, intact, from your turbo and perform this actuator rod mod on your garage bench. Just remove the cotter pin from the end of the rod and the two bolts that secure the WGA mounting flange onto the compressor housing as well as the vacuum hose and do the job out on the bench.
There is no need to disassemble the WGA. just secure the rod within the vise jaws and perform a clean cut. If you're careful, there should be no need to clean up the threads afterwards. At most you might have to touch up the end thread with a file or a die. But usually the backup nut itself will thread right on there.
I don't remember if I use a hacksaw or some sort of thin, rotary cutoff wheel, but either should work. Just be careful to be ultra consevative and only cutoff about a 1/4" piece and then try it out. If that doesn't get you where you wanna be then perform the operation again, removing another 1/4" from the tip.You don't wanna cut too much off. So, don't be in a rush.
In most cases you won't ever need to remove much more than 3/8 of an inch from the overall length of the actuator rod. So, again...be careful. You may wanna check with Mike first though.
There is no need to disassemble the WGA. just secure the rod within the vise jaws and perform a clean cut. If you're careful, there should be no need to clean up the threads afterwards. At most you might have to touch up the end thread with a file or a die. But usually the backup nut itself will thread right on there.
I don't remember if I use a hacksaw or some sort of thin, rotary cutoff wheel, but either should work. Just be careful to be ultra consevative and only cutoff about a 1/4" piece and then try it out. If that doesn't get you where you wanna be then perform the operation again, removing another 1/4" from the tip.You don't wanna cut too much off. So, don't be in a rush.
In most cases you won't ever need to remove much more than 3/8 of an inch from the overall length of the actuator rod. So, again...be careful. You may wanna check with Mike first though.
Last edited by sparky; May 27, 2007 at 04:59 AM.
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