How much boost can an Evo VIII run???
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Newbie
Joined: Aug 2003
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From: Seal Beach, CA
How much boost can an Evo VIII run???
Hey gang,
I know the Evo's come at 19.5 from the factory. I'm wondering what's the hold up from going higher. Is it the turbo itself? CR? Engine?
How high can you go, and with what parts? Just curious. Thanks!
I know the Evo's come at 19.5 from the factory. I'm wondering what's the hold up from going higher. Is it the turbo itself? CR? Engine?
How high can you go, and with what parts? Just curious. Thanks!
well, just to give you an idea, the dealership was working on my car for a long *** time due to some boost problems, when they finally got it fixed it ran about 22psi, and my friend (the evo tech) talked to the fuel engineer and said the car would be fine at 22psi on 91 octane.. hope that helps
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Joined: Jul 2003
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From: San Diego
Originally posted by hel_if_ino
well, just to give you an idea, the dealership was working on my car for a long *** time due to some boost problems, when they finally got it fixed it ran about 22psi, and my friend (the evo tech) talked to the fuel engineer and said the car would be fine at 22psi on 91 octane.. hope that helps
well, just to give you an idea, the dealership was working on my car for a long *** time due to some boost problems, when they finally got it fixed it ran about 22psi, and my friend (the evo tech) talked to the fuel engineer and said the car would be fine at 22psi on 91 octane.. hope that helps
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Originally posted by DrMerl
Simply by upping the boost? What makes the Mitsu ECU different from the Subaru ECU in that if you fiddle with boost the computer wont go nuts trying to reel things back in (timing/mixture) and drivability sucks - not to mention running lean up top, on a supposedly super rich WRX, when going from 14 to 16PSI. I think if it were that easy wouldnt all the big tuners just sell you a MBC for $50 and be done with it?
Simply by upping the boost? What makes the Mitsu ECU different from the Subaru ECU in that if you fiddle with boost the computer wont go nuts trying to reel things back in (timing/mixture) and drivability sucks - not to mention running lean up top, on a supposedly super rich WRX, when going from 14 to 16PSI. I think if it were that easy wouldnt all the big tuners just sell you a MBC for $50 and be done with it?
Originally posted by chinalfr
I have run as high as 1.6 bars. No problem whatsoever. But I'm now running average 1.4-1.5 bars.
1 bar = 14.5 psi.
I have run as high as 1.6 bars. No problem whatsoever. But I'm now running average 1.4-1.5 bars.
1 bar = 14.5 psi.
Thread Starter
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Joined: Aug 2003
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From: Seal Beach, CA
14.508 psi = 1 Bar.
That's the typical used figure anyway.
As far as the Subaru/Mitsu ECU's are concerned...
"What makes the Mitsu ECU different from the Subaru ECU in that if you fiddle with boost the computer wont go nuts trying to reel things back in (timing/mixture) and drivability sucks..."
I find this hard to believe. If my 13-year old Digifant-1 ECU can compensate for changes in boost of over 60% (from 8.3 to 20 psi), then I see no reason why a state-of-the-art ECU can't handle a difference of 3 or 4 psi. The computer doesn't "go nuts" trying to adjust the timing and mixture...that's the WHOLE PURPOSE of the ECU to begin with! It's SUPPOSED to adjust those things to compensate for boost, temperature, octane, etc. to keep the car running right and from detonating itself.
That's the typical used figure anyway.
As far as the Subaru/Mitsu ECU's are concerned...
"What makes the Mitsu ECU different from the Subaru ECU in that if you fiddle with boost the computer wont go nuts trying to reel things back in (timing/mixture) and drivability sucks..."
I find this hard to believe. If my 13-year old Digifant-1 ECU can compensate for changes in boost of over 60% (from 8.3 to 20 psi), then I see no reason why a state-of-the-art ECU can't handle a difference of 3 or 4 psi. The computer doesn't "go nuts" trying to adjust the timing and mixture...that's the WHOLE PURPOSE of the ECU to begin with! It's SUPPOSED to adjust those things to compensate for boost, temperature, octane, etc. to keep the car running right and from detonating itself.
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Joined: Mar 2003
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From: Sarasota
Originally posted by DrMerl
Simply by upping the boost? What makes the Mitsu ECU different from the Subaru ECU in that if you fiddle with boost the computer wont go nuts trying to reel things back in (timing/mixture) and drivability sucks - not to mention running lean up top, on a supposedly super rich WRX, when going from 14 to 16PSI. I think if it were that easy wouldnt all the big tuners just sell you a MBC for $50 and be done with it?
Simply by upping the boost? What makes the Mitsu ECU different from the Subaru ECU in that if you fiddle with boost the computer wont go nuts trying to reel things back in (timing/mixture) and drivability sucks - not to mention running lean up top, on a supposedly super rich WRX, when going from 14 to 16PSI. I think if it were that easy wouldnt all the big tuners just sell you a MBC for $50 and be done with it?
Have you ever tried to use a S-AFC or a GReddy E-Manage on a Subaru ECU??? It doesn't work out too good.
From my results on the dyno, the evo ECU will pull timing and make the car run very rich with higher boost. This doesn't mean that more power can't be had. For example, back when a ebc and cat-back were my only mods, I made 232 whp at 19.5 psi, and 248 whp at 22.1 psi. However, bigger power gains can be had with "leaner" fuel mapping ... opposed to just upping the boost, since only upping the boost will cause an "overly rich" condition.
The best thing to do IMHO is to run as lean as safely possible with as much boost that is safely possible ... this can be attained on dyno w/ wideband 02.
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Joined: Jul 2003
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From: San Diego
Originally posted by evo1
Have you ever tried to use a S-AFC or a GReddy E-Manage on a Subaru ECU??? It doesn't work out too good.
From my results on the dyno, the evo ECU will pull timing and make the car run very rich with higher boost. This doesn't mean that more power can't be had. For example, back when a ebc and cat-back were my only mods, I made 232 whp at 19.5 psi, and 248 whp at 22.1 psi. However, bigger power gains can be had with "leaner" fuel mapping ... opposed to just upping the boost, since only upping the boost will cause an "overly rich" condition.
The best thing to do IMHO is to run as lean as safely possible with as much boost that is safely possible ... this can be attained on dyno w/ wideband 02.
Have you ever tried to use a S-AFC or a GReddy E-Manage on a Subaru ECU??? It doesn't work out too good.
From my results on the dyno, the evo ECU will pull timing and make the car run very rich with higher boost. This doesn't mean that more power can't be had. For example, back when a ebc and cat-back were my only mods, I made 232 whp at 19.5 psi, and 248 whp at 22.1 psi. However, bigger power gains can be had with "leaner" fuel mapping ... opposed to just upping the boost, since only upping the boost will cause an "overly rich" condition.
The best thing to do IMHO is to run as lean as safely possible with as much boost that is safely possible ... this can be attained on dyno w/ wideband 02.
I do feel better now that data has been given to support a response and it sounds reasonable. From what it sounds like the stock fuel injectors have enough PW for the ECU to compensate, also sounds like the stock turbo starts to get inefficient around 21-22psi. Is part throttle response still as nice as at factory boost? Thanx
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From: van
now for example: 2003 evo8, after market: Upgraded Greddy exhaust, upgraded K&N intake, Greddy oil catch can, HKS cam gears and cams, upgraded clutch, APEXI AFC and Electronic boost controller custom mounted, HKS Blow off valve, Aluminum turbo header cover, upgraded intercooler, very quick 340HP.
with these types of mods what kind of boost should it be running... safely? im not sure as to what boost it is running now do it not being mine yet haha
with these types of mods what kind of boost should it be running... safely? im not sure as to what boost it is running now do it not being mine yet haha
now for example: 2003 evo8, after market: Upgraded Greddy exhaust, upgraded K&N intake, Greddy oil catch can, HKS cam gears and cams, upgraded clutch, APEXI AFC and Electronic boost controller custom mounted, HKS Blow off valve, Aluminum turbo header cover, upgraded intercooler, very quick 340HP.
with these types of mods what kind of boost should it be running... safely? im not sure as to what boost it is running now do it not being mine yet haha
with these types of mods what kind of boost should it be running... safely? im not sure as to what boost it is running now do it not being mine yet haha