450whp 2.5L AVO600
09-13-2004, 11:12 AM
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Join Date: Nov 2002
Location: Hillsboro, OR
Posts: 25
Car Info: H6-3.0T+GT35R
450whp 2.5L AVO600
Setup:
USDM STI 2.5L Block, stock internals, with two low compression cylinders.
ARP Head Studs, Stock STI Head Gaskets
JDM Version 7 STI RA Spec C Heads and Cams w/ AVCS, 9.5:1 CR.
MRT FMIC,Perrin Intake, custom 3" inlet tube
PE800 Inj, Static FP at 55psi, Boost-A-Pump, -6 Fuel lines, Perrin Rails, Supra Fuel Pump (-1020)
HKS headers, Perrin Uppipe, BPM TT Exhaust
AVO600 Turbocharger in stock location (GT35R based turbo, -14 CHRA) w .86 A/R Turbine housing
JDM Version 7 STI RA Spec C ECU (AG971) with EcuTek Tech Reflash
UTEC w/launch control
STI RA Spec C 6 Speed Transmission, Rear hubs, Diff, etc.
Hyper Single Clutch and Lightweight Flywheel
The usual electronic goodies: AVCR, TunaWB, Knocklink, Gauges, etc.
Tuning Details:
Target Boost ~26psi, no taper at redline
Fuel: VP 103 Unleaded
Dyno: Matrix Mustang Dyno, "Monica".
Calibartion: As per the usual, a stock STI a few days before put down 235whp. This isn't your fathers dynojet.
Tuning Results:
Summary - 451whp at 7250rpm, 352 w torque at 6250rpm. Torque was pretty flat, above 325 lb-ft from 5200 to redline. This is 92% over what a stock STI gets. This is in the 480-500whp dynojet results. I suspect the low side, as to get above 500 dynojet whp, I would proboably need some C16.
The turbo is an AVO600, which is a non-rotated, stock uppipe and downpipe flange turbo. Intake goes under the manifold just like stock. I suspect this might be the highest hp car with a stock mounted turbo (no NOS of course).
As many of you know, I have been purposfully pushing this block to help better understand the limits of the stock STI block. As many other tuner and engine builders have noted, the stock pistons are a significant limit on this block. Even cars with stock turbos have seen failures of the ring landings. For the last two months, I have been pushing as much boost as possible. I have not ran a tank of less than 96 octane in more then two years, so fuel hasn't been the limiting factor. Detonation has been non-existant over this period as well, primarly because of continue tune refinement, and lots of knock detection equipment.
Before the tuning session, I started to experience a few small idle issues, as well as a reduction in vacuume pressure at idle. Typical signs of ring seal issues.
This tuning session started as an attempt to locate the source of a strong oil smell after getting on boost. I've had the AVO600 installed for a couple of months, and have been trying to locate the souce of the smell for some time. I figured the dyno is the best place, since I can stand right over the motor under boost. Sure enough, the dyno was quick to reveal the problem. When lifting the throttle, a huge cloud of oil smoke comes out of the exhaust, and partially out of the intake. This is a result of oil accumulation in the crankcase system at high boost levels, and then being sucked into the manifold via the PCV once you are off boost. The car has been doing this for some time, although on boost pulls shows no oil in the exhaust.
The engine has clearly experienced a failure in the piston/ring seal, as a compression test later highlighted. Since I was already on the dyno, I figured I might as well play around some and see how it would do.
Since I have Spec C heads on an STI 2.5 Block, my compression ratio is somewhere north of 9:1, not ideal for lots of boost. My first pull was at wastegate pressure, so I could check the baseline AFRs. The car put down 330whp, and boost was right around 18psi.
I turned the boost controller on, which was set for 24psi, and the next pull was right at 400whp. A few more pulls with the boost learning a bit more, fixing a few fuel issues, and adding just a touch of timing up top pushed the car to aboug 430whp. Upping the boost just a tad more so it would hold 26psi to redline pushed hp to a bit above 450whp. I did a bunch of pulls at this level, all with similiar results. The motor sounded great, was nice and smooth, and torque delivery was spot on. It really was the eaisiest 450whp I have seen. Engine seems to love the boost, minus the huge oil cloud.
I also did a few quick test with the water injection. With it off, knock activity at very high rpm was occassional, not significant, but more then background. With it on, peak power fell only 8hp, but knock activity was much much quieter. I didn't have time to go back in and tune with it, but the 8hp I suspect would be easy to get back.
Fuel delivery was not a problem. (as it was before). With the Boost-a-pump set to 20%, pump voltage was right about 14.5 volts. Maximum fuel % was around 92% at 8000rpm, with no pressure fall off at fuel pressure levels of 5.5 bar. (80psi).
EGTs were right at 1580. Never peaked over that. I pulled the car off the dyno and drove it home. Pull in 4th was just plain awesome. As for the turbo, there is a lot left to pay with. I had a few pulls with spikes up to 2.0 bar(29psi) above 7k rpm. The turbo has no problem holding boost of at least 26-28psi all the way to 8k rpm. NOS for spoolup would be very helpful.
Last but not least, when I got home, I did a compression check. 140,145,92,71. Two very bad pistons, but boy does the car feel great. Power output was less then I would expect at that boost level, but that is mostly becuase timing was limited because of the stupid high compression ratio. That will be solved shortly.
As per typical, here are a few graphs along with some data analysis:
The dyno was setup to pull only to about 7200, so it stopped recording.. I suspect the HP would be flat to at least 7800. Seat of the pants says the pull just keeps going until I bump the 8300 rpm rev limit.
I don't have an accurate boost plot, since the stock sensor was pegged from spoolup to redline. MAF Voltages peaked at 4.9volts BIGMaf, which is something in the 5.1-5.2 volts stock MAF.
AFRs were in the high 11s, could go a bit leaner, but this made a bit more power because of the high CR. Timing was ramped to 26 at redline, but mostly in the 22-24 range, again limited by the high CR.
On Saturday, Tim, Eric and I pulled the motor out of the car, pulled the heads off, and pulled the pistons out. Sure enough, one pistons is cracked, and the second is right behind it. Cylinder walls look great, piston tops are in perfect shape. Typical ring landing failure. These pisonts just can't handle this kind of boost. (no news there).
Ron sent me some CP pistons that are dished so the CR will be more like 8.2:1, so that will help quite a bit. Will have the pistons today, build tomorrow, and get it back in the car this week. More on the piston issues to come.
Jeff Sponaugle
PDXTuning
USDM STI 2.5L Block, stock internals, with two low compression cylinders.
ARP Head Studs, Stock STI Head Gaskets
JDM Version 7 STI RA Spec C Heads and Cams w/ AVCS, 9.5:1 CR.
MRT FMIC,Perrin Intake, custom 3" inlet tube
PE800 Inj, Static FP at 55psi, Boost-A-Pump, -6 Fuel lines, Perrin Rails, Supra Fuel Pump (-1020)
HKS headers, Perrin Uppipe, BPM TT Exhaust
AVO600 Turbocharger in stock location (GT35R based turbo, -14 CHRA) w .86 A/R Turbine housing
JDM Version 7 STI RA Spec C ECU (AG971) with EcuTek Tech Reflash
UTEC w/launch control
STI RA Spec C 6 Speed Transmission, Rear hubs, Diff, etc.
Hyper Single Clutch and Lightweight Flywheel
The usual electronic goodies: AVCR, TunaWB, Knocklink, Gauges, etc.
Tuning Details:
Target Boost ~26psi, no taper at redline
Fuel: VP 103 Unleaded
Dyno: Matrix Mustang Dyno, "Monica".
Calibartion: As per the usual, a stock STI a few days before put down 235whp. This isn't your fathers dynojet.
Tuning Results:
Summary - 451whp at 7250rpm, 352 w torque at 6250rpm. Torque was pretty flat, above 325 lb-ft from 5200 to redline. This is 92% over what a stock STI gets. This is in the 480-500whp dynojet results. I suspect the low side, as to get above 500 dynojet whp, I would proboably need some C16.
The turbo is an AVO600, which is a non-rotated, stock uppipe and downpipe flange turbo. Intake goes under the manifold just like stock. I suspect this might be the highest hp car with a stock mounted turbo (no NOS of course).
As many of you know, I have been purposfully pushing this block to help better understand the limits of the stock STI block. As many other tuner and engine builders have noted, the stock pistons are a significant limit on this block. Even cars with stock turbos have seen failures of the ring landings. For the last two months, I have been pushing as much boost as possible. I have not ran a tank of less than 96 octane in more then two years, so fuel hasn't been the limiting factor. Detonation has been non-existant over this period as well, primarly because of continue tune refinement, and lots of knock detection equipment.
Before the tuning session, I started to experience a few small idle issues, as well as a reduction in vacuume pressure at idle. Typical signs of ring seal issues.
This tuning session started as an attempt to locate the source of a strong oil smell after getting on boost. I've had the AVO600 installed for a couple of months, and have been trying to locate the souce of the smell for some time. I figured the dyno is the best place, since I can stand right over the motor under boost. Sure enough, the dyno was quick to reveal the problem. When lifting the throttle, a huge cloud of oil smoke comes out of the exhaust, and partially out of the intake. This is a result of oil accumulation in the crankcase system at high boost levels, and then being sucked into the manifold via the PCV once you are off boost. The car has been doing this for some time, although on boost pulls shows no oil in the exhaust.
The engine has clearly experienced a failure in the piston/ring seal, as a compression test later highlighted. Since I was already on the dyno, I figured I might as well play around some and see how it would do.
Since I have Spec C heads on an STI 2.5 Block, my compression ratio is somewhere north of 9:1, not ideal for lots of boost. My first pull was at wastegate pressure, so I could check the baseline AFRs. The car put down 330whp, and boost was right around 18psi.
I turned the boost controller on, which was set for 24psi, and the next pull was right at 400whp. A few more pulls with the boost learning a bit more, fixing a few fuel issues, and adding just a touch of timing up top pushed the car to aboug 430whp. Upping the boost just a tad more so it would hold 26psi to redline pushed hp to a bit above 450whp. I did a bunch of pulls at this level, all with similiar results. The motor sounded great, was nice and smooth, and torque delivery was spot on. It really was the eaisiest 450whp I have seen. Engine seems to love the boost, minus the huge oil cloud.
I also did a few quick test with the water injection. With it off, knock activity at very high rpm was occassional, not significant, but more then background. With it on, peak power fell only 8hp, but knock activity was much much quieter. I didn't have time to go back in and tune with it, but the 8hp I suspect would be easy to get back.
Fuel delivery was not a problem. (as it was before). With the Boost-a-pump set to 20%, pump voltage was right about 14.5 volts. Maximum fuel % was around 92% at 8000rpm, with no pressure fall off at fuel pressure levels of 5.5 bar. (80psi).
EGTs were right at 1580. Never peaked over that. I pulled the car off the dyno and drove it home. Pull in 4th was just plain awesome. As for the turbo, there is a lot left to pay with. I had a few pulls with spikes up to 2.0 bar(29psi) above 7k rpm. The turbo has no problem holding boost of at least 26-28psi all the way to 8k rpm. NOS for spoolup would be very helpful.
Last but not least, when I got home, I did a compression check. 140,145,92,71. Two very bad pistons, but boy does the car feel great.
Power output was less then I would expect at that boost level, but that is mostly becuase timing was limited because of the stupid high compression ratio. That will be solved shortly.As per typical, here are a few graphs along with some data analysis:
The dyno was setup to pull only to about 7200, so it stopped recording.. I suspect the HP would be flat to at least 7800. Seat of the pants says the pull just keeps going until I bump the 8300 rpm rev limit.
I don't have an accurate boost plot, since the stock sensor was pegged from spoolup to redline. MAF Voltages peaked at 4.9volts BIGMaf, which is something in the 5.1-5.2 volts stock MAF.
AFRs were in the high 11s, could go a bit leaner, but this made a bit more power because of the high CR. Timing was ramped to 26 at redline, but mostly in the 22-24 range, again limited by the high CR.
On Saturday, Tim, Eric and I pulled the motor out of the car, pulled the heads off, and pulled the pistons out. Sure enough, one pistons is cracked, and the second is right behind it. Cylinder walls look great, piston tops are in perfect shape. Typical ring landing failure. These pisonts just can't handle this kind of boost. (no news there).
Ron sent me some CP pistons that are dished so the CR will be more like 8.2:1, so that will help quite a bit. Will have the pistons today, build tomorrow, and get it back in the car this week. More on the piston issues to come.
Jeff Sponaugle
PDXTuning
Last edited by sponaugle; 09-13-2004 at 11:41 AM.
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