What is the MAX boost for a VF30

fatray · 07-16-2003, 03:18 AM

I need to know what I can crank my VF30 up to and what RPM will it start to go bad.

My motor should be able to handle 25 PSI with no problem?

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hotrod · 07-16-2003, 05:39 AM

Most of the IHI turbos seem to run up to about 18 psi with out much fuss. On the VF22 which has a longer use history, they seem to fail quickly if run at high pressure ratios, especially for folks who run on track day type situations where they hold high boost for extended periods of time.

Some folks seem to get away with 20+ psi on them but I suspect they only briefly flash up to high boost pressures (stop light Grand Prix) rather than hold high pressures.

What your engine can survive is more a function of how it is tuned than what the manifold pressure is.

400 odd hp ( which requires close to 24 psi to flow the 600 cfm required ) seems to be the highest folks are getting with any reliability on the stock engine internals and only if carefully tuned.

Larry

fatray · 07-16-2003, 12:20 PM

Hey thank you very much for the info. I would be holding boost only once in a while, couple times a day. Depends on how spunky I feel. I am no longer stock BTW.

wrxtuner02 · 07-16-2003, 12:35 PM

i ran 20 psi for about 20,000 miles on my vf 30 on a STG 4 kit. Ran abou 22 on track days but i figure that was outta the efficiency range.

MY99 2.5GT · 07-16-2003, 02:15 PM

You really need to look at a Flow Map and AR ratios to see where efficiency starts to drop off. Match that to your engine size and you should have a pretty good understanding of where more boost pressure will actually cost you HP.

Anyone have maps for a VF30? As stated above most of the WRXs I have seen around here, we are a little above sea level, start to run out above 19psi without any type of intercooler sprayer or nitrous.

davidm_sh · 07-16-2003, 02:21 PM

I had a VF22 with about 35,000 miles running it at 2.4 Pressure ratio then I turned up the boost to about 3.2 Pressure ratio and it only lasted about 8,000 miles before blowing blue smoke under boost. All in all I was pretty impressed with the turbo.

07-16-2003, 03:18 AM	#1
fatray Scooby Specialist Member#: 18150 Join Date: Apr 2002 Chapter/Region: MAIC Location: Baltimore MD Vehicle: 2002 WRX Wagon EJ207 Velocity Red, Liberal kit	What is the MAX boost for a VF30 I need to know what I can crank my VF30 up to and what RPM will it start to go bad. My motor should be able to handle 25 PSI with no problem? * Registered users of the site do not see these ads.

07-16-2003, 05:39 AM	#2
hotrod Scooby Specialist Member#: 14141 Join Date: Jan 2002 Location: [email protected] @ 5800 ft on 13T Vehicle: 2002 Impreza WRX	max pressure and longivity Most of the IHI turbos seem to run up to about 18 psi with out much fuss. On the VF22 which has a longer use history, they seem to fail quickly if run at high pressure ratios, especially for folks who run on track day type situations where they hold high boost for extended periods of time. Some folks seem to get away with 20+ psi on them but I suspect they only briefly flash up to high boost pressures (stop light Grand Prix) rather than hold high pressures. What your engine can survive is more a function of how it is tuned than what the manifold pressure is. 400 odd hp ( which requires close to 24 psi to flow the 600 cfm required ) seems to be the highest folks are getting with any reliability on the stock engine internals and only if carefully tuned. Larry

07-16-2003, 12:20 PM	#3
fatray Scooby Specialist Member#: 18150 Join Date: Apr 2002 Chapter/Region: MAIC Location: Baltimore MD Vehicle: 2002 WRX Wagon EJ207 Velocity Red, Liberal kit	Awsome Hey thank you very much for the info. I would be holding boost only once in a while, couple times a day. Depends on how spunky I feel. I am no longer stock BTW.

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07-16-2003, 12:35 PM	#4
wrxtuner02 Scooby Specialist Member#: 22700 Join Date: Aug 2002 Chapter/Region: MAIC Location: West Virginia Vehicle: TRD FJ Crusier SE 76 MG Midget Special	i ran 20 psi for about 20,000 miles on my vf 30 on a STG 4 kit. Ran abou 22 on track days but i figure that was outta the efficiency range.

07-16-2003, 02:15 PM	#5
MY99 2.5GT Scooby Specialist Member#: 5030 Join Date: Mar 2001 Chapter/Region: MAIC Location: Martinsburg, WV, USA Vehicle: 1999 Legacy 2.5GT 19 Audi RS3, 13 Armada	You really need to look at a Flow Map and AR ratios to see where efficiency starts to drop off. Match that to your engine size and you should have a pretty good understanding of where more boost pressure will actually cost you HP. Anyone have maps for a VF30? As stated above most of the WRXs I have seen around here, we are a little above sea level, start to run out above 19psi without any type of intercooler sprayer or nitrous.

07-16-2003, 02:21 PM	#6
davidm_sh Scooby Specialist Member#: 5994 Join Date: Apr 2001 Location: Fort Collins, CO Vehicle: 2004 Impreza WRX STi Java Black	I had a VF22 with about 35,000 miles running it at 2.4 Pressure ratio then I turned up the boost to about 3.2 Pressure ratio and it only lasted about 8,000 miles before blowing blue smoke under boost. All in all I was pretty impressed with the turbo.