VF-52 peak boost

[drvsdwz]

just a little curious here. I spoke with one of you guys at the meet last month in Brunswick saying that they were hitting 21 psi all the way up to redline, and all that was needed was an xpt tune, walbro fuel pump and tbe.

I'm a little skeptical about this because i just installed a walbro pump yesterday(loud as hell!) and tuned it, and can't reach above 15.5psi at 6900 rpm.

If anyone can elaborate(supporting mods, and tuning) on things needed, it would be appreciated.

I'm hitting 21 psi by 3500 rpm, 20psi by 4600, 19 at 5000, 18 at 5400, 17 at 5800, 16 at 6200 and 15.5 at redline. I see a trend of 1 drop psi every 400 rpm starting at 4600, is that a tuning issue?

Mikey, do you have any insight?

 

[Nate]

There is NO WAY anyone is holding 21psi on that turbo to redline. Especially with an XPT map. They were talking out their butt. Your boost taper figures seem pretty close to right on. I would have to review some of my logs, but I think I'm holding that or slightly better at redline, but not much more. Honestly though, I would be VERY hesitant to be hitting anywhere near 21psi at any point on a stock TMIC. They are known to fail over 17-18psi. (Ask me how I know). When yours goes pop, let me know, I have a brand new one I can sell you. Or just turn your boost down ASAP.

This all being said, with the right tuning (XPT won't get you there, so don't bother) you can run safely 20-21psi (hard to get without knock on Maines 91 octane). You should only really be able to hit those boost numbers in gears above 3rd. And you are definitely going to need some sort of intercooler.

 

[drvsdwz]

Thanks Nate, I thought it seemed a little off the wall. i don't run it at 21 psi all the time, i have multiple maps i can use with my accessport. When i win the powerball, i have a list of mods ready after i buy the sti special edition

 

[RyanR]

There is NO WAY anyone is holding 21psi on that turbo to redline. Especially with an XPT map. They were talking out their butt. Your boost taper figures seem pretty close to right on. I would have to review some of my logs, but I think I'm holding that or slightly better at redline, but not much more. Honestly though, I would be VERY hesitant to be hitting anywhere near 21psi at any point on a stock TMIC. They are known to fail over 17-18psi. (Ask me how I know). When yours goes pop, let me know, I have a brand new one I can sell you. Or just turn your boost down ASAP.

This all being said, with the right tuning (XPT won't get you there, so don't bother) you can run safely 20-21psi (hard to get without knock on Maines 91 octane). You should only really be able to hit those boost numbers in gears above 3rd. And you are definitely going to need some sort of intercooler.

That's because it wasn't an XPT map(nate is right, they can't get you there), and last time I checked my mouth is properly attached to my face haha. This was my 09 WRX.

I requested 21 and received ~19.5-21PSI to redline (set to 6300rpm) depending on IATs with NO intercooler/knock issues ever. That rig absolutely ripped. Just sayin'

 

[Iboc_C64]

I still can't believe you traded out of it. I would die if I had to give up mine.... well maybe that's a little over dramatic but I love my Black 2009 WRX Hatchback.

 

[BG @ BrenTuning]

at 100% duty cycle on the stock solenoid - you can make 22-23psi to hold 14-15psi to redline on a VF52. Anything further is impossible without an EWG. They make 325whp or so even with 14-15psi at redline.

 

[RyanR]

at 100% duty cycle on the stock solenoid - you can make 22-23psi to hold 14-15psi to redline on a VF52. Anything further is impossible without an EWG. They make 325whp or so even with 14-15psi at redline.

exactly, that's why I knocked back the redline threshold and always shifted @ ~5800 so I could get at least 19.5psi @ 10.1afr @ 5900. No point pushing the thing to 7k unless you're going for top speed

. I wanted crazy midrange for offroad/snow adventures.

powertrain mods:

-perrin intake

-custom homebrew mandrel bent 3.25" stainless divorced DP w/ metallic cat

-tsudo 3" catback

-grimspeed ebcs

-walbro 255

-innovate lc-1

-homebrew romraider tune

-250+ miles of data logging and tune refinement

I still can't believe you traded out of it. I would die if I had to give up mine.... well maybe that's a little over dramatic but I love my Black 2009 WRX Hatchback.

I have an 05 sti creampuff now so it's all good haha....

 

[Ryan]

Remember, pushing 19+ lbs. of boost on Maine's crap 91 is pushing it.

 

[RyanR]

Remember, pushing 19+ lbs. of boost on Maine's crap 91 is pushing it.

truth. you HAVE to have an a/f meter and log every once in a while to make sure things are running smooth, check learning view weekly, etc... it's a lot of maintenance, but it's also a lot of fun. anyway, car is gone to a new and very happy owner.

time for project sti