Buying a Boost Controller for my rb20, this car/engine is still COMPLETELY stock. I was wondering, besides the neccesity of getting a fmic, and the obvious boost controller. I was wondering if I can safely boost this up to say, 10-12 psi of boost without re-tuning or doing anything to my engine/ecu?
If it does need to be retuned/edited. Leme know what you guys suggest. Thanks!
You can run 11-12 psi safely with no tune. Any more than that and you run risk of shredding the amazingly reliable ceramic turbine wheels out of your turbo. Most likely the exhaust wheel. You don't NEED a FMIC but it definetly helps. If you have exhaust, intake front mount, Atmospheric BoV and running a little higher boost a tune does help but isn't a nessecity... You just wont be getting the full ,efficent power of those mods.
Last edited by Ghost; 06-22-2011 at 11:06 PM.
You gotta pay to play.
If u upgrade exhaust(cat back and downpipe) and also upgrade your intake and maybe get a FMIC u should get around 10 to 12 Psi without a boost controller.
But that's the expensive way of doing it, lol!
You gotta pay to play.
Doesn't the ecu restrict the turbo? I swear I heard someone say something about the govern not only restricting speed, but boost, rev limiter, etc. Idc bout rev limiter, I already found my sweet spot for shifting. Thats off the point, anyways. Lol Can the exhaust system/intake serious up the boost that high?
No to the first question. The ECU regulates the amount of fuel to be injected in correlation to the amount of air being inducted or compressed into the cylinders via the turbo. The turbo itself is a completely mechanical device propelled by the velocity and heat of exhaust gases being expelled from the engine under load. The more efficiently (faster) the gasses flow, the hotter they become (downpipe, exhaust kit, intake, FMIC, etc) and the sooner, faster and more efficiently the turbo spins creating more boost, so yes to that question except for one thing. A wastegate. This keeps your turbo from boosting over a preset psi level. Once the preset pressure is reached, it opens and bypasses the excess pressure and gasses around the turbo to help maintain "stock" psi. This is where your boost controller comes in. The boost controller inhibits the exhaust pressure gasses to the wastegate actuator keeping it closed longer, and resulting in higher maintained boost level... In a nut shell... Sorry on night shift right now so very watered down Explination...
Last edited by Ghost; 06-23-2011 at 05:40 PM.
You gotta pay to play.
Podfilter, 3" exhaust from dumppipe, modified stock BOV, hybrid RB20 turbo at 12psi, stock ECU tune made the entire powerband from peak boost at lower rpm to close to peak hp lean with my car on dyno. ECU was pulling timing (ECU detecting knock) as A/F ratio hit 13.5:1 on dyno at peak boost at lower rpm (3500rpm+) and then second run I think was 12.8:1 (I assume it was running on knock fuel map). When you want it under 12 for A/F ratio at peak boost, it's a bit of a worry. At peak hp (7500rpm, 12psi) it had a 11:8.1 A/F ratio.
My understanding from a dynochart I've seen for RB20DET with full 3" exhaust from dumppipe, split dumppipe, FMIC, podfilter, is it suffers the same problem my cars engine encountered with running lean and ECU pulls ignition timing, dumps more fuel in, etc. That's when running 13.5psi.
I would say at least 10psi and under to keep A/F ratio safe (under 12.0:1 A/F ratio) and hopefully stop ECU from pulling ignition timing. But stock RB20DET internal wastegate actuator spring pressure is around 12psi (edit: on my car) which is as low as boost controller probably will allow you to go.
An option is finding a auto R33 RB25DET internal wastegate actuator that's rated at a lower psi than manual internal wastegate actuator from a R33 RB25DET. It should allow you to lower boost level to under 10psi.
If tuning ECU, fit Nistune for stock ECU which allows tune to be changed anytime you need to or want to. Also I would upgrade fuel pump, injectors and fit a Z32 AFM with Z32 AFM plug / pigtail wired in to take full advantage of the tune.
Last edited by Skym; 06-23-2011 at 07:51 AM.
The most epic signature ever "epic".
Yes, indeed, Let's Roll, (Yes, Let's ride the automobile)
I'm running 11 psi with a 14 ish spike via manual B/C, 3" turboback, podfilter, no FMIC and no leaning or boost or powerband issues. Pulls good and hard, odd backfire cause of BoV, but my last pull was around 190 ish whp. No tune... Yet.
You gotta pay to play.
The internal wastegate actuators do vary with spring pressure from car to car (I guess explains the hp difference with factory cars when they test a few cars on dyno).
For example, R32 RB20DET internal wastegate actuator (auto, manual) is meant to be around 11.36psi-12.78psi when tested on bench.
The R32 RB20DET internal wastegate actuators tested on bench for my car were both at around 12psi. So I don't think I could run it below 12psi.
Last edited by Skym; 06-23-2011 at 07:54 AM.
The most epic signature ever "epic".
Yes, indeed, Let's Roll, (Yes, Let's ride the automobile)
My gts-t had a full turbo-back exhaust, intake, 255lph walbro pump, fmic, synapse recirculating bov, and a hallman boost controller set at 13psi.
Man did that thing rip. Don't go above 13psi... Or **** will shatter.
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