turbotaloon95

iTrader: (7)

Sorry to jack this thread, but my question seemed appropriate here.

I just installed a boost gauge and my evo 8 hits 16psi and pretty much stays right there. Isn't it supposed to spike at like 19psi or so?

Another quick question...at idle, my vac is about -18 in/Hg. Is that normal? Or do I have a vacuum leak somewhere?

cobrav

this whould help..you can find in in the beginning..section..

What engine does my car have?
All currently produced American market evo's have the 2.0 liter 4g63 turbo motor.

How much boost is my car running stock?It depends on the year:
03-04s run 19.5psi at 3500rpm, which tapers to 16psi by 6500rpm
05-06s run 20.3psi at 3500rpm, which tapers to 17psi by 6500rpm

How big is my stock turbo?
Evo's come with different variations of the 16g turbocharger:
03-04 = 16g6 with a 9.8cm^2 turbine housing
05 = 16g6 with a 10.5cm^2 turbine housing
06 = 16g6 with a 10.5cm^2 turbine housing and larger compressor housing

What is stock fuel pressure?
43psi with the vacuun hose off and plugged.

How much does fuel pressure increase when I am boosting?
1:1 = 1psi per 1psi

What size are the stock fuel injectors?
560cc

How big is the stock fuel pump?
03-05 = Same size as a Walbro GSS342, and flows 160lph@12v

evoarri

Your vacuum should be right there it is normal. if you think you have a leak you can buy a small propane tank like a hand held and open it slightly with the car running and put it near vacuum hoses and if you hear your car rpm's go up slightly then you have a leak.. just found my car had a leak when mine was at 15 and now mine is at about 18-19 so i dont think you do but if your not sure its an easy way to test.

josher8

picked up an HKS EVC 6 (latest and greatest) which allows you to control boost at any RPM. U can eliminate the taper with setting changes. Love it! I must have a leak though from the sounds of it cuz my evo 9 stock boost when I hooked up the EBC was around 14 psi and tapered to 10.5 or so

turbotaloon95

iTrader: (7)

Well I installed a mbc and noticed that the vacuum hoses for the stock solenoid was all messed up. That's why I wasn't seeing stock boost. The previous owner must have put it back incorrectly or did some mod I am unaware of. Anyway, I used all new hoses and set the mbc to just about 20psi. Now boost spikes at 20spi and drops to only about 18-19psi by redline. However I managed to hit fuel cut in 4th gear at just under 20psi and 5700 or so RPM.

juanpdu

13-10 evo 9

M-Dub

I am looking at a 2005 Evo 8 and with it's aftermarket boost gauge it shows about 12-14psi

Boosted Tuning

iTrader: (12)

Its running waste gate boost and the stock solenoid isnt hooked up correctly with the correct boost pills.

This is common when a car has had a MBC and then been returned to stock.

M-Dub

IS there a how to fix this or something...

sorry new to the evo world here.

How to adjust this back?

impact blue

iTrader: (1)

very interesting info

Rival Legendary

I have an 03 evo 8 and my boost pressure keeps spiking to 1.53 bar (roughly 22pounds) which at that point my bov purges without my saying so. Am i having boost control solenoid problems? or is it something else entirely?

Thank in advance.

Nick Reynolds

hey guys, quick question. I own an 03 evo 8 with a stock turbo which I just replaced the tensioner pulley and idler after the belt shattered it. ever since it has been fixed i feel like i have a leak in my turbo. My psi is not where it should be at 3500rpm. i can almost hear the leak and i believe it is on the cold side of my manifold, not sure though. Anyone had this problem? Any help would be much appreciated.

whotippedmycow

iTrader: (4)

Thanks for the anwser!

Humble

Sounds like you have a boost leak, boost spiking is a symptom of a boost system or boost adjustor leak...

Humble

0.8 Bar or 11.603 psi is factory boost for an EVO VIII or EVO 8.