OK, I just did the SMK swap and put all the gauges form the bottom to the top and put the Radio on the bottom. Thsi was done to be actually able to see th gauges while driving. SO I find an opend stretch of High way and floor it from a stop, I watch teh gauge, it is in bar.

It goes up to 1.15-1.2 MAYBE and that is it, it doesn't spike or fall off, just shoots up to that pressure and never falls off nor gets up to the 19.5PSI as advertised. Any reason why? I am almost certain that this is hurting my performance and may be why some EVO's ran such low HP numbers while others broke the bank.


BTW 1.25BAR = 18PSI max but I really am only getting 1.1BAR after the initial spoolup which is 16.17PSI, not what I am looking for.

Either way Joe P will do the boost controlling from now on, any thoughts on why such low boost on a stock Evo?

 

Mines usually read at 1.32-1.34 BAR on a Greddy boost gauge.

 

It's the cone type filter!
(Reference another post)

You definitetly have a problem. All I can think, other than ecu screw up, is either a leak in one of the hoses or a lack of air getting into the turbo from the inlet.

The fact it doesn't drop off tells me the ECU knows it's not there yet. Does it slowly climb as the RPMs increase so it is at it's highest at like 6500? That would make me think a IC leak.

Where did you tap the vacuum hose, or is this a factory guage set?

 

The gauge was installed by Mitsu, all was done by them, The oost does fall off towards teh end, I just don't get up to 19PSI, Everything else is stock and untouched. Maybe a MBC will cure my problem, it goes on tomorrow.

 

Yeah but what scares me there is if it is making the boost and the guage is lying. You'll have lots of boost then if you set the MBC to that guage and it is wrong.
I would figure out the problem before you go MBC. Plus, if it is lacking boost and needs to go to the dealer, you'll be taking the MBC off anyway.

 

Maybe I am wrong, I hope soo but it is doubtfull being that I am never wrong......

 

Wrong about what?

If the guage is inaccurate and you want to boost into the 20's, I guess you'll find out if you were wrong.

 

Hmmm, It does spike real quick, maybe to that set pressure, but the car does not stay at 19PSI for anything longer then an instant, 18.3 PSI then tapers down.

I think the 19.5PSI is only the recorded spike and was detuned to allow it to stay under a 20+ Spike, car is not set to run 19.5 PSI, maybe 18 tapering down to 165PSI, but not 19PSI.

 

mine has never exceeded 1.33bar it's hits it exactly everytime. 1.33=18.5. So I know mine is just right.

An instant is all it will be when you hit peak boost because after that it starts to taper off. I have no idea if there's something wrong or not with your car...I'm confused.

 

First off how is 1.33 bar = to 18.5 PSI?

1bar = 14.7 PSi exactly the atmospheric presso at sea level.

so 1.33 times 14.7= 19.55, your right on the money. From a ROLL off at 300RPMS the boost goes right up to 1.25 and then falls off, I never checked it on a launch.

 

Haha, you're right it's not 18.5. It's actually 19.29.
1.01325 bar = 14.696 psia
1 = 14.503824
yields 19.29

The old lady is a chemical engineer. She's so hot when she rattles off this stuff.

I must have been using a shady internet conversion table to get the 18.5. It made sense at first because I thought max boost on the Evo was supposed to be 18.5. Obviously it's spiking at 19+. Depends on gauge calibration/brand and motor I suppose.