My brand new 2006 Evo MR (550 miles on it) only shows 1.2 bar boost at 3,500 rpm, and then it tapers to BELOW 1 bar of boost at 6,500.

Anyone know why this could be happening? Here are my thoughts:

100+ degree weather
AC was on


if this car really is only boosting 1.2 bar, then oh boy I cant imagine what 1.5 bar feels like... My 2005 Evo MR boosted 1.5 bar consistently... so why isn't my new Evo? Thanks

 

anyone have any ideas?

 

You probably have a boost leak, test it and see what happens.

 

I just noticed after installing a boost guage in my IX GSR that sometimes it will go to 21psi and drop slowly to 19. Other times it hits 16psi and stays at 16. Then other times, it will hit 21, drop to 16 and then bounce back and forth between 16 and 19 before settling at 16. I'm confused...

 

Are you reading this off a newly installed boost gauge? If so, check your tube going to the gauge...

 

I used the "hard" line that autometer supplies because I used a soft rubber line on my eclipse and it got pinched before.
It will also do all of those things during the same 10min ride home. Everytime I shift, I look at the guage and it shows something different. *shrugs

 

Well, you're definitely going to see different boost levels at different rpms. YOu mentioned shifting, so unless you're shifting into the next gear below 3000rpm, you're never going to see peak boost. The only way to see the peak boost spike is to roll into boost from low rpm. If you row through the gears shifting fast while boosting, you'll only see the after-spike taper.

 

You know what, that's exactly what it is. I went for a ride and tested your theory. Thanks man!

 

way to hi-jack my thread tony_b ....


My boost gauge is a stock mitsubishi boost gauge that comes on the MR. If I floor it in any gear, the most boost I see is 1.1 to 1.2 bar @ ~3,500 rpm... which then tapers down to BELOW 1 bar as 6,500 rpm approaches.

I don't know why the car would have a boost leak with less than 1,000 miles on it. Its still fast (faster than my 8 i think), but yet my 8 would hit 1.5 bar with no problem. Any ideas?

 

I thought our problems were somewhat similar and that since we both have IX's, someone may post some useful info that both of us could use.
Now that I read what you just posted, it def sounds like a leak. I know it sounds funny because you have a car with very low mileage but a LOT of people are having issues with piping blowing off so I don't think a boost leak would be that unheard of.
And sorry for the hijack. At least I didn't get it off topic.

 

im assuming u live in AZ its hot dude i used to only get 1.2 bar. if u wanna change this get ahold of me if ur in az . i have a forge MBC for u

 

I live at about 5000 ft. elevation and it has been 100+ degrees this past month and my boost consistently peaks at 18.5psi with the occasional spike to 19.5-20psi (this happens rarely on really cool nights) so I guess hot temps. may affect your peak boost. What about elevation? could this affect your peak pressure or just spool time? Anyone who lives at high altitude care to chime in?!

 

of course elevation sucks dude. u have to deal with the elevation crap and heat... i have the heat buts its like 1400 ft. here

 

hehe, its okay I understand.. I'm not mad or anything.


As for my problem I suppose it could be a boost leak, but I wonder if its just the 100+ degree weather making it hard for the turbo to boost that high.

 

air is thicker when its hot. larger molecules equals richer. I seem to boost higher at daytime then night so yeah