so I've been chasing down a potential boost leak for the past week or so. I've replaced the throttle body seals and checked all the intercooler connections. Keep in mind the car is entirely stock. I still have the plastic bodied stock BOV but I've purchased a metal bodied MR style BOV that I should be receiving today or tomorrow.

That should eliminate all of my possible leak locations.

i have a Defi D-gauge boost guage on my steering column and I and fairly consistently peaking at around 16-17 psi on the gauge. I have been looking at using a MBC but I don't want to have the boost set too high if the guage is reading incorrectly. I did a search and couldn't find anything, but do any of you know if this particular gauge has a history of being inaccurate? If I use a MBC I only plan to turn it up to 20 psi or so, maybe 21 if that is still safe on the stock car.

Any thoughts?

Here is my boost gauge.

 

you could build your own boost leak tester with one trip to home depot, that way you will know for sure if you have a leak and where it is

turning the boost up to 20-21psi is fine on a stock car. I would suggest a tune to take full advantage of every pound you increase.

 

Why do you think you have a leak or that gauge is inaccurate? If your car is stock, that is about all the boost you shoule be seeing anyways.

 

I have a boost leak tester and I'm not worried about leaks anymore after fixing the items I listed. I'm asking more about the gauge and whether or not it is accurate. A stock car should be boosting to about 19psi right? So according to my gauge I'm a little short of that. 16-17psi is low.

If I add a MBC and set it to read at 20psi on my gauge, will I need to have the car tuned, or is that within the limits of what the ECU can handle?

 

run a 3 bar map and log the car - only way to know for sure?

 

03-04 EVO's should be peaking at a little over 19psi, 05-06 EVO's at 20.3 psi

 

i'm dealing with the same thing, peaking around the same on my digital AEM gauge. our problems most likely lie in a slight leak at the throttle body. it's happened before and it's incredibly common.

i just haven't gotten around to checking it out yet. probably this weekend. don't think it's your gauge.

 

"...I still have the plastic bodied stock BOV"

 

i got my car completely stock and once i had my boost guage on, it constantly showed me peak @ 17-18 psi. Check with the others and they all said its perfect..

Got the JDM BOV and a MBC set to 19 PSI for now. Spoke to 4WS and he said i can boost it upto 21 without a tune and its all good.

So seeing this, i think your boost guage has nothing to do with it.. tho a boost leak test will clear out all the doubts.. im in the process of doin mine soon coz i just wanna check..

Let us know.. Best of luck!

 

I already said I've changed the throttle body seals, so that's not it.

yes and I have a JDM MR one to put in. I'm hoping it helps but we'll see. The question still remains, does anyone know if the Defi D-gauge is prone to being inaccurate?