I have a Vishnu Stage 1 XFlash, with a signature turbo back exhaust. I just got my boost gauge installed, and I was watching it. I noticed that at idle, it seems to hold around 14 -16 vac. And that when I get on it, the gauge will jump up to what looks to be around 24 - 25 PSI, then settle back down around 20 - 21 ( hard to watch at that speed ) up until around 6000 RPM. Then at around 6000 RPM, it seems to start backing off, until it goes almost down to 12 - 13 PSI at 7000 RPM. Is that normal, or do I maybe have a boost leak? Thing is that it does this pretty consistently.



I'm just concerned because I don't have much more time to get new parts in, if I need them, before the May dyno day.

Thanks

 

Those numbers seem odd. The boost is about 2-3 psi high on the top end and 3-4 psi on the low end. What brand of gauge are you using? I would get a passenger to confirm those numbers. After 6000 RPM the boost begins to drop to 16-17 psi.

 

Hi RallyRedEVO, if you can make it up to see us at our shop before dyno day we will take a look at it...
this is why it is so important to make a boost gauge #1 on your mod list.

 

Hey Andrew! This is Paul.

It's an AutoMeter gauge sport comp.

Here is a link to the gauge.....
http://store.summitracing.com/partde...art=ATM%2D3303

I'm pretty sure that I installed the gauge correctly, but if I didn't would it ever make it to the higher PSI? And would it be able to hold for a long period at the 20 - 21 range?

I'll try to get a passenger today, make a few runs and watch it.

 

Where did you install the boost line in the engine compartment? They suggest to install it after the throttle body. I have mine installed on the passenger side of the intake manifold on the tube that has the plastic wrap around it.

 

Let's hook up for lunch and I'll take a look at it.

 

Good deal Noize, I'll call you.

I used that same line with the plastic wrap around it.

 

95% you don't have a boost leak IMO. I think we'll get it figured out with ease. I won't be in the office until around 10am, so call my cell.

 

Event-Horizon, I am pretty sure that is where I have mine plumbed to. I Tee'd a line and put it off of one of the two lines next to the FPR.

 

This is the document I followed on which line to tap. Andrew, this is the same one you showed me isn't it?

http://www.jonesland.com/evo/BoostGauge_Install.htm

 

Haven't autometer gauges been plaguing lots of folks w/ inaccurate readings?

 

I'd say that it isn't the most accurate, but it seems to at least be a consistent reading of what is going on. It may be off by a bit, but can still indicate if things are out of the norm.

 

Make sure you have the 2 clips on the air box, the black screws, that was my problem and I was having the EXACT same problem, if you want to check remove the cold air scoop and see if that helps.

 

Car is fine. Needs some of Shiv's "custom pill medicine" at the dyno day and all will be perfect. It hits 24psi and tapers to about 16psi. Undoubtedly, some of this is the gauge itself.

Lesson learned: Go Omori or go home.

 

Ok here is one for you guys...

First off let me say that I do not have a Vishnu tuned car. That being said I seem to be having problems with my boost.

The problem appears to be in 1,2, and 3 gear...4th and 5th seem ok. I am able to get 1.4 (20.58) bar spike and hold in 4th and 5th gear all the way to red line. However in 3rd the best I can get it 1.3 bar and then drop a little around the 6000 mark. 2nd gear is like spike at 1.3 but drop to 1.2 or 1.1 and 1st gear is 1.2 or 1.1 max.

Does anyone have a clue as to what might be causing this. The car seems less torquey. It will still accelerate but not as hard as before, especially in the low gears.

I have had it pressure tested up to 30+psi so I do not believe it is a leak plus the boost does not drop in 5th at all and pretty much hold true in 4th as well. The issue is that I just can't get it to boost up as high in 1,2 and 3rd.

Any ideas???

thanks,
-Doug