Lack of pressure would most likely cause boost creep before a spike

 

on mine... i just installed it over the weekend. now all it does is sit at a -20 and boosts at 0 and maybe of +5. anyone have any ideas as to why this is doing this? when idle doesnt it have to be zero?

 

Don't you think that in 5th gear your boost will hold too high for too long?

 

Urbandk,

Good video but let me tell you something bro, I peak 31psi on stock turbos on the Evo 9 and Evo 8 MR(Evo 9 with some race gas, Evo 8 with methanol and some race gas). I also have the defi gauge just like that with the controller.

I am telling you that your boost is nothing compare to others and by the way, I review your video and paused and it peaks at bearly 24psi and not 25PSI..

Try this:

Carlos

 

Try running 25 plus PSI and you will see the drop. The drop is inevitable. I can lower my boost levels to 21-22psi(peak) and could also claim that my car holds the maximum boost to the redline but that is not the issue.

When you run ushc amount of boost on stock turbo the boost will drop rapidly pass 6500rpm.

Carlos

 

Uhmm.... Any gauge has their margin of error. Considering that Defi is perhaps one of the best gauges in the market I would give more accuracy to ther Defi than other cheap $50 ones.

I compared my Defi gauge with the oem Mitsubishi gauge, also with the Mustang Dyno boost sensor and ultimately with Al's boost reading sensor and I am telling you that the Defis are not bad at all.

Carlos

 

Dude, you are so correct on that. Up to last month I was truly getting frustrated with my 30plus psi spikes on my Evo 8 MR. The boost was untolerable, it would jump like a shootgun then rapidly drop.

I am very very happy since I put the 3"HF back. Boost now spikes progressivley and stays in the top steady. The spiking is gone.

After driving with a test pipe for that long I am cosnidering just keeping the 3"HF for a while and do some 1/4 mile testing with iut.

Carlos

 

That's normal. I'm on 91 octane and spike to the same level then hold 22psi through the power curve. A little spike like that is harmless. It's when you hold those levels that you can start to worry.

 

In any case, I am hitting fuel cut where I'm at right now. I have been flashed, but apparently my boost is higher than the flash expected.

Here is a pull in 3rd from 2000 RPM. It actually peaks onces, drops, and peaks again before hitting fuel cut. WTF???

http://myhome.spu.edu/johnsbr/evo/boost2.mpg

 

If you have been flashed then I see your boost normal when you are peaking. 24psi is not exceptionally high at all.

Who flashed and what mods do you have? In cold weather you can get sometimes up to 2 psi more.

Carlos