Right now I am getting about 1.3 bar spike then it goes to 1 bar then at 7500 about .7 bars. I took the car out last night and tried everything I could think of too get more boost but I had 0 luck, I did the 159.4 I changed the delay way up I also changed the Turbo boost error correcting, if I remember right at the top it's -16 I changed it to -4 then to +4 with no change. I dont want to make a ton of boost because I am getting a MBC installed today, what I do want is to know how to control the boost taper and get the boost as solid as I can with as little spiking as I can.

 

Eliminate taper:
1) Forge WGA or tighten WGA tension two whole turns
2) MBC of course
3) Do the above and add 10.5 hotside

Eliminate boost spike (with MBC):
1) Tap MBC from compressor outlet pipe (use OEM nipple) and mount MBC as close as possible as you can to it while still within reach
2) The most important factor to eliminate spike is to keep the line from MBC to WGA as short as possible

 

Thanks for the post, I will do this on Saturday and post up my PSI graph

 

my car does the same thing though it spiked slightly higher since i changed the MIVEC map and the air was denser last night after it rained. just bite the bullet and do an MBC.

Doesn't the EVO IX turbo already have a 10.5 hotside, btw?

 

Yes, as does the 2005 Evo VIII.

 

Have you changed the boost control load offset? Have you increased the maximum wastegate duty cycle to 100%? Checked hoses for tightness? Changed restrictors?

 

I'm sorry I thought it was an 03.

 

HI

It is a bit strange, I eliminated taper on my stock Evo VII, did you change the values for all the boost target maps?

MB

 

I would be more inclined to say faulty boost guage or boost leak.

 

dude just read what he drives. It's a IX MR. already has the hotside. And the forge wga won't fit on these.

Simple fix. MBC. IX's respond really well to ebc also, but if you're not to advance on tuning one of these and are not ready for a headache then don't get one.

Go with either a Forge or Halman. And tighten everything down. All your hoses and clamps.

 

I am installing a MBC this Saturday. All the other 3 9 evo's around here do the same thing as far as boost and when tuned with the same things I did to mine so MBC it is

 

Why don't people persist in getting the ECU's boost control to work? I know we can't log wastegate duty cycle, but surely careful restrictor alteration would get what we want?

I didn't simply because the previous owner had an EBC on and the stock solenoids were not present.