need your help guys....FD : i have got a large street port and mp t70 turbo..running off a hks cast manifold and custom down pipe. wastegate is vented. custom downpipe through to 100mm exhaust.

now at 10 psi its like my car has a cold...it sounds and feels like a restriction then all of a sudden it clears and boost continues to climb...but it only happens a 10 psi???

I have a few thoughts on this

1. could it be the manifold?

2. could it be the wastegate spring?

3. could it be the boost controller?

help the noise is driving me crazy...it sounds like someone has stuffed a rag up my exhaust!

 

What ECU are you running and what are your injector sizes?

 

yeah sounds like tuning to me. Are you checking your afr's when that happens? It could be overly ritch causing that issue. So besides that how does the t70 feel on your street port? When does it boost by? and when do you get full boost?

 

PFC and 550/1608

 

AFR are fine tried taking fuel out and chucking more in made no difference.

starts by 2000....Full boost by 4500.....and it fduking quick!

on my last engine which had small ports it made 425 rwhp...so i'm expecting big things when i get this sorted.

 

What lb. wastegate spring are you running?

 

i think its either 7 or 10 psi

 

Perhaps test the map sensor to ensure its getting a clean sweep of voltage throughout its operating range.

Might have a "rough" spot at 10psi

 

NIce! what hotside do you have on that thing? I have a .96 but will make my downpipe fit both the .96 and 1.32 to try them both out while I'm tuning it. It's great to hear good stories with these turbos. I don't think I'll be disapointed.

 

hotside 1.00

i am about to change my map sensor to a gm 3bar one.

 

Hi Elnr,
I see your secondary injectors are 1680cc
Is the staging set at 10 psi?