I got a question thats been plagueing me and Ive tried almost everything.
Quick setup:
D16y8 built bottom end
SRP pistons, Eagle rods, ARP studs
Stock head
2.5 Dp and exhaust
Hondata
550 injectors
t3/t4 .50/.48 (not sure on the trim)
15 psi, 245whp 202ftq
My goal was 300+!
So obviously, just turn up the boost right? Well, the boost will not go past 15psi!!! I have a turbosmart MBC and a 10.153 Tial wastegate spring. Ive tried everything. No boost leaks anywhere, no exhaust leaks anywhere. I have posted this and got some ideas, like take the vacuum lines completly off the wastegate, tried that, still 15psi. I havent put a bigger spring in yet, but some people say that this wont matter. Do you think a bigger spring will raise the boost in my situation or is something else wrong. I dont know the trim on the turbo, because when I had it rebuilt I forgot to ask.

 

sounds like your BOV is not closing all the way.... what BOV are you using?

 

did you replace stock map sensor? its only good for so much boost before need like 3 bar, is the boost control good?

 

where is your dump tube located and also do you have a filter on your turbo. if so where is it located

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 0618turbocivic &raquo;</TD></TR><TR><TD CLASS="quote">did you replace stock map sensor? its only good for so much boost before need like 3 bar, is the boost control good?</TD></TR></TABLE>

doesnt matter if its stock map sensor. it can still read over 11psi.

 

yea i know but like he said it wont go pass 15psi... im saying the stock map sensor is only good for so much and since wont go pass 15 psi im seeing if he replaced it

 

10.153 Tial wastegate spring.

the wastegate spring opens fully at 10psi, but that doesnt mean that enough exhaust pressure wont push THE VALVE OPEN at another high pressure ratio, EVEN WITHOUT A SIGNAL!

at 15psi intake pressure its not unlkly for the exhaust pressure to be close to double depending on the manifold and turbine housing.

try a harder wastegate spring.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by komat &raquo;</TD></TR><TR><TD CLASS="quote">

doesnt matter if its stock map sensor. it can still read over 11psi. </TD></TR></TABLE>

It can't read past 11.7psi.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">sounds like your BOV is not closing all the way.... what BOV are you using?</TD></TR></TABLE>

are the bov suppost to close at idle?? mine don't

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">

It can't read past 11.7psi.</TD></TR></TABLE>

what i ment is you can still tune it 15psi with a stock map sensor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by komat &raquo;</TD></TR><TR><TD CLASS="quote">

what i ment is you can still tune it 15psi with a stock map sensor. </TD></TR></TABLE>

How would the ECU know which maps to run if the map sensor quits reading at 11.7?

 

I am running Hondata with a gm 3bar. The two things that I think might be wrong are, the wastegate spring is opening at 15psi or the turbo cant spool past 15psi. The car has been tuned to 245whp and 202ftq, but my goal was 300+, so I ended up short. Any more help would be nice.

 

I have an XS BOV. But I have actually shimmed the BOV spring to make stay closed harder, so I dont think its the BOV.

 

If the stock map sensor only reads 11.7 map then u just tune the last collum for 15psi. not the right way too do things but it can be done.

 

The car can read 3 bar, I just cant get the boost there. I will retune it as soon has I figure this **** out.

 

i had the same problem and i discovered that the xs rfl bov leaks at high boost. i got a hks style bov and it solved theproblem i picked up 15whp

 

I made a boost leak tester that I used to pressurize to about 11-12psi to look for leaks. I sprayed soap over everything and the BOV had no leaks. And like I said I shimmed the BOV spring down tighter to make sure it stayed closed until it was needed.

 

The same exact thing happened to me on my setup, it drove me nuts. Disassembled and reassembled everything, still no luck. It turned out to be the air filter!

Try taking it off and see if you can boost higher.

 

I gonna try that and see. I tell you what if that funckin **** works Im gonna be PISSED!