Hey guys im running 16 psi with this turbo and it drops to 10.3 psi at redline in fourth gear. Killing my power up top. Is this normal with this turbo. Car only made 219whp 222lbs torque at that number with boost falling of. Im gonna post the dyno graph when i get to kinkos and scan it up. Any ideas in the meanwhile.

Motor- Built d16z6 9:1
bmc race log manifold
tial wastegate (9 pounds spring)
turbo xs boost controller
full 2 1/2 exhaust
uberdata 1.7
2.5 bar map sensor

 

Could the 2 inch crush bent piping from the turbo to the intercooler be killing me or causing a pressure drop?

 

#1 a small dp is gonna make u loose power up top
#2 the turbo is small.. its always gonna lose some power up top

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jmcmil6 &raquo;</TD></TR><TR><TD CLASS="quote">#1 a small dp is gonna make u loose power up top
#2 the turbo is small.. its always gonna lose some power up top</TD></TR></TABLE>

#1. How is a 2 1/2 downpipe mandrel bent with no cat and a full 2 1/2 exhaust restricting me at this power level and small turbo?

#2. Your right but 6psi of pressure?

 

yea thats a pretty small turbo, i would try running an open downpipe and seeing if it helps at all

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1boostedcivic &raquo;</TD></TR><TR><TD CLASS="quote">

#1. How is a 2 1/2 downpipe mandrel bent with no cat and a full 2 1/2 exhaust restricting me at this power level and small turbo?

#2. Your right but 6psi of pressure?</TD></TR></TABLE>

#1 and 2. I had a similar set up on a h22 at about the same amount of boost w/ a t3/t4 .48 ar.. i had a 2 1/2 dp w/ same size piping to a 3inch straight thru muffler... my power died off top end as well. after being advised to "always" run "at least" a 3inch dp at least right from the turbine..i decided to try dropping my exhaust and run straight dp... well my boost when from 12psi to 18psi... and the car was a completely diff animal....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jmcmil6 &raquo;</TD></TR><TR><TD CLASS="quote">

#1 and 2. I had a similar set up on a h22 at about the same amount of boost w/ a t3/t4 .48 ar.. i had a 2 1/2 dp w/ same size piping to a 3inch straight thru muffler... my power died off top end as well. after being advised to "always" run "at least" a 3inch dp at least right from the turbine..i decided to try dropping my exhaust and run straight dp... well my boost when from 12psi to 18psi... and the car was a completely diff animal.... </TD></TR></TABLE>

wow. ill try that. thanks for the help

 

no problem.. but be careful. from the boost increase i popped my motor

 

sounds like your pushing the limits (or exceeding them) with that turbo... 16 psi is a lot for a straight t3.

I'm running the same turbo on my b20a (prelude) and i have a drop off over 5000rpm and i'm only running 6psi

bigger turbo needed my friend

 

yeah i just dont wanna shell out 600 more bucks for this thing. I mean its christmas and i plan on buying a ring for my gf and stuff.

 

it should hold at least 13 all the way. I have done it before even with a 45trim t3 and a 2.5" turbo back exhaust.

Make or borrow a pressure tester and attach it to the turbo inlet to see if you have any leaks. Also what type of intercooler do you have? air filter? blow off valve?

 

no air filter. turbo xs rfl. i really think it has to do with the crush bent piping on the turbo to intercooler side.

 

btw- its a johnnyracecar 6 inch. old style

 

boost leak at your silicone hose connectors?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elpiar &raquo;</TD></TR><TR><TD CLASS="quote">boost leak at your silicone hose connectors?</TD></TR></TABLE>
i checked all my couplers but theres one from the turbo side that has a small lil rip in it. but its not a hole. but maybe when the motor is under a great deal of load it may be open up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1boostedcivic &raquo;</TD></TR><TR><TD CLASS="quote">yeah i just dont wanna shell out 600 more bucks for this thing. I mean its christmas and i plan on buying a ring for my gf and stuff.</TD></TR></TABLE>

Buy the turbo, she will understand....especially if you haven't told her about the ring yet

 

ya.. bigger turbo, ive got a .42/.48 on my ls, it doesnt hold 10 psi... usually drops to about 8 around 56-5800. spool time is nice, but thats about it...

 

well guys it looks like i will have to wait till valentines to get engaged. new turbo it is.

 

why dont you make a pressure tester for $5 first. you might be surprised. not that I dont think you need a bigger turbo, but you should try to maximize what you have first IMO.

I presure test one or two cars a week and probably 1/2 or them have a leak of some sort.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bailhatch &raquo;</TD></TR><TR><TD CLASS="quote">why dont you make a pressure tester for $5 first. you might be surprised. not that I dont think you need a bigger turbo, but you should try to maximize what you have first IMO.

I presure test one or two cars a week and probably 1/2 or them have a leak of some sort.</TD></TR></TABLE>

how does that work?

 

a buddy of mine told me to get a silicone coupler, and on one end of it, take a pvc pipe cap and drill out a hold to accept a nozzle u can hook an air chuck up to... and then connect that assembly to your turbo inlet, and pressurize your system. u would need some sort of gauge i woudl think, to indicate pressure drop... i havent tried this yet, but im sure it would work pretty good