Nextelbuddy

i recently had a T3/67 HO and have a tial 38mm with 1 bar spring. with my setup i would always read 14.5 psi on my autometer and datalogs matched. never creeped or spiked just solid 14.5 psi

all i changed to was a 60-1 with a stage 5 wheel .63 ar housing and now my boost goes to 17 psi.

i dont get any creep or overboosting/spiking just goes to 17 psi and sticks. its solid.

if all i changed was the turbo why would i be boosting more now?

i am just running off the spring with no ebc or mbc currently

i talked to a few people and they said that its possbile that switching from a .82 housing to a smaler .63 housing could be creating more back pressure and the higher boost level?

any thoughts?

B18 CYA

What size exhaust do you have? How;s your dumptube routed? I had a t3/60-1 with a .63ar exhaust, held 15psi fine, switched to a .82ar exhaust and boost pressure still stayed the same.

Nextelbuddy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18 CYA &raquo;</TD></TR><TR><TD CLASS="quote">What size exhaust do you have? How;s your dumptube routed? I had a t3/60-1 with a .63ar exhaust, held 15psi fine, switched to a .82ar exhaust and boost pressure still stayed the same.</TD></TR></TABLE>

running 3 inch exhaust all the way back. to a magnaflow muffler 3 inch in dual 2.5 outlet out

my wastegate is routed back into my downpipe about 1.5 feet from my turbo.

it was like this before with the HO turbo

when i removed the HO turbo and just bolted in the 60-1 now i get higher boost level. nothing else has changed.

btw i have a 3 liter I6 motor not a 4 cylinder if that helps any.

DaveF

i dont have any sugestions but

turboM3 thats sick, let see some pics under the hood

Nextelbuddy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dturbocivic &raquo;</TD></TR><TR><TD CLASS="quote">i dont have any sugestions but

turboM3 thats sick, let see some pics under the hood </TD></TR></TABLE>

al my pictures are in my garage in my sig. click the link.

unfrtunately the way the motor sits in the bay with the 30 degree tilt yo cna not se the turbo itself. Top mount is coming soon though


bump for the day guys. anyoe else have any ideas on why the higher boost with smaller turbo or maybe im just being too paranoid.

im only being panaoid like this because i bought my H.O. turbo and it took a dump after 1 month and i want to be sure nothing else will happen

beepy

Where is the wastegate signal being ported off of? Wastegates should work the same regardless of the turbo, but it depends where the boost gauge signal vs. the wastegate signal is being taken.

I'll just assume you are taking the wastegate signal from the volute of the compressor, and the boost gauge signal from the intake manifold. Your new, smaller, more efficient turbo heats that discharge air less, therefore there is less pressure drop across the intercooler. This would equate to higher manifold boost although the turbo was still producing the same output. Are your boost signals arranged like this?

Nextelbuddy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">Where is the wastegate signal being ported off of? Wastegates should work the same regardless of the turbo, but it depends where the boost gauge signal vs. the wastegate signal is being taken.

I'll just assume you are taking the wastegate signal from the volute of the compressor, and the boost gauge signal from the intake manifold. Your new, smaller, more efficient turbo heats that discharge air less, therefore there is less pressure drop across the intercooler. This would equate to higher manifold boost although the turbo was still producing the same output. Are your boost signals arranged like this?</TD></TR></TABLE>

no, i have always had my WG signal coming from the intake manifold as well as my boost gauge.

nothing has changed when changing turbos.

oh well guess ill never figure it out lol it is what it is

93supercoupe

Im gonna have to say that w/ the bigger exhaust housing, Less exhaust gasses went threw the WG, but now w/ the smaller housing, more gasses are passing threw the WG, and maybe it cant keep up.

I know it usually in spike form, but myabe something like this is happening.

coneheadsracing

Can you try the wastegate signal from the turbo compressor side?

Your wastegate won't open up until the boost hits whatever it is suppose to with the spring.

Maybe the fact that you went to a smaller exhaust side, it'll spin up faster, is it possible the compressor wheel is actually packing more air then the last turbo? With it not reacting until the intake sees the 15 psi, your turbo could be making 17-18 i'm just making those number up. I've read in Maximum boost that it is better to take the reading from the compressor housing, and your guage off the motor, as that is what your motor is seeing, but it is suppose to help with over boosting.