Here's a quick list of mods:
00 Honda Civic SI (b16a2)
Drag Turbo Kit
8.8:1cr JE pistons
eagle rods
AEM EMS
AEM Uego wideband
GM 3bar map sensor
RC 440's
AEM FPR 1:1 riser
Walbro high output intank fuel pump
Precision SC50 .63ar
Tial 35mm wastegate
2.5 inch downpipe to 2.5-3 inch testpipe all the way out to a thermal 3inch

When I boost it holds boost around 11psi to 7000rpm (with a 6psi spring in the w/g) but between 7000rpm to 8000rpm it climbs up to 16-18psi!!! Once I put the JE pistons this has started to happen... before on my stock pistons I would boost 8.8-9psi perfectly to redline even with the 3 inch Thermal and the junkie DRAG manifold... Whats going??? on I'm so sick of dumpin any more money into this car

 

What boost controller are you using?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbozxi &raquo;</TD></TR><TR><TD CLASS="quote">What boost controller are you using?</TD></TR></TABLE>

NONE

 

I would assume you have a loose connection or a hole in one of the vacuum lines from turbo to wastegate have you checked them?

 

yea I had a ripe and I replace it the other day, but it was at the nipple so it didnt effect anything... But I replaced it anyways with some new vaccum hose! I don't get it I even got a new fire ring wastegate gasket too cuz my tial one blew up on me!

 

How much timing you are pulling. Just a thought, maybe your exhaust gas temperture is higher than usual.

 

not sure? but this happen with my Hondata system too when it was tuned and now I have the aem ems not tuned yet and its doing the same thing but I think it spikes even higher now!!!

 

Your problem is your wastegate. I would double check the vac line you have to your wastegate, make sure it's on the side of the wastegate and not the top. The top of the tial is suppose to be for a boost controller.

 

its one the side of the wastegate

 

I had this kind of problem before but mine spiked during the winter when the air is really cold and the motor wasn't ran for very long before I hit it.

 

but why does it hold boost all the way to 7k but from 7k-8k it spikes?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 9psiTurboSI &raquo;</TD></TR><TR><TD CLASS="quote">but why does it hold boost all the way to 7k but from 7k-8k it spikes?</TD></TR></TABLE>

what are you using for your vaccum source? to me it sounds like the source you are using is too weak.

mike

 

the back of the intake manifold where to cruise control vaccum goes into

 

The big problem about boost spike is because of the Drag manifold.. Drag manifold, the wastegate location is in the 4th runner which cause boost spike all the time in higher boost setting.. If I was you, I would of ditch that manifold and goes with inline pro, full race, rev hard.. etc...
2nd. I think it because of the boost controller.. Check all the vacuum on those and where u tee it at..

Dont boost that high again until you find the answer... Boost spike can blow up motor very easily.. Check your hondata. Set the boost cut in your hondata so they wont run crazy boost...

 

I have a 6.5lb spring in my wastegate, and it only boosts to 5.5psi. I think there is def. something wrong. I don't think the manifold can make it spike that bad, so like everyone says, check the vacuum lines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by youngkow &raquo;</TD></TR><TR><TD CLASS="quote">I have a 6.5lb spring in my wastegate, and it only boosts to 5.5psi. I think there is def. something wrong. I don't think the manifold can make it spike that bad, so like everyone says, check the vacuum lines.</TD></TR></TABLE>

a manifold CAN and WILL make it spike that bad, i have seen it time and time again on that model drag manifold.

but yea, check the basic stuff...(im sure u already have)
mike

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo-Honda &raquo;</TD></TR><TR><TD CLASS="quote">The big problem about boost spike is because of the Drag manifold.. Drag manifold, the wastegate location is in the 4th runner which cause boost spike all the time in higher boost setting..
</TD></TR></TABLE>

Not that it matters but isn't it the 1st runner?

 

great! now I have to spend even more money on a new manifold and downpipe

 

a CHEAPER alternative might be to get a bigger wastegate...have an adapter welded on the stock place to fit a 40mm or something..

mike

 

Trying getting your boost pressure feed for the waste gate from the vacuum line that go's to your fuel pressure regulator from the inlet mani, just T it off it is said to be the best place..

 

ill try that!!!