For the passed three years i have been battling boost creep issues, had a unknown size of greddy wastegate(40mm?) with a manifold made my Panspeed. Changed to a tial V44 and changed the wastegate runners on the panspeed manifold, was a little better after that. Scrapped the panspeed manifold and had a custom one build with the v44 the creep slowed down, it would hold 12psi fine (10psi spring) one raised with a boost controller it would creep. Now I just went and bought a synapse 50mm wastegate knowning that it will clamp to my exsisting flange on the manifold and hoping the creep will finally be gone. Looking at the flanges there is a obvious differance in opening, My question is to people who have swapped to this gate if you retained the v44 flange on the manifold leaving the larger valve seat in have you noticed a difference? Im trying to not take the manifold and get it re-welded.

Thanks

 

hmmm...are you saing the V-band flange is a different size? if so..your going to have to get the correct size flange on there or the v-band won't clamp...its a different size. If your talking about just changine the valve seat you may want to start with the smallest valve-seat available and if you get creap move to the larger one..... Do you have a pic of the manifold?

 

the v-band are the same size in circumference its just the inner diameter i am worried about

 

It will not work,

 

Id be surprised if it fixes your problem anyway.

I'm having to run dual runners and dual Tail 44's now.

 

The solution to your problem is run more boost... It won't creep at say 15-16 psi which you can safely run on pump gas.

thewird

 

OP, do you have a pic of this manifold? Is the wastegate re-routed back into the downpipe?

 

no picture on the manifold and the wastegate isnt re-routed into the downpipe, i was think about re-routed it there to see if it creates a vaccum effect sucking the exhaust through the wastegate. basically the manifold has one 2inch pipe right below the t4 flange and both runners go into that. guy how made the manifold never had a issue with is design on his car.

 

no harm done in running it with the large seat to at least see where it holds, you may be surprised at how well the Synapse valves do their job. the most difficult part is picking the correct port configuration to do what you need it to do since they are a little more complex than your typical wastegate.

if it still creeps then you may just want to bite the bullet and either upgrade the wastegate runner again or run dual wastegates. alternate already stated running more boost will also eliminate the creep once you find where it is happiest.

dumped wastegates will always eliminate creep better, plumbing it back into the exhaust will just make it more pronounced and difficult to control no matter how you plumb it in, exhaust always builds pressure which reduces the wastegate's ability to bypass the turbo.

 

How is your wastegate hooked up? (describe the vacuum line setup) If your having no issues at low boost, then your problem is not the wastegate. With more boost, you use the wastegate less. Also, what are your boost controller settings?

thewird

 

I was running from the turbo compressor to bottom port on the tial, now from the UIM to the bottom port. I can't remember what the controller is set at still figuring the greddy out but when I had my blitz ebc type s I had the gain up at around 20 with my current manifold and gate. She would creep at the top of third 8000rpm hit cut then top of fourth around 7000 it would hit cut

 

The only correct way to hook up the bottom port of the wastegate is at the turbo compressor (or anywhere before the intercooler but compressor preferred). The boost controller can be connected on the UIM but I prefer it Tee'd into the compressor as well as I find it much more consistent that way. Do this and lower your gain to 5% and leave it there. This will solve your problem.

thewird

 

what your saying is to compressor -> bottom port then top port -> ebc solenoid -> Tee'd into comp-> bottom port?

 

Im quite interested in the port configurations because i may just ditch the boost controller all together since i just would like to run 15psi all the time. one less thing to have aswell

 

Not my diagram but it was the first one I found with Google images, this is the only correct way to hook up a wastegate/boost controller... Boost controllers allow you to setup the turbo to spool quicker then if running just on wastegate alone fyi so moving to the synapse and ditching the boost controller is backwards thinking.



thewird

 

been down that route before. Tial to synapse .. no fix. Back using a tial!

 

It's funny how many cars I get to tune from professional performance shops with the boost controllers hooked up wrong, too small vacuum lines, or just a shitfest in general. It's such a simple too if you understand how the system works...

Make sure you use a metal T as the plastic ones might melt depending on how you route it. It's just a precaution anyway.

thewird

 

Interesting, both tial and Greddy diagram are very different... Defiantly will try this with my v44 if it doesn't change a thing then 50mm goes in. Thanks for that

 

My last FD had creep issues... I had trouble keeping it below 18+ psi and never could redline it or run WOT. This was with a 3574 and the old style long runner manifolds from aspec. I went from a tial 44mm to a JGS 50mm (same flange) and it made a huge difference. For the first time, I was able to keep boost below 15/16 psi to 8k.

I still had some creep though (13 up to 15 psi from 4500 - 8000 rpms). I bought a Blitz Dual SBC boost controller and everything was finally rock solid.

 

Like I said if your not having creep issues at 10 psi and the issues only come when you raise the boost, the problem is 100% NOT the wastegate or manifold design. Connecting it like this will almost certainly fix your problem. I deal with this crap all the time with customer cars for tuning. Make sure there are no leaks in the system either.

thewird