Van hates internal wastegates

Anyone ever have issues with boost creep? My old setup (stock 2.5 with a garett, intercooler, and 3" exhaust) would boost creep up to about 18 psi even with the wastegate flapper unhooked. My new setup is a 2.5 with a BMF intake, log manifold, hybrid Turbo, and a big valve head. I can control boost to 5 psi until 4500 rpm then it starts climbing. At 6500 rpm I am at 20 psi.

I don't see many people running external wastegates on their 8v engines so why doesn't mine hold boost well?

Sent from my SM-G900V using Tapatalk

I'm a little confused by it as well. The only thing i've personally encountered is that there is a difference in creep between 2.5" and 3" exhaust systems. I don't think i've ever experienced boost creep with a 2.5" exhaust, even with mitsu and open downpipe.

Other than exhaust size it's just a reflection of your engine moving more or less CFM at whatever psi of boost. So a better flowing setup might creep more than a worse flowing setup with the exact same wastegate/turbo/exhaust.

In other news, 20psi and 6500 rpm on that setup sounds exciting. ;)

Do you already have a raised rev limiter to be hitting 6500?

Current exhaust is about 24" including the 90* bend so it can definitely flow. what's even more weird is that I had this same setup (Turbo and swingvalve) on a spirit R/T and there was no noticeable creep with boost set at 15 psi.

It's pretty scary in 3rd gear trying to hold on. can't wait to get it tuned in a little better and turn up the boost even farther.

I'm running an old version of robs code that the rev limiter doesn't even work in. Just haven't got around to changing it over. I did a pull to 7000 and it felt like it wanted to keep going, might need to pull the offset key out of the cam.

Sent from my SM-G900V using Tapatalk

You have to port the sh!t out of the wastegate pathway, I spend at least an hour or two on that passage, heck I'm running a big compressor Mitsu(the WORST creep situation) on Woody and creep is only about 2-3 PSI. I like to widen the wall of the turbine housing there anyway so opening that side for WG flow has extra benefit anyway. TU sells a larger puck, then you can REALLY grow that WG pathway.

yep, if it's creeping then the hole isn't big enough.

I got the fix for you.
You need to give it the same treatment MeanMini got.
You can get a 38mm puck from TU. They also have a 35mm.

This has pretty much eliminated my creep.
Attachment 57945

Quote:

---

what's even more weird is that I had this same setup (Turbo and swingvalve) on a spirit R/T and there was no noticeable creep with boost set at 15 psi.

---

If you look inside a TIII turbine housing it has a larger wastegate orifice and the design seems to prioritize more flow towards the wastegate than a TII housing. So that's not totally surprising.

Quote:

---

Originally Posted by Vigo

If you look inside a TIII turbine housing it has a larger wastegate orifice and the design seems to prioritize more flow towards the wastegate than a TII housing. So that's not totally surprising.

---

This turbo came off my spirit R/T, I never owned an R/T with a factory turbo. Either way we'll see how it does at the dyno this saturday and the track sunday.

Good luck!