I am using a heat treated peakboost "ac" ramhorn with a 38mm wastegate flange with a 38mm to 44mm vband adapter connecting my 44mm tial wastegate...

i am using a t1 turbo blanketed precision 6265 turbo and the wastegate has a 9psi spring that is crepping to 13/14psi.

if i cut off the 38mm flange and replaced it with the proper vband to have a direct fit 44mm tial wastegate would that difference be enough to stop the creep i am experiencing?

my additional concern is that i want to modify my dump tube to recirculate into my 3" down pipe... would this make boost creep even worse?

 

Maybe that 9lb spring is really a 15lb spring.
The wastegate adaptor shouldnt have anything to do with that creep..
A wategate is quite a simple working part . Keeps closed to hold boost in opens to release extra exhaust
Maybe a boost controller issue.

 

LOL. Creepboost strikes again!

In all seriousness, though, have someone lob the 38mm entry off the manifold completely, and replace it with a proper 44mm gate entry and flange.

 

If its the peakboost ramhorn I'm thinking of the WG placement on those already isn't very good. Adding an adapter onto it will only make it worse. I would definitely have someone redo the flange.

As for rerouting your dumptube, I'm not to sure.

 

the 38mm flange opening measures 37mm and the 44mm v band flange opening 42mm. i wonder how much 5 mms would help? anyone have any ideas because id hate to do that work and it still not fix the car... wonder if anyone has been in this dilemma..

 

Lol, you need to stop, but I'm sure you are right.

 

If you don't want to take the risk of doing the work and it not working I would just get a different manifold. Just by the design of the manifold the WG has somewhat poor placement

 

My setup is very different than yours (I have a GT3076 on a cast DRAG manifold) but I had boost creep issues before. Some ways back I looped my wastegate back into my downpipe. Surprisingly, the boost creep went away and now my boost falls off at higher RPM. I have no explanation why, but that was my experience.

 

You need to do what D-Rob suggested above, or find another place for an additional wastegate.

 

I would guess that helped because the velocity from the exhaust in the downpipe helped to evacuate the fumes from the wastegate.

Maybe? Just a guess

 

"its all in the tune" lmao

 

Hmmm... Maybe. If you want a reference of how I did mine, it looks like this:

 

x2.

Like a chain is only as strong as it's weakest link, an exhaust is only as open as it's smallest diameter. In this case, while you're running a 44mm gate, it's only effective as a 38mm.

And yes, the 5mm will make a HUGE difference.

Or possibly rerouting caused enough back pressure in the exhaust and exhaust turbine to slow the turbine down enough to keep it under control.

 

Actually, the real reason is due to elevated exhaust pressures after recirculating the WG back into the downpipe.

However, this elevated exhaust pressures is also raising your EGT's and lowering your overall power. That's why wastegate dumped to atmosphere increases power.

Having a wastegate dumped to atmosphere is like having a 3.0" + 1.75" exhaust in terms of exhaust flow capacity (under boost). Recirculating back into the downpipe is similar to downsizing your exhaust, thus, also lowering power and increasing EGT's/exhaust pressures.

 

I appreciate everyones input, I think i am just going to cut off the 38mm flange and weld in a 44mm direct flange for my wastegate and hope for the best

with the additional input on the power losses of a dumptube... i think im going to debate on this further to see if its worth it... i am looking for ways to reduce sound so that is a huge reason why as well as reducing the horrid smells from up front... what an increase in diameter of the dumptube benefit me more and locate it further down to the bottom of the oil pan to recirculate?

 

I really was just guessing on a whim :p Learn something new every day, thanks guys

 

Yup, learned something too. Exhaust pressure after the turbine slowing it down sounds likely to me.

Might not be be the best solution for you DelSol, due to so much power loss. For me it was worth it. I get a lot of enjoyment spooling 5th gear up to high boost on the freeway and whizzing by with minimum exhaust noise/maximum turbo spool noise.

 

That pic is a comparison between my old setup and my new setup. My old setup was a 38mm which was recirculated into a 2.5 inch downpipe. I did this setup originally because I too was concerned about sound. This setup cannot properly control a 6262. New setup is an open dump 44mm with a 3 inch downpipe. Picked up about 40whp between the two.

 

If your point was towards the recirculating waste gate, it is void do to the ".5" increase in down pipe size, because that alone could net those kind of power gains depending on the power level. Additionally, that old dump tube is thinner than the new one pictured...

I would be interested to see the power changes someone has experienced by simply adding a recirculating dump tube on the same size exhaust piping that was previously used without causing boost creep and see if the recirculation causes creep...

I am standing by for a full page reply from Tony the Tiger... the guy is a genius

 

I cut of my 38mm gate and put on a precision 46mm and all my probs went away.

 

awesome! how low of boost have u been able to hold without creep? whats the setup... i see your sig says 30R

 

On my old 30r setup(have not gotten the new 6262 setup up and running yet) I had a 15 psi spring in it, and it held 15 psi rock solid.

 

So do you think recirculating the WG into a 3.5" or 4" exhaust would NOT reduce the creep because the pressure in the DP wouldn't be elevated, or at least not elevated as much?

 

I have been able to hold 13psi with the setup I posted but I am trying to be able to hold 9psi for 1st and 2nd gears (in hopes of gaining traction down low) and then use boost by gear to turn up the boost for 3, 4, and 5 (well not really 5 lol)

 

You must've misunderstood...the old dump is thinner because it is smaller. It was 38mm recirculated. The new one is 44mm and open.

Let me be clear - YOU WILL HAVE BOOST CREEP if you recirculate that dump with that big of a turbo, whether is 38 or 44. Either leave it open, or step up to a 60mm.