internal waste gate con
 

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Well let me be one to say that i am glad i am going external for this build.

Yes, I realize my downpipe is not optimum, that's why this thread. If I decide to retain the internal wastegate, I would rather do a divorced muffled dump tube using one of these:

SuperTrapp 344-2005 - SuperTrapp Disc-Only Mufflers - summitracing.com

than a bellmouth. That would be the easiest solution at this point, rather than having to deal with mocking up and welding a new 2.5" downpipe.


Define precise. If its no better than what I can achieve with EBC and the existing internal setup, then its too much hassle really.

Do you have any data on what typical gains are on a stock TD04 using a bellmouth? dyno plots, datalogs etc or even just a number would be helpful.

External gates can react quicker to changes in boost than an internal gate. Less likely to overshoot when boost comes on for example. They also hold more solidly when in boost. Look at my boost curve with a MBC and external gate. Note, I don't have it configured for dual port yet. Once I do, spool should improve further.

IMO:

Dual port EWG + MBC is better than internal WG plus EBC. Both would spool about the same, but mine will not overshoot, or require tuning, or change when temps drop, etc.

Brake boosting:
Attachment 208378

i can make mine look really flat too....

http://boostedmiata.com/logs/drive_home.jpg

Pat pretty much covered the other question, but here is my take on the dp:
bellmouth downpipe with 3" exhaust and tuning usually nets a good 40whp on wrx's that I have seen. May be a bit more may be a bit less. The response and torque curve jumps significantly, and while the td04 still runs out of breath up top (on a subaru) it is still way better than with that pos plate with small pipe that they call a downpipe that it comes with stock.

I would just keep the iwg if I were you. You are already done with your build and have it set up this way I'd leave it. But thats just me. If you were starting on a build right now I'd recommend ewg though.

This would simplify my planned build for an external gate immensely but goddamn is that a rubber mount on the end? How the hell will it hold up to heat?

I need to look for some reviews.

Edit: Seems to be noisy for DSM guys. Would cost a fair bit more than just rerouting back into the DP for me anyhow.

Bad, good, better, best

Stole this from the downpipe FAQ over at NASIOC.

Go all the way to the right.

And hook it back in. If you buy one big 1 3/4 j-bend from Summit, you'll have more than enough curves to do that. I've driven cars that dump separately, and you can't get on boost without everyone in a mile radius knowing about it.

That's what I'm planning to do... Pics! :cool: