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Old 09-13-2011, 12:16 AM   #1
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Default Your opinion please: anything wrong with this downpipe design?

Do you see anything wrong with this downpipe? Is it too restrictive? The wastegate outlet seems too small and angled to me? Is it going to affect anything?



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Old 09-13-2011, 12:19 AM   #2
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not great, but should work
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Old 09-13-2011, 12:23 AM   #3
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If that is a wideband, isn't it way the fuuuuck too close?
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Old 09-13-2011, 12:46 AM   #4
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Originally Posted by blaen99 View Post
If that is a wideband, isn't it way the fuuuuck too close?
Yeah I would be worried about heat and the sensor, especially without a heatsink.
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Old 09-13-2011, 12:49 AM   #5
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didn't even pay attention to the sensor. yes it will fry within a couple weeks that close
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Old 09-13-2011, 01:13 AM   #6
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Depending on the rest of the setup...boost creep anyone?

And yes that sensor is toast.
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Old 09-13-2011, 01:48 AM   #7
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Thanks guys. It's 2.5" from here onwards. I will get it redone.
I posted a separate thread on missing 60bhp.
https://www.miataturbo.net/engine-performance-56/where-my-top-end-power-60335/
Other than what was suggested in the thread, could this be the reason? Does it make that much of a difference between a shitty outlet and a well designed one?
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Old 09-13-2011, 01:59 AM   #8
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yes i think this could definitely be your culprit. Was this the same downpipe that was on your old setup that made more power?
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Old 09-13-2011, 02:51 AM   #9
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No it was a different downpipe that flows a lot better. But there we other variables such as changing headgasket and running cops.
I will check my cams, check my exhaust for collapse and they are both fine, then I will redo this. Thanks.
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Old 09-13-2011, 03:00 AM   #10
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You are losing power from 5000rpm up - the worst downpipe in the world won't cause that. You have something mechanically wrong with your setup - either a big boost leak, incorrect cam timing, or something of that sort. It has nothing to do with design of parts or anything like that.
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Old 09-15-2011, 01:45 AM   #11
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Also get real studs instead of those 39 cent ace hardware ones.
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Old 09-15-2011, 07:25 AM   #12
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Quote:
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Also get real studs instead of those 39 cent ace hardware ones.
Those are class 12.9 steel.
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Old 09-15-2011, 08:38 AM   #13
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My problem is that it doesn't appear the wastegate will open fully. otherwise it's not that big of a deal...
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Old 09-15-2011, 09:40 AM   #14
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Quote:
Originally Posted by Braineack View Post
My problem is that it doesn't appear the wastegate will open fully. otherwise it's not that big of a deal...
That's a good point. In my other thread, my problem with the missing 60bhp is on full boost. That's when the waste gate should be fully open.

In my current setup, the waste gate can fully open. But whether if it is flowing fast/smooth enough is another question.
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Old 09-15-2011, 11:01 AM   #15
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well, you'd make MORE power if the wastegate wasn't opening

You sould look how my T3 wastegate opening merges with the DP and then complain.

This is what the openings look like:



and the merge within a VERY tight area out a signle dump tube:



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Old 09-15-2011, 11:19 AM   #16
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yeah, if anything, that dp will either prevent the wastegate flapper from opening all the way, or just severely limit flow out of the flapper opening. in either case, you would be seeing boost creep (tons, in the case of it not opening all the way).

also, as has been pointed out, that wideband bung is approximately 12 parsecs too close to the turbine outlet... plug that up and relocate the wideband further downstream. a decent amount further.
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Old 09-21-2011, 10:00 PM   #17
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Wow that setup is restrictive! What brand is that? It almost looks like the SS autochrome parts from a while back.
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Old 09-23-2011, 10:04 PM   #18
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Quote:
Originally Posted by Braineack View Post
well, you'd make MORE power if the wastegate wasn't opening

You sould look how my T3 wastegate opening merges with the DP and then complain.

This is what the openings look like:



and the merge within a VERY tight area out a signle dump tube:


Dang that merge is beyond pathetic yo. I guess if it works though **** it
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