Exhaust back pressure....
04-14-2013, 10:26 AM
#251
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Re: Exhaust back pressure....
In regards to why I started this original thread, I snapped two shafts on the 67/65 and both were PTEs new smaller shaft. They rebuilt it a third time (all for free and great communication and time each time) with an older, larger shaft and she has been going strong for over 50 passes now. I've been logging back pressure and it is right around 1.2 with the new exhaust housing.
04-14-2013, 06:10 PM
#252
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Re: Exhaust back pressure....
thats not necessarily a good thing tho haha. just wanted to hear some constructive criticism to assure myself. it sounds like the 1.10 housing will help midrange power, which seems to be the strong point of running it over the 1.25, especially on an open manifold. but now that im building a new manifold for it, I feel like i should just go divided. wastegate priority seems like it would be so much easier to achieve with a big 60 on an open manifold though, and thats something that i'd like to consider when designing this setup.
04-14-2013, 06:31 PM
#253
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Re: Exhaust back pressure....
Twin 44's are not necessarily a good thing either. Two wastegates result in different backpressure between banks. Bridging them together equalizes all the runners. I have tried both divided and undivided on the same setup and see no difference. The divided housing seems to have no benefit in drag racing IMO.
04-14-2013, 06:53 PM
#254
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Re: Exhaust back pressure....
Twin 44's are not necessarily a good thing either. Two wastegates result in different backpressure between banks. Bridging them together equalizes all the runners. I have tried both divided and undivided on the same setup and see no difference. The divided housing seems to have no benefit in drag racing IMO.
04-15-2013, 07:22 PM
#255
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Re: Exhaust back pressure....
None. Tried the divided housing in hopes that it would drive the turbo harder and produce alittle more boost. Spool was not a concern. It did NOT spool any sooner and produced NO additional boost. Back to the undivided Tial V-band housing this year 
04-15-2013, 08:51 PM
#257
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Re: Exhaust back pressure....
ok so what about merge angles? has anyone tested angles to see if a steeper angle has a more negative effect? i know its talked about a lot with na headers, but what about turbo stuff? i remember reading something about how a 10* merge might not perform as well as say a 12-14* merge, even though its more gradual, due to the higher volume. is there a "sweet spot" or am i over complicating things?
04-16-2013, 01:08 PM
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04-16-2013, 09:29 PM
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