ClimberDHexMods Posted June 17, 2010 Author Share Posted June 17, 2010 It's a twinscroll variable physics 45-80lb/min monster So the wheels expand a contract their length based on shaft speed... I like it [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
Full-Race Geoff Posted June 19, 2010 Share Posted June 19, 2010 What is the optimal diameter exhaust post turbo for a 44lb and 55lb turbo, respectively? i feel 3" is optimal for damn near everything, especially if there is an internal gate. Second, have you experienced a length of pre-EWG tee runner length where boost control starts to be impacted? For example, 1 foot of straight pipe, 8", 6", etc? adding length begins to increase the volume of the manifold which hurts spool to a degree (thats the main discussion of this thread). The issue which effects boost control is not so much the length of the WG runner, but the transition to wastegate inlet Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted June 19, 2010 Author Share Posted June 19, 2010 i feel 3" is optimal for damn near everything, especially if there is an internal gate. adding length begins to increase the volume of the manifold which hurts spool to a degree (thats the main discussion of this thread). The issue which effects boost control is not so much the length of the WG runner, but the transition to wastegate inlet Thank you! You are very generous with your time! [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
mwiener2 Posted June 30, 2010 Share Posted June 30, 2010 Teaser Pic!! http://i974.photobucket.com/albums/ae227/5250Performance/IMG_2754.jpg My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted June 30, 2010 Author Share Posted June 30, 2010 Have you looked at any n/a crossmembers? Slightly easier downpipe run... [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
mwiener2 Posted June 30, 2010 Share Posted June 30, 2010 I have a plan for the exhaust (there's no 'downpipe' on a FMT) My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted June 30, 2010 Author Share Posted June 30, 2010 I have a plan for the exhaust (there's no 'downpipe' on a FMT) Obviously not, but you did know exactly what I meant, so I'll stick with it [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
Boostin1657615274 Posted July 1, 2010 Share Posted July 1, 2010 Check out the exhaust manifolds on the new BMW N63 twin turbo v8 engine: http://legacygt.com/forums/attachment.php?attachmentid=86936&stc=1&d=1277956160 twin twin scrolls On the search for a new DD... Link to comment Share on other sites More sharing options...
mwiener2 Posted July 1, 2010 Share Posted July 1, 2010 Now that's just plain silly My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted July 1, 2010 Author Share Posted July 1, 2010 love how they go so far as to engineer all that, yet the yellow and blue pipes tee at a straight 90*, no V joint in sight. A) doesn't matter, or B) was good enough... [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 1, 2010 Share Posted July 1, 2010 Check out the exhaust manifolds on the new BMW N63 twin turbo v8 engine: http://legacygt.com/forums/attachment.php?attachmentid=86936&stc=1&d=1277956160 twin twin scrolls I wrote about that here: BMW-twinscroll-goodness I think we can start to expect more of those sorts of things in the near future. http://i248.photobucket.com/albums/gg194/littlebluegt/TStech1.jpg http://i248.photobucket.com/albums/gg194/littlebluegt/TStech2.jpg Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
NSFW Posted July 1, 2010 Share Posted July 1, 2010 Secondly, TS is much more than just theory; its been around for 30 years and im honestly amazed that some well regarded "tuners" have such a hard time embracing this. I don't think it's contentious that twin scroll works better than single. What is contentious is how much better it is. More specifically, is it sufficiently better to justify the added expense? What's missing is a proper comparison. A pair of dyno charts showing the same motor, compressor, and turbine with single and twin scroll exhaust housings. Is that really asking too much? In all your testing did you never actually do such a comparison? Link to comment Share on other sites More sharing options...
Boostin1657615274 Posted July 1, 2010 Share Posted July 1, 2010 What's missing is a proper comparison. A pair of dyno charts showing the same motor, compressor, and turbine with single and twin scroll exhaust housings. Is that really asking too much? In all your testing did you never actually do such a comparison? I actually think it is too much to ask for on crappy chassis dynos in a tuner shop. That's the kind of testing that needs to be done on engine dynos in labs under controlled conditions. Subaru engineers have the data I'm sure but unless you can find an SAE paper it's going to be tough to get accurate information. I did post that type of information for two non-boxer engines. The Mazda tests were pretty much exactly what you are talking about: http://legacygt.com/forums/showpost.php?p=2964555&postcount=17 The whole cost thing just comes from the fact that the until 2010 models the 2.5 liter engines were not engineered for them, which forces you to buy or create low production parts. On the search for a new DD... Link to comment Share on other sites More sharing options...
NSFW Posted July 1, 2010 Share Posted July 1, 2010 All I can say is that as a consumer, I don't open my wallet without evidence that I'm getting something for my money - in this case, proof that the extra cost for twinscroll is justified. Can I upgrade to a 35R without trading off powerband width? If I stick with a 30R will the power come on sufficiently sooner to justify the extra cost? Conversely, if I wanted people to buy my product, I'd try to show them how much of an improvement my product would provide over the usual approach. An engine dyno would be better, but I don't much care; I'd be satisfied with results from a chassis dyno. I've seen the results from enough pulls from my car that I have a pretty good understanding of how repeatable they are / aren't. Anyway, I just realized this is a thread about low-mount setups, not twin scroll setups, so I'll pipe down. Link to comment Share on other sites More sharing options...
Boostin1657615274 Posted July 1, 2010 Share Posted July 1, 2010 Anyway, I just realized this is a thread about low-mount setups, not twin scroll setups, so I'll pipe down. The thread is about low-mount twin scroll setups such as the one that comes from the factory in 2010 models. On the search for a new DD... Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted July 1, 2010 Author Share Posted July 1, 2010 The thread is about low-mount twin scroll setups such as the one that comes from the factory in 2010 models. Can we confirm first that the factory USDM 2010 LGT header is divided and equal length, but single scroll flanged and single scroll turbine housing? Well, it is. Talk about 'not quite either.' My thought is that if you're going to bother doing a low mount turbo, might as well cough up the extra time on welding and make it a true twinscroll for an aftermarket turbo. That can be filed under personal decision. Don't know what the talk is about added cost, since a good BW turbo is less than $1k, TS 35R doesn't bump up the cost wildly over SS 35R, and the piping is only slightly more cramped than single scroll, so a minor added cost of time. Two wastegates is the only other issue I see, but you could still get away with one. Thread is about low mount turbo, but digging into things like TS vs SS isn't going to hurt anything, and may help. Would be lovely to see direct lab comparisons, but really how often is the aftermarket that fortunate? Perhaps a dedicated non-turbo model specific TS thread could be created (already exist?) and used to compile decent comparisons of similar turbos with SS vs TS. [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
Full-Race Geoff Posted July 2, 2010 Share Posted July 2, 2010 you are underestimating the issue of the wastegates. there is a solution coming, but its not available yet. Link to comment Share on other sites More sharing options...
mwiener2 Posted July 2, 2010 Share Posted July 2, 2010 Got both headers done and it's getting tight fast. I might have to re-think some piping. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 2, 2010 Share Posted July 2, 2010 Got both headers done and it's getting tight fast. I might have to re-think some piping. pics? Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
mwiener2 Posted July 2, 2010 Share Posted July 2, 2010 not till tues My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Boostin1657615274 Posted July 4, 2010 Share Posted July 4, 2010 Can we confirm first that the factory USDM 2010 LGT header is divided and equal length, but single scroll flanged and single scroll turbine housing? Well, it is. Talk about 'not quite either.' http://legacygt.com/forums/attachment.php?attachmentid=85415&stc=1&d=1274961369 Did you miss this pic from Subaru? Did you not read my posts? It's a low mount twin scroll turbo with equal length divided manifold. The front cylinders go to one scroll and the rear cylinders go to the other. The firing order alternates between front and rear so you get the pulsing effect. There's nothing to debate about on this point. That's the design Subaru chose. It also seems to have an outer layer (the "sliding structure") to retain heat inside the manifold, just like exhaust manifolds used on a lot of other cars these days. On the search for a new DD... Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted July 4, 2010 Author Share Posted July 4, 2010 I read all your posts. The turbo itself does not have a divided housing, which is why I said what I said. Normally the twin scrolls are left and right, not top and bottom, which would explain the lack of a VF36/37 style divided turbine housing. To what effect the non divided vs divided turbine housing makes a difference on a divided manifold, I have no idea. My reservation is that I don't imagine a twinscroll header feeding a single scroll S200 to be comparable to the same header feeding a divided housing. If in fact the opposite is true, it will be a lot easier to make a divided turbo manifold. But, I have done several drawings of under-engine twinscroll header/turbo systems, and it is significantly tighter and more complicated than the solution Subaru chose for the 2010. It makes sense that they would design something simple and compact instead. [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted July 15, 2010 Author Share Posted July 15, 2010 Anyone know anything about swapping our engine cross member or whatever it's called with one from a 2.5i? I know an impreza guy did it. Going to look at that option as well as the prospect of just swapping over a 2.5i sway bar and having an arch fabricated into the brace on the driver side this weekend. Just looking, not doing anything anytime soon. I suspect it would be more beneficial to have the "down pipe" (aka post-turbo exhaust pipe) run back on the driver side. Might make it easier to fit a proper header collector in there. Maybe. Last thought was to use one of the fog light inlets as a ram air inlet. Was looking at a Shelby Cobra air box and thought it could be made to fit in front of the passenger wheel well. Changing the filter would be a lot of fun though... [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
mwiener2 Posted July 15, 2010 Share Posted July 15, 2010 I have 2 different ideas for the "downpipe". neither of which require any modification of the crossmember My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ClimberDHexMods Posted July 15, 2010 Author Share Posted July 15, 2010 I have 2 different ideas for the "downpipe". neither of which require any modification of the crossmember What are they? Or only one of us putting cards on the table? [CENTER][B][I] Front Limited Slip Racing Differentials for the 5EAT now available for $1895 shipped, please inquire for details! [/I][/B][/CENTER] Link to comment Share on other sites More sharing options...
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