Custom 3" 4 bolt expansion dumps ah? The SZ ones are like $625us and $60 delivery, like 750au or so. I'm interested in what you come up with aswell Niall.
One of my mates came up withe a cheap easy way of making them for T25 frame tubo's. Get a bit of 3" exhaust tube and wack it in big hydraulic hose crimper. It will shrink it down to about 2.5" (or whatever you need) which will fit into the 4 bolt flange nicely while still leaving room for the divorced wastegate. Cheaper and easier than mucking about with making your own expansion pieces. All you need is a $10k crimper Not quite as nice as the SZ ones, but you could probably make a set of under $100 if you are handy with a welder.
i dont think divorced is the way to go with a T25 size exhaust housing and 28RS wheels. space is already at a premium and i think that in our case overall flow is more important than worrying about waste gate turbulance. I wasnt able to do any back pressure measurements but from trying different dumps at different boost pressures on my car , the stock dumps far out flowed the tune agent style. with these 3in expansion dumps they fit right to the very outside of the flange so there is no interruption of flow from the exhaust housing at all. I will then be following through with 3in pipe, madrel bends and "high flow cats"
Ah ok, for some silly reason I thought you were getting divorced ones made up. You got any piccies yet? I'm guessing they are similar to UAS's mega dollar ones? Keen to see them when they are done
Sounds great bud!! Keep me posted of updates if you don't mind, and if you're making these available for purchase to members, please count me in!
Pics to come soon i promise. Ill have it off the ground soon for first oil change so you guys can see my glorious 3in turbo back exhaust. Its now got hand made bellmouth 3in dumps as some of you have seen in the other thred, O2 sensors relocated to underneath for easy access. ive got the first half meter of teh exahust braced off the gearbox so its not all swinging off the dumps, really straight with minimal bends, through the center section there is exactly 1m or straight pipe. lol. All bends are mandrel and its in Mild steel. The other things ive done this time round is another stock bottom end rebuild after killing a piston. I lowered the compression ratio as this was a factor for destroying the last engine. Ive gone with 1.6mm cometic gaskets, decked the block etc to suit obviously. I really worked over the heads and manifolds this time, did alot of chamer work, removing the spark plug bosses etc, which will also drop compression a touch. heavily ported the stock exhaust manifolds and perfectly gasket matched everything, i had done a bit of matching on this motor before but not enough in some areas. The difference now is really quite noticeable, its hard to pinpoint whats responsible for the big improvements since i did them together but, It hasnt seemed to lose any responsiveness or off boost torque from lowering the comp which i was afraid would happen. Spool up time, throttle response etc has all been improved it feels like a much better motor in that area. On boost performance is much better than before and miles ahead of a stock motor. It pulls very willingly to 7700rpm with the area 6-7krpm being where it seems to really pull through fast. As its a new motor i turned all my boost control settings down, on 8 psi it felt pretty good, maybe 270rwhp on the arse dyno, now up to 13psi it breaks traction on boost in 2nd. Id guess well over 300rwhp there, very keen to get it on the dyno and crank the boost. Id really like to bolt my whole exhaust onto a stock TT and see how it goes, might try that some day. So pics coming soon and thanks for reading !
After driving your zed the other day id say on the 13psi it was well into the mid 300's. I dont think it was far off my xr6t @11psi. I do think your underestimating it alot. It pulls harder than me for the 3 years of being single!!! All i can say is when the engine gets pulled out of my zed down the road it will be out for a while to get it to where yours is atm!!!
Theres some crappy phone pics of the "Phillips Performance" exhaust.. lol see how the O2 sensors are alot easier to access there. And heres the bit you all want to see, a dyno run i did today, This is a no bullshit run, hot day, conservative dyno, close IT and AT's. Im really happy with the power level for that boost. Its on a nice safe tune at the moment which does need alot of work. Great starting point though. For those who are going to ask me the mod list. Rebuilt motor stock pistons,rods and crank ARP main and head studs Cometic 1.6mm head gasket. Extensive head and manifold port work Combustion chamber modification and all port matching done 3 in turbo back exhaust stock turbo housings with GT28RS cores 555cc injectors Tuned stock ECU FMIC HKS air filter AVCR set to approx 18psi
