Challenger Posted September 25, 2011 Share Posted September 25, 2011 In the process of making my downpipe and had a question. Right now it would be easiest for me to just run a section of straight pipe between the wasegate outlet and the downpipe. The dump tube would come into the downpipe at a 90 degree angle (dump tube is perpendicular to the downpipe). My question is from a fluids standpoint, how bad is this for flow out of the exhaust turbine? Will this have a significant impact on performance compared to routing the dump tube into the downpipe where they "Y" together smoothly? (Dump tube and downpipe are closer to parallel and blend together) Specs: L28et Stock exhaust manifold Hx35w T3-T3 adaptor with 38mm wastegate port between turbo and manifold 38mm external wastegate. 3 inch downpipe 1.5 inch dump tube Thanks Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted September 25, 2011 Share Posted September 25, 2011 (edited) Are you notching your wastegate tube and downpipe? Why can't you just 45 degree (or more) bend and notch that in? Edited September 25, 2011 by BLOZ UP Quote Link to comment Share on other sites More sharing options...
Challenger Posted September 25, 2011 Author Share Posted September 25, 2011 (edited) Yeah, Ill be notching it however I do it, Im just curious about the angle. It wont be to hard to make it come in smoother so Ill be doing that, but I am still curious how bad it is to have it at 90.... Edited September 25, 2011 by Challenger Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted September 26, 2011 Share Posted September 26, 2011 Just make it a screamer pipe out the side of the fender lol Quote Link to comment Share on other sites More sharing options...
Challenger Posted September 26, 2011 Author Share Posted September 26, 2011 Do they make mufflers for 1.5 inch pipe? haha Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted September 26, 2011 Share Posted September 26, 2011 (edited) I've heard it's "bad", and that's about it. Corky Bell also says it's "bad". I'd take his advice and angle it in. Plus it will look like a wastegate to downpipe connection instead of some boiler system. Do they make mufflers for 1.5 inch pipe? haha Yeah, I've seen some on Summit. I thought about the same thing you have. Edited September 26, 2011 by BLOZ UP Quote Link to comment Share on other sites More sharing options...
Nelsonian Posted September 26, 2011 Share Posted September 26, 2011 I have yet to run this setup as my car is in pieces, but talking with Austin(240hoke) who made this downpipe, I recall he was very pleased with the results. This is his old setup including the turbo and downpipe. I had my stock manifold modified to match the tial 38mm wastegate to the small pipe. He has a video on here somewhere of the car making some pulls both from inside and out. I know that does not definitely answer your question, just showing what some others have done. Quote Link to comment Share on other sites More sharing options...
260DET Posted September 28, 2011 Share Posted September 28, 2011 45 degrees is good because it allows the two sets of exhaust gasses to merge more smoothly than they would if intersecting at 90. Smooth flow is a faster flow. Quote Link to comment Share on other sites More sharing options...
Challenger Posted November 18, 2011 Author Share Posted November 18, 2011 I suppose Ill show what I ended up doing, this is the only picture I have on my phone... hopefully you can see the radius on it. Quote Link to comment Share on other sites More sharing options...
Dan_Austin Posted November 19, 2011 Share Posted November 19, 2011 Nicely done. The angle of picture may be tricking me, but that appears to be a 180 6" radius cut in half. If that's the case, I am a whole lot less nervous about that part of my project. Quote Link to comment Share on other sites More sharing options...
Challenger Posted November 20, 2011 Author Share Posted November 20, 2011 (edited) Yeah, thats all I bought. One 180 degree 3 inch, 6 inch bend radius sounds right. My downpipe was in some ways much simpler than others would be. I have my holset spaced out about 3 inches to the drivers side of the engine so the routing is much easier. I don't have the transmission in the way like the normal position of the turbo. Ill try to get some pictures of the downpipe installed. Edited November 20, 2011 by Challenger Quote Link to comment Share on other sites More sharing options...
FricFrac Posted November 22, 2011 Share Posted November 22, 2011 http://www.mandrel-bends.com/catalog/mandrel-bends-34/409-stainless-steel-14-gauge-74/3-00-stainless-steel-409-4-00-radius-180-degree-mandrel-bend-1012.html 4" bend radius gives you the extra room if you need it... like on the S130 with the firewall, etc... Quote Link to comment Share on other sites More sharing options...
Challenger Posted November 22, 2011 Author Share Posted November 22, 2011 Oh yeah, the ZX is awful for that. Again the turbo being spaced out changes a lot. I bet the 4 inch might have made issues with the steering rack. Besides, the direction it was pointing didnt really have any major obstructions so the large radius worked great. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted July 18, 2012 Share Posted July 18, 2012 (edited) Pics of the finished product? I'm in the middle of converting mine as well. The shop is wanting to tap a fitting into the manifold to weld to instead of welding directly to it, I figured I'd give that a shot and weld as a backup. Edited July 18, 2012 by TrumpetRhapsody Quote Link to comment Share on other sites More sharing options...
Challenger Posted July 19, 2012 Author Share Posted July 19, 2012 Thats the only one I have, not around the car to take pictures. I havent spent alot of time on it but I am having issues with controlling my boost, it is creeping way above what the spring says it should. I dont know if its another problem, who knows. Quote Link to comment Share on other sites More sharing options...
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