Gixxer Squid Posted September 8, 2012 Share Posted September 8, 2012 Did lots of searching but little information here. Is there a benefit in porting the exhaust manifold. Yes it may spool quicker but does anyone have hard numbers to support this? Pulling turbo off to change some things and thinking I may pull exhaust manifold as well and do some porting and polishing if it may be worth it. Would obviously match to the gasket. I wouldn't mind having turbo spool a bit quicker but 100 rpm less may not be worth the time , money or hassle in pulling everything off. Thoughts? Much benefit in porting the 6 ports or main port feeding turbo?? J Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 8, 2012 Share Posted September 8, 2012 Jeff P's Anglefire "Extreme 280ZXT" page covers this. Quote Link to comment Share on other sites More sharing options...
Gixxer Squid Posted September 8, 2012 Author Share Posted September 8, 2012 Jeff P's Anglefire "Extreme 280ZXT" page covers this. Guess I should have read further.....its already on my computer bookmark Quote Link to comment Share on other sites More sharing options...
johnc Posted September 8, 2012 Share Posted September 8, 2012 IMHO, its worth it in conjunction with other engine efficiency mods - its one of the little things that really adds up in combination with a bunch of other little things. If its the only thing you do to improve engine performance, its not worth it. Quote Link to comment Share on other sites More sharing options...
Gixxer Squid Posted September 9, 2012 Author Share Posted September 9, 2012 (edited) IMHO, its worth it in conjunction with other engine efficiency mods - its one of the little things that really adds up in combination with a bunch of other little things. If its the only thing you do to improve engine performance, its not worth it. Tony, All Jeff said was that he had porting work done and I saw his handmade exhaust manifold. Didn't really discuss whether there was noticeable differences.. John: Guess it boils down to what you consider "other efficiency" mods. Car is Rebello built stroker, cam,oil & intercooler, gt 35, new baffled tank with internal fuel pump, OS Gikken LSD, Full suspension on all four corners, larger stainless fuel lines etc..... List way to long. Ended up going with the Kumho 701's 275 rear. Not happy with the turbo itself coming on after 4k rpm so gonna change a few things, ( ID2000 injectors and converting to E85) I have spent lots on this baby and while I have turbo off, thought I might be able to do some additional tweaks for air flow, just trying to figure it if spending the extra will make that much difference in the set up. Obviously not necessarily from a HP or Torque, but if its going to be negligible in going to all the work to do this than I will spend money elsewhere. Few pix I just took. James Edited September 9, 2012 by Gixxer Squid Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 9, 2012 Share Posted September 9, 2012 No photos visible. As I recall Jeff gave pretty detailed photos of the port work done at the head juncture which increased port flow considerably The BIGGEST reason given by most for going to a tubular exhaust manifold on a turbo is the perception that it "flows better than the restrictive cast manifold"-- but when you cut apart a stocker, like Jeff Shows, the internal diameter of the Euro Manifild is actually larger than the SFP 1 5/8" tubular one he bought for excessive $$$. When you then realise this, and see the bumps and restrictions at the head juncture, it becomes easy to remove flow obstructions that are obvious -- giving you the cast Manifild with a "tubular equivalent" on the exhaust port to Manifiold. Depending on the engine it was installed upon his spool was a couple hundred RPM's earlier, and obviously no impediment to power production to over 7200 RPM's. As far as I know Jeff's setup is the only one I know of making 650+ HP on stock based intake AND exhaust Manifolds. He did it for a reason, and do far the only quantifiable reason for removing a stock manifold was found on the intake side, where the stock runners are costing us 30CFM per hole compared to the Cannon Triple manifold and either a plenum or ITB Setup. The exhaust side, ported to be tubular equivalent on the flange to head area does not appear to require replacement to 650+HP at 7200 rpms (and he's just afraid to run it higher, I'm working on him about that...!!!) Quote Link to comment Share on other sites More sharing options...
Gixxer Squid Posted September 9, 2012 Author Share Posted September 9, 2012 (edited) Thanks Tony, Obviously its not going to hurt anything so I will so some porting when the turbo is pulled this week. Regarding the pix....?? I accessed hybridz from my girlfriend computer and photos show up in thread, not sure why you can't see?? Photo's showing up for anyone else?? http://imageshack.us/photo/my-images/823/img0439hyc.jpg/ http://imageshack.us/photo/my-images/193/img0441vi.jpg/ http://imageshack.us/photo/my-images/9/img0434ko.jpg/ http://imageshack.us/photo/my-images/171/img0435zw.jpg/ http://imageshack.us/photo/my-images/18/img0444bw.jpg/ Edited September 9, 2012 by Gixxer Squid Quote Link to comment Share on other sites More sharing options...
Noddle Posted September 11, 2012 Share Posted September 11, 2012 Hi, A few years ago I looked at doing this, but for me it was to much work, and for my setup, it may have not been worth the cost, ( L24 ) I did ask Jeff this, and his reply, which may be useful to others, I hope he does not mind me sharing.. Hi, I was checking out your pictures here http://www.angelfire...zxt/page11.html and i was wondering if you had any from the other side, showing where you had welded up the outside of the runners. thank you for your time Hi There, I was looking for pictures of the welding completed on the manifold. Unfortunately, I did not snap any shots of the before and completed part. I did have to grind the radius in each side of the manifold to fit the fat washers again correctly, but the dremel with the cutoff wheel was the perfect diameter to make the new radius for the securing washers. The manifold is fully opened up at each runner. The turbo inlet took significant work to open up. The front main tube through the header to the turbo inlet was opened up significantly. So the header now lets the engine breath well. there was a little more but not relevant to this topic. Nigel Quote Link to comment Share on other sites More sharing options...
Gixxer Squid Posted September 11, 2012 Author Share Posted September 11, 2012 Hi, A few years ago I looked at doing this, but for me it was to much work, and for my setup, it may have not been worth the cost, ( L24 ) I did ask Jeff this, and his reply, which may be useful to others, I hope he does not mind me sharing.. Hi, I was checking out your pictures here http://www.angelfire...zxt/page11.html and i was wondering if you had any from the other side, showing where you had welded up the outside of the runners. thank you for your time Hi There, I was looking for pictures of the welding completed on the manifold. Unfortunately, I did not snap any shots of the before and completed part. I did have to grind the radius in each side of the manifold to fit the fat washers again correctly, but the dremel with the cutoff wheel was the perfect diameter to make the new radius for the securing washers. The manifold is fully opened up at each runner. The turbo inlet took significant work to open up. The front main tube through the header to the turbo inlet was opened up significantly. So the header now lets the engine breath well. there was a little more but not relevant to this topic. Nigel Thanks. Pretty sure I am going to do it anyhow. Unfortunately its going to be the manifold only and not the head where exhaust ports match anyhow which really may mean I am not getting much benefit. I guess when I pul it off and take a look inside to see if there are areas for improvement or air flow restrictions I will do so. Maybe there will be more improvement on the inlet and exhaust side of the turbo, will determine that as well. Car gonna be in the shop a while so may as well get dirty while its apart. Since I will have it off, thoughts on ceramic coating it or I think I saw, Jett hot. I would LOVE to have inside of the cast manifold done too, guess they have you sign a waiver, lol but saw many people on threads that have had this done, would assume air movement if coated right would significantly flow air better. Quote Link to comment Share on other sites More sharing options...
djz Posted September 16, 2012 Share Posted September 16, 2012 What a/r is your exhaust housing and is it a ball bearing turbo? 4k seems like a very late spool for a turbo that small. Quote Link to comment Share on other sites More sharing options...
FricFrac Posted October 22, 2012 Share Posted October 22, 2012 What a/r is your exhaust housing and is it a ball bearing turbo? 4k seems like a very late spool for a turbo that small. +1 - most ppl run the "GT35R" and have been very happy with it. 4K seems way late for this turbo so I'm assuming your running a much larger A/R As for porting the stock manifold there are a few runners which are quite restricted by "bumps" and the inlet to the turbo doesn't match in size and the corners are quite sharp. There's not a lot of work to reduce the bumps and smooth the transitions into the turbo. I think the small effort is worth it. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 22, 2012 Share Posted October 22, 2012 Jeff's GT35R with 0.63A/R housing makes full boost at 3200rpms. Any other time below that he gets 3psi, until 3200, then full boost. Lesson: Proper driving technique is to not go WOT before 3200rpms. Just like driving a cammed car! Quote Link to comment Share on other sites More sharing options...
johnc Posted October 22, 2012 Share Posted October 22, 2012 IMHO... A powerful L6 engine, regardless of induction type, has a power band from around 3,500 rpm on up. That's just the nature of the beast. Efforts to make power and torque below that numbers is wasting time and money. Gear the car to work with that power band minimum and everything become magic. Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 23, 2012 Share Posted October 23, 2012 Couldn't agree more John, the stock L28ET would boost 8# at 2500 rpms as a way to get the American foot happy with bottom end torque. Jeff's cam comes "on" after boost threshold, same as an N/A car would. His car accelerates like a built Rat-Motored 72 Vette except that when you pass 4500 the thing just puts you back in your seat harder and it's still on the climb when he shifts (prematurely) at 7200. People don't drive "on the cam" like they should, and with Turbos, it's even worse. If people drove the cars properly, they would be satisfied with far less 'bragging horsepower' as the car won't be overbuilt to pull stumps like a Big Block V8 at 1500. Quote Link to comment Share on other sites More sharing options...
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