bradyzq Posted October 26, 2009 Author Share Posted October 26, 2009 Daeron, You have no need at all to apologize. If anything, you are trying to keep the peace! BTW, I just noticed in your previous post (#15), you typed 6-3-1. I have been trying to get the conversation going about a 6-3 setup, with 3 pipes out under the car. I'm pretty sure you just made a typo there though. But in case you were thinking (and maybe johnc was too) that I was talking about a 6-3-1 header, well, I wasn't! Quote Link to comment Share on other sites More sharing options...
Daeron Posted October 27, 2009 Share Posted October 27, 2009 Daeron, You have no need at all to apologize. If anything, you are trying to keep the peace! BTW, I just noticed in your previous post (#15), you typed 6-3-1. I have been trying to get the conversation going about a 6-3 setup, with 3 pipes out under the car. I'm pretty sure you just made a typo there though. But in case you were thinking (and maybe johnc was too) that I was talking about a 6-3-1 header, well, I wasn't! I think I was responding to john's bringing it up.. but my thoughts on the triple pipes is just.. where do you PUT them?? One on the driver side, in front of the rear wheel, one behind the rear wheel, and one exiting out the back? Three side by side offset to one side on the back? A triplet in one circular arrangement, centered? One at each side, and one in the center? Remove the hatch, install a pantera hatch, and do three of the thru-the-truckbed "Semi pipes?" My intellectual thoughts on the effects of the design are irrelevant, as they are not informed enough to answer any questions. So you get a little humor instead. Quote Link to comment Share on other sites More sharing options...
bradyzq Posted October 27, 2009 Author Share Posted October 27, 2009 Not that I really thought about it overly hard, but for routing, if you can fit a 3.125" single exhaust, you should be able to fit the trio of 1.5" pipes glommed together. If you separate them, it should be easy to find space, but much harder in terms of extra pipe bending, etc. For exit, I was thinking of a horizontal triple exit in the center of the rear valence under the bumper. Of course, this goes with a fuel cell occupying the former spare tire compartment. Quote Link to comment Share on other sites More sharing options...
johnc Posted October 27, 2009 Share Posted October 27, 2009 The reason john is coming off as snippy is very complex and subtle. No, I'm just snippy sometimes. I am not an expert on exhaust systems. I've learned a little through monkey-see monkey-do but I still make mistakes. A few weeks ago I built an exhaust for a BMW M3 running in STU and we lost horsepower on the dyno. After some more work on my part (the secondary tubes off the 6 into 2 header were 2" too short) we got it all back but didn't see any gains. Swapping out one 90 degree bend for two 45 degree bends and being really creative with the undercar "packaging" and we got some good gains on the dyno. I made two mistakes on this exhaust and it took a 15 minute call to Kinetic to clear up the issues for me. The above is why I'm reluctant to delve into this subject on an Internet message board. Quote Link to comment Share on other sites More sharing options...
ozconnection Posted November 3, 2009 Share Posted November 3, 2009 I think there is some support for your ideas of a triple piped exhaust system, from the aspect of low gas restriction. None of us can talk from experience here (I don't think?), as I know no-one who's actually built one for an L Series. You could be the first!! From what I've read and understand on the topic, camshaft timing plays an important role. Lets not discount firing order, induction setups, and cylinder volumes as other important components in the 'overall' picture but if there was a point to start with, it seems this one is a good one. We all know the firing order is 153624, the crankshaft determines this and each firing event occurs 120 degrees apart. This number is significant. When we look at very stock cams, their seat to seat duration can be as small as 240 degrees. Coincidence? No! (On the induction side of things, look at the twin carb setup.....this is also significant!) The pressure waves that pass through the exhaust system can be used to scavenge an adjacent cylinder of exhaust gasses and even draw air/fuel into the cylinder during the valve overlap period, if setup correctly. Now, realising this, the connection of pipes should be so that there is an exhaust valve opening connected to one that's just closing. So, that means that cylinders 1,2, and 3 are connected together and 4,5 and 6 are connected together in the other group. This will satisfy the above requirement of even, 240 degree (alternate bank) pulsing in the two separated exhaust systems. The fact that everyone uses a bigger cam than a 240 degree cam may be a good or bad thing, dunno exactly. I can only assume that a longer duration 'may' help, giving more time for the above mentioned scavenging events to take place during valve overlap. So, a triple exhaust may work along similar lines, but you'll have to try this one and let us know how you get on with it. Posting a couple of dyno sheets with back to back run would be invaluable, noting in particular any changes to the AFR's as this will effect the engines' performance significantly and alter the resultant torque curves, potentially leading to false impressions if not corrected for. The order of pipe connection with the triple exhaust will be the 'acid' test. And the lengths and diameter of the pipes will offer a degree of tuning, for sure. Dunno if this helps any, just thought I'd throw it in there. Cheers. Quote Link to comment Share on other sites More sharing options...
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