Escortn Posted June 13, 2021 Share Posted June 13, 2021 Lads and ladettes. It's been a while since I've posted here. I've missed you all dearly. Straight into it then aye. I recently acquired a buggered head from an SR20DET to mock up some hi rise headers I've been wanting to make up. I don't have a project or anything to put them on it's just something I've always wanted to fab up. Anyway, after modelling in Inventor to get my rough shape I've mocked everything up but now I've run into my dilemma and I'm after opinions on which router to take. Yes I'm asking for the internet's opinion on something. As they stand now I have the hi rise sections on a nice even slope, 4th being the highest and 1st being the lowest. This looks good but they are not equal length. If we treat Runner 1 as 0mm then Runner 2 is +13mm, Runner 3 is -13mm and Runner 4 is +11mm. I can achieve equal length by raising the rise on 3 and lowering 2 and 4 but I will lose the nice straight slope. So my question is should I chase looks for clout or the bragging rights of equal length? Photos because that's what we're here for. Just note that this is before I lowered 2 and 4 15mm to get the even slope. Ta. 1 Quote Link to comment Share on other sites More sharing options...
Escortn Posted June 13, 2021 Author Share Posted June 13, 2021 . 3 Quote Link to comment Share on other sites More sharing options...
Roman Posted June 14, 2021 Share Posted June 14, 2021 I voted equal length however... High rise headers dont really have any point apart from cars where theres very limited space. IE. Left hand drive cars and getting spaghetti past a steering column. So make it look good and evenly spaced if its a piece of shed art. Equal length if its an engineering exercise to test your skills. Both if you have an exceptional level of patience... Interesting thought - you can have equal length but not equal volume. As a straight pipe with the same centreline length as a 90 deg bend has a different internal volume. Fussing over +- mm or 5 of length might be a moot point if you have different volumes in each. Subscribed to post, looking forward to updates 4 Quote Link to comment Share on other sites More sharing options...
Escortn Posted June 14, 2021 Author Share Posted June 14, 2021 11 hours ago, Roman said: Interesting thought - you can have equal length but not equal volume. As a straight pipe with the same centreline length as a 90 deg bend has a different internal volume. Fussing over +- mm or 5 of length might be a moot point if you have different volumes in each. Ah yes, I see what you mean. I have managed to use the same amount of bends on each runner, main intention of this was so that I didn't have to muck around trying to cut up a heap of different degrees. Every runner has a total of 4 90 degree bends and on each runner one of the bends has been cut in half to get 2 45s. Based off of that I think I've unintentionally gained equal volume as well? I think I've decided to go with equal length (the majority is that way also) but ill see if I can still get a decent slope on the runners. 2 Quote Link to comment Share on other sites More sharing options...
Escortn Posted June 17, 2021 Author Share Posted June 17, 2021 Have gone down the keep it equal route. Managed to get everything tacked and the collector on. Fitted it to the motor I have and thought they sat way to high. After this I decided to take as much as I could out of the tops. Since Runner 1 is the shortest when it comes to height it determines how low I could go. Managed to get 26mm lower out of all of the runners and visually it looks like it will be sweet Will be test fitting to an S15 in the next few weeks just for safety sake, then I can finally get stuck into fully welding. 9 Quote Link to comment Share on other sites More sharing options...
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