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Oct 10, 2019 20:05:55 GMT
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About 5 years ago my mk2 jetta gti stopped working. I left it on the road for 6 months till the dvla started giving me grief then i got it collected and crushed. Probably only needed a fuel pump relay.
Bit stupid really seeing how mk2 prices are going now.
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Ive no idea! Got to still be around somewhere.
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If you were wondering, which someone may be I guess.. The 2 recess bits in the pic here are where the headphone sockets go on suitably equipped versions. For rear seat passengers?
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Tbh you are going to have to spend a fair bit on bends , flanges and pipe. And if your going to do with a mig your going to want to go for thicker stuff which will cost more . And most bands are stainless which is not ideal for your situation . I really thick you would be better off if you could get your mate with a tig to do it and you buy the parts. All you would have to do would be to measure the gaps around where the manifold is then remove it and he can work within that . Trouble is , if you going to buy £ 100 worth of bits , and he has to spend x amount of hours doing it then how much would that cost ? Either that or try to get hold of another manifold from somewhere and adapt it. I wouldn't try cutting and rewelding oem stuff , you just don't know what it's made of and how it will behave . My mate only has mig, but his welding is superb. His labour wont cost me, unless i ask him to do something super complex. Ill work out what bits id so i can work out costs before i make any decisions.
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Lack of feel and the possibility of gloves getting caught are the issues. The thought of gloves caught in rotating tools makes my skin crawl! I did once have a grinder with a flap wheel kick back and slap me flat in the chest. Fortunately I was wearing an apron, which tangled right around the wheel and stopped it dead. Apparently I went rather white... The one thing I really hate seeing is angle grinders without guards on them. Some of the videos I use in class have some great fabrication but without the guards makes me wince. It seems to be primarily Americans, but I've seen a couple of Aussies (in America with borrowed equipment, admittedly) and even the odd well-known Brit doing it too. Ive had half a dremmel cutting wheel stick in my eye once. Pulling it out was a journey of discovery 😂 Ive also had a finger caught between the guard and the knotty wheel in a grinder though. I'm probably not the best person to talk about power tool safety. In unrelated news, i found an old v5 for the ghia the other day with your name as previous keeper. Was a blast from the past!
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Last Edit: Oct 9, 2019 21:05:53 GMT by VW
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Lack of feel and the possibility of gloves getting caught are the issues. The thought of gloves caught in rotating tools makes my skin crawl!
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Used the end of the crossmember to repair the grot from before. Only problem is, it's not quite the same shape. No stepped shape for the pan to sit on, and a little too long, so after we'd drilled 12mm holes to plug weld through, we nipped about 8mm off the end as the photo shows. Welded up and the pan half fits up to the spine again now! I don't wont to be all 'told you so' and that malarkey - don't want to be 'I know better either' but I have some issues with this pic & the angle grinder activity (having witnessed some not so nice injuries over the years that these can inflict) lack of gloves and yes we have all done it - but lack of full face protection / hearing protection when its so readily available - I can highly recommend one of these which is the go to in my workshop 3M G500 series - Ideal piece of kit - they don't mist up like goggles and means that the user can still wear glasses - the ear defenders keep the visor from falling off your head when in awkward positions too - they can be expensive but shop around a little and you will find them at the right price - I think mine was about £30 ish - I'll shut up now Got to say, i probably agree with the full face mask and definitely ear defenders. However, from what ive read, gloves are generally not considered a good idea with rotating machinery like drills, lathes, and grinders etc.
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I seem to be constantly paranoid its loosing power unless i rag it everywhere 😂
I guess this is the price you pay for actually knowing how cars work.
That blissfully ignorance of drive it till it dies as you don't recognise the signs must be wonderful.
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For no particular reason, this is the original and the space available.
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The link above provides this...
A reduction in primary pipe Diameter of 1/8 of an inch will move the torque peak down by 650-800 RPM. Conversely an increase in diameter of the header will raise the engine speed at which max torque occurs,by approx the same RPM,for each 1/8 of increase.
Adding length to the primary pipe will increase low speed and mid-range power, with corresponding reduction in power at max RPM.
Shorter primaries give an increase in high speed power, at the expense of reduction in the midrange. However,there will be little change in peak torque or the engine speed at which it occurs.
Now this sounds important to me due to what I'm trying to achieve. Its a van, so torque is important, but the vans main failing, as ever, is going up hill. This is no problem at say under 40-50mph, it will happily accelerate up hills in 4th from 30mph, but at higher speeds it is. The van is quite quick really, considering, up to 40-50mph and has overdrive so will get up to 70 quite happily and sit there all day. But dual carriageway hills end up in donwshifts and high revs and lower speed. So, maybe id be better off with shorter primaries. This suggests torque wont change but any power increase will be higher up. Sounds more like what I'm after really. I wouldnt want to move the torque range though so 4 2 1 with short ish primaries?
Back to the possibility of modding an mx5 manifold then maybe.
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Last Edit: Oct 9, 2019 13:01:19 GMT by VW
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Bit restricted in bends though isnt it? Mocking up isnt a bad idea though, could use thin rod to lay out pathways for the center of the pipework and measure between to check the pipe diameter fits.
If it goes like the 2 stoke exhaust i did though ill just chop stuff into handy looking sections then trim and tack till its where i want it. That was just one pipe though so pretty easy.
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No doubt, but it's bloody difficult to match the internal volumes to the nth degree, I don't think having a couple of inches variance across the tubes will matter hugely in this instance. Ill get them as close as space, awkwardness to make, or available materials determines. Hopefully that will end up being reasonably close. I guess i could water fill each primary to see how close they are? When i get chance ill take some pics and some mearurements, then take off the manifold and downpipe and make a jig so i can make it on the bench. Ive been meaning to put a flexi in the downpipe for years anyway so this is a chance to do that too. It will also stay on the stock exhaust system so I'm obviously not going for all out best possible performance. Just get rid of the main restriction. I have a month or so to contemplate my options as this is all prep for winter jobs when it will be unused for a while.
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Last Edit: Oct 9, 2019 12:34:23 GMT by VW
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I did cross my mind that making a manifold is the perfect opportunity to stick a turbo on it. Would mean i could stop my search for flat top pistons too. Ive turbo converted a car before though and although i could do a better job now, i know ill just end up pushing the boost till it pops. Which from what ive read, the slant will. Low boost would probably be ok, but i know what I'm like 😂
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I think I used this www.mezporting.com/exhaust_length.html to get some sort of ballpark for tube sizes and lengths and it gives sensible sounding values. You won't be able to it exact, but it's a good starting point given tube generally only comes in predetermined diameters and lengths might be aspirational.. as JB says, you might as well get it as good as you can especially if you've got the space available. 4:1 for a power-based exhaust, 4:2:1 for torque. Thanks, ill have a play with that.
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Admittedly so, but if the oe one is so awful, surely anything would be an improvement? If you are going to the trouble of making a new one, do it to the best of your abilities 😊 Agreed. However, the best of my abilities might still not be that great 😂
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The most common car ones are these, still rare though, janspeed i think This pic crops up too Manifold in first picture is what you want to aim for. Primary runners of equal length. Second manifold is a wate of time. You couldn’t make the runners more unequal in length if you tried 🤣🤣 Indeed. Id try and get the primaries as equal as possible. There is a fair bit of space so shouldn't be too hard. The strange thing with the second one is it looks quite nicely made even if its not designed too well.
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Last Edit: Oct 9, 2019 7:00:26 GMT by VW
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Would a nearside Rover V8 one (I’m thinking P38 Range Rover) be worth looking at as a starting point? Might not be ideal in terms if optimised lengths but got to be better than the stock one? Most are compromises between theoretical and practical anyway. I had noticed they may be close, worth looking at once ive got some measurements.
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I like the latches, like half a french resistance home made pen gun 😂
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I'm sure it is, but that aint going to happen 😂 I can weld sort of ok and have a rubbish welder. Fortunately a friend who owes me a favour is an amazing welder and has proper kit (but not tig) so ill probably try and rope him into it. Ultimately though you cant even see it in the engine bay so I'm not bothered what it looks like. I watched all the skid factory bedford vids, i really like their work and the way they do their shows. I am not a welding specialist but using tig could have something to do with less stress in the manifold and therefore less prone to cracking It would be nice, if it was an option id rather it was tig welded.
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This is another, but i think id rather have no connections. I don't like the last Y either. This is actually available but i think would still need chopping a fair bit.
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