froggy
Posted a lot
Posts: 1,099
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Jan 15, 2014 17:04:12 GMT
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Having a tortuous path with diverters plus the added issue of the main throttle downstream of the supercharger will have surge problems to some extent where running the blower into the turbo inlet gives the longest air spring for want of a better word .
The mini bypass could be operated by a central locking solenoid via a Hobbs switch to both open the valve and turn off the compressor clutch but I very much doubt the blower causes any sort of restriction given the low power levels .
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pork
Posted a lot
Posts: 1,663
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Jan 15, 2014 18:25:59 GMT
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Jan 15, 2014 19:16:37 GMT
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Having a tortuous path with diverters plus the added issue of the main throttle downstream of the supercharger will have surge problems to some extent where running the blower into the turbo inlet gives the longest air spring for want of a better word . The mini bypass could be operated by a central locking solenoid via a Hobbs switch to both open the valve and turn off the compressor clutch but I very much doubt the blower causes any sort of restriction given the low power levels . I agree, that is why I would personally prefer two completely separate intake paths with the change-over valves upstream of the turbo and supercharger as described in the fourth last post of page 30, and forget about compound charging. 'Air Spring' is a great description of the air in the system, but in both cases the intercooler volume also comes into it. I personally would prefer to keep a throttle valve on the intake manifold in any case just for the strong vacuum signal this gives. The supercharger may or may not cause a restriction to the turbo. I think this will depend on the specific combination of engine, turbo and supercharger. When the supercharger is run at a low pressure ratio it will be able to shift a larger volume of air for the same rotational speed, so it MAY be able to cope, but only actual pressure testing of the completed system could confirm this one way or the other. I have some serious doubts. Again, if it isn't a restriction to higher airflow rates even when operating like this, it makes me wonder if there is really any great point in having the turbo there at all? Pork, I thought you said that you wouldn't have enough space for a side-by-side dual throttle valve change-over arrangement? That manifolding looks BIG! I'm very curious what your 'flappy valve' design will be like.... this is the part that I'm really not so sure about with regards to effective pressure sealing.
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pork
Posted a lot
Posts: 1,663
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Jan 15, 2014 19:38:55 GMT
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Lol, it looks it, but the charger is tiny, Half if the mani is hanging out the front of the car (hidden inside bumper) Il get a pick on the car later, there other curse word in the way lol
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gazjon
Part of things
Posts: 632
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Jan 15, 2014 20:29:36 GMT
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Just chop a massive hole in the bonnet and having it poking out American style lol
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Mk2 Cavalier saloon Mk4 Astra Van z20let
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pork
Posted a lot
Posts: 1,663
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Jan 16, 2014 17:23:11 GMT
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Pics..... It's all got a. Little cramped in there now lol
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pork
Posted a lot
Posts: 1,663
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Jan 16, 2014 17:28:10 GMT
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I've tested the supercharger today to see what air flow goes thru run it's disengaged.........next to nothing, and that was with a compressor blow gun at 7 bar. So there's gunna be no need to block off charger when turbo is boosting........so I thought this might work.... I have a disc cut perfect to the pipe size, was wondering if this would be to restrictive ?
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pork
Posted a lot
Posts: 1,663
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Jan 16, 2014 17:32:45 GMT
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I havnt finished the pipe/manifold yet, This was just a test to see whether it all lines up and clutch works, I guess it will be quieter when it's piped up, I have removed A LOT of sound proofing to that came with the charger (would melt where it is ......
Anyway.....
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sowen
Club Retro Rides Member
Posts: 2,245
Club RR Member Number: 24
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Jan 16, 2014 17:44:44 GMT
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I don't really care about the ins and outs of how to plumb it all in, but damn, that sounds brilliant! I really do love the way you're doing this, putting it together and trying it out, most people would still be number crunching now and convincing themselves it's a bad idea and never actually do it. You sir, are a legend
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pork
Posted a lot
Posts: 1,663
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Jan 16, 2014 17:48:17 GMT
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Haha, many thanks!
It does sound pretty awesome!
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pork
Posted a lot
Posts: 1,663
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Jan 16, 2014 17:50:32 GMT
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The number crunching thing ain't me.....envy those who can though Can't wait to try it out
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sowen
Club Retro Rides Member
Posts: 2,245
Club RR Member Number: 24
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Jan 16, 2014 21:43:27 GMT
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I can do the basics, calculating theoretical maximum air pumped through to give a vague idea of what it won't go over, then get bored and want to stick something together! I simply have no interest in compressor maps, and don't have any plans to learn either. If it looks like it'll work, it probably will, if it doesn't, make it work
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pork
Posted a lot
Posts: 1,663
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Jan 16, 2014 21:56:04 GMT
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Build it, drive it, break it , fix it
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sowen
Club Retro Rides Member
Posts: 2,245
Club RR Member Number: 24
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Jan 16, 2014 22:02:29 GMT
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Build it, drive it, break it , fix it Quoted for truth
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pork
Posted a lot
Posts: 1,663
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Jan 17, 2014 17:50:15 GMT
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stevietuck
Posted a lot
Never argue with idiots,they drag you down to their level then beat you with their expertise!
Posts: 1,350
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Nice work bud this is going to be epic!
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Jan 18, 2014 11:21:59 GMT
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I can do the basics, calculating theoretical maximum air pumped through to give a vague idea of what it won't go over, then get bored and want to stick something together! I simply have no interest in compressor maps, and don't have any plans to learn either. If it looks like it'll work, it probably will, if it doesn't, make it work I think that everyone is keen to get on with constructing the actual system components and getting it running in that situation, but the success of the end result is really largely dependant on getting the basic selection of critical parts like a turbocharger at least in the ball park of being optimal. Sure, you can take an educated guess at it judging from things like a turbo's exducer bore size, but this really is just like having a stab in the dark. The important point is that no two turbos are going to have identical efficiencies at any point in their operating range, and it is thermodynamic inefficiency which is responsible for putting lots of unnecesary heat into the intake air. If it is really bad, you just end up with very hot (and expanded) air at high pressure but with low density that gives very little nett gain in air actually entering the engine. Matching turbo or supercharger characteristics as closely to the engine as possible is therefore fairly crucial. Even then though, real world testing is still necessary to confirm that it is about right. I don't honestly understand the reluctance that people often seem to have to doing the basic calculations required.... they are very simple and of the kind that the average primary school student could cope with. The compressor flow maps are also widely available on the internet in most cases, and it is then just a matter of plotting some points onto them.... it could hardly be much easier. For example, here is the basic calculation involved for a low pressure turbo installation I did a while back... Armed with the pressure ratio and airflow rate that your engine would need with forced induction at any chosed boost level, the rest is a walk in the park. While a turbo or supercharger pulled from a similarly sized engine MAY work fairly well on another installation, when you start swapping in parts lifted from other sources like those intended for large capacity diesel engines etc, there is really no alternative to checking it through properly. The best analogy I can think of is that it is a bit like going into a shoe shop and asking for a pair of shoes. When asked what size, style or colour is needed, the assistant is told that it doesn't matter.... the customer will just buy whichever ones are most easily available! That said, there is always room for experimenting and trying out different things. This is not meant as any kind of criticism, but in addition to a well researched project idea being more likely to work fairly well straight from the off, if the "break it" and "fix it" phases can be kept to a minimum less time and money will be wasted on it in the long run. Even when building something purely for the fun of it, it is surely better if it actually works as well as it is possible to make it work? Anyway, I am in no way knocking this project or any others like it, the-out-of-the-box thinking and obvious enthusiasm on it is admirable, and I really hope that it works out.
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Jan 18, 2014 15:57:29 GMT
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I can do the basics, calculating theoretical maximum air pumped through to give a vague idea of what it won't go over, then get bored and want to stick something together! I simply have no interest in compressor maps, and don't have any plans to learn either. If it looks like it'll work, it probably will, if it doesn't, make it work I think that everyone is keen to get on with constructing the actual system components and getting it running in that situation, but the success of the end result is really largely dependant on getting the basic selection of critical parts like a turbocharger at least in the ball park of being optimal. Sure, you can take an educated guess at it judging from things like a turbo's exducer bore size, but this really is just like having a stab in the dark. The important point is that no two turbos are going to have identical efficiencies at any point in their operating range, and it is thermodynamic inefficiency which is responsible for putting lots of unnecesary heat into the intake air. If it is really bad, you just end up with very hot (and expanded) air at high pressure but with low density that gives very little nett gain in air actually entering the engine. Matching turbo or supercharger characteristics as closely to the engine as possible is therefore fairly crucial. Even then though, real world testing is still necessary to confirm that it is about right. I don't honestly understand the reluctance that people often seem to have to doing the basic calculations required.... they are very simple and of the kind that the average primary school student could cope with. The compressor flow maps are also widely available on the internet in most cases, and it is then just a matter of plotting some points onto them.... it could hardly be much easier. For example, here is the basic calculation involved for a low pressure turbo installation I did a while back... Armed with the pressure ratio and airflow rate that your engine would need with forced induction at any chosed boost level, the rest is a walk in the park. While a turbo or supercharger pulled from a similarly sized engine MAY work fairly well on another installation, when you start swapping in parts lifted from other sources like those intended for large capacity diesel engines etc, there is really no alternative to checking it through properly. The best analogy I can think of is that it is a bit like going into a shoe shop and asking for a pair of shoes. When asked what size, style or colour is needed, the assistant is told that it doesn't matter.... the customer will just buy whichever ones are most easily available! That said, there is always room for experimenting and trying out different things. This is not meant as any kind of criticism, but in addition to a well researched project idea being more likely to work fairly well straight from the off, if the "break it" and "fix it" phases can be kept to a minimum less time and money will be wasted on it in the long run. Even when building something purely for the fun of it, it is surely better if it actually works as well as it is possible to make it work? Anyway, I am in no way knocking this project or any others like it, the-out-of-the-box thinking and obvious enthusiasm on it is admirable, and I really hope that it works out. An average primary school kid could do them.......glad I didn't go to your primary school ;-)
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I'm just an average man with exceptional hair.
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pork
Posted a lot
Posts: 1,663
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Jan 24, 2014 18:07:06 GMT
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Tried wiring up into the rev counter light today Experienced a problem.......here's a video off what's going on..... The black rev counter wire I'm joining the relay coil too only shows 12v when light is illuminated and 0v when off, but when I add the coil wire it dimly illuminates the light when it's meant to be off, the light should just be on or off, no in between lol. It's operates the coil once, but then I have to remove the wire to stop dim light, otherwise the coil stays engaged...,.::::if any of that makes sense Video may help
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pork
Posted a lot
Posts: 1,663
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Jan 25, 2014 17:58:39 GMT
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Had a big push at things today Changeover valve Cured signal problem to relay with a transistor , now the relay disengages the clutch pulley at whatever rpm I set the rev counter light too Here's how it's all looking Now most of the major construction is done, I thought I'd take it out, only to find out that those central locking solenoids don't like being on for any long period off time.......it burnt out allready If I manually closed the valve, I could use the s/c thru 1st, but then when turbo takes over and opens valve, it stays open, so once revs dropped and s/c engages, the boost from it just recirculates......dam Then, I blew the supercharger outlet gasket........dam, so it's all gotta come out and see what's wrong Think what I'm gunna do for the changeover valve is put a light spring to reset/pull valve back to closed position, then the turbo boost should over power that light spring to open it......if that makes sense lol I'm getting 2-3 psi on idle too
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