Alex Birtwisle Posted June 17, 2003 Share Posted June 17, 2003 Been pondering this one for a while now. It seems a lovely way to get more power so why aren't we doing it 🤔 Space is a bit tight but there is plenty of room underneath the plenum/tbs and in an SV there is yet more space.Why not drive the altenator from the rear axle like some of the old GT racers... that would leave a lot more room in there....... hmmmmmmm someone tell I am being silly .... please ❗ S713UMY 1.8K Viper Blue and Black Link to comment Share on other sites More sharing options...
V7 SLR Posted June 17, 2003 Share Posted June 17, 2003 You're not being silly. I'm thinking about one for my next engine. Don't really want to go down the turbo technics route though as they use 8 injectors and a belt-driven turbo. I'd rather use a "proper" supercharger although where I'd locate one is more problematic than with the TT one. The TT s/c is very small. I think a K with 200+ftlb torque ALL THROUGH THE USEABLE REV RANGE would be lovely. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
Old Septimus Posted June 17, 2003 Share Posted June 17, 2003 When I was hillclimbing my Lotus S3 in the early 80s I competed against another Lotus S3 which was supercharged at Valence near 7oaks. The engine was an Xflow and the blower had two extended spiral helical gears which compressed the air (?Comprex) and was bolted onto a fabricated manifold with a belt drive off the crankshaft nose. Carb was a large SU and was set up as a "sucker". It all fitted because the Lotus has fewer frame tubes than a Caterham. Car was materially faster than mine ( and driver was doubtless better) but the flywheel bolts sheared on the second run and the flywheel fell off. Never saw it again. Link to comment Share on other sites More sharing options...
V7 SLR Posted June 17, 2003 Share Posted June 17, 2003 Sprintex. They went out of business, but someone at Autosport this year was showing off another screw-type which was remarkably similar to the Sprintex I bolted to my A-series engine. German company. Product looked good. Small, (relatively) light and works like a dry sump scavenge pump... i.e. it moves air even at hand-cranking revolutions. I reckon that'd generate max torque at idle. 😬 Still got the problem of where to mount it. Think there's room on top of my engine now that I've got a flatter cam cover, although there's the problem of getting the drive over the existing cam belt pulley housing. I can't put it under the TB's as the d/s pump lives there and I don't want it on the hot side of the engine. Need to think about intercooling and pressure in whatever airbox I use too. A screw type s/c generates a lot of pressure (which is why they're so good at low revs). Haven't even considered what compression ratio I'll need. Think I'll need the advice of more learned people than I'll ever be. There's a chap in Bromsgrove who's done this to his Elise. I'll probably ask him. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
Bare Posted June 17, 2003 Share Posted June 17, 2003 You may not like this Viewpoint .. rethink the Compressor..perhaps a Turbo instead. Superchargers produce less power than a Turbo setup... in a DIY situation. (there are arguements for other conditions as well, but that's another huge can 'o worms best ignored) Turbo is easier, despite it's apparent complexity, but more power is available, earlier as well than a Non OEM (as in a meticulously engineered and developed) Compressor setup.. But don't let this dissuade you.. Half the fun is the building . Link to comment Share on other sites More sharing options...
Super_Rich_Bernie Posted June 17, 2003 Share Posted June 17, 2003 Amherst Villiers, the man behind the Blower Bentley, designed a supercharger installation for the Phantom III Rolls where a second small engine drove the blower. The second engine could be running at maximum speed, providing maximum boost when the main engine was running at 500rpm. This might be rather extreme, but could a small electric motor drive a blower mounted in the nose of the car? The motor obvioulsy needs energy, but that could be provided when the car is cruising at constant speed, rather than when accelerating. Benefits - the blower can be spinning at optimum speed all the time, you can control the blower pressure via an electrical control system - i.e cut it in for acceleration only, it doesn't take any power directly from the engine to spin it, more flexibility of mounting. Downside - weight, and you would need some complex system to charge the battery when not accelerating. There must be a catch somewhere??? Jonathan Link to comment Share on other sites More sharing options...
Joe 90 Posted June 17, 2003 Share Posted June 17, 2003 Jonathan, I did the calculations for this scheme a while a ago, and I'd love to give it a go. A modest boost of 0.5 bar (7 p.s.i. in old money) should be acheivable, boosting a 140 BHP engine to about 195 BHP. I envision using a turbo-charger style centrifugal compressor for efficiency, which means using a 700W motor running at speeds of at least 25,000 RPM. Availability of suitable motors is the biggest obstacle, as most motors meeting this requirement are AC and only suitable for intermittent use. Does anyone out there know better? P.S. This is not original, it was used on pre-war Mercedes LeMans racers, but I think modern electronics can overcome the original deficiencies. Crash team to the Upgradeitis ward, the withdrawal symptons are getting worse ❗ Link to comment Share on other sites More sharing options...
Peter T Posted June 17, 2003 Share Posted June 17, 2003 A turbocharger, which is a supercharger driven by engine exhaust gas heat energy, is undoubtedly the most efficient type of supercharger in terms of both mechanincal and thermal efficiency.Quoted from Turbocharging & supercharging by Alan Allard. I have studied this book many years ago, if you are really interested in going this route then i suggest you read some of the chapters regarding thermal efficiency. C7 PWT Pure Steel XE. Link to comment Share on other sites More sharing options...
JCM Posted June 17, 2003 Share Posted June 17, 2003 Just to add my bit here, you can get an electric motor driven turbo, I saw a company a couple of years ago at a show selling them. I might even have the details if you would like them. I run 400ftlb of torque and 400+ bhp in a seven from a heavily modified cosworth YB. I do a few endurance events and quite allot of track days and you can not beat that pure pull of the torque coming out of corners and even better in the mountains! Link to comment Share on other sites More sharing options...
Joe 90 Posted June 17, 2003 Share Posted June 17, 2003 Alan Allard's book is well worth a read as it is a good mix of theory and practice. I don't know if it has been updated with some of the more recent technology, but it covers a lot of ground. JCM, yes I would be interested if you still have the details. Crash team to the Upgradeitis ward, the withdrawal symptons are getting worse ❗ Link to comment Share on other sites More sharing options...
Peter T Posted June 17, 2003 Share Posted June 17, 2003 No i don't think it has been updated. C7 PWT Pure Steel XE. Link to comment Share on other sites More sharing options...
edmandsd Posted June 17, 2003 Share Posted June 17, 2003 Unfortunately Quaife aborted the build of a supercharged BDG Caterham after a lot of bits had been fabricated by Dave Aby aka KAM Developments. Home of BDR700 Link to comment Share on other sites More sharing options...
Super_Rich_Bernie Posted June 18, 2003 Share Posted June 18, 2003 JCM That would make lots of sense - drive the turbo with a motor until the exhaust pressure is up and the turbo can spin optimally on that alone. Removes the lag. Jonathan Link to comment Share on other sites More sharing options...
murph7355 Posted June 18, 2003 Share Posted June 18, 2003 Didn't Lancia do just that - a crank driven supercharger and a turbo in one installation? Link to comment Share on other sites More sharing options...
Nigel Riches Posted June 18, 2003 Share Posted June 18, 2003 Just add my 2 pennyworth here, I supercharged my x-flow powered 7 in the late '80s, with an old Shorrocks charger, a 2" S.U. carb, and a great deal of measuring, cutting, filing and welding. A new camshaft specifically ground with 114 deg lobe centres, 8:1 Transit van ( A.E. Parts ) pistons, and a Micro Dynamics ignition were amongst the parts installed to get the beast to run, and run it did, but hot starting was always a problem, possibly due to the long run of pipe to the inlet manifold, overheating was also a factor in the short lived existence of this "fiddle", a better rad could have had that sorted, in the end one of the cam lobes went A.W.O.L, probably due to having and eternity churning over trying to make the thing fire for the first time, but the increase in "GO" was very noticeable, it won't ever be easy to undertake this kind of thing from a D.I.Y. point of view, but the challenge of "you'll never get that to work" was, in the end proven correct, but it did briefly, more time and fettling, and who knows, may still have been on the car. I still have the 'charger and all the pulleys, brackets and shafts, carb, etc, and still wonder.........got a couple of pictures somewhere if anyones interested, could get them scanned in and posted out. I can recommend the Allard book previously mentioned and some other books from the U.S. where "blowers" are more common place, if you are wanting a good long term session in the garage bonding with your car, this just might be the thing to look at. Have fun, I did, regards Nigel. 1982. 5 speed, clamshells. B.R.G / Ali. The True Colours. Link to comment Share on other sites More sharing options...
Joe 90 Posted June 18, 2003 Share Posted June 18, 2003 I wasn't thinking of a hybrid and exhaust turbine driven system as there are a number of practical difficulties. A purely electrically driven system would have no lag, and could generate more boost at low rpm than at high rpm. Crash team to the Upgradeitis ward, the withdrawal symptons are getting worse ❗ Link to comment Share on other sites More sharing options...
bert Posted June 18, 2003 Share Posted June 18, 2003 Not sure if the specs will be right for you but the world of model electric flight is producing some pretty interesting electric motors... example brushless jobbies Any good? Link to comment Share on other sites More sharing options...
Joe 90 Posted June 18, 2003 Share Posted June 18, 2003 Interesting, but only low speed, and RC models don't require high durability. Crash team to the Upgradeitis ward, the withdrawal symptons are getting worse ❗ Link to comment Share on other sites More sharing options...
jackb_ms Posted June 19, 2003 Share Posted June 19, 2003 Last winter i had a very good look at super charging my 21. The main advantage of the supercharger is that it doesn't produce as much heat as a turbo. Which is a very good thing in car which have heat troubles There is something on the market called an e-ram which is in fact a fan inside a K&N air filter http://www.electricsupercharger.com/ I wanted to control the speed of the fan according to the position of the throttle which will result in the quick death of the electrical motor as it in only design to work at full throttle. The other option is to go for an Eaton supercharger, or pinch the one from your neihbour's Merc 230 Kompressor. This unit will fit nicely under the bonnet of a 21 and i'm sure an SV will accomodate it. The addition of an intercooler is recomended as well. Jack Link to comment Share on other sites More sharing options...
Joe 90 Posted June 19, 2003 Share Posted June 19, 2003 The www.electricsupercharger.com site is interesting, as it's closer to what I was thinking of. It' looks like it's aimed at yank V8s, judging by the CFM figures. Interesting. Crash team to the Upgradeitis ward, the withdrawal symptons are getting worse ❗ Edited by - oliver sedlacek on 19 Jun 2003 09:05:16 Edited by - oliver sedlacek on 19 Jun 2003 09:06:01 Edited by - oliver sedlacek on 19 Jun 2003 09:06:38 Link to comment Share on other sites More sharing options...
Bare Posted June 19, 2003 Share Posted June 19, 2003 Sadly.. the "E Ram" is pure Garbage.. These are simply Snake Oil, widely regarded as a Poor Joke here in the States. The Powerboat Bilge evacuation Fan they pass off as a Supercharger has been PROVEN to reduce hp , simply by it's obstruction of the intake airway. The poor little is Motor simply incapable of delivering any significant volume of air at any significant pressure Link to comment Share on other sites More sharing options...
jackb_ms Posted June 19, 2003 Share Posted June 19, 2003 Cheers Bare Does this mean that the idea of a fan inside a air filter is not a good idea? Jack Link to comment Share on other sites More sharing options...
Bob Corb Posted June 19, 2003 Share Posted June 19, 2003 Proper electric superchargers do exist and they have there own special use. They are combined with turbo installations to provide almost instant boost when the engine speed is too low for a turbo to produce any energy. Turbo manufacturers are also working on integrating electric motors into the body of an otherwise std turbo to spin them up at low engine rpm. A vehicle thus equipped will be on the market soon... Bob Link to comment Share on other sites More sharing options...
Joe 90 Posted June 19, 2003 Share Posted June 19, 2003 Bob, can you point me at any of the better products? Oliver Crash team to the Upgradeitis ward, the withdrawal symptons are getting worse ❗ Link to comment Share on other sites More sharing options...
Gridgway Posted June 19, 2003 Share Posted June 19, 2003 so what was wrong with the TurboTechnics supercharger again? Graham Link to comment Share on other sites More sharing options...
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