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MG Midget and Sprite Technical - Arnold where are you?
| I'm geting p*ssed off with TDI vans driven by grinning Stig like gypit fuds trying to run me off the road, i think an Eaton may be in order, can you help? cheers Brad |
| Brad (Sprite IV 1380) |
| Eh? Dave |
| Penwithian |
| You obviously need one of these: http://cgi.ebay.com/ebaymotors/Triumph-Spitfire-MG-midget-1500-Supercharger-Kit_W0QQcmdZViewItemQQ_trkparmsZ66Q3a2Q7c65Q3a3Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem200255529477QQitemZ200255529477QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories I know I do! R |
| Richard 1979 1500 |
| Brad Why not just put a K in and be done with it? You all ready have the 5 speed box, brake and suspension mods. The only thing you will lose is the automatic rust protection + having to remove the engine every 1000 miles Shaun |
| Shaun |
| Shaun, because i was born awkward i suppose. I mean why do a straight engine swop, which has been done many times before, have the car back on the road quickly, when you can go the Eaton route & possibly not have the car back on the road for ages. Apart from the fact that superchargers are cool. Dave, that's a Scottish expression, i could explain it, but it's a bit near the mark & i'd end up banned from the site. |
| Brad (Sprite IV 1380) |
| I would have thought that 1380cc would be sufficient. Perhaps it's not just about the engine's output Let the TDI white van chappies grin all they like as they go past on the straight then you can smile enigmatically when you pass them again on the twisty bits and under braking. Perhaps I've missed the point and it's not actually about being overtaken by vans. You just feel the need for a nice new big lump of metal strapped to the side of your engine. I met a guy on Tuesday at the ace cafe who's replaced his MGB's engine with a Montego 2 litre turbo deisel unit. He reckons it's great. Unfortunately the car was in a different part of the country so I didn't see it. |
| G Lazarus |
| S'why I have gone for the "alternative" Konversion...far more entertaining and given the access that you have to kit it should be no problem!! Oh and there are minis who have turbo'd or charged it as well and with injectors its easy to add in nitrous.... |
| Toby Anscombe |
Is it written phonetically? Wouldn't want to mispronounce it as I discuss a TDI van drivers parentage with him! Andy |
| a borris |
| I think strap-ons are Arie's department. |
| Brad (Sprite IV 1380) |
| Nothing in the add about an oil feed pipe to the 'charger; surely there must be one? Also - can't see it fitting under a Spridget bonnet? It doesn't bother me if other road users want to go faster than me... frankly, I'd rather let them by than drive side-by-side along a single carriage-way road, or out-gun them and have them collide into the rear when I next apply the brakes. I know I have 2 very quick cars... I don't need to show the performance to a dork in a van... A |
| Anthony Cutler |
| Anthony, If you're referring to the Eaton superchargers they contain their own oil reserve and don't require a feed from the engine, IIRC they can be topped up if necessary. |
| David Billington |
| David - Thx for clarificarion! A |
| Anthony Cutler |
| OK, I have a supercharged Sprite (Mo$$ USA kit). I don't want to be "showy" fast. But it is nice to have the option of tromping the pedal (without dropping to a lower gear) and have some acceleration. It gives you one more means of getting away from careless drivers. |
| Trevor-Jessie |
| I think part of the vans advantage is they have IRS, some of the roads around me are seriously rough. I'm going as fast as i can, but being thrown arond like a rag doll in the sprite. When it comes to a good section of road, then the sprite wins, easily. Andy, you say it as its written, but its nothing to do with his parentage. |
| Brad (Sprite IV 1380) |
| I don't suppose anyones got a diagram for an Eaton inlet manifold have they? |
| Brad (Sprite IV 1380) |
| Brad, What are you actually looking for?. I have most of a mini inlet tract here including supercharger, intercooler, and bypass valve but not sure what you're referring to by inlet manifold as that might be the inlet to the supercharger or the manifold on the engine leading to the head ports. |
| David Billington |
| knowing brad as I do I think he would be after the dimensions of the charger to head ports as next team he is near the engineerongg shop he may get one made up Shaun |
| Shaun |
| Shaun, that would be right. I've just ordered a supercharging book from Amazon, so going to have a read first, then see what i would need to do. David, what exactly have you got, for which type of mini? cheers Brad |
| Brad (Sprite IV 1380) |
| Brad, Image of the parts I have from a mini Cooper S I believe.  |
| David Billington |
Pic of supercharger outlet face. |
| David Billington |
| here I am... ;-). Well, I dunno if I understand everything said here, but I never ever regret the eaton route. The one and only thing one has to know is that tuning fuel and timing is pretty complicated. I started with the blow through turbo SU carb (HIF44), it worked but I had a few lean spots. I think that with a wide band AFR like the LC-1 one can solve these problems. I choose the EFI route, this was / is a real adventure. Attached the SU route I took in the past  |
| a.o. arnold |
| I've just had to fire up the ark as the puppy has stripped my vaio keyboard of keys :-( Arnold, the EFI sounds a bit complicated. Have you any diagrams / picures of the Eaton bracket. Also what parts would i need apart from a M45, is an intercooler necessary? cheers Brad |
| Brad (Sprite IV 1380) |
you need the MG Turbo carb, plus fuel pressure regulator, turbo hose, return fuel line to the fueltank, high presssure fuelpump. No need for the intercooler. I made the bracket while the supercharger was in place, I have no drawing but I use the alternator connection. I do have a drawing of the blower |
| a.o. arnold |
and a better one
 |
| a.o. arnold |
| Thanks Arnold, looks like a plan is forming. I already have a red top fuel pump, regulator & a fuel tank with a return line. So it's really just a M45 & a carb, can i use my DHLA or would i need a turbo version ie a lotus job? Also where have you put the alternator? thanks Brad |
| Brad (Sprite 4 & GT3) |
| Is this the correct type of regulator? http://cgi.ebay.co.uk/Mini-Metro-Turbo-Fuel-Pressure-Regulator-ERA-MG_W0QQitemZ350118663192QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item350118663192&_trksid=p3286.c0.m14&_trkparms=72%3A1299%7C66%3A4%7C65%3A12%7C39%3A1%7C240%3A1318 |
| Brad (Sprite 4 & GT3) |
| Yep, that's perfect, you can change the fuel pressure with this one. But BE CAREFUL. There are two options for supercharging, draw through or blow through. The blow through means no mixture is going through the blower (which is what I did) and has a few advantages and disadvantages + more flex where to put the blower + possibility for future intercooler + better respons + less danger for fuel leaks + I was told by Eaton the Teflon on the rotor is not fuel resistant (so fuel in the blower might damage it) - you need a special turbo carb - you need a fuel pressure regulator - a bit more complicated Arnold |
| a.o. arnold |
| As Arnold rightly says you need to decide on Blow through or suck through. If you go for the blow through then the regulator you have identified is required but you will need a fuel pump that can overcome the pressure of your boost by at least 2 PSI. I can run my blow through Turbo at 15 to 20 PSI so I use an injector fuel pump that has a resistor in series to reduce the initial pressure. Not sure how much boost you want to run or how much pressure a red top produces. A suck through is more simple of the fueling side. |
| Bob (Robert) Midget Turbo |
| I'll put a gauge on the red top & see what it can do. Any other advise? cheers Brad |
| Brad (Sprite IV 1380) |
| hey arnold, Remeber you will have to rebuild the engine back to stock form in order to get the most out of a supercharger. prop |
| Prop |
| Arnold, if the vanes arn't petrol compatible (and i've no reason not to believe you), then i guess its going to be a blow through system. I may be wrong here, but isn't the Moss one a suck through? |
| Brad (Sprite IV 1380) |
| Brad, I don't know what kind of blower that is. I called Eaton a few years ago and I am using a blowr form a Merces 230 Kompressor (that sounds good uhh). I forgot to mention some mods. Keep everything stock (cam) reduce the maximum amount of advance (I put a hose over one of the 'pegs' in the dizzy advance mechanism), and use a LARGE EXHAUST, with minimum backpressure (I use a sold called turbo muffer and about 50mm exhaust pipe diameter |
| a.o. arnold |
| The Moss units are suck through. There are many MGB owners running Eatons in this arrangment and have racked up a bunch of miles. I'd prefer blow through, but the simplicity of the suck through is great. |
| Trevor Jessie |
| I believe Eaton have relaxed their attitude on the Teflon - they now say it wasn't in the design parameters but it doesn't appear to cause problems. In any case the black Teflon coating was only applied to 'Fifth Generation' mini blowers - the earlier ones were bare alloy. Tom |
| Tom Coulthard |
| As well as the Moss system, there are Mini set-ups marketed in this country by VmaxScart and Jonspeed using suck-through with an HIF44 (though a nice fat 2" SU - HD or HS8 - could be even better). http://www.vmaxscart.co.uk http://www.jonspeedracing.co.uk As well as the kits, both companies are now selling the parts separately - VmaxScart on the superchargers page on their site, Jonspeed on eBay. Tom |
| Tom Coulthard |
| So with suck through i can keep my red top pump/ filter king regulator / stage 4 head, the heater fan & DHLA then but lose the kent 285 cam. Sounds a lot easier. |
| Brad (Sprite IV 1380) |
| you can go for a mild road cam (like an sw5) there are enough mini's driving around with wild cams and blowers http://img.photobucket.com/albums/v34/oz1275/dyno-result.jpg stolen from this thread http://www.theminiforum.co.uk/forums/index.php?showtopic=44730 sorry the pics have died but the specs are in there somewhere anny way stay easy on the overlap an you should be fine |
| Onno Könemann |
| Brad - it would be perfectly possible to keep your 45 DHLA (is it a trijet?), but the jet selection could be tricky - do you have a dell'Orto-aware RR? The advantage of the SU is in its automatic balancing of intake pressure and fuel supply. There's talk of pulsing with Roots blowers, which would also give the SU a theoretical advantage, but in practice it doesn't seem to be a major concern. The Eaton's vanes are anyway helixificated to alleviate the problem. You could also keep your 285 cam. The theory behind short cams with blowers appears to be 'you've gone to all the effort of pressurising the inlet tract, why throw some of it away with valve overlap?' This leads to engines which have large amounts of lowdown torque, but fall off a cliff at 5,5 - in other words feeling just like a modern turbodiesel: certainly does the job, but not that much fun. The problem with longer cams on a suck-through set-up is the potential for backfiring, which can stall the blower, risking damaging its drive gears and even removing chunks of Teflon from the rotors. In practice this doen't seem quite such a dire problem. Though the Moss kit includes an elegant 'sneeze valve' to give backfire pressure relief, the VmaxScart and Jonspeed kits appear to do without them - and they have been selling to Mini people for quite a few years now in the case of VmaxScart. There is also a physical advantage of suck-through over blow-through, in that the lowering of pressure in the inlet tract actually cools the mixture one or two degrees on its way in - not a huge gain but in the right direction. Intercoolers can't be used with suck-through, because they distil the fuel out of the mixture, but they also don't cool as much as some people expect. There are graphs of the heating effects of Eaton blowers in the books (or on the net) and it is clear that, though they will happily spin to 14,000 revs, the temperature of the charge starts to rise quite markedly over 10,000 revs or so. But that's getting into pulley sizes and boost pressures ... Hours of endless fun! Tom |
| Tom Coulthard |
| Thanks Tom / Onno, i'll do some searches & see what i can come up with, would prefer to do something myself rather than buy it in though, unless its cheap! I have a bit of experiance with delortto's, got the present set up ishy on two RR's, then tuned it in myself to get rid of the flat spots, took a while but it was fun. |
| Brad (Sprite IV 1380) |
| The Vmax product looks good, but at 475 just for the manifold is a bit dear for me, i'm sure it's makeable with a bit of thought & time. They do say that the bonnet may need modifying with a suck through set up, has anyone experiance of this? |
| Brad (Sprite IV 1380) |
| Brad Have you ruled out adopting the turbo system from an MG Metro? Tamsin was using around 1-bar boost to make her 1275 Midget seriously quick a couple of years back... A |
| Anthony Cutler |
| Anthony, i just fancy a supercharger thats all. cheers Brad |
| Brad (Sprite IV 1380) |
| Anyone know what the M45 modifications are? http://cgi.ebay.co.uk/Mini-SuperCharger-Parts-Charger-Inlet-Manifold_W0QQitemZ140285376198QQihZ004QQcategoryZ43122QQcmdZViewItem i reckon i could get this made for less than 275.00 |
| Brad (Sprite IV 1380) |
| The Mounting it "flat" may not be an option under the hood of a midget. Those SC are bigger than they look. Interesting that you fancy a SC over a turbo. I'm considering a turbo for my other car. |
| Trevor Jessie |
| Brad Your just scared at whats going to happen under my bonnet next year!!!!!! Shaun |
| Shaun |
| And of course no reason why you shouldn't fit a supercharger AND a turbo, like the VAG TFSI... What worries me about that Jonspeed pic is the pronounced downward tilt towards the front - the blower mounting appears square with the output shaft. The 'pussycat on a radiator shelf' mounting is clearly making the best of a bad job for the Mini - for a Spridget you might have to excise a large piece of bonnet and attach a similarly-sized Bagpuss over the hole. Job done - and a charming tribute to the late Oliver Postgate. However, this mounting unneccessarily traps exhaust heat under the blower, as if heat management wasn't already a problem. There is another issue with the Mini kits in that they both use a piggyback crank pulley with the standard V-belt drive retained and an added ribbed belt drive for the blower. This would probably foul the pre-1500 crossmember. The Moss kit uses a special alloy ribbed pulley not sold separately (of course). However, the last classic minis used a serpentine belt drive and concomitant crank pulley - if you can find one - NOS ones are mostly gone now. As you will have noticed, the Moss kit mounts the M45 sideways (fine by Eaton's specs), which allows throughflow of air and a lower mounting - good for CG, of course: so much more important than not having to saw holes in your bonnet. To achieve this, they have cast a lovely period-looking finned alloy inlet manifold and plenum chamber, which no doubt helps them justify their retail kit price of nearly 2.5K. I have a steel inlet manifold I got off eBay that I'm plotting to use. It's a wishbone two-into-one barrel of a 45DCOE, which was used in Mini (Miglia?) racing a while ago. I will try to get a pic of it if you're interested. Tom |
| Tom Coulthard |
| In the autocross world, I would tend to prefer an engine-driven supercharger over a turbocharger. The reason is that, although tc generates better numbers, sc tends to be more linear and more predictable, and less likely to jump in suddenly and shove you completely out of your tires' traction circle. Trying to keep an engine "on turbo" during an autocross can be very challenging indeed. From my perspective, if you are doing forced induction in order to generate numbers for bragging purposes, by all means throw a turbo on there. If you want controllable power that is there when you want it, go with the pulley-driven supercharger. David "YMMV" Lieb |
| David Lieb |
| David, I'm thinking of putting a turbo on my Midget (the car I'd use for long drives). I think with FI (like Glen's) I could get better mileage and have better power at speed than with the supercharger. |
| Trevor Jessie |
| Jessie, I would agree with you. For touring use, a TC that only kicks in when asked makes sense. For road racing use it can make sense as well, depending on the track. For autocross use, it does not. I suppose with an unlimited R&D budget, it could be made to make sense, but why would you be autocrossing with an unlimited R&D budget? I was trying to address the question of why someone would prefer a supercharger over a turbocharger. Autocrossing is a good example of an application wherein the linear power qualities of a supercharger are highly desirable. Touring is a good example of an application where the power on demand aspect of turbocharging makes sense. I guess we have a good reason for adding a few more Spridgets to our stables... As if a good reason was necessary ;-) David "I need a larger stable" Lieb |
| David Lieb |
| I was just comparing the prices of a s/h MG Metro Turbo installation to an (inevitably) new S/C... ... still, if you've got the spare ££££, by all means spend it. A |
| Anthony Cutler |
| and to ad a couple totaly emotional reason all of the classic midgets (pre war and tc's) have had a history of supercharging. in the period (60's) supercharging was the way to go. |
| Onno Könemann |
| Ahhh Turbo or Supercharger? Before I fitted my Turbo a couple of years ago I had actually been considering it for about 5 years. Not sure I fully understood the characteristics of a turbo engine and I certainly did not give due consideration to the supercharger, again I was ignorant of the characteristics of a supercharged powered engine. After having one fitted and tuning an engine so equiped I have now a far better understanding of what it can do. I have also been able to understand the supercharger better and its comparrison to the Turbo. The point about a long duration and high overlap cam is a good one. To make an engine rev and make great power we all know how important the high overlap cam is, but we also realise how that is a problem with forced induction. However what I now realise is that because as the revs rise then the turbo spins higher and makes more pressure the effect of a normal cam's restriction at higher revs is somewhat negated by having far more pressure to blow mixture in and thus fill the cylinders at these higher revs. Unfortunately many turbo applications using a waste gate do not have the ability to make use of these high pressures at high revs and simply dump it through the waste gate. This is now the area that I am working on to up my performance. On the other side of the coin is the SC. Where the Turbo accelerates and builds more pressure as revs increase (throttle opens) the SC does not tend to increase in pressure. That is because it is geared directly to the engine and it is therefore a direc airpump that gives more pressure as the engine uses more. Therefore as David Lieb said the SC gives better power and torque for bursting performance on an autotest whereas we all know about Turbolag. However the turbo is far better in my opinion at higher revs and the lag from a standing start is not such a problem, why does anyone want to spin their wheels or break halfshafts. :-)) I think the SC is an easier instalation but the Turbo is far cheaper. I personally would like one of each but for now will make do with my turbo. Hopefully if I can keep my job over the next few months I will be able to keep developing my engine just to see how far it can go. |
| Bob (Robert) Midget Turbo |
| Gents, just got a book from Amazon on supercharging, so going to read up on it before i decide to go suck or blow job (madame), mind it's nearly Xmas so i may be lucky. Had the sprite out today, hit the soft cut rev limiter a few times at 7K, forgot the misus was in the car :-) don't really want to lose that revability, but would like a bit more oummph behind it. Ant, if i do this then believe me it won't be a cheque book job. Like my 9" brake conversion that just cost me calipers & rotors really. Which i may do a limited production run of just for a quiet life. cheers Brad |
| Brad (Sprite IV 1380) |
| Brad, Which book did you get. I have the book "Turbocharging & Supercharging" by Allan Allard, it's been around awhile but still has good info. The ebay manifold looks easy to do, my local laser profiler has a minimum order of about £50 and those plates look to be easily less than that. IIRC from having made a few sidedraught manifolds the material that can be used is 1.5" x 5/16" CRS for the manifold to head plates. Regarding the machining, I would have guessed they removed the part of the casting bridging the outlet as with their manifold plate being so close it might be restrictive, also the tapping of the inlet to fix the plate onto it. |
| David Billington |
| DIY supercharging by Pat Ganahl, printed by CarTech. So the ''modified part'' would be a bit of filing & some geezer running a tap in to the supercharger! I have a molested 1.5" twin SU (before i went side draft) ali inlet manifold that may just be the job for a cut n shut job to the supercharger. cheers Brad |
| Brad (Sprite IV 1380) |
| David, how much do you want for the M45? cheers Brad |
| Brad (Sprite IV 1380) |
| Brad, Sorry but it's not for sale. |
| David Billington |
| Oh thats a shame, you must be looking at the same mods i am then? |
| Brad (Sprite IV 1380) |
| Brad, More likely the K series I have in the garage destined for the sprite. I expect I'll get the car back on the road and then look at fitting the supercharger though. |
| David Billington |
| sorry to gate crash but Dave can you do me a favour please. Take an engineering look at my bearing replacement article and tell me if it sounds correct. I have now assembled my front hub (that had play) with the new 40 degree angular contact face adjusted bearings and all the play has disappeared as was hoped, just need an engineering critical eye to find any flaws please See here. http://www.mgcars.org.uk/mgcc/midgetreg/Frontwheelbearings.shtml |
| Bob (Robert) Midget Turbo |
| Bob, Seems good but in paragraph 4 it seems to suggest, to me anyway, that taper rollers can just be done up and they are OK. I think it needs to be stressed that all rolling element bearings, be they deep groove ball bearings, taper roller bearings, angular contacts and the rest must run with the correct internal clearances or there will be problems. As you say in paragraph 2, too loose gives you play, too tight leads to hot running, shorter life, and potentially catastrophic failure. I've seen the results of taper rollers failing on a Ford Granada stub axle in a GT40 replica where the rollers welded into a nice blue/black mess and sheared the stub axle off because the guy that fitted the hubs didn't know about setting them and just did them up tight. Paragraph 3 typo constuction -> construction. May be more grease than really necessary for the bearings and that can lead to the bearings running hotter than normal. Good work, hopefully this will greatly benefit the spridget community. You going to start selling the bearing kits?. |
| David Billington |
| My goodness Bob, why is everything you do biased towards the MGCC? |
| Tarquin |
| What do you mean the information is freely available, not sure I can access any other site to put it on. |
| Bob (Robert) Midget Turbo |
| My word, if only there was a free site where you could create pages of detailed technical information so that others could read and comment on it. Silly me, that would be a bad idea. Much better to keep it within a particular club..after all "This BBS should be totally independent of anyone or any organisation, unfortunately it is often used by some for furthering their own desires but that is fought against at every opportunity." |
| Toby Anscombe |
| Where is a free site that I can put this information on? I give a link directly to it if someone wants it, do you see the difference? r are ou deliberately trying to be clever? |
| Bob (Robert) Midget Turbo |
| I think he is referring to the FAQ wiki. Maybe? |
| Trevor Jessie |
This thread was discussed between 10/12/2008 and 22/12/2008
MG Midget and Sprite Technical index
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