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Car Forum / MINI / November 2003Upgrade Questions
Having just recently changed vehicle to a Mini (from a Land Rover as it happens, so the culture shock is a little extreme!), I'm already making plans to further modify my Mini however there's a few questions I haven't been able to find answers to on-line and I was hoping that people here might be able to help me? [1] roller-tipped v. full roller rockers Presumably the full rollers offer an efficiency gain over the roller tipped? Is it worth paying the extra #100 or so for full rollers? The second part to this question is that I notice that various ratio rockers are available (1.3,1.5 ad 1.7:1). Having done some searching of this newsgroups past using Google it would seem that 1.5:1 rockers have the effect of making the engine more "cammy", presumably the same would be true to an even greater degree of the 1.7:1 variety but what about the 1.3:1 ratio? [2] side impact bars IIRC, the late production Mini had the doors modified in include side impact bars? Assuming that my recollection is correct, is it possible to retrofit these doors to an earlier (internal-hinge) Mini? (This goes against my goal of trying to reduce the weight, however the extra impact protection might be worth it?) [3] glass v. carbon fibre body panels As I said in 2, one of things I want to do to improve my the performance of my Mini is to reduce it's weight. Some of this is quite easy to do (eg: remove the rear seat and leave the spare wheel at home), however looking forward into the future the replacing the bonnet and boot-lid with lighter alternatives is probably on the "to do" list. Looking through the Mini Sport catalog I got a while ago there appears to be the option of either glass fibre or carbon fibre (the latter costing more). Is there any weight advantage to the latter? Any other suggestions (preferably of the non-extortionately expensive variety!) to reduce the weight would be of interest ... Thanks in advance for your help ...  SignatureThese opinions might not even be mine ... Let alone connected with my employer ... Yes, the later doors will fit if its a mk 3 onwards, you want safety, fit a safety cage, some insurance companies don't get nasty with this either, I use Frizzell, get a fia approved one, & you will need to fit it correctly too, not just a case of bolting it in, the mounting points will need reinforcing, you could opt out for one without the rear diagonal, still sit people in the back, roller rockers should be matched to other things, type of engine, you want a stage 1 or a fully modded full race stage 5, its an open playing field, the A series is probably the most modded UK engine there is, but the standard unit is quite economical, what ever you do to increase the power will use more fuel, Steve. > Having just recently changed vehicle to a Mini (from a Land Rover as it > happens, so the culture shock is a little extreme!), I'm already making [quoted text clipped - 38 lines] > > Thanks in advance for your help ... Without getting onto the subject of engine modification too much, in short. Roller tipped rockers are better than full roller rockers on a road engine, because when full roller rockers fail you end up with lots of bits of metal roller where it doesn't need to be e.g in the oil pump etc. Full roller rockers are fine on a race engine that is rebuilt regularly, but the disadvantages out weigh the advantages for a road car. I wouldn't go higher than 1.5:1 on a road spec engine personally. > Yes, the later doors will fit if its a mk 3 onwards, you want safety, fit a > safety cage, [quoted text clipped - 52 lines] > > > > Thanks in advance for your help ... >IIRC, the late production Mini had the doors modified in include side >impact bars? Assuming that my recollection is correct, is it possible to >retrofit these doors to an earlier (internal-hinge) Mini? (This goes >against my goal of trying to reduce the weight, however the extra impact >protection might be worth it?) So-called side impact bars are a con. They are designed to pass crash test standards and advertised to appeal to the gullible. Any rescue worker will tell you that they are just another piece of metal to damage you in an accident and make it harder to cut you out of the car. Real trick, of course, is not to have the accident in the first place. Now if people spent as much time worrying about the active safety of their driving as they do about the passive safety of their cars...........<g> Regards, David Betts davidb@minilist.org The Mini Gallery: http://www.ofoto.com/I.jsp?m=64635537103&n=1366070334 > [1] roller-tipped v. full roller rockers > > Presumably the full rollers offer an efficiency gain over the roller > tipped? Is it worth paying the extra #100 or so for full rollers? Use just the roller tip ones. Needle rollers are designed to roll, not recipricate. Actually, the gains made with roller rockers is negligable anyway. The ratio is the potential gain, but only if used in combination with other mods. > The second part to this question is that I notice that various ratio > rockers are available (1.3,1.5 ad 1.7:1). Having done some searching of > this newsgroups past using Google it would seem that 1.5:1 rockers have > the effect of making the engine more "cammy", presumably the same would > be true to an even greater degree of the 1.7:1 variety but what about the > 1.3:1 ratio? 1.3:1 is effectively blueprinting the standard ratio. Higher ratios give some clearance problems and you have to be very careful with spring binding. In my view, you are much better off choosing the right camshaft and ignoring high ratio rockers. Or at least only fitting the appropriate rockers for the cam, engine size, CR, etc that you end up with. > [2] side impact bars > [quoted text clipped - 3 lines] > against my goal of trying to reduce the weight, however the extra impact > protection might be worth it?) As David states elsewhere, these were fitted to scrape through tightened type approval laws. They are not linked to the A or B pillars so offer little protection to the door intruding on side impact. > [3] glass v. carbon fibre body panels > [quoted text clipped - 7 lines] > be the option of either glass fibre or carbon fibre (the latter costing > more). Is there any weight advantage to the latter? There is little to choose between the two in weight terms. But assume that the fit and finish will be poor. There are few on the market that are really high quality because nobody will pay realistic prices for GRP or carbon fibre. A decent boot lid or bonnet should cost upwards of ?80 based on the time it takes to lay up the product. Any cheaper and corners are being cut. > Any other suggestions (preferably of the non-extortionately expensive > variety!) to reduce the weight would be of interest ... Rip out all the sound proofing (if you had a Land Rover, you won't mind the noise!) and remove all excess trim. You will be amazed at how much this lot weighs! And you could use plastic side windows. SignatureRgds Steve steve@dsnclassics.co.uk www.dsnclassics.co.uk > Rip out all the sound proofing (if you had a Land Rover, you won't mind the > noise!) and remove all excess trim. You will be amazed at how much this lot > weighs! And you could use plastic side windows. IE - radio, dash, heater, passenger seat, chrome, plastic, carpet. Doesn't sound a lot of fun to drive for the sake of being slightly faster. ;) The Muffin Man > > Rip out all the sound proofing (if you had a Land Rover, you won't mind > the [quoted text clipped - 9 lines] > > The Muffin Man Nope! But you would be amazed at how much quicker it makes any car. It is the original Lotus concept. Weight is the enemy. And the Lotus Seven will blow away any Porsche or Ferrari through the twisty bits with less than half the power. And remember, the OP was used to a Land Rover!!! SignatureRgds Steve steve@dsnclassics.co.uk www.dsnclassics.co.uk > Nope! But you would be amazed at how much quicker it makes any car. It is > the original Lotus concept. Weight is the enemy. And the Lotus Seven will > blow away any Porsche or Ferrari through the twisty bits with less than half > the power. But driving fast is no fun without Bachman Turner Overdrive playing loud ;) The Muffin Man Im more of a Led Zep or Opera fan when I'm out having a fast spin Me > > Nope! But you would be amazed at how much quicker it makes any car. It is > > the original Lotus concept. Weight is the enemy. And the Lotus Seven will [quoted text clipped - 5 lines] > > The Muffin Man Lets face it, whatever your tastes, The Ace of Spades at full volume when accelerating 1380cc's of throb around the outside of a roundabout while the Bavarian Motor Wrecker in the inside desperately tries to keep up, eventually pulling up behind you is the way to go ;) The Muffin Man > Im more of a Led Zep or Opera fan when I'm out having a fast spin > [quoted text clipped - 12 lines] > > > > The Muffin Man And if you point the base unit out the boot it goes even faster! SignatureRgds Steve steve@dsnclassics.co.uk www.dsnclassics.co.uk -- Rgds Steve steve@dsnclassics.co.uk www.dsnclassics.co.uk > Lets face it, whatever your tastes, The Ace of Spades at full volume when > accelerating 1380cc's of throb around the outside of a roundabout while the > Bavarian Motor Wrecker in the inside desperately tries to keep up, > eventually pulling up behind you is the way to go ;) > > The Muffin Man Steve twisted the electrons to say: > And remember, the OP was used to a Land Rover!!! ... and a normally aspirated diesel at that! You know, 0-60mph by some time next week! SignatureThese opinions might not even be mine ... Let alone connected with my employer ... > Steve twisted the electrons to say: > > And remember, the OP was used to a Land Rover!!! > > ... and a normally aspirated diesel at that! You know, 0-60mph by some > time next week! Mines a V8 and it still takes 3 days and a following wind! 0-20mph is awesome though! SignatureRgds Steve steve@dsnclassics.co.uk www.dsnclassics.co.uk I can't offer anything worthwhile about rockers, but I seem to remember a story about side impact bars in VW polos (older models) punching through the pillars behind the doors, and sealing the doors shut in accidents. :-( Carbon fibre should be stronger for the same weight. If you really want to reduce the weight of your car you should look at a plastic flip front (fairly big job) and replace the rear subframe with a beam and coil over shocks suspension. Personally I think I'll try a diet first :-) Alistair Gunn sounds like a far north kind of name. Which end of the country are you from? Allan > Having just recently changed vehicle to a Mini (from a Land Rover as it > happens, so the culture shock is a little extreme!), I'm already making [quoted text clipped - 41 lines] > These opinions might not even be mine ... > Let alone connected with my employer ... Allan twisted the electrons to say: > Carbon fibre should be stronger for the same weight. Aye ... but the question is are they stronger for the same weight, or lighter for the same strength? Yeah, I know I could just email the supplier and ask but where's the fun in being all logical like that? > If you really want to reduce the weight of your car you should look at a > plastic flip front (fairly big job) and replace the rear subframe with a > beam and coil over shocks suspension. Kinda big jobs and I'd have to confess that I don't think I'd really want to go *that* far ... I think dumping the rear seat (and maybe the spare wheeel), swapping the boot lib, bonnet and battery for something lighter are probably about as far as I'll go. (Though changing the windows *might* happen!) > Personally I think I'll try a diet first :-) Given my ribs are showing already I don't think there's much weight left on me to lose! > Alistair Gunn sounds like a far north kind of name. Which end of the > country are you from? Yorkshire ... Opinions differ on whether this counts as far north, depending on whether you hold with the "civilisation ends when you pass the Watford Gap services" or "anyone from south of the Tyne is a southerner"! <grins> SignatureThese opinions might not even be mine ... Let alone connected with my employer ... Snipped > > Alistair Gunn sounds like a far north kind of name. Which end of the > > country are you from? [quoted text clipped - 3 lines] > the Watford Gap services" or "anyone from south of the Tyne is a > southerner"! <grins> Lol I go with, the "Clan Gunn museum" is still 400 miles North of you, veiw. :-)) all you fellas in the main are far north from me.... Tim in New Zealand > Snipped > > [quoted text clipped - 9 lines] > I go with, the "Clan Gunn museum" is still 400 miles North of you, veiw. > :-)) > Alistair Gunn sounds like a far north kind of name. Which end of the > country are you from? I wonder, is he any relation of Peter? The Muffin Man Comments are embedded: >Having just recently changed vehicle to a Mini (from a Land Rover as it >happens, so the culture shock is a little extreme!), I'm already making [quoted text clipped - 13 lines] >be true to an even greater degree of the 1.7:1 variety but what about the >1.3:1 ratio? I can't see where full rollers are any better than roller tip from a performance point of view. Full rollers would avoid rocker shaft wear but this is such a slow process that it can't really use up much power. One thing to keep in mind is that higher ratios will require some repositioning of the pillars to keep a reasonable geometry between the rocker tips and valve stems through the arc of the rocker movement. It's often easier to have a high lift cam ground and use 1.3:1 rockers. Most of the roller tip rockers will provide better geometry and better matching between individual rockers ratio than those from the factory. >[2] side impact bars > [quoted text clipped - 3 lines] >against my goal of trying to reduce the weight, however the extra impact >protection might be worth it?) I've always thought the side impact bars were just another piece of metal to hit you in a wreck. In order to provide protection, the ends of the bars would have to sit to the outside of the inner door frame significantly to have sufficient support to keep them from popping into the cabin. If you look at a Volvo, the door bars overlap the A and B pillars by about 1 1/2 inches on each end. The door frame also has three steps in it so it's pretty hard for the door to get knocked into the passenger compartment. On the other hand it takes a pretty big car to hold all those safety features. Someone suggested getting a roll cage. Personally I think that having a roll cage on a street car is more dangerous than not having one. The main problem is that a roll cage puts a piece steel several inches closer to your head than it would normally be in a Mini. On the track this isn't as much of a concern since you will be wearing a helmet. Without a helmet a significantly smaller shunt will bring your head in contact with the cage. Foam covering on the bar doesn't protect your head, it only helps to keep your helmet from getting cracked. If you have any doubt let someone hit you in the head with a foam covered steel pipe. ;^) Something like the old style single hoop roll bars might be better. They generally sit farther behind the driver. >[3] glass v. carbon fibre body panels > [quoted text clipped - 12 lines] > >Thanks in advance for your help ... The only real advantage to carbon fibre is that it is stiffer. This will keep the boot lid from flexing and opening itself unexpectedly. This is pretty common with the glassfibre bootlids on race Minis. One of the most significant ways to reduce weight is to replace as much glass as you can with plastic. The window winding mechanisms also weigh a lot. Cheers, Kelley > I can't see where full rollers are any better than roller tip from a > performance point of view. Full rollers would avoid rocker shaft wear > but this is such a slow process that it can't really use up much > power. The full roller rockers actually cause greater wear than the bushed ones. All the load is transmitted through line contact of rollers whereas the bushes give a much larger surface area to spread the load. The flip side of that is that bushes pick up dirt and turn themselves into sand paper! But basically, roller bearings are not designed for reciprocating action. SignatureRgds Steve steve@dsnclassics.co.uk www.dsnclassics.co.uk |
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