 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / MINI / September 2005GRP Front ends
Has anyone had problems MOTing their minis with grp frontends on? I have a solid mounted subframe but have been told by two mot testers so far that it is dangerous because the front of the sub frame isnt supported properly, they don't seem to realise that the subframe supports the body and not the other way round! has anyone got any ways that they have got round this problem as I am not fitting 'brace bars' when they don't achieve any purpose other than a nice place to mount things on! Is it just me?! :-) miniman Although you are probably correct I dont think you will ever convince an MOT man! As a matter of interest though, when I had such a front end (solid mounted and with brace bars) one of the brace bar mountings came adrift at the subframe end and this definately affected the handling under heavy braking ie it squirmed around alot more! The brace bars do control the flex in the subframe if nothing else. Dave > Has anyone had problems MOTing their minis with grp frontends on? I have a > solid mounted subframe but have been told by two mot testers so far that [quoted text clipped - 7 lines] > > miniman > Has anyone had problems MOTing their minis with grp frontends on? I have > a solid mounted subframe but have been told by two mot testers so far [quoted text clipped - 7 lines] > > miniman If we do anything like that here an engineers certificate of compliance is required which stays with the car and can be sighted each inspection. This includes even a LHD to RHD conversion, Clubman kit cars, any modifications at all. I think it would be a wise move to re think your options unless you have worked out the stress factors as I can't see a "solid" subframe hanging off the body is solid. rm Hi, Brace bars MUST be fitted. Without them you will not get an MOT. Keith (ex MOT tester) > Has anyone had problems MOTing their minis with grp frontends on? I > have a solid mounted subframe but have been told by two mot testers so [quoted text clipped - 8 lines] > > miniman >Has anyone had problems MOTing their minis with grp frontends on? I >have a solid mounted subframe but have been told by two mot testers so [quoted text clipped - 4 lines] >when they don't achieve any purpose other than a nice place to mount >things on! Sorry mate, but you are quite wrong here. The front bodywork does contribute to the strength of the structure and is not 'supported by the subframe'. The purpose of the subframe is to hold the engine and gearbox and provide mountings for the front suspension - not to provide structural strength to the monocoque. You should not replace it with a GRP flip front without incorporating additional bracing. Regards, David Betts davidb@minilist.org The Mini Gallery: http://www.ofoto.com/I.jsp?m=64635537103&n=1366070334 Hey, Ive fitted a STEEL flip front to the front of my Mini and still installed brace bars, just in case the MOT place has a problem with flip fronted cars. Only so they have one less excuse to fail my car....... >>Has anyone had problems MOTing their minis with grp frontends on? I >>have a solid mounted subframe but have been told by two mot testers so [quoted text clipped - 16 lines] > The Mini Gallery: > http://www.ofoto.com/I.jsp?m=64635537103&n=1366070334 Extract from The Old Testiment by David Vizard............. For some forms of competition, fiberglass fronts are explicitly banned. This is usually the case for offroad events such as rallycross, autocross and stage rallying where body strength is at a premium. Even when glass fronts are allowed, some scrutineers demand supports from the original body sub frame mounting point on the front of the car, up to the bulkhead. The fitting of such stays may well satisfy the scrutineer's desire for safety, but in actual fact, such a stay does little to nothing to increase the front-end rigidity. It does give a useful mounting point for such things as oil coolers and coils, etc. This business of front stays with fiberglass fronts has been a sore point with many scrutineers for quite some time. The best way to look at it is not to assume that the engine subframe unit, which is very heavy, is fixed to the body by only those mounting bolts through the floor and through the top of the suspension tower, but the other way around, that is, that the body, which itself is pretty light, is fixed to the engine, subframe, suspension assembly via those points. It must be remembered that most of the weight of a Mini is carried within the front subframe itself anyway. Apart from this, if you study the loads subjected during acceleration, braking, and cornering, the fix ing of the subframe to body is perfectly adequately catered for by those bolts through the floor and through the towers. Another area in which body strength is a prime requirement is that of safety in a crash. The standard Mini shell is neither good nor bad at withstanding an impact; it's just about the same as any other unit-construction vehicle. With a front-end collision, it can be a little better than most because of the situation of the engine within the subframe, but to be as safe as possible for competition work of any sort, a roll cage must be fitted inside the car. Who is going to argue with the words of the great man himself? Notwithstanding the above I put bars on my steel flip front car (yet to take the test) because I had heard of the problem some folks had had with the MOT. Cheers > Has anyone had problems MOTing their minis with grp frontends on? I > have a solid mounted subframe but have been told by two mot testers so [quoted text clipped - 8 lines] > > miniman > Extract from The Old Testiment by David Vizard............. > [quoted text clipped - 33 lines] > > Cheers Nice one turbojo! Thats what I call a very good explanation on these matters and we all know DV is god!!!! :-) To further the debate a little more I would like to add that after taking it to the last MOT station which refused to test it and furthermore insisted that the tower bolts go through into the rubber springs and that I had cut out the chassis plate so that he couldn't test it, even though it is a van and never had a chassis plate as it has always been stamped on the scuttle rain channel (which I showed him!), I decided that I really couldn't carry on arguing with someone that is quite so ignorant and drove over to John Cooper Garages (The holy sanctuary to all things mini!) and spoke to one of their team, He took one good hard look at it and said "looks fine to me" , then being the ever so helpful chaps that they are they said that they would phone up the ministry and double check as it seems to be a grey area that no testers can quite get to grips with. Today I popped in to JC garages and after having a good chat to the head technician, he told me that he had phoned the ministry and they have said ' as long as the body is held securely then there is no problems with the front sub frame being fitted without brace bars, as all the front mounts are doing is acting as mounting points for the body' Try telling that to an MOT tester, maybe they just don't have the time to phone the ministry if they come across a problem like that! miniman I won't argue with DV concerning a race car that is inspected regularly but on a street car there are other considerations. Here's a little thought experiment to illustrate why the front of the subframe needs some means of location at the front. On a flip front Mini with no "front stays" disconnect the subframe mounting bolts from the floor. You now have a front subframe that hinges around the tower mounts in the vertical axis of rotation, and to a smaller extent in the horizontal axis of rotation. Reconnect the floor mountings and motion in the horizontal axis of rotation is easily eliminated with very little stress on the mountings. Motion in the vertical axis of rotation is also reduced. The reason I say reduced is because the towers are attached to the most ridged structure in a Mini. This is why I chose to think of this as a hinge point. The bulkhead crossmember isn't going to move. The floor mounting is, well... , attached to the floor. This is not a particularly ridged structure and it is now being subjected to reversals in stress on every acceleration / deceleration cycle. It is common for light steel structures subject to stress reversals to quickly work harden and develop stress fractures. Front stays will help reduce the load on the floor, not as well as fully welded front sheet metal but it will help. Either way, those with flip front Minis should inspect their floors regularly. If they have rubber mounted subframes I would suspect that the rubber mountings will be beaten to death in short order. The standard steel front sheet metal provides excellent location for the front of the front subframe and takes significant stress off of the floor mount. Much better than most of the stay structures I've seen. Each wing and flitch panel form a channel style box structure with two channel cross members connecting them at the front. This is a very ridged structure in both the vertical axis of rotation and the horizontal axis of rotation. It also provides energy dissipation, crumple zones, in a crash. This is an experiment I've done on two occasions. The structure works well. Cheers, Kelley >> Extract from The Old Testiment by David Vizard............. >> [quoted text clipped - 62 lines] > >miniman > I won't argue with DV concerning a race car that is inspected > regularly but on a street car there are other considerations. [quoted text clipped - 36 lines] > > Kelley Sorry I forgot to mention that I had plated the floor area where the subframe lower mounts are with some reasonably thick steel plate to dissipate the loads a little better, my idea of solidly mounted along with all the usual metal replacements for the rubbery bits everywhere! and I have also seam welded and gusseted the whole thing just for safety's sake :-) I am still under the impression that the subframe being the heaviest part of the car is just pulling along a very light shell by all the aforementioned mounts and If I was going to worry about crashing the thing then I would fit a roll cage and bolt that through to the subframe as well! Is there any crash test data available for old minis that anyone knows of? how does a clubby do? Anyway, I got my MOT today (minus brace bars) and am happy that after four years of serious abuse nothing has cracked, snapped, bent, deformed, or otherwise gone a bit weird, if it had then that would be when I question my octane abuse habits! miniman By definition, no one ever plans to have an accident... a roll cage in a Mini doesn't really make it safer. It just moves your head closer to a piece of steel tube. My rule is no helmet, no roll cage. You're free to make your own rule. Plating the floor will help a bit but you still have considerable leverage working against you. It's not clear to me what you've seam welded and gusseted. If it's the subframe it doesn't help the problem I would anticipate since I expect the subframe to move as a unit. Keep in mind that I don't expect you to have a short term problems with your plan other than the lack crumple areas in case of a crash. I don't know where you get the idea that the drivetrain and front subframe are the heaviest part of the car. The drivetrain and subframe weigh about 400 lbs. The entire Mini weighs about 1500 lbs. That leaves about 1100 lbs. for the drivetrain to pull along. This of course doesn't count occupants. Congrats on the MOT... Kelley >Sorry I forgot to mention that I had plated the floor area where the >subframe lower mounts are with some reasonably thick steel plate to [quoted text clipped - 16 lines] > >miniman This is an interesting conversation. I am torn between welding in a roll cage for my Moke versus leaving it open. I use the vehicle quite heavily for commuting here in SoCal. Anyways one idea proposed by a shop was to weld the cage to the subframe but without welding to the body. What do you think of this idea? Also regarding roll cage, except if you wear helmet at all time I have a concern for impacting that cage with the naked head.  SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net > By definition, no one ever plans to have an accident... a roll cage in > a Mini doesn't really make it safer. It just moves your head closer to [quoted text clipped - 38 lines] >> >>miniman > This is an interesting conversation. > [quoted text clipped - 8 lines] > Also regarding roll cage, except if you wear helmet at all time I have a > concern for impacting that cage with the naked head. This refers to the roll cage. Don't weld it to the subframe (you have two) or attach it either. The stress is more evenly distributed through the body shell when plated and bolted in. Structural considerations should be taken into account when welding anything to a certified body as this will alter the loadings, which in the result of an accident, my not be favorable. rm > This is an interesting conversation. > [quoted text clipped - 8 lines] > Also regarding roll cage, except if you wear helmet at all time I have a > concern for impacting that cage with the naked head. That is why they make roll bar padding. see any race supply shop. dave theen racer > This is an interesting conversation. > [quoted text clipped - 8 lines] > Also regarding roll cage, except if you wear helmet at all time I have a > concern for impacting that cage with the naked head. That is why they make roll bar padding. see any race supply shop. dave theen racer > This is an interesting conversation. > [quoted text clipped - 8 lines] > Also regarding roll cage, except if you wear helmet at all time I have a > concern for impacting that cage with the naked head. That is why they make roll bar padding. see any race supply shop. dave theen racer > This is an interesting conversation. > [quoted text clipped - 8 lines] > Also regarding roll cage, except if you wear helmet at all time I have a > concern for impacting that cage with the naked head. That is why they make roll bar padding. see any race supply shop. dave theen racer With all due respect Dave, roll bar padding is to keep the bar from cracking your helmet not your head. Cheers, Kelley >> This is an interesting conversation. >> [quoted text clipped - 12 lines] >dave theen >racer > With all due respect Dave, roll bar padding is to keep the bar from > cracking your helmet not your head. [quoted text clipped - 18 lines] >> dave theen >> racer What about going all out crazy and fitting bucket seats and five point harnesses? I don't think your head would be able to hit anything if you were strapped down with all that lot on! miniman I already did the race harness but having a tough time finding bucket seat that will bolt into the Moke direct. I wish I had better welding skills. SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net >> With all due respect Dave, roll bar padding is to keep the bar from >> cracking your helmet not your head. [quoted text clipped - 24 lines] > > miniman I'm starting to think this is my personal pet peeve thread... ;^) Most people I know who have 4 or 5 point harnesses on street cars refuse to keep them properly tightened because it's uncomfortable. Just like the folks who slip the shoulder belt behind them on a 3 point seat belt. Another consideration is that you really need a cross bar behind the seats to attach the top straps of the harness. Running an extra 3 feet of webbing to the rear parcel shelf adds considerable stretch to the harness. In a front end crash with a 3 point seat belt, your chest moving forward tightens the lap belt pulling your hips down and to the rear of the seat. This helps move your head away from the windscreen by moving the pivot point of your body. Stretch is less of a factor due to the geometry. With 4 or 5 point belts every bit of stretch or slack moves your head closer to the windscreen. Having side bolsters in a seat will help a little to prevent head impact with the roll cage. Often though, your head is only an inch or two from the top bar of the cage. I think it's doubtful it would help much in even a modest impact. Check how far your head is from the top rail above the door and then measure in about 2 inches. This should be the cage bar position My brain is my second favorite organ so I think this stuff is pretty important. Cheers, Kelley >> With all due respect Dave, roll bar padding is to keep the bar from >> cracking your helmet not your head. [quoted text clipped - 24 lines] > >miniman Come on Kelly, If you give someone the safest car in the world and they don't manage to do a simple thing like tighten up their harness or fit their seat belt properly then they probably deserve whats coming to them! Do you have problems in the US with people slipping the shoulder restraint behind them? that sounds rather bizarre as I have never seen anyone in the UK do that! I must say that five points do have their problems like not being to reach the headlamp switches(extensions required!), radio, passenger window winder, glovebox, CDs on the floor, mobile under the seat, ashtray, babies in the back seats........... Sounds great! loads of extra mental energy stored ready to help you avoid crashing in the first place because you were distracted! > I'm starting to think this is my personal pet peeve thread... ;^) > [quoted text clipped - 24 lines] > > Kelley I have NEVER seen someone wear there belt in such fashion in SoCal. Granted I have seen more stupider things done behind the wheel but this belt thing is not one of them SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net > Come on Kelly, If you give someone the safest car in the world and they > don't manage to do a simple thing like tighten up their harness or fit [quoted text clipped - 39 lines] >> >> Kelley My point is that people do things that they think make a car safer, roll cage, 5 point harnesses, which actually make them less safe when they're driven on the street. A shoulder belt slipped behind is hard to see and is probably more common than you would suspect. A couple of years ago the state of Washington, where I live, finally put into effect a law requiring drivers to use seatbelts. Better late than never, right. There were a surprising number of people trying to get around it by slipping the shoulder belt behind them. There were several on the local news arguing that they didn't deserve the ticket they received since they technically had a seat belt on. I'm truly amazed at the lengths people will go to trading comfort for safety. There are also those that argue that they don't need seat belts since they have air bags. I discovered a long time ago that when someone decides to make a turn from a side street into the front of your car there isn't much you can do about it. I got hit head on by a Jeep Cherokee in my Mini. My foot was moving toward the brake but I still don't know if it ever got there. Avoiding distractions while driving is all important but sometimes there's no avoiding an accident. Just for reference the front of a Mini is extremely strong. Cheers, Kelley >Come on Kelly, If you give someone the safest car in the world and they >don't manage to do a simple thing like tighten up their harness or fit [quoted text clipped - 11 lines] >extra mental energy stored ready to help you avoid crashing in the >first place because you were distracted! > My point is that people do things that they think make a car safer, > roll cage, 5 point harnesses, which actually make them less safe when > they're driven on the street. <snip> > Cheers, > > Kelley Exactly! Except that many people who fit that kind of stuff in a road car don't do it to make the car safer, they do it to look "cool". Safety is boring old fart stuff. So you see harnesses adjusted with the buckle over the belly button, straps over the shoulder but not plugged in, cage held together with bolts 3 inches too long, pointing inwards. Lock "buckle over the belly button" Educate me please on what is wrong with that, and the proper way to use it. Thanks. SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net >> My point is that people do things that they think make a car safer, >> roll cage, 5 point harnesses, which actually make them less safe when [quoted text clipped - 16 lines] > > Lock > "buckle over the belly button" > > Educate me please on what is wrong with that, and the proper way to use it. > > Thanks. You have to secure your hips. So wear the lower belt as low as possible. Got it. Thanks. SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net >> "buckle over the belly button" >> [quoted text clipped - 4 lines] > > You have to secure your hips. Can I hazard a guess that your heart is your primary favorite organ then? SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net > I'm starting to think this is my personal pet peeve thread... ;^) > [quoted text clipped - 55 lines] >> >>miniman Exactly, the padding is for the helmet and not for the naked head. SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net > With all due respect Dave, roll bar padding is to keep the bar from > cracking your helmet not your head. [quoted text clipped - 21 lines] >>dave theen >>racer If anybody is going to have a cage in a street car, they are not going to wear a helmet. I sure would rather hit my head against a padded roll bar than unpadded.. Don't ya think.. Dave > With all due respect Dave, roll bar padding is to keep the bar from > cracking your helmet not your head. [quoted text clipped - 19 lines] >>dave theen >>racer I have to agree with you Dave, I would rather be hit in the head with a piece of steel wrapped in foam than a bare piece of steel. Of course, I'd rather not be hit in the head at all. Cheers, Kelley >If anybody is going to have a cage in a street car, they are not going >to wear a helmet. I sure would rather hit my head against a padded roll >bar than unpadded.. Don't ya think.. >Dave > I have to agree with you Dave, I would rather be hit in the head with > a piece of steel wrapped in foam than a bare piece of steel. Of > course, I'd rather not be hit in the head at all. Ok, so If I got a piece of pipe and covered it with padding, I suppose you wouldn't mind if I wacked your head with it ? I'd say, if you want a roll-cage, then drive with a helmet. If your not willing to wear a helmet on your commute to work, then don't fit a roll cage. >> I have to agree with you Dave, I would rather be hit in the head with >> a piece of steel wrapped in foam than a bare piece of steel. Of [quoted text clipped - 7 lines] >willing to wear a helmet on your commute to work, then don't fit a roll >cage. Agreed, Nicholas. Probably the best way to not get hit in the head at all. Cheers, Kelley > By definition, no one ever plans to have an accident... a roll cage in > a Mini doesn't really make it safer. It just moves your head closer to [quoted text clipped - 37 lines] >> >> miniman Right! I am off to weigh it and prove you wrong, My drivetrain is 181kg which we all know is far lighter than 400lbs! And just because it's got an MOT doesn't mean that it is safe......... :-))))) .....I think that's all to do with the Nut holding the steering wheel......... Have a good weekend! You shouldn't use rubber lower mounts with a flip front fitted. > I won't argue with DV concerning a race car that is inspected > regularly but on a street car there are other considerations. [quoted text clipped - 104 lines] > > > >miniman >I won't argue with DV concerning a race car that is inspected >regularly but on a street car there are other considerations. [quoted text clipped - 37 lines] > >Kelley one of the nicest brace-constructions I have seen has been home-made by one of our club-members: http://home.versatel.nl/idefix1977/Foto%27s/projecten/Mike/foto%27s%20pagina%206 /flip%20flap.jpg YMMV, Theo van den Bogaard >> I won't argue with DV concerning a race car that is inspected >> regularly but on a street car there are other considerations. [quoted text clipped - 40 lines] > by one of our club-members: > http://home.versatel.nl/idefix1977/Foto%27s/projecten/Mike/foto%27s%20pagina%206 /flip%20flap.jpg YMMV, Theo > YMMV, > Theo van den Bogaard That looks far better than some of the dodgy aftermarket ones that are doing the rounds at the moment, a lot of them just seem to be a bent bit of tube that has no real strength under compression as they would bend even more under load! I was looking at the VTEC and vauxhall conversions and noticed that they recommend fitting a removable front to make access easier for fitting, what they don,t seem to supply as part of the box section sub frames is a bracing bar to the top mounts, which seems a bit silly if they are really neccessary, have any VTEC engined mini owners had problems with subframes falling out of their cars? Does anyone still use rubber mounts? As they never seem to last more than a year on most minis! miniman I have to agree, that's the nicest structure I've seen. The crash effectiveness could probably be considerably improved by adding a brace from the top bend in the top bar of the side structure to the lower bar. It would keep the bend from collapsing on impact. For all of the structure that's been added there is still a lot of room around the engine. Cheers, Kelley >one of the nicest brace-constructions I have seen has been home-made >by one of our club-members: >http://home.versatel.nl/idefix1977/Foto%27s/projecten/Mike/foto%27s%20pagina%206 /flip%20flap.jpg > >YMMV, >Theo van den Bogaard Nice but is the gauge of the steel used sufficient? SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net >I have to agree, that's the nicest structure I've seen. > [quoted text clipped - 15 lines] >>YMMV, >>Theo van den Bogaard Nice but is the gauge of the steel used sufficient? SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net I think so, but I'll have to ask .. since you like it, here's another pic: http://drcwww.uvt.nl/~bogaard/dl/bracing.jpg wiring is also running in the tubes .. Maybe I'll have to ask Mike to do a write-up on it ;-) cheers, Theo van den Bogaard >I have to agree, that's the nicest structure I've seen. > [quoted text clipped - 18 lines] >>YMMV, >>Theo van den Bogaard Brilliant. I've always wanted to "loose" the wires like that. SignatureQuickSilver - Visit my world Searching for a Class A Coach in SoCal http://AustinMini.OsiTech.Net > Nice but is the gauge of the steel used sufficient? > [quoted text clipped - 20 lines] >>>YMMV, >>>Theo van den Bogaard > Extract from The Old Testiment by David Vizard............. > [quoted text clipped - 46 lines] > > > > miniman The great man wrote those words around 1973. That was when a megabyte of computer memory filled a whole floor of a building, and a lot of things have moved on since then, including vehicle safety standards. DV said "The standard Mini shell is neither good nor bad at withstanding an impact; it's just about the same as any other unit-construction vehicle." If that was true then, it certainly isn't true now. I knew somebody that got the engine and gearbox in his and his wife's laps when the subframe folded up and back in a head on accident, and that was with a full steel front. I really think you should put braces on it, regardless of what your local MOT man thinks. If in doubt, try to visualise that engine coming through the windscreen. HTH Lock
|
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.