I'd flush the underside with 14g mild steel sheet, from cill to cill, from the front bulkhead to the rear axle hump, turning the back edge up a couple of inches to form a toboggan' effect for reversing without catching on obstacles. Ditto the petrol tank and rear bodywork. Obviously protrusions like springhangers and lower wishbones get skidded back and front to prevent hang ups. Sump guard, 10g but not too wide, you need somewhere for the radiator flow to exit. A bit of heat resistant foam between the sump and the guard will help to prevent loose stones getting trapped between, one good belt and they can punch a hole in the sump or at least dint it in so far that the big ends catch inside and make an alarming noise. You might want to calculate the weight of these mods then test it out by putting the same weight into your car and driving it around a bit, the reduced performance might encourage you to economise a bit on my suggestions.
Darren - IMHO its horses for courses. If you want to go out there and do all the ACTC rounds a Sprite is probably not a good choice. Ground clearance is limited by small wheels and no matter how high you jack the suspension you will still drag the diff in the ruts. Then the diff on the A series axle is not up to hard use in modern trials.
However, if like many of us you are out to enjoy yourself and pick and choose the events to drive in a car you like, it would be fine to start out with very little modification. If you gave never done a trial before start out with your local clubs single venue PCT's to give you a flavour of finding grip. For this you won't need any mods as they are generally on grass which is soft.
For the adventure element of Classics move onto MCC Class 0. For this raise the suspension a little and guard the tank if its below the floor and fit a sump guard (aluminum checkered plate with smooth side down).
If you aren't in a hurry go down to Exeter services at breakfast time on the Exeter Trial. There will probably be a few cars like yours there and you can have a good look at them and chat to the drivers.
and dont forget the exhaust also a alternative to a full sump guard is to braze a 3mm plate directly to the sump this will save some weight ,given the small cc of this car ,the exhaust could do with some sort of u channel to protect it along its length and a u bend up over the rear axel and the sliencer as tight to the boot floor as poss ,the axel hand brake bracket could do with a skid plate underneath as said previously the a series diff is not very strong but there is a stronger modification but it is not cheap ,if a front anti roll is fitted throw it away
Keep the weight up the front to an absolute minimum .I normally try and use 5 bar pattern alloy plate[very strong and a pig to bend] should be able to get some from local scrappy or if you know of any commerical lorry body builders try and get some off cuts especially from cattle truck bodys they use loads of alloy type plating .No need to spend a fortune on guards....No pun intended to the Marlin special part supplier....
This is towards the top end of what is used, thanks to Dave for the photo and to the driver for posing for so long whilst Dave lined up for a good shot. (That is probably not true).
2 inch steel plate or buy a Marlin mate! Im sure there's plenty of Spridget Midgets out there who can advise tho. Good luck Peter
ReplyDeleteI'd flush the underside with 14g mild steel sheet, from cill to cill, from the front bulkhead to the rear axle hump, turning the back edge up a couple of inches to form a toboggan' effect for reversing without catching on obstacles. Ditto the petrol tank and rear bodywork. Obviously protrusions like springhangers and lower wishbones get skidded back and front to prevent hang ups. Sump guard, 10g but not too wide, you need somewhere for the radiator flow to exit.
ReplyDeleteA bit of heat resistant foam between the sump and the guard will help to prevent loose stones getting trapped between, one good belt and they can punch a hole in the sump or at least dint it in so far that the big ends catch inside and make an alarming noise.
You might want to calculate the weight of these mods then test it out by putting the same weight into your car and driving it around a bit, the reduced performance might encourage you to economise a bit on my suggestions.
Darren - IMHO its horses for courses. If you want to go out there and do all the ACTC rounds a Sprite is probably not a good choice. Ground clearance is limited by small wheels and no matter how high you jack the suspension you will still drag the diff in the ruts. Then the diff on the A series axle is not up to hard use in modern trials.
ReplyDeleteHowever, if like many of us you are out to enjoy yourself and pick and choose the events to drive in a car you like, it would be fine to start out with very little modification. If you gave never done a trial before start out with your local clubs single venue PCT's to give you a flavour of finding grip. For this you won't need any mods as they are generally on grass which is soft.
For the adventure element of Classics move onto MCC Class 0. For this raise the suspension a little and guard the tank if its below the floor and fit a sump guard (aluminum checkered plate with smooth side down).
If you aren't in a hurry go down to Exeter services at breakfast time on the Exeter Trial. There will probably be a few cars like yours there and you can have a good look at them and chat to the drivers.
Check out http://www.classictrials.co.uk/Gas03092.htm for a piece about Keith Petit's trialling Frogeye.
Michael
You've all missed moving the fuel tank into the boot.
ReplyDeleteand dont forget the exhaust also a alternative to a full sump guard is to braze a 3mm plate directly to the sump this will save some weight ,given the small cc of this car ,the exhaust could do with some sort of u channel to protect it along its length and a u bend up over the rear axel and the sliencer as tight to the boot floor as poss ,the axel hand brake bracket could do with a skid plate underneath as said previously the a series diff is not very strong but there is a stronger modification but it is not cheap ,if a front anti roll is fitted throw it away
ReplyDeleteKeep the weight up the front to an absolute minimum .I normally try and use 5 bar pattern alloy plate[very strong and a pig to bend] should be able to get some from local scrappy or if you know of any commerical lorry body builders try and get some off cuts especially from cattle truck bodys they use loads of alloy type plating .No need to spend a fortune on guards....No pun intended to the Marlin special part supplier....
ReplyDeletethanks peter
ReplyDeleteThis is towards the top end of what is used, thanks to Dave for the photo and to the driver for posing for so long whilst Dave lined up for a good shot. (That is probably not true).
ReplyDeletehttp://hoits.smugmug.com/popular/2/515789333_UotBx#515794940_tbxYs-A-LB
That exhaust looks vulnerable
ReplyDeleteWhats the best heat resistant foam to put between the sump and the guard?!
ReplyDelete