NO budget MR2 Racecar.

[GoFastOrDieTryin]

I have just swapped my VR4 Legnum for a Mk2 MR2,and race it in a new budget race series here in Northern Ireland. I have already been out racing it once and got two seconds and a win.There was zero preparation to the car as i was just there to make up the numbers (my brother runs the series and bought the car to sell on as a racecar), but i fell in love with racing again and made the swap.....

BUT,theres a problem. Im a student and the term Low Budget doesn't come close...But im studying Motorsport technology so i want to make/bodge/improve as much as possible.My brother and I make rollcages so that cost wont be an issue,and I have free access to a rolling road as part of my course so i am going to make the most of it also!

The first issue is that MR2's gain alot from a stiffer anti-roll bar,these are quite expensive,so i had thought of drilling an additional hole (if i can get a good enough drillbit!) to reduce the leverage of the ARB hence making it stiffer?

The car was lowered when i got it,but iv done some research and aparently MR2s work better with a slightly softer front end,to get a bit of weight transfer.The springs in it are quite stiff and the only way i could get it to brake well without locking the front everytime,was to put a heavy wheel in the front.They aren't adjustable coilovers,so would there be any way to shorten a pair of standard springs to have the front soft but without the height?

Sorry for the lengthy post,but i want to have this a regular race winning car on zero budget,as the car that beat me last day was a 182 Clio worth around £9k!

All help much appreciated!!

Pete

[NewYankee01]

Originally Posted by GoFastOrDieTryin

I have just swapped my VR4 Legnum for a Mk2 MR2,and race it in a new budget race series here in Northern Ireland. I have already been out racing it once and got two seconds and a win.There was zero preparation to the car as i was just there to make up the numbers (my brother runs the series and bought the car to sell on as a racecar), but i fell in love with racing again and made the swap.....

BUT,theres a problem. Im a student and the term Low Budget doesn't come close...But im studying Motorsport technology so i want to make/bodge/improve as much as possible.My brother and I make rollcages so that cost wont be an issue,and I have free access to a rolling road as part of my course so i am going to make the most of it also!

The first issue is that MR2's gain alot from a stiffer anti-roll bar,these are quite expensive,so i had thought of drilling an additional hole (if i can get a good enough drillbit!) to reduce the leverage of the ARB hence making it stiffer?

The car was lowered when i got it,but iv done some research and aparently MR2s work better with a slightly softer front end,to get a bit of weight transfer.The springs in it are quite stiff and the only way i could get it to brake well without locking the front everytime,was to put a heavy wheel in the front.They aren't adjustable coilovers,so would there be any way to shorten a pair of standard springs to have the front soft but without the height?

Sorry for the lengthy post,but i want to have this a regular race winning car on zero budget,as the car that beat me last day was a 182 Clio worth around £9k!

All help much appreciated!!

Pete

gotta love the youthful enthusiasm, race winning car for no budget? everyone wants that, find the worlds best mechanics i.e yourselves and youll be there but isnt that what all race teams proclaim to have?

[Al Weyman]

If you want to go the soft spring route you have no choice but to budget for the Anti-Roll bar or make one yourself or the car would be as per standard.i.e. not much good. Despite what you may read you can indeed cut down coil springs without them braking I have done this on my IROC-Z Camaro as the race springs supplied from the States were too long. Cut them with an angle grinder and finish the ends as per the original springs which will need a bit of heat to squash the last coil, also then grind a flat on the end as they were. I think its not doing this and quencing in cold water that leads to problems, let them cool down on their own. BTW cutting a coil off WILL UP SPRING RATE!!!! Go on line for a spring rate calculator they are quite accurate and you can then work out what you have and what you will end up with.

[GoFastOrDieTryin]

Originally Posted by NewYankee01

gotta love the youthful enthusiasm, race winning car for no budget? everyone wants that, find the worlds best mechanics i.e yourselves and youll be there but isnt that what all race teams proclaim to have?

Well surely youthful enthusiasm is much better than old todger pessimism?? I refuse to think that in clubman type series', a bit of know how will bridge any gap that can be got with shiny bolt in bits!

Originally Posted by Al Weyman

If you want to go the soft spring route you have no choice but to budget for the Anti-Roll bar or make one yourself or the car would be as per standard.i.e. not much good. Despite what you may read you can indeed cut down coil springs without them braking I have done this on my IROC-Z Camaro as the race springs supplied from the States were too long. Cut them with an angle grinder and finish the ends as per the original springs which will need a bit of heat to squash the last coil, also then grind a flat on the end as they were. I think its not doing this and quencing in cold water that leads to problems, let them cool down on their own. BTW cutting a coil off WILL UP SPRING RATE!!!! Go on line for a spring rate calculator they are quite accurate and you can then work out what you have and what you will end up with.

Yeh in some of our past racecars we have cut springs and they work really well,lower the car and tend to be quite stiff! Thats why i wouldnt want them in the front of the MR2,the lowering springs in it at present are too stiff even. You mentioned the effect heat has on a spring,i had thought of getting standard springs and slowly heating them in a basic oven we made for heating alloy wheels before paint ( just a garage heater pointing into a 4 ft square steel box ) and once they are really hot,compress them by setting the car ramp down on them. If they were left like that to cool slowly,would they still be tempered and brittle?

You mentioned making an anti-roll bar. Is the spring rate of an ARB simply dependant on the thickness of the bar? There is a spring manufacturer not far from me,i suppose i could enquire and see if they could make a replacement ARB using thicker steel?

[Al Weyman]

The anti roll bar rate is also effected by the leverage action not just the thickness of the bar, a good reasonably priced book on all this sort of stuff is How to Make your car handle by Fred Phun well worth a read.

[andrewc]

There are some on the Toyota Sprint Series who have some fast MR2's run on very tight budgets. Try and contact some of them to discuss options. Two brains better than one, and maybe they've tried some stuff and can comment on what works and what doesn't

[GoFastOrDieTryin]

Originally Posted by Al Weyman

The anti roll bar rate is also effected by the leverage action not just the thickness of the bar, a good reasonably priced book on all this sort of stuff is How to Make your car handle by Fred Phun well worth a read.

Yeh thats why i had considered trying to drill the ARB,reduce the leverage and tighten it up a bit.

Originally Posted by andrewc

There are some on the Toyota Sprint Series who have some fast MR2's run on very tight budgets. Try and contact some of them to discuss options. Two brains better than one, and maybe they've tried some stuff and can comment on what works and what doesn't

Yes i just had a wee search and found their website,il have a wee search through the forum and try to take some notes.Thanks for the head up on the series!

[phoenix]

Originally Posted by GoFastOrDieTryin

You mentioned the effect heat has on a spring,i had thought of getting standard springs and slowly heating them in a basic oven we made for heating alloy wheels before paint ( just a garage heater pointing into a 4 ft square steel box ) and once they are really hot,compress them by setting the car ramp down on them. If they were left like that to cool slowly,would they still be tempered and brittle?

If you heat the springs to soften them in order to shorten them, they will lose their temper and will need to be re-heat treated properly back to original hardness. Otherwise they will remain soft and get shorter every time you hit a bump!

Having said that, weight transfer under braking is not a function of spring stiffness. It is a function of the height of the centre of gravity, the wheelbase, the position of the center of mass fore/aft and the rate of negative acceleration.

For the anti roll bar, instead of drilling it, is it possible to design a mounting which clamps onto the bar such that the pickup position can be moved/adjusted by slackening the clamp, moving the mounting up/down the anti roll bar and then clamping it tight again? I think this could be achieved by by modifying the roll-bar end of the drop links. Alternatively, local heating of the flat part of the anti roll bar to soften it enough for drilling another will not have any adverse effect on the bar stiffness. Just keep the rest of the bar cool by wrapping in wet rags or similar.

[GoFastOrDieTryin]

Originally Posted by phoenix

If you heat the springs to soften them in order to shorten them, they will lose their temper and will need to be re-heat treated properly back to original hardness. Otherwise they will remain soft and get shorter every time you hit a bump!

Having said that, weight transfer under braking is not a function of spring stiffness. It is a function of the height of the centre of gravity, the wheelbase, the position of the center of mass fore/aft and the rate of negative acceleration.

For the anti roll bar, instead of drilling it, is it possible to design a mounting which clamps onto the bar such that the pickup position can be moved/adjusted by slackening the clamp, moving the mounting up/down the anti roll bar and then clamping it tight again? I think this could be achieved by by modifying the roll-bar end of the drop links. Alternatively, local heating of the flat part of the anti roll bar to soften it enough for drilling another will not have any adverse effect on the bar stiffness. Just keep the rest of the bar cool by wrapping in wet rags or similar.

Hmm,suppose il not do anything drastic untill i get the fuel tank in the front and get the 'cage in and get whatever weight reduction i can done.
Im also going to get a brake bias valve out of the back axle of a corsa ( or something similar) from a scrapyard and modify it so i can adjust it.

Yes,loving the idea of the clamps,so simple!

Im out again next weekend but i have an assignment to do so will be doing just the basics/necessities. Cage, decent Tyres and Decat!

[SWRC Wayne]

Dang it Kiddo, ye shudda just ask'd me!

To soften front end with nooo expense, just grab a pair of standard springs and we'll lower the bottom spring cup til the desired ride height is achieved.

Thus giving you the softer front end / spring rate you are after whilst retaining that low 'stance'.


Now, to correct your brake bias, get cutting your front pads!

[GoFastOrDieTryin]

Rather than risk my good adjustable shocks,would it not be better to have the platform adjustable with clamps of some sort?

[Al Weyman]

I have heard all about not cutting and heating coils but its my experience it can be done successfully. I had no choice but to cut a coil off some race springs supplied incorrectly to me and was reluctant at first till I took my mates advice. I cut the coil off with an angle grinder then I had to heat the top coils to collapse them as per original and then grind the tang flat as it was like originally and let the spring cool naturally and not plunged in water. The mod was a 100% successful and has not sagged or broken and has transformed the handling. You can believe this or not but I have done it and it works perfectly. Personally I think the problems start when you dont finish the ends off correctly so they are cocked and not flat which is putting an uneven pressure on the first coil of the spring which could lead to failure also if you water cool the spring it doesnt help.

[phoenix]

Originally Posted by Al Weyman

I cut the coil off with an angle grinder then I had to heat the top coils to collapse them as per original and then grind the tang flat as it was like originally and let the spring cool naturally and not plunged in water. The mod was a 100% successful and has not sagged or broken and has transformed the handling. You can believe this or not but I have done it and it works perfectly.

Which car was this on, Al? Yet to see your racing results since any of your mods on any of your cars (post a link or two if you would). Are you winning now? Be great to know if you are.

[SWRC Wayne]

Originally Posted by GoFastOrDieTryin

Rather than risk my good adjustable shocks,would it not be better to have the platform adjustable with clamps of some sort?

Oh yes, it would. Same sentiment though, but with some good clamp-age employed

[SWRC Wayne]

FYI, this is the very car in question...



... and this is where it is being raced...

[magpie9000]

What race series was this?
Is it still going?
Just built an MR2 for track days but a race series woukd be far more fun