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[lozzzzzz]

All painted up now, and the large fuse holder that powers everything accpet the starter motor is now mounted where the old wiper motor would have been. 





Just the washer bottle to go back in now.

More to come

[albitz]

Superb project.If I had a garage etc. I would love to do something like that.

[lozzzzzz]

Thanks Albs

Its a car day today

All work is done till tomorrow, so I've spent this morning doing lots of research and deciding exactly what brake set up I need for the car.  I remember that the upgrade set up I had before was a little weak on the rear.  So the fronts would lock up a long before the rears.  Now this means that the full baking potential wasn't reached, although they were amazing at not fading.  If the rears could have done more work then fronts would have had more grip available so could apply a great slowing force before locking up.  Brake ballance is really important so I've done a kind of case study of a selection of cars comparing their weight distribution with their brake power distribution. 

Some of the cars on the list are ones I've owned and driven them, and some were picked because they are known to be awesome driving machines, oh and my bro's capri is on there too to check the new set up he's making.   

There are a lot of columns for breaking down the calculations, but the first and last two columns are the important ones.  You can see that the old Scim set up has a very front strong system at 65:35, and this is why the brakes might not have performed well when really applying the load. 



The new system will use the Cosworth RS 4x4 273mm rear discs with their original calipers, the front will use the Focus ST 170 300mm discs and Omega Calipers.  This combination comes out at a 59:41 front rear bias, which is really close the that of the E36 M3.  The other obvious importnat facter is the weight distribution of the car, with the lighter engine up front and the added weight of the LPG tank, battery, Fuel pumps, heavy diff (very heavy), and larger brakes, I would imagine the car is approaching 50:50 weight distribution as with the M3, I'll be checking this asap. 

If anyone is interested in doing something like this for an ugrade the info on piston size and everything else was from this website:
http://www.brakepartssuperstore.org.uk/contents/en-uk/d2.html

So the necessary parts will be in their way soon

Now to the garage to do some real work.

[Shackeng]

Great job, Lozz, looking forward to the test drive report.

[lozzzzzz]

Thanks Shackeng, but its some way off yet

[lozzzzzz]

Wow, might have made a school boy error with the calcs, its a function of piston area not diamter.  So the new calcs look like this (pretty different in fact)



The new set up puts quite far from that of the M3 now, but there is a bias valve in the line to the rear so the rear brakes can be turned down a bit.  Or if I was to buy the 324 mm front discs fromt eh Focus RS, then it would be back to being the same as the M3.  I think i'll stick with the 300mm and turn the valve in a bit.

[aaronjb]

Nice calculations, lozz For the terminally lazy among us .. care to make the spreadsheet available somewhere?

I'm interested in comparing the MR2, 300ZX and future setup on the kit car.. and your spreadsheet will already have the formulas, presumably, for me to whack the figures in to

[tunnie]

Soooo much space around that engine bay!

[lozzzzzz]

Yeah its good that there's still room left, there's still a bit to go in there. 

I'd be happy to make it available, what is the easiest way of doing that on here??

[aaronjb]

DropBox would work to share it, if you have it.. otherwise I can PM you my email address and stick it on mine

[Kevin Wood]

Don't forget that, under maximum braking, some weight will transfer to the front axle so you might want to err on the side of caution and bias it a little towards the front compared to what the static weight distribution suggests, if you don't have a proportioning valve in the rear circuit.

[lozzzzzz]

Right finally figured out dropbox

I've out a load of instructions in the file and the link tot he website I used for getting the info, the columns that do the calcs are mostly hidden to make it easier to see where you need to put the info in..  Here's the dropbox link:
http://dl.dropbox.com/u/2488666/Brake%20Comparison.xlsx

Kevin, the spreadsheet takes that into account, the idea of the sheet is to compare the weight distribution of different cars with their brake power distribution front and rear.  You can see that for a car with weight distribution of 50:50, the brake distribution is about 67:33, to account for the wieght transfer that you mention under heavy braking. 

Hope it helps

[lozzzzzz]

OOOoooo..     just thought, Centre of gravity makes a difference too.  A car with a very very low CofG with not be able to transfer so much weight to the front wheels under heavy braking.  A car with a very high CofG with transfer l a large portion of its wieght to the front wheels under heavy braking.  So when looking to something to compare with the car you're making brakes for pick something of a similar height. 

[Kevin Wood]

TBH, if starting from a relatively "clean sheet", as you are, and determined to get the brake balance spot on, I might be inclined to fit a twin master cylinder setup and bias adjustment. As you say, there are lots of factors (suspension compliance is another variable is how much weight transfers forwards). Rather than hope to hit the jackpot first time, why not give yourself some adjustment?

[lozzzzzz]

It would be the ultimate set up, but there are a couple of reasons I want to avoid it really. 

Firstly I spent a while getting hold of a brand new servo and master cylinder.

Secondly, having driven a friends car with the set up you mention (and of course no servo), I don't really like the pedal feel.  You have to apply a massive amount of pedal force for resonable braking, its almost to the point where you can't lock the wheels on a dry road.  His car is 1500kg, where mine should be less than 1300, but still. 

I do have a bias valve that I'll be refitting into the rear circuit, I hear they're not the most accurate things, so I'll get the braking as close as I can by design and use that for adjustments if necessary.  Its a shame thats its a compromise, but do you see my point?