Project "Marginal gains..."
Turbo Mini Forums

There's a few cars on here that have paid a reasonable amount of attention to weight saving and have ended up mid 500kgs, the boat anchor and gearbox add about 40kg over the A series and the Metro / MGF front knuckle and brakes easily adds 8 - 10kg as there are no lightweight alternative parts so to equal the same level of weight saving of these cars puts me in the high 500kgs, but we'll see where I get to.

is there any other way to lose more weight from the knuckles?
How much would it be to get new ones made from billet alloy/titanium?
I'm guessing that if you have got to spend loads of money to lose more weight then unsprung weight is the best investment

Unsprung is a reasonable area to try and save weight depending on what you plan to use the car for, moreso for rotating unsprung weight but the problem is getting one off parts made for sensible money, I've made a few enquires about getting stuff made and few places even want to quote. The knuckle would be especially expensive in terms of kg saved /£ spent.

Having sat down and gone through it... Ironically the biggest area to save weight is an alternative engine to the XE but would potentially mean it starting from scratch so not going to happen if I am ever to finish...

Some of the options currently being considered or trying to get parts made are:

Rear disc conversion

Heelboard mounting of the rear suspension could save me a few more kg's and but the weight distribution is already more front biased than I'd choose

CF doors, albeit wetlay for those available is a much bigger overall weight saving for the money spent, but no idea how well they fit and how stiff they are but if they are 1.75kg as advertised it's a decent saving.

Not using the 'Works' style dash I made a few years ago

Lightweight silencer

Lighter seats than the buckets I have

Usual engine stuff, lighter flywheel etc

Split rims

Continued chipping away at saving weight on every bit

Edited by Aubrey_Boy on 17th Oct, 2017.

Have you got an alloy block xe?

Last time I looked they were £2500 +vat + some machining, but yes a good 19 - 20kg ish saving, so about £150 / kg (So pretty good) but I'd really look elsewhere first before spending that on an XE block I think, dunno how much they have been used or proven? especially with a turbo?

Edited by Aubrey_Boy on 15th Dec, 2016.

Hi Spencer,

german Tuner Spiess gained approx. 10 Kgs only by working on the block.
Cutting not used cast iron from the block, grinding, sanding and polishing the block inner and outer.
I have the Infos somewhere on my computer, but didn't find it yet.

And, please stay on the C20LET engine, you have done so good work on it, it would be a shame to cancel that :).

Cheers

Ruediger

Hi Ruediger,

No, no plans to change the XE, I have saved about 1kg from the block so far, wow 10kg is a serious saving, I'd need to section some scrap blocks to have more confidence where to take more material, to be honest I only removed some of the unused bosses and a light linish.

I'd be very interested in the article if you can find it

Cheers

Spencer

I have a scrap block I would donate to your research

Thank you very much whereabouts are you?

I live in Bracknell, have a farm and workshop in Somerset but work in Staines! So basically anywhere along the a303 m3 corridor is convenient!

Cheers mate I'll have to see when someone is next down that way, not likely in what's left of this year though.

Where are you located?

Birmingham area

Edited by Aubrey_Boy on 17th Oct, 2017.

I have started posting on Instagram also my name on there is turbomk1golf

Nothing is impossible it just costs more and takes longer.

If you can wait I work in Cheshire a few times a year teaching critical care course, next time is February.
I might be at autosport show too

Hi, yeah Cheshire sounds fine, maybe meet up en route at an M6 junction whatever best suits you?

Thanks again

Alternator done

New on the left original on the right:

K-Nut and ally poly vee pully and a little bit of work on the alternator body mean I am just over 2.5kg altogether now compared to just over 3.0kg previously.



So it's worked out about £210/kg saving in this instance which is becoming a pretty typical figure now for most areas I am looking at trying to save weight.

Sometimes it pays not to work it out though... The K-Nut on it's on works out at £338/kg saved.... The ally pulley was a much better £/kg purchase

Cheers

Edited by Aubrey_Boy on 5th Jul, 2017.

Healthy saving

Where did you get the pulley from? Off the shelf?

XE Turbo on 10's? No, not exactly....

Using a scrap Rosepetal for mock ups......

For a long time I toyed with making 10" work with this build but the work here is intended for another.....

Here we have what I consider to be the best 'off the shelf' package as far as hub level lateral offset goes... 4.75 x 10" Rosepetal with the spacer removed (ET40) which is essentially an FIA App K setup (As far as offset goes), to do this we have to do a bit of machining to the part which is the brake disc, no not the 'disc' part itself but the bit which butts up to the drive flange. Additionally we have to modify the OEM AP caliper as the bleed nipple hits the rim.... Everything I have read suggests that the historic boys grind standard bleed nipple away for clearance.... This seems a bodge to me so a better solution is to move the bleed nipple as shown here.

DSC_8035 by Aubrey Boy, on Flickr

With 10" wheels I have for a long time wanted to try and see what could best be done as far as minimising lateral hub level offset (not scrub radius) as this is the main factor which controls what people think of as torque steer but what I think of as far as something which corrupts the torque we feel at the steering wheel when strange stuff happens....

The main issue with 10" wheels is the practicality of getting the upper and lower ball joints inside a 10" wheel (which we can't while retaining sensible kinematic behaviour...) So all we can do is move everything as close as we can to the rim itself and that's it....

The steering arm is plenty clear:

DSC_8044 by Aubrey Boy, on Flickr

Having sorted the bleed nipple now the lower ball joint is the limiting factor (A series Metro balljoint in ally hub):

DSC_8051 by Aubrey Boy, on Flickr

A K-Nut will help a little not much else we can do

Going by the lower ball joint clearance I have a little wiggle room, so I have further modifed the brake disc part and the drive flange so I can get to what is essentially an ET 43-44 offset and no more:

DSC_8089 by Aubrey Boy, on Flickr

Lower ball joint still clear....

Overall still not as good as the 13" K series Metro / MGF setup I am running with ET44 (as far as hub level offset) but the best I can think of with a 10" setup, also I tried this with a 'K series' steering arm and it cleared fine.

So this is what I'd try as being the least "torque steery" 10" setup but with a fair amount of work and maybe only with a heavyweight caliper?

So I'd like to see if any of the lightweight calipers can fit in this package as it will save at least another kg per side

Cheers

Edited by Aubrey_Boy on 2nd Jul, 2017.

Which hubs are those? Very interesting post!

not sure if this is useful, but i will stick it up anyway ..


http://www.turbominis.co.uk/forums/index.php?p=vt&tid=294194

Edited by robert on 18th Oct, 2017.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Cheers Robert, all info is useful....

Miniminor, these are Minisport ally knuckles, other than weight I have happily been using A series Metro knuckles with proper ball joints, but I can't get N.O.S. anymore so got these and saved a little weight too, quality wise they seem ok other than the fact that it looked like the storeman kicked them all the way to the salesman.....

Cheers

I have a friend who is a prototype engineer for a well known brake company,
I can ask him to see what the lightest calipers he can make are,

Thanks. The reason I asked is because i know that the kad hubs have non std balljoint placement/angles at least.