Was good to see you circulating at Buttonwillow last weekend. Did you manage to solve your brake pad problems?

 

Oh interesting! That wasn't me, perhaps another lemons team got a MINI?
My MINI has been occupied with some upgrades for the Sonoma race next weekend, the big addition being the new fire suppression system.

As for the brakes, after I tore them down from last race I'm leaning more towards heavy glazing, possibly resulting from improper bedding, as the cause for the bad performance and eventual shuddering. I have new rotors, pads and reman calipers to go round, so hopefully with better bedding there will be less issues this race.

One issue I ran into are the race pad options for the R56S (aka. R53 JCW) front calipers. Carbotech has options but their bedding is finicky, especially up at the RP2 compound level, and there's no ST43 pads, or Hawk Blues available. Hawk has DTC-60 but they seem a bit too aggressive. If things don't go well this next race, I'll either look at stepping down to something like a Carbotech XP10 which I've had no problems bedding in the past, or going back to the original R53 calipers with some ST43 or Hawk Blues.

Here's a picture of the most severe front rotor.

 

Ha! Yes, another blue coupe, it never occurred to me that there'd be more than one of you crazy people out there... I mostly left them alone when they were pitted since they were working hard sorting through their pad stock.

Good luck with the compound juggling, hope things go better for you next weekend!

 

Current R57 owner, getting ready to jump off the deep end and build an R53 for Lemons/Chump Car. Done any more races? Any updates on reliability and tips on how to avoid spending the whole day in the pit?

 

Great stuff. Following.

 

This sounds like so much fun! There are several build-for-race threads here on NAM that I follow.

Not sure if this helps, but I have been fighting brake issues since I first got my 2012 Cooper S and put Wilwoods on it for track day events. Short story is that I found at Watkins Glen (really hard on brakes) things would get too hot for the pads. This included Wilwood’s Poly H pads. I would get what would feel like wrapped rotors. But I think what it really was was melted pad material. This went away with some minor improvement in cooling and going to the Hawk DTC60 pads. I had a friend who ran the Hawk DTC70 pads, with no issues and he was crazy fast in an R53.

Do you have any allowance to change out the brakes? The Gen 1 JCW front brakes are the same as the Gen II Cooper S brakes. If you can make that change, it would be worth it for the larger rotors. Should be an easy find in a salvage yard.

You mentioned in an earlier post about the reliability of the SC. I would think that would be dependent on the oil that is in it. If you haven’t changed it, that might be something to consider.

Hope to read more of the adventures of the Blue Cooper...

 

The MINI has been doing great on track, much better than I have been doing keeping this thread updated.

We have successfully run 5 races this year, just finishing up last week with the last race of the year at Sonoma. We finished 11th overall and 2nd in B class, out of a total of about 135 cars.
This year we drove to and raced at; Sonoma (twice), Buttonwillow, Thunderhill and The Ridge. Most of these tracks are close by except for the 13hr drive to Washington state for The Ridge, for which we bolted in a second seat and two of us drove all the way up, raced, then drove home. Next year we plan on driving to Colorado for the full 24hr race there, about an 18hr drive for us.

Reliability has been very good so far and the stock power has been plenty for the tracks we race at. Most of the upgrades and work between races has been on "driver comfort" in the interior, I've also built a custom telemetry system to see all ECU values (temps, pressures, fuel levels, speeds, etc) from the pits, which has been important for getting the most out of our small tank of fuel.

For the brakes, I switched to using Raybestos ST-43 pads, which have been nothing short of amazing. We just changed the front pads at the last race, which lasted for a total of 3.5 races (7x ~7hr days) plus two track days. Those front pads had maybe 25% pad left, while the rears have over 50% pad left after 4 races, the two trackdays and all the street driving. I'm happy to say that the brakes are a solve issue for now, although I am still looking to add ducting for cooling if we do the full 24hr race.

One problem we did run into at last weeks race was the stock exhaust hangers aren't really suited for racing abuse, after the one-ball mod has been done. There's little restricting the side-to-side movement of the remaining rear exhaust which leads to destruction of all the rubber mounts after a short time. That's an issue I need to solve over the winter break.

Here's a video from last race and a couple of more recent pictures. I still need to do a proper update with all of the build photos I have.

 

I follow a thread of a R53 owner who does track events in the “soggy Pacific NW” and he too is liking the Raybestos brake pads. You might enjoy his thread (if you have a spare week to read it... ):
https://www.northamericanmotoring.co...n-project.html

Love the hula doll...

And the roof rack. MINIs are so versatile...

Congrats...

 

@angusp (if you're still around) or anyone else who did a similar build for Lemons,

What was your solution for the sunroof? Sheet metal? What gauge? Where'd you get it?

 

First Post!
Welcome to NAM!

The best place to buy metal (sheet included) is from Metal Supermarkets. Over the years I have bought a lot from them. Great to deal with and they will provide you with just what you need. They’ll cut it for you.

16ga (0.060” thick) or 14 ga (0.090”) should be just fine for just covering the opening. It’s not structural.

 

lap or butt weld on the sunroof?

 

Either would take real skill to not have the whole thing to not turn into a a warped mess.

I think most people, for this application, would overlap a piece of sheet metal on the roof metal, seal/glue it with some silicone adhesive and then pop rivet it in place before the silicone cures.

 

41317175108

back before it was discontinued you could get a whole new factory slicktop roof for like $550 !

requires much time & patience to do the swap,
but quite a few people have done it

carbon fiber plugs are popular in the UK with the track lads,
a bit pricey at around £700 but can be found secondhand for half that




back in the U.S.,
Button Down Motorworks made a plug with what appears to be Dzus fasteners . . .

https://buttondownmotorworks.com/gallery/mini-cooper/
.


if i was attempting a sheet metal version,
would do lots of research to find good technique,
various sources may provide great advice to save frustration of trial & error,
like this post from Ratsun forums makes good sense . . .

"Now you have someone with welding gloves on hold the piece up in position, while someone with a welder tacks the piece in position, do not try welding, you only tack sheet metal, otherwise it will WARP, you must tack it, then move 4 inches, tack it, move 4 inches, ect, ect, ect, once you get all the way around, then you tack it between each weld all the way around, then you start to skip gaps, you don't want to tack any closer than 4 inches apart, so you keep going around over and over tacking every 4 inches till the welds almost touch each other like in the photo below."



and,
if you've never seen this thread, it is well worth a read just to see the neat stuff getting done

https://www.mig-welding.co.uk/forum/...ooper-s.19678/



@rkde
also posted the process up here on NAM:

https://www.northamericanmotoring.co...chop-mini.html

 

some great references 🙏