R20 BTG - Supreme Motorsport Track Car Build


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On Saturday I did some post-trackday cleaning and checkups. I'd reset the trip at Donington and managed 209 miles on track, that's 105 laps of the National circuit!


The car was pretty filthy and was covered in rubber pickup that had been flicked up from track:



Also in refuelling from my Jerry cans I'd dribbled a bit of fuel down the side of the car that had picked up a load of dirt. Formula 1 style Flow-Viz, innit.


I wheeled her out and opened the doors and boot to give her a good airing and hoovered out the inside. Nothing major, just more flock dust and some little stones in the footwell area:


Whilst the hoover was out, I got the rest of the Donington gravel out from the nooks and crannies :oops:


I'd put her back on the trailer still with the Autec Wizards and slicks on. I jacked her up on 4 axle stands and whipped off the wheels for a check of the tyres. One of them had no visible wear dots so I reckon that's probably dead. The other three were OK. Note to self, the gravel lane leading to my house is no good for keeping slicks nice and clean. I'll have to remember to put the road tyres back on at the circuit next time.



I've got another part-worn Michelin Slick S9D compound to go on:



Then a snow foam wash and scrub down, she ain't no detailing queen so no two bucket method here, just a snow foam, rinse, snow foam and mitt, then rinse and dry. Managed to get the worst of the rubber marks and dead flies off. Cleaned the brake dust off the calipers and checked pad wear. All fine as expected after only one track day. Reset all the dampers to soft, and covered the Gaz Golds in ACF50.


Went round with the torque wrench and torqued all the studs up to 20NM, a couple were a bit loose.


Checked fluids, topped up oil and coolant:


Still looking good:



Back on the OZ Ultraleggeras and Cup 2s for road use:


Need to get the Pure Motorsport mounts installed before the next track day on 19th May, again at Donington Park.


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Did you install loctite on the studs? Re-tightening them will likely break that bond.

The rubber marks are an absolute pain. I’ve not found anything which gets it off easily.

Oh, and VP filling jugs are defo a worthy purchase. You’re not meant to store fuel in them, but they are spot on for filling.


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Did you install loctite on the studs? Re-tightening them will likely break that bond.

The rubber marks are an absolute pain. I’ve not found anything which gets it off easily.

Oh, and VP filling jugs are defo a worthy purchase. You’re not meant to store fuel in them, but they are spot on for filling.
They were loctited when first installed, but haven't renewed it yet. A couple were finger tight. I've ordered some Loctite 2700 so I'll re-glue them next time I'm doing some maintenance.

I'll check out those filling jugs, got a link?


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As Crunchy says I’d definitely take the studs out, loctite them and torque up. Just re-torquing will just break the bond on the original loctite
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The sump gasket has been changed twice on mine, don't think it's that. The crankshaft seal has also been changed. Could be some of oil cooler pipework, we'll have to see
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Bit of an overdue update this one, grab a cuppa. Donington was on 19th April which began by collecting the rental trailer again. Can't fault this Brian James A4, it tows really nicely.


Got R20 BTG loaded up and strapped down:


The forecast was all over the place, so I took all three sets of wheels (Michelin Cup 2, R888R and Slicks). I didn't have anything that would be considered a 'wet' tyre really.


Love this shot:


The Disco 4 makes a mega support vehicle, 60 litres of Super Unleaded, tools and spares, trolley jack, impact gun, extension leads, a couple of camping chairs , two helmets and lunch all fit in the boot with loads of room to spare.


The day started off warm and dry so was straight on the slicks picking up where I left off last time. Thankfully no trips to the gravel trap this time. The car was running well.


There was a 750MC meeting at the weekend so there were a lot of racers using it as a test day. I don't mind this normally as long as they adhere to the track day rules, but there was a bunch of BMW 116 race cars that were testing that were being a right pain in the arse all day. The Clio is a lot quicker than them pretty much everywhere on circuit but they just wouldn't get out of the way. On several occasions they were just refusing to keep right on the straights and indicate, despite people sitting up their arse for lap after lap. Eventually I ended up having to overtake them on the right. They also caused a few red flags throughout the day.

I'm pleased to report the pit lane marshalling was drastically improved, I don't recall any close encounters on people exiting the pit lane into Redgate.

There was a grey cloud looming in the distance just before lunch and me and my mate reckoned we could get one last session in before the rain came. We left the pit lane and by Craner Curves the drops started hitting the windscreen. The back end of the circuit was dry so we carried on but by the time we came past the pits again the heavens had opened with a thunderstorm. Rain turned to hail and it was just bouncing off the track. I was still on slicks at this point so tiptoed around and dived into the garage. Thankfully I'd rented a garage for the day again because the entire paddock ran for shelter. It got so bad they red flagged it for an early lunch.

Screenshot 2021-06-09 at 10.05.44.png

Over lunch we took the slicks off and put on the R888R. The rain didn't last long and by the end of lunch the sun had come out and the track was drying out.


I took the opportunity to be the first one out after lunch to see what the track was like. It was a bit greasy in places, the first lap was just an investigation lap and then I started to pick up the pace. I had a couple of snaps of oversteer coming through the Old Hairpin in 4th when it was still a bit slippy, that certainly wakes you up a bit. I didn't bother to slacken off the damping so I was still running it pretty stiff from the morning session.

There doesn't appear to be any photographs from after lunch, maybe the photographer fucked off when it started raining. For the rest of the day I left the R888R on, as although the track stayed dry, there were rain clouds looming for most of the afternoon and I had the occasional drops landing on the windscreen.

All in all a good day, managed 186 miles on track (98 laps).

The following weekend I gave it the usual post-trackday clean and checkup. Was a bit grimy on the back end.



The front discs look a bit scabby but still life left in them.


I've bought a pair of Godspeed G Hook to go on one these pads are worn out:


Dried and put away:



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It's not all sunshine I'm roses though I'm afraid. You may recall earlier in the thread I complained about the car jumping out of 5th gear and rocking back and forth quite badly in 3rd and 4th. I have also exchanged messages with a few of you on this subject too! Well after Donington it was time to investigate. The Pure Motorsport mounts did nothing to stop what I thought was the engine/gearbox rocking back and forth. The problem was still there. I also had the airbox and battery out to tweak the shifter cables to see if that was the problem. It wasn't.

The only solution was to get the box off and have a look at the internals. Matt (@R27WTF) offered to look at this for me, but distance and logistics got in the way (we're 250 miles away from one another!), so instead I took it to a trusted mechanic who took it apart to investigate.

Not good news. A lock ring (Part 23) seems to have failed on the input shaft, which in turn has allowed everything from Part 21 upwards to float up and down the shaft:


This in turn has destroyed one of the splined washers and mush it to oblivion (Part B started off life looking like Part A):


This has also destroyed the needle bearing (Part 35):


The movement also caused damage to the gears themselves:


I don't think anyone is at fault, it's just one of those things that happens. Thankfully the Gripper diff is fine as the needle bearings were retained in their housing and trapped between its neighbours. One more track day might have caused way more damage, so I'm thanking my lucky stars.

Supreme Motorsport have been fantastic yet again, we boxed up all the bits and sent them back to @R27WTF - on inspection he wasn't happy with retaining any of the bits, even the input shaft which looked a bit chewed up. Everything has been replaced, new gears, new syncros, new bearings, even a new input shaft.



This has been couriered back to my mechanic to put back together once he has time. At the moment, R20 BTG is sitting high up in the air on a ramp without a gearbox. I'm hoping to get it back this week and I'll report back once I have the car.

In the meantime, we enjoyed a great week in Cornwall over half term:





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Great pics mate. Glad it’s getting sorted too!
I’ve just put a set of Godspeeds on the front of mine (still with the old pads), and they’ve cured all my vibration issues.

They’re a little nosier, but it just adds to the race car feel :tearsofjoy:
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Collected the car on Wednesday evening and everything seems to be sorted. It's going into all gears (and crucially staying in them!) and no longer popping out of 5th. There is also no rocking back and forth in 3rd/4th, none whatsoever. Touch wood, it's now sorted. Feels like a totally different gearbox (which, in effect, it is!).

I did have an engine oil change done at the same time (it had done 2 x track days), and obviously the gearbox oil has also been changed as part of the gearbox strip down. The positive part is that the Gripper diff has now effectively had a 'running in' oil change after approx 400 hard track miles.

We replaced the main seal behind the flywheel (again) as it was continuing to leak. My mechanic found a slight scratch in the engine casing which I think was causing the seal not to 100% seal. He's cleaned it up and given it a bit of a polish and so far appears not to be dripping any more. Whilst it was up in the air, he gave it a once-over and spotted that a bolt was missing from the exhaust manifold (new one installed), replaced a few nuts and bolts that looked a bit tired, and welded in some new captive nuts where they'd been replaced with rivets. It's now had a clean bill of health again ready for the next track day.

Only the matter of the £850 bill to pay now for diagnosis, gearbox removal, strip down, boxing the bits up, and putting it all back together plus the bits and bobs listed above. :coldsweat:

Gave it a quick wash last night and put it back in the garage on the CTEK charger.


I've got some updates to come with regards to GoPro mounts so watch this space...

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