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Mini Tech Part 2 - Red Booster fitted to Super heavy duty Clutchfix 570 Ft Lbs clamping clutch

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Hi all,


Following on from part 1 - where I had Ben at Clutchfix (3rd Generation of Clutch Builders who will probably forget more than I know on clutches) build me a all singing and all dancing clutch to cope with the "Rather daft & Loopy" near 350 BHP / near 400 Ft Lbs torque of my Full race JED Rover 5.2 V8.

See Here

Now, when I was young and stupid (vs now much older and still as mad :P ) I have rather "Done My Back in" ..er somewhat....a lot... :rofl:

So, bear in mind when I say the clutch was a Tad hard on the left foot that's 2 spinal operations over the years, countless osteo visits ...massages (no proper ones not those :rofl: ) and being stretched on a rack at the physio dept..... care of the NHS ...my back is "Not great"

When you consider a Stock Clutch from LR fresh out of showroom / Valeo 336 Ft Lbs Ft Lbs clamp, a Clutchfix standard HD 370 Ft Lbs clamp and my er "Thing" 570+ Ft Lbs, you can see that it will be harder. To be honest if my back wasn't as it is might live with it, but, having driven it for some time it was throwing my back out a bit ...so I did some research

Yes, I could have maybe made my own kit, but I dont have the time running a small business, so I took the plunge and fitted a Red Booster Kit.


Great Kit, bloody dreadful instructions, quite the worst I have had to cope with, so though a independent write up and review would be a good idea.

Pics show most that you need to know but to fit

1. Remove the bloody brake pedal box, its says in the instructions you don't need to but it then if fitted feels like doing a genealogical inspection on a female mouse who is shy. Take the bloody thing out its 6 bolts !

2. Don't use their spring or penny washer use the original, better fixing via the bent tab and stronger spring

3. If a later over centrer unit throw the assister spring away - not needed !

4. Assemble the base carrier and plunger , and we also changed all the bolts from 4.8s to 8.8s as there is some serious forces involved....but we are OCD fussy.

5. Once back on the truck the absolute KEY thing is the adjustment of the clevis pin to mounting on the servo unit this is the one at the rear of the unit closest to the bulkhead and at the top. This is 101% key to getting the pedal to behave and be on / off in the middle of the push down of the pedal,  we followed the instructions to their letter and had a clutch that would not work, it wasn't pushing down enough. Reason was their spring not pulling the pedal up fully, with the old spring back on and the pedal fully raised we adjusted to clearances so the pin JUST fits without being forces, 4 rotations on the shaft made all the difference between no clutch and full clutch  

6. They also supply a reservoir. We haven't yet fitted this, the idea being thanks to a clever Mate Jon W who explained it is you ONLY have full vacuum on tickover, at "bat-out-of-hell" rev you don't, so the reservoir is for gear changes on the move. However , as this is a 2 ton + Brick and a LT85 gearbox its not M3 gear change on the Nürburgring ring territory so we are running without to see, ...IF... its heavier on the move then we will fit it, not doing makes life a lot easier in a tight bay.

7. Its a tight Fit, more so in mine as being a V8 90 it has the biggest Servo on brakes, but it JUST fits, so even on my version these are ok. 

All in all I now even with a dodgy back and a 570 Ft Lbs clutch have a nice clutch which makes it much lighter. I would also say that a 370 ish clutch with one of these may well end up giving you either no feel at all or a very very light clutch.

There is a lot of nonsense talked about clutches, there are some copyists on the market who are legends in their own minds but are not as clever as they think they are, and some of the pattern stuff is just - well junk.

I turned to Clutchfix with my own thoughts and ideas, they convinced me I was on the wrong route and to trust them to build what they knew from 3 generations of experience would be right, and it is, only fitting a Red Booster as it is waaaaay OTT on a clutch, and me with a damaged spine from the joys of spreading my body on tarmac exiting superbike years ago LOL.

Chuffed. If you need a clutch call on Ben at Clutchfix and listen.

Know their stuff.

As to if you really need a red booster - they make a vast difference, but setting up that bloody linkage is key !









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3 minutes ago, Hybrid_From_Hell said:

"Rather daft & Loopy" near 350 BHP / near 400 Ft Lbs torque of my Full race JED Rover 5.2 V8.






Is that it :ph34r:

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How badly did you injure yourself fitting it ? 😆


  • Haha 2

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12 hours ago, Mo Murphy said:

How badly did you injure yourself fitting it ? 😆


Measured in pints or digits?

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