14 replies to this topic

[NDT]

I've asked this on turbominis too.

I'm building up my engine and box - it's an MG Turbo so I've got the verto clutch currently.

Realistically I want a solid torquey ~120hp engine. Maybe a bit more later.

I will only run 10"s so torque will probably be limited by traction.

I have other quick cars so it doesn't need to be psychotically fast.

 

Anyone got advice on which clutch to use?

1) Do I need to go RTS at this point?

2) Will an uprated turbo setup be OK?

 

thanks for any help!

 

Nick

 

[hazpalmer14]

You'll be fine with a uprated friction plate at 120hp. Standard they were 93hp so it isn't a vast increase. I think the rally plate is the one to use.

[MiniMadRacer]

Is it a road car as well or just a drag one ?

[NDT]

Is it a road car as well or just a drag one ?

Weekend road fun only - maybe the occasional track day but I've got another car which is better suited to that.

[mini13]

I'd use what you have there, and just put a decent friction plate in it, if you find it slips then think about the uprated turbo verto.

[Steve220]

From my experience - I used the uprated 180mm clutch plate and the AP 20% increased pressure cover. At 7 psi it slipped. Replaced with an RTS, no issues at 18psi.

[NDT]

From my experience - I used the uprated 180mm clutch plate and the AP 20% increased pressure cover. At 7 psi it slipped. Replaced with an RTS, no issues at 18psi.

thanks Steve, that's useful.

I don't fancy slipping at 7psi.

Probably best to build it once and be done with it.

Nick

[Steve220]

From my experience - I used the uprated 180mm clutch plate and the AP 20% increased pressure cover. At 7 psi it slipped. Replaced with an RTS, no issues at 18psi.

thanks Steve, that's useful.
I don't fancy slipping at 7psi.
Probably best to build it once and be done with it.
Nick

Absolutely! Hindsight teaches us not to waste your money trying to achieve the minimum, invest in doing it right first time!

[NDT]

Makes me wonder what SC use wih their Rotex supercharged conversion. Peak torque is about 135 lbft.

[Steve220]

Makes me wonder what SC use wih their Rotex supercharged conversion. Peak torque is about 135 lbft.

RTS. They order from Pad Jo (Simon), like most other people after one.

[Hpal]

Hi All,

 

Just tacking onto this thread regarding clutches for a turbo engine. I'm in Australia so second hand verto stuff to make an RTS is thin on the ground and would have to buy new.

 

So, I'm building a 1275 turbo engine, not sure on specs yet but will use fusion fabs low mount setup and gt1752. Maybe 140-150hp, not sure yet to be honest. I have an 1100s block, new cam6232 crank, A+ rods, dam5626 gearbox (A+), and a verto clutch housing/cover. 

 

I have no idea on verto clutches. I had assumed that I'd need to build an RTS clutch but if I can get away without then that would be good. I looked at the Stuart Gurr video of a clutch build, and it appears as if its just two clutch springs stacked together, which gives more clamping pressure BUT less wear on the thrusts than a heavy pre-verto? Do I have that correct?

 

So, I was thinking along the lines of a MED Stage 2 balanced flywheel/clutch assembly which they say gives up to 150 ft/lb torque capacity. Am I correct in saying that this, for my use, will do the same thing as an RTS clutch with two springs? Different torque capacity though but still enough. Assume the MED one is just a heavy spring, eg heavier than the standard on but not quite as heavy as the twin spring setup? 

 

How does the verto setup put less pressure on the thrusts? Is it just in its inherent design in being longer spring fingers?

 

It would be nice to just use the MED unit, as long as it's up to the job.

 

Cheers

 

 

med-verto-ultra-light-st2

Edited by Hpal, 29 January 2026 - 12:52 PM.

[Ethel]

The Verto is much like clutches found on most modern stuff. The fingers of the spring plate provide the leverage to overcome the clamping pressure. Because they're all contained in flywheel assembly the reaction forces  to compressing the spring also act in the assembly - opposite to the release pressure. A Pre-Verto  shows it clearer by what it does instead - the leverage is from the long clutch arm. It pushes on the release bearing that (ultimately) pushes against the crank. The reaction force pushes on the clevis pin in the "wok", that in turn pushes on the engine block in the opposite direction to the crank.

 

The Pre-Verto does still have a trick up its sleeve - as the diaphragm compresses all of the force will be stored internally if the diaphragm is totally flattened. Carefully set up it can put just enough load on the crank thrusts required to ensure the (not quite flat) diaphragm pops back to its original shape.

[Hpal]

Yep, so it kind of is hard to push initially, then knuckles over that point and is 'easier' to hold and maybe not putting so much load on the thrusts at that point. 

Just so I can get my head around the RTS twin spring idea, it's literally two springs stacked to make one heavy spring, right?  So, I'd be ok going with verto ST2 kit from MED at 150 ft/lb torque capacity? There's not some special RTS thing that it does that I'm not getting?

[Java_Green]

I am not that keen on adding more inertia than necessary so I went for the MED verto option that is specified to cope with torque figures up to 150 ft lb. It is still not running so have not tested it yet.

[Ethel]

Yep, so it kind of is hard to push initially, then knuckles over that point and is 'easier' to hold and maybe not putting so much load on the thrusts at that point. 

Just so I can get my head around the RTS twin spring idea, it's literally two springs stacked to make one heavy spring, right?  So, I'd be ok going with verto ST2 kit from MED at 150 ft/lb torque capacity? There's not some special RTS thing that it does that I'm not getting?

 

As I understand it, yes. Double the springs, double the force. (ish)

 

The original RTS write up was on  turbominis.co.uk

 

https://www.turbomin...p=vt&tid=437563

 

https://www.turbomin...p=vt&tid=612867