Clutch torque capacity

[anonymous-user]

The initial message was deleted from this topic on 27 February 2025 at 17:10

[Boosted LS1]

I'd defo go for the organic.

[stevieturbo]

Niponeoff said:

Is there a safety factor built into the clutch torque rating?

I have a NA engine producing 245 lb/ft, max 8500rpm.

I've been recommend two clutches

260 lb/ft organic
317 lb/ft ceremetallic puk

Both have a sprung centre. I'm thinking I'll for the organic as it will feel better on the road, but its a bit close to my max capacity.

Engine is a series 1 millington gooig on an escort, predominantly for the road.

How long is a piece of string ?

It all varies with the vehicle, usage, power delivery, application...etc etc etc and of course clutch manufacturer.

If it is genuinely for road use and will be driven, no hard launches etc then definitely organic. Whilst paddle clutches can of course be driven, and most very well....they are never ever as nice as an organic plate no matter what anyone tries to tell you.

Do they offer a stronger cover ?

TTV make a lot of nice stuff, and could easily offer a much higher rating than that with an organic disc. Really in terms of clutches these days, even 260lbft is pretty low when that's very bog standard mainstream cars that can make that sort of torque, and diesels a lot more.
So it should be very easy to achieve more in a "performance" application.

[stevieturbo]

Niponeoff said:

Well I did say how long the piece of string was. I also said it was a millington. You sound like you've never heard of one?

I had a 270hp duratec that made 176 ft/lbs of torque, that was quick.

The millington makes 245, that's huge for an NA 4 pot. It's an all out race engine.

I have a 485hp cosworth in the same car and a millington escort would make it look pedestrian in anything other than a straight line, which is why I'm changing it (after much thought!)

I have a strong cover on another car and I don't like it, so I don't want a heavy clutch.

The way millingtons make power I'm worried I might be too close to the capacity. BUT, as you say, for a road car, I want the best mannered clutch I can get away with.

Does anyone know if there is a safety factor. You know, slips at 300, so state 260 as a specification?

It's very obvious what a Millington is.

But it is not obvious what the car is used for, will you ever be launching on slicks, is it entirely on the road on road tyres, what weight is the vehicle etc etc ? And of course how abusive the driver might be, whether deliberate, or not.
The piece of string is completely unknown.

And as it's a n/a motor, and will lack torque in general, that will help the clutch, not hinder it. 245lbft is not huge at all. As said, that's bog standard diesel these days, and they have light pedals and organic clutches.

And no, it's silly asking for a "safety factor", because every application will be different, and every manufacturer will be different. One driver could destroy the clutch in 10 miles, another could make it last for 100,000 miles.

I've had clutches with a rating claimed at say 850lbft hold well in excess of that, and I've had clutches claiming 1200lbft+ slip at well under it.
It's never as clear as it should be, because it is not a simple static environment...plus some manufacturers just spout st and can't be trusted.

But as already said, if you want an organic clutch with a rating higher than the quite pedestrian 260lbft, TTV can make you one for whatever you need.

Although I would be surprised of other makes don't have something off the shelf with a higher rating too. A heavier pedal with smooth engagement is easier to drive with than a very sharp clutch with a light pedal.

http://ttvracing.com/clutches/

[stevieturbo]

Niponeoff said:

I think I'll go for the organic, road use. I can change the plate out if it gets eaten!

I know you think your being funny with the pedestrian torque comments, but comparing a diesel to a millington is laughable.

I have a built 4.0 in my 996T pushing over 1000hp, it's also got a 997 GT2 gearbox so I lost the accumulated clutch of the turbo, coupled with the beefier clutch, makes for a considerably heavier pedal. Todd Knighton has a dual clutch setup which works like stock so I think I might change it for that, but that means more disassembly. I just want to get it right this time.

My Porsche wouldn't see which way a millington escort went, even with a paltry 245ft/lbs...

There's nothing funny about it, it's simple fact. Torque is torque, and torque at lower rpm will be far harder on a clutch than at higher rpm as your engine will make.

[SturdyHSV]

Niponeoff said:

I know you think your being funny with the pedestrian torque comments, but comparing a diesel to a millington is laughable.

stevie is rarely being funny (if you know what I mean ), he knows his onions.

I'd agree comparing a diesel to this fabled millington probably is laughable, because I'd imagine it'd have a much harder time behind the diesel where it'd most likely ramp up the torque far quicker and be in a heavier vehicle, whereas 250lbft from a high revving NA 4 pot in a light escort that is presumably not on wide slicks is going to be a cakewalk, unless you're planning on a lot of high rpm clutch kicks and have pretty grippy tyres.

Personally I'd agree with your intention to go with the organic clutch, it'll be far nicer to drive for what'll probably be 90%+ of usage, and I'd imagine the progressive torque delivery of a revvy NA will give it a comparably 'easy' 250lbft.

Alternatively if you're going to be drag racing it, launching on a prepped surface with a sidestepped clutch at peak torque on squidgy slicks then personally I'd be looking for more overhead and lean towards the 310 rated one.

Assume from the torque it's the 2.5 litre? I bet that'll sound angry at idle

[Panamax]

stevieturbo said:

There's nothing funny about it, it's simple fact. Torque is torque, and torque at lower rpm will be far harder on a clutch than at higher rpm as your engine will make.

^^^ This. When road testing a car for clutch slip you typically floor the throttle in third gear at low speed. It's the automotive equivalent of standing on your bicycle pedals in an attempt to keep going uphill.

[CrutyRammers]

A couple of years ago I changed a slipping organic (ACT) to a Competition Clutch hybrid thing - it's ceramic pucs but not on paddles, more like a normal clutch plate but with ceramic pucs in place of the normal material. Was fully expecting it to be a bit heavy, fierce or otherwise nasty but....it's just normal. Surprised me after all the horror stories tbh.

[PhillipM]

Sounds like an ideal application for a Kevlar unit tbfh - as driveable as normal organics but with better heat tolerance.

[stevieturbo]

small diameter and paddle clutch, will do nothing for driveability, light pedal or not.

7.25" is more of the ilk of actual competition clutches for those who seek the lightest MOI of clutches.

For anything road, I would not be opting for that sort of thing ( unless the vehicle was mega mega light too....like a motorbike lol )

[CrutyRammers]

Yeah mine is much wider than that!

[stevieturbo]

paddle or organic ?

With a twin, could definitely go organic for nice driving. Looks a nice sturdy cover.

[PaulKemp]

Here’s a thought… Talk to Millington they’ll put you right

[Evoluzione]

To describe anything or anyone as 'nice' is an insult unless it or they are anything other than.
Also, since when has something described as 'nice' means it performs adequately?

[stevieturbo]

Do you even need a locking washer ?

I have used them in the past, and they too look "nice".

Although I do feel they would have been even nicer, if a little wider. They just seemed very thin. Maybe that's a necessity of design.

[Evoluzione]

Niponeoff said:

Evoluzione said:

To describe anything or anyone as 'nice' is an insult unless it or they are anything other than.
Also, since when has something described as 'nice' means it performs adequately?

You don't like the look of shiny new car parts?

Here's some more:

The socks are just for storage, but they're on 50 dco webers.





HD concentric slave, waiting for some spacers to get the correct stroke:



I didn't actually know what the thread size was in the flywheel so spent a few quid getting the correct HT bolts. So I've invested in some thread gauges going forward. They were 5/8 UNF. I thought they would be metric M8x1.0.

What do people think of schnorr washers?

I prefer something which performs, lap times and race wins are what matter, not looking 'nice'.

[stevieturbo]

Evoluzione said:

I prefer something which performs, lap times and race wins are what matter, not looking 'nice'.

With a cutch, I couldn't give a hoot about lap times or wins.

It just needs to grip and drive nice.

[Evoluzione]

stevieturbo said:

Evoluzione said:

I prefer something which performs, lap times and race wins are what matter, not looking 'nice'.

With a cutch, I couldn't give a hoot about lap times or wins.

It just needs to grip and drive nice.

You're Irish therefore you have little understanding of intricacies of the English language

[stevieturbo]

Evoluzione said:

You're Irish therefore you have little understanding of intricacies of the English language