Finally!! McLeod

[J_Maher_AMG]

The point is the stock clutch will not handle 700 crank hp. Lethal has proven this months ago. But stuntman thinks otherwise.

I know I'm just busting your balls. I'm no clutch expert, but I would be shocked if the stock unit couldn't hold those power levels. It isn't hp that destroys the clutch anyway, its the torque. And compared to some other cars, particularly boosted motors, the 5.2's torque levels aren't crazy high, especially if kept NA.

At 700 chp for example, I doubt the torque rating would be beyond 510-520 ft-lbs, if that. I don't know of any stock clutch from any even semi-performance cars that couldn't take a 80-100 ft-lb increase in torque and not be fine. Hell, my old WRX could easily take an extra 160 ft-lbs and I beat the hell out of it, never even slipped after 3 years of abuse. And I wasn't even close to the point where a new clutch was required. I just don't see the stock clutch being that weak in our cars. Drag racing is obviously very hard on clutches when launching right, but even driving aggressively on the street, shifting hard, etc. you are not going to blow the clutch up with a 15-20% increase in torque IMO. Might shorten the life a bit, obviously, but nothing drastic I wouldn't think?

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[Stuntman]

The point is the stock clutch will not handle 700 crank hp. Lethal has proven this months ago. But stuntman thinks otherwise.

You're right. Ford built the GT350s clutch weaker than the base GT, which there are tons of 700hp supercharged cars running on the street and road course without issues

I guess the GT350s clutch can't handle an extra 174hp but the base GT can handle an additional 265hp. You might want to swap in a stock GT clutch.

 

[Voodooo]

You're right. Ford built the GT350s clutch weaker than the base GT, which there are tons of 700hp supercharged cars running on the street and road course without issues

I guess the GT350s clutch can't handle an extra 174hp but the base GT can handle an additional 265hp. You might want to swap in a stock GT clutch.

If you like to take chances and push stock parts to the limit of destruction be my guest. I myself don't like broken parts or taking that risk. Why would I built a engine and use a stock clutch? Even if I were to put NOS or FI on a GT350, GT 5.0, Honda Fit etc...I still wouldn't use a stock clutch. Same goes for axles, opg's, etc.
If the brakes on the GT350 weren't as awesome as they are I'd upgrade them also. Let's say for example I had a base mustang GT. Without the performance pack. With the 4 piston front brakes and single piston rear brakes. I would not waste my time tracking the car with those brakes. I would upgrade to a much better brake package. Same goes for people that put a supercharger on a 5.0. Sure you can hope and pray the stock opg's last, but why take the chance of a destroyed engine?
I agree clutchs are rated by tq. And HP is a measurement of tq. But almost every clutch manufacturer advertises its product by HP rating. Let's not forget TQ and RPM. I'll agree the stock GT350 Clutch may work with 700-800-900 hp. But at what abuse and for how long?
Not all GT mustangs with power adders have stock clutches. Show me how many race their cars with a stock clutch that last and out performs a aftermarket clutch. If you're talking a street car that sees no track time, than yes I'll agree a stock clutch will support 700+ hp.

5252x526/7500=368 tq.
5252x700/7500=490tq.
I realize that's not a lot and the clutch may survive. But I'd rather upgrade.

 

[Stuntman]

Gearing is a torque multiplier. The true torque at the wheel is MUCH greater in 1st gear during drag racing than in 2nd-3rd gear on the street/road course. On top of that, the launch for drag racing is VERY hard on clutches, especially when using sticky tires on a prepped track.

You need a lot more clutch capacity when drag racing than street/road racing. -That's my point.

I look forward to your 700hp FPC build. FPC's are no joke when you have a 5.2L with a massive 93mm stroke. You'll be paving new ground and will be meddling with powers (harmonics) you can't possibly comprehend. Their's a reason you don't see FPC V8s with the displacement or stroke as the Voodoo.

IMO, I'd just throw a CPC and cams in and build that to 700hp without dealing with the harmonic issue. It will be much easier in the long run and there will be no issue with the McLeod clutch.

 

[Voodooo]

Gearing is a torque multiplier. The true torque at the wheel is MUCH greater in 1st gear during drag racing than in 2nd-3rd gear on the street/road course. On top of that, the launch for drag racing is VERY hard on clutches, especially when using sticky tires on a prepped track.

You need a lot more clutch capacity when drag racing than street/road racing. -That's my point.

I look forward to your 700hp FPC build. FPC's are no joke when you have a 5.2L with a massive 93mm stroke. You'll be paving new ground and will be meddling with powers (harmonics) you can't possibly comprehend. Their's a reason you don't see FPC V8s with the displacement or stroke as the Voodoo.

IMO, I'd just throw a CPC and cams in and build that to 700hp without dealing with the harmonic issue. It will be much easier in the long run and there will be no issue with the McLeod clutch.

It's funny because now you're agreeing with me when all along I already said this in so many words. The stock clutch is fine for normal spirited driving but in real world track abuse it will not last forever.
I've been drag racing for nearly 30 years. I agree with you. I'm aware of the tq and gearing. Also don't forget vehicle weight.
I know a 700+hp cross plane would be easier, but I like a challenge!

 

[Stuntman]

It's funny because now you're agreeing with me when all along I already said this in so many words. The stock clutch is fine for normal spirited driving but in real world track abuse it will not last forever.
I've been drag racing for nearly 30 years. I agree with you. I'm aware of the tq and gearing. Also don't forget vehicle weight.
I know a 700+hp cross plane would be easier, but I like a challenge!

Nothing changed from what I said on page 1:

The dual mass flywheel & clutch are specifically tuned for the harmonica of the FPC. I wouldn't change it. Lethal found the limits of the stock clutch, which would probably handle 700 crank HP for street/track use. You may have longevity issues at the strip.

0.02

It's not my money but if you have plenty to burn, I look forward to your build since no one else in the world has successfully done it.

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