High Torque Clutch

[BRX]

TL;DR: I'm about to pull the trigger on an Exedy Twin Disk but rather not if I could find a cheaper alternative to hold +500tq.


I swapped a 5.7L Toyota V8 (381hp/400tq) into my 86 and was able to mate the stock AZ6 Transmission to it until I can afford a T56 swap later this year.


Before I did the swap (Built FA20 with 14-20 psi) I had a Southbend Stage 3 Daily (400tq) for 2 years. It started to show some wear but I liked how it drove so I swapped the friction plate with a new one along with the Southbend flywheel. 1000 miles later I went to the drag strip and a day later on the highway it would slip sometimes in 5th and always in 6th when trying to accelerate.


When I did the swap I resurfaced the flywheel and got a Stage 4 Southbend that is claimed to hold 450tq. Drove it for roughly 500 miles as easily as I could and while we were tuning on the street at nowhere near full throttle it would slip in 3rd, 4th, 5th and 6th just like before but much worse. 1st and 2nd it would just spin the tires.


I'm pretty sure the clutch was not broken in properly due to the high torque output and peak torque at 3600 RPM even though I didn't floor it.


So I would assume I would need at least a "+500tq" Clutch . Either way I'm looking for a temporary solution until I could get my hands on a T56. An Exedy Twin disk would be ideal but too expensive to justify as temporary. The Exedy Stage 2+ by Crawford is also rated at 400-600tq but I'm worried it would be the same as the Stage 4 Southbend I have right now.


Anyone out there with +500tq in an FA20? What clutch are you using?

[spitfire481]

FX725

[BRX]

Originally Posted by spitfire481

FX725

This thing might actually work. Thanks!

Why isn't this clutch listed in any of the popular 86/BRZ online stores though?! Even directly googling it I could only find it on Real Street Performance...

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[spitfire481]

Originally Posted by BRX

This thing might actually work. Thanks!

Why isn't this clutch listed in any of the popular 86/BRZ online stores though?! Even directly googling it I could only find it on Real Street Performance...

Sent from my Pixel 2 XL using Tapatalk

no idea. we run them in a few cars. have one behind an 800whp fa20 and my old 700whp fa20 with no issues.

[Irace86.2.0]

Originally Posted by spitfire481

no idea. we run them in a few cars. have one behind an 800whp fa20 and my old 700whp fa20 with no issues.

The 86’s transmission can hold that much? For how long will that hold? I thought it was glass.

[spitfire481]

Originally Posted by Irace86.2.0

The 86’s transmission can hold that much? For how long will that hold? I thought it was glass.

they don't lol. I went through a few then did a custom tko600 swap before i did a 2j swap

[Irace86.2.0]

Originally Posted by spitfire481

they don't lol. I went through a few then did a custom tko600 swap before i did a 2j swap

Someone in another thread advised to have the weekest link be the clutch instead of the transmission. The idea is that burning through clutches is cheaper than burning through transmissions. Good advice?

[BRX]

Originally Posted by Irace86.2.0

Someone in another thread advised to have the weekest link be the clutch instead of the transmission. The idea is that burning through clutches is cheaper than burning through transmissions. Good advice?

Not sure how that would work. I mean if you're burning your clutch and slipping you can't put any power down. Even if you wanted it to use up the clutch to save the transmission you can't really do it unless you use one that's rated for lower torque than you're making. In any case you're just wasting money as the clutch will be done for almost immediately.

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[Irace86.2.0]

Originally Posted by BRX

Not sure how that would work. I mean if you're burning your clutch and slipping you can't put any power down. Even if you wanted it to use up the clutch to save the transmission you can't really do it unless you use one that's rated for lower torque than you're making. In any case you're just wasting money as the clutch will be done for almost immediately.

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Yea in his 700-800hp applications for track use then a strong enough clutch to hold the power is needed because racecar events, but in the world of street cars and high hp daily drivers that are pushing the limits of their components (perhaps gambling until the next upgrade like a T56), I personally would rather have the clutch go before the transmission. With that said, I don’t know what a used transmission goes for; maybe it’s a toss up.

[BRX]

Originally Posted by Irace86.2.0

Yea in his 700-800hp applications for track use then a strong enough clutch to hold the power is needed because racecar events, but in the world of street cars and high hp daily drivers that are pushing the limits of their components (perhaps gambling until the next upgrade like a T56), I personally would rather have the clutch go before the transmission. With that said, I don’t know what a used transmission goes for; maybe it’s a toss up.

They're about 500-1000 on eBay depending on condition. You're gonna need to drop the transmission Everytime you swap a clutch. All said and done, I think it will cost the same, actually swapping the transmission might cost less in labor and require less time but much higher shipping if you couldn't find one locally.

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[Irace86.2.0]

Originally Posted by BRX

They're about 500-1000 on eBay depending on condition. You're gonna need to drop the transmission Everytime you swap a clutch. All said and done, I think it will cost the same, actually swapping the transmission might cost less in labor and require less time but much higher shipping if you couldn't find one locally.

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Yea I agree if those are the prices.

The only difference would be a slipping clutch will warn the driver that it is going to fail; either that too much heat was created or torque exceeded the limits, and it begins slipping, and in the typical scenario, someone could limp the car home or back off. Sometimes a clutch will disintegrate. If the transmission blows then call the tow truck because usually it just disinigrates. Occasionally someone can limp it home in one gear.