Should I go with twin disc clutch?

[Project91Tsi]

Ok, so on the new build with Eagle rods, and Ross 8.2 pistons, I have elected to go with a Magnus street SMIM, as well as recently purchasing a Borg Warner S256 ETT .70 A/R with a Fat Fab T3 header. My goal is to be in the 22 psi range on pump gas, and 30-35 psi on race fuel depending on tune issues with ECMlink. I have FIC 1100 high impedence injectors, a 255 Walbro rewired, so I don't think fuel should be any issue, but is my ACT 2600 sprung street disc going to give out very early??? Any thoughts on my best clutch options would be greatly appreciated. BTW it is a rarely driven "street" car, meaning I do drive it on the street, and some on the track, but usually less than 2k miles a year anyway, so driveablility isn't my worst concern....

 

[cyclonekid77]

Im running an S256 on my car rite now. Im also using a ACT 2600 clutch with a street disc. The manufacture date on the pressure plate is from 04 haha. Im running 27psi on E85. 23* of timing up top. It is making realy good power and the clutch holds it just fine. Put about 500 miles on the build so far and im sure its got plenty more in it.

 

[twicks69]

You really don't "need" it, based upon power levels, but if you want it for the fast shifting, I would go with a Quarter Master gear drive clutch assembly with the street or race friction materials. The street material is ceramic based while the race material is a sintered bronze ferrometallic material.

Tim Zimmer via Evo Phone

 

[Project91Tsi]

Thanks for the input Twicks, much appreciated!

 

[AwD4g63TsI]

From what I've researched you should stay with a single disk as long as you can. People have been getting tranny input shaft splines wear prematurely because of twin disks. And this is with everything working properly.

 

[kilo4]

I suggest the Quarter Master HD gear drive twin disc "street". No worries on pre mature input shaft wear. The pedal pressure is almost stock but will handle up to 700 ft lbs of torque. I'm currently in my break in process and can't wait to try it out.

 

[my98gsx]

the twin disc is not needed, i switched from the street disc to a sprung 6 puck and love it. mines held up for 3 years without problems while street driving. if your pressure plate is in good shape you can just change the disc (ide replace the tob while your in there though) off topic i think you should re-think your intake manifold choice. (i know, and itll probly start a war with magnus buffs, but they break and dont hold up - go with a jmf, with a new act clutch and youll have a nice setup) good luck

 

[99gst_racer]

Ok, so on the new build with Eagle rods, and Ross 8.2 pistons, I have elected to go with a Magnus street SMIM, as well as recently purchasing a Borg Warner S256 ETT .70 A/R with a Fat Fab T3 header. My goal is to be in the 22 psi range on pump gas, and 30-35 psi on race fuel depending on tune issues with ECMlink. I have FIC 1100 high impedence injectors, a 255 Walbro rewired, so I don't think fuel should be any issue, but is my ACT 2600 sprung street disc going to give out very early??? Any thoughts on my best clutch options would be greatly appreciated. BTW it is a rarely driven "street" car, meaning I do drive it on the street, and some on the track, but usually less than 2k miles a year anyway, so driveablility isn't my worst concern....

That 2600 PP will be plenty for your power goals. The QM gear drive clutch is sweet, but if you want to save some money, then just replace your street disk with a ceramic 6-puck disk like this one.

 

[97gst_spyder]

Is there any downside to a twin-disk setup except price?

 

[Project91Tsi]

From what I've researched you should stay with a single disk as long as you can. People have been getting tranny input shaft splines wear prematurely because of twin disks. And this is with everything working properly.

The new gear drive from quartermaster uses a single disc on the input shaft, instead of two separate floating hubs, which allows them to run the single disc on the full length of the splines (1.550" vs .850" on the separate hub design) This is meant to prevent increased wear on the input shaft.

That 2600 PP will be plenty for your power goals. The QM gear drive clutch is sweet, but if you want to save some money, then just replace your street disk with a ceramic 6-puck disk like this one.

With the 2600 PP, my street disc was still quite worn after about 5k miles. The facing on the pressure plate was quite hot, haven't had it to the machine shop to see if it can turn out, but it looked to have several hot spots. The street disc itself, while worn out obviously, also showed severe wear on the rivets holding the clutch together, and had broken springs. Yes, I am pretty hard on my clutches, that's why I have an awd DSM. I don't want the springs breaking out of those on a regular basis, and the thought of the stockish pedal feel on the twin disc was really appealing.

In addition, the 17 pound combined weight of the entire clutch and flywheel together sounds really appealing!

 

[99gst_racer]

I hear ya there. I picked up the QM gear drive set-up for two main reasons; it will never slip under any amount of load that I'll give it, and I'll be able to shift far qucker than before.












<---------- I made this power with an ACT2600 PP with a clutchnet 6-puck disk though, so it's a very capable combination.

 

[Project91Tsi]

<---------- I made this power with an ACT2600 PP with a clutchnet 6-puck disk though, so it's a very capable combination.

Wow, that might have been the best information I've gotten yet 99gst. Thanks for that, it was kind of the power per clutch information I was looking for. Might give that 6 puck a shot then, worst case scenario, with the amount I drive the car, I upgrade to the twin disc in a couple more years. Thanks again!

 

[mattmullin]

Less load on the crank thrust bearings with a twin disk, less pedal pressure on the twin disk than my rally car wit the 2600 in it.