horsepower to 6spd manual

kaczarcollision · 12-06-2007, 09:11 PM

what is the max amount of flywheel hp a stock zf 6spd will handle? after the limit, does just the clutch need upgraded? if so what are the options to look at?

**TYREBOYZ_DEMAXIN** · 12-07-2007, 05:25 AM

the most aftermarket HP you wanna add to a stock ZF6 is about 90 flywheel HP and roughly 60RWHP.i'm not sure what a good clutch cost or who has a good clutch but i know that the South Bend Clutches are very popular..

gunmetalsi · 12-07-2007, 06:43 AM

would have to agree with Tyreboyz on the South Bend clutches, as I've heard that they are one of the very best out there

**Diesel Nut** · 12-07-2007, 08:10 AM

SOuth Bend all the way. Not the cheapest clutch on the market but worth every penny. AND - by far the BEST customer service you could ever ask for.
AS for the transmission, nothing needs to be upgraded really to handle the additonal power than I can see.

For your truck -

in a solid flywheel upgrade, you can get friction materials good for 400, 450, and 500hp, depending on your needs. If you are going to get a little loopy with the power, and want to still tow and have a nice, smooth clutch, the Dual Disc kits from South Bend will hold significantly more power and still engage smooth and easy. They are actually easier to drive than a single, but rather expensive.

So, lets start here. What are your plans? How much more power do you want? DO you tow? How heavy/often?

**05_LLY** · 12-07-2007, 01:18 PM

How much wiil the stock clutch hold? the clutch will hold a great deal of power but the fly wheel will go bad with even stock power levels if you tow or pound on the truck a great deal. First sigh of a flywheel going bad will be a hard to push pedal and then after you get the hard pedal down it will want to stick to the floor. IF that happens just pull it back up with your foot and it will be ok for a bit but i would start looking into a new one. I run a SBC dual disk ceramic, Its not the smoothest or quietest clutch out there but it will hold anything u can put to it!!!

A south bend single disk kit with the SMF (single mass flywheel) will hold around 450 rwhp and drives as good or better than stock!!!

**05_LLY** · 12-07-2007, 01:28 PM

Heres some pics of the stock junk setup!

Notice the bolt hols in the flywheel, how the two plates arent lined up, this is what happens the torqe of the engine actually starts to sperate the two plates causing the pressure plate to push in to the throwout bearing. Therefor making it just like u are pushing in the clutch and then it slips. Once it dose this the flywheel plates stay unaligned like this making it a real PITA to get the flywheel bolts out!!

kaczarcollision · 12-07-2007, 07:12 PM

thanks for all the info. diesel nut, my plans are to tow OCASSIONALLY, its just a daily driver but i want the scare the kids kind of power. what am i looking to spend on a clutch setup to be safe with like say 500 rwhp

**05_LLY** · 12-07-2007, 07:28 PM

For 500 rwhp i would do a cermaic dual disk just to be safe, u might be ok with a feramic single disk but but thats up to u! For a ceramic dual disk your looking ataround $1800 for a single IIRC they run around 12-$1300. For a dual disk feramic they are like $2200!

The dual disk are EXTREEMLY jumpy when trying to back up a trailer, most guys use low range to back up with a trailer so they dont have to try and slip the clutch! The 2wd guys just have to ride it out when backing!!

CEB0217 · 05-24-2008, 06:52 PM

sorry to bring up an old post but i have a question on the topic and i just joined any way if i have had my flywheel replaced at 30,000 is it warrented i have about 63,000 in it know oh ya it was replaced cuse of the rattle that im told they all have and ya i tow a trailor and hull my camper with a total weight of 19,600# i also play on the sand dunes and in snow from time too time and it is a crewcab duelly