Hey guys, was wondering if anyone happens to know at what hp/tq a healthy luk 13" slips. I know im going to be right on the margin but if i could find a couple first hand accounts that would be great. Ive heard of people having no issues with 160 or 180 injectors and stock turbo with a wicked wheel and chip but i dont speak powerstroke so im not sure how much power that is. Search engine summary seems to think it will hold 400/800 and while i couldnt verify that number, it was conservatively correct on the 12.5" at 350/700. Im planning to have my idi flywheel drilled to accept the 13" pressure plate. The 12.5" luk has been amazing for the last 40k or so with the 110cc and s362 (~300/650 to the tire) has never given me any doubts whatsoever, all the while having an amazing pedal and yoinking around some questionably heavy loads. With that said, i know in at least one specific instance the 12.5" starts slipping at 342/759. Once i get the 150cc on there i could see 400+ and almost 900lb/ft. I dont really expect the luk to hold that, im not sure if my particular pump and combination will make that. Im willing to turn it down a little if necessary to get the clutch to hold, but i would like to try to get some real world numbers before i commit one way or another. Im fairly tall geared, 3.73 and 35s and i pull 8-10k fairly regularly, sometimes 15k, (15-17k and 22-23k gross), rarely a bunch more (~33k) for short distances.

Since it will inevitably come up, theres several reasons im not inclined to go with southbend / valair. I know they dont offer them anymore, but a couple people had run the ceramic idi clutch and fared worse than the luk in terms of holding power, manners, and feel. Ive driven them with the hd pressure plates and felt like i was going to rip the master out of the firewall, i dont feel like replacing the pedal assembly again, and the wifes bad genes cant handle it (multiple knee surgeries). I installed a ceramic hybrid in the bosses 6.7 ctd that they recommended (sbc iirc) after the factory clutch was slipping after being deleted, even after break-in the thing slipped worse than the dual mass and CHATTER. Saving the most important for last, i cannot understate just how absolute-insanely *** their customer service is... valair never bothered to get back to me after multiple attempts, here is an excerpt from an email exchange with sbc, "I also want to point out that asking for something we clearly do not offer (a clutch solution), while simultaneously disparaging our competitor (i said they didnt get back to me) and our website (3 pages of "our products are good" and zero useful metrics, cant search by application, mislabeled applications) does not encourage us to work with you." Pretty sure theyre supposed to encourage me to buy from them, but i also thought they did more than repackage parts too.