Engine/Transmission (1994 - 1998) Loosing clutch, need suggestions, please!

[JGK]

My SB Con O started slipping over the weekend. Almost exactly 3 years old and just under 40K miles on it. I'll be calling Peter for help shortly. However, in the mean time, I thought I'd post for help. I'm thinking of going to twins this spring - shooting for somewhere around 600hp +/-. My truck is a daily driver and I run mostly empty and tow very infrequently. What clutches are being used in this power range that are still daily-driver/street friendly (if that's possible!)? I tried a search and found lots on "twins" but not much that includes "clutch" discussions in those threads.



Thanks,

-Jay

 

[drawson]

Jay, I am really happy with my SBC DD 3850 10 puck clutch. It tows great. DD don't disengage as fast as the single disc clutches so drag racing style shifting is slower. It isn't as smooth as the Con O but not bad at all when loaded. The peddle preussre is alot greater than the Con O.



My question for you are you sure you are going to stop at 600 HP? If so you could go with the lighter sprung DD set ups.

 

[JGK]

Dee,



Yeah, at this point I think that's going to be my limit. To go further, we're talking maybe a different P-pump, bigger injectors, yada, yada, and so forth, and more street-ability compromises. I'm having a tough time justifying the whole twins plan today. Even spreading it out, the cost is huge. With the dual disk rated at 600+, we're talking bigger input shaft. Then, for the twins, add o-rings and studs (which is planned for late next month - a group ring job here locally), and we're at $2500 to $3000 and I haven't bought the second turbo or piping yet! Wheeeee...



Thanks for the reply,

-Jay

 

[JGK]

With all the members out there runnin' twins, I know there's a few that are doin' it with a 5 speed Won't at least a few more than Dee step up and tell me what they're using and how it's working out? I need to make a decision in the next day or so.



Thanks,

JK

 

[drawson]

Jay it is spendy but the twins are well worth there $. As far as needing an injection punp to hit higher HP. It isn't needed. As long as the internals are sound the 215 Pumps can get close to Piers Stupid pumps putting out when you are ready to jump higher HP let me know & I'll hook you up with the local injection pump guy... My pump is only about 100 CC below Maddog's with stock delivery valves. With a holy intercooler and only 46 PSI of boost it made 598 HP :{

 

[Dr.Bob]

Is 40 normal for SB or did you abuse the clutch?

 

[Nick2]

if youre still looking for a clutch, sled puller has one on the classifieds for a $1000. just a thought

 

[JGK]

Dr. Bob,



The Con O is rated for 350 hp, I believe, but I've known people who ran them with over that. I've been pretty gentle. Only an occasional street comp. No track use. I do enjoy pressing into the throttle at 65 MPH on the freeway and running it up fast to get around slower traffic, which I'm sure stresses it. At a little over 400 hp, I'm sure I'm over it's recommended rating. It was only a matter of time. Just sooner than expected.



As to the clutch in the classifieds, I'll look into it. Thanks.



-Jay

 

[Dr.Bob]

40k doesn't seem like very good service, I got 123k out of my stock and still going.

 

[Forrest Nearing]

600+ HP = dual disk

 

[JGK]

Decided to go with a SB dual disk. Will also upgrade the input shaft to 1-3/8" (a requirement with the dual). Blew the winter budget right out the door. Considered the dual disk in the classifieds, but after getting the new input shaft, the difference between that clutch and the new shaft vs Peter's DD, which includes the shaft, wasn't that much, and I get a new clutch with Peter's support.



Thanks all.

-Jay

 

[Mark_Kendrick]

Decided to go with a SB dual disk. Will also upgrade the input shaft to 1-3/8" (a requirement with the dual). Blew the winter budget right out the door. Considered the dual disk in the classifieds, but after getting the new input shaft, the difference between that clutch and the new shaft vs Peter's DD, which includes the shaft, wasn't that much, and I get a new clutch with Peter's support.



Thanks all.

-Jay

You'll love that clutch. Don't stomp shift a NV4500 at 600hp... it'll come apart

 

[Got Smoke?]

Decided to go with a SB dual disk. Will also upgrade the input shaft to 1-3/8" (a requirement with the dual). Blew the winter budget right out the door. Considered the dual disk in the classifieds, but after getting the new input shaft, the difference between that clutch and the new shaft vs Peter's DD, which includes the shaft, wasn't that much, and I get a new clutch with Peter's support.



Thanks all.

-Jay

What plate load/setup did you get?



I have the 12 ceramic button/3850lb plate load in my truck and love it. A friend has the same clutch in his truck and he loves it too. I can't wait to try it out on the pulling track next year.



Hope to maybe do a little research for Peter as well, I have a 3rd Gen pressure plate on my setup (bought the clutch used from a 3rd Gen guy), and my buddy has the correct 2nd Gen pressure plate. My dual disk shifts considerably faster than his. I have talked with Peter very little about this, but still want to look into it more.



Originally if I pushed my clutch pedal all the way to the floor the throwout bearing (I think) was bottoming out and making a noise and you could feel a rattling/thumping in the pedal. I just got used to not going all the way to the floor with the clutch pedal. Well here very recently I have been able to push my clutch ALL the way to the floor without the above problem. However its intermittent, as it sometimes I can still go all the way to the floor and sometimes I still get the noise/vibration. Driving the two trucks (mine and my buddies) mine definately shifted faster to begin with... ... now when I can go all the way to the floor with the pedal it DEFINATELY shifts faster! Oo.



Peter said the above problem could be solved with one of his new adjustable slave/master cylinder kits, but I haven't gotten one of them yet.



I hope to eventually see if I can help Peter to design a quicker shifting dual disk, since a lot of people would be interested in it.

 

[JGK]

Mark,



I went with the 6 button 3600. It is a daily driver and I intend to keep it that way - no plans for pulling or racing at the track. Yeah, I could have gone with more buttons and more clamping, but I decided it just isn't necessary for my use.



-Jay

 

[Fred Swanson]

Jay, consider getting the 3600 lb. 10 disk. That is what I have in mine, and with the bronze insert flywheel, it almost feels like a stock clutch, albiet with a little more pressure. It is very smooth engaging, and driving empty or towing, it is superb.

 

[JGK]

Fred,



Thanks for the suggestion. I went with Peter's recommendation after talking with him. Perhaps the 10 would be better in the long run. However, the clutch is already on its way. Should be here by mid-week. Going in next weekend.



Merry Christmas!

-Jay

 

[Fred Swanson]

Here Jay, this is what you are getting. You will enjoy it.

#ad

 

[CurtisvilleCummins]

I have a 3850 12 and really like it. nice to pull out in 2nd again.

 

[JGK]

Fred,



That looks almost too darn pretty to cover up!



-Jay

 

[JGK]

New clutch (and larger input shaft) is in! Quite a project, but we took our time. That clutch is an amazing piece of engineering.



First impressions are that it will take a little time to get used to the grabby-ness at take off, but Peter said that should smooth out as it breaks in. Takes a bit more leg muscle, but not bad. And when disengaged, it rattles a bit! Folks next to you at stop lights give you funny looks if their window is down. But, hey, its a big noisy diesel. Growl!



Unfortunately, it will be another week before I can drive it as it went in today for a bit of body work (ambushed by a shopping cart early last month).



-Jay