At what power level does one need to start worrying about upgrading to a billet forward drum?

 

Anyone?

 

On their website, CK Performance claims you need the billet drum for anything over 300 ft lb.

 

It seems that weight and traction are the greatest detriments to the 200-4R stock forward drum. I am honestly not sure what the slightly beefed 350 (the usual - headers, mild cam, reworked heads) in my Vista cruiser is putting out in terms of torque, but it does feel very peppy regardless. With that, the car does have 3.73's, steeper gears too help with longevity, the car is tail heavy so it really hooks up and goes. Results: six years later, the forward drum is still holding on. Researching and researching some more, it seems that for 350's, the 200-4R's will work for a moderately used in terms of performance application with a few vital, but important mods. The real problem digging in a little deeper with reading up was the inconsistency of the metallurgy of stock drums. The cost of added insurance of the hardened drum/billet shaft versus running with a stock part that may or not fail is an individual choice.

 

I would say CK's claims are a bit too hard for me to take at face value since a stock GN and GNX put out more than 300ft/lbs and they were just fine AFAIC. I think CK may be doing a bit of 'creative advertisement' perhaps. Not saying they're lying or wrong, but I always take advertisments like that with a grain of salt. I'd rather hear some real life success/failure stories from non vendors.

Thanks for the info.

 

I built a 2004R trans for my 69 Cutlass about 15 years ago, in anticipation of doing my first Power Tour with my Olds. The trans was a typical (for the time, this was before the hardened drum was available) rebuild with factory high performance parts. At the time, the car ran in the high 12 second range. The maiden voyage was done on street legal slicks, my thinking was if the trans would hold up being pounded on the street with sticky tires it should last on street tires. The trans seemed to work just fine. On the return home I was driving one a long street, I saw the traffic light change to red. I got off the throttle in anticipation of having to stop, I could feel the entire drivetrain "relax". Hit the throttle, engine freewheels. No forward gears, no reverse. Pulled the trans back out, found a broken forward drum. I put another stock drum back in and shelved the trans.

Fast forward 10 years, I bought my 87 Cutlass. Used the trans in that car, it ran low 13s and worked just fine. I bought a 10 inch converter to replace the stock Grand National converter, while the trans was out I decided to open it up to see how things looked. I found I couldn't pull the annulus gear off the forward drum shaft, the splines were twisted inside the gear. The shaft was hanging on for dear life! I need to say the splines twisting was not the same place the first forward drum broke. You can imagine how that conversation went with my wife, after spending 500 bucks for a new converter, I needed to spend another $400 to repair a trans that worked just fine!

I have several friends that have high 11 second Grand Nationals that have never broken the forward drum. The moral of my long story is the forward drum is a unpredictable weak link. If your paying somebody to build the trans the labor, fluid, tow and other supplies to repair the forward drum if it breaks will probably be more than buying the upgraded part the first time. I'm guessing thats the reason for CKs recommendations.

 

Hmmm. Sounds like I'd be playing with fire by not upgrading the forward drum unless I'm one of the lucky ones and I usually don't fair too well in the luck department. I know I'm fine for now with my tranny behind my weenie 350, but I have much more power in mind for the future.

 

hi,my experience with the 200r4 is a learning expirence with my turbo regal '87..the original i still have after buying one from art carr in calif.this is the one i want to put behind my '66 425 next year.i ran 12.1 @114mph and still had the stock forward drum..lucky i guess!.tv cable adj. is very critical on these.not sure of rear end gearing that i will use.anyway the 200r4 is a very good tranny when set up right..

 

I wasted one w/ a 300 whp 350 (can't recall torque #'s). Goosed it on a roll & then noticed it wasn't shifting quite right & had a new slight noise, put in a new heat treated part. Trans is sitting in the back of my garage for a few years now after 2-3 shift eventually started to flare @ WOT. I definitely have a love/hate relationship w/ these 200's. Love the way they operate but hate how fussy they are to nail the calibration on, especially when you have to drop the pan every time to make adjustments.

IMO they held up to the (near) stock Turbo cars because they weren't getting hit as hard & early w/ big torque.

 

well i've been reading this thread and others going way back to jan of this year to get a feel for this swap.tons of good info,as said before,stick with the guys with know-how for this tranny,do it once do it right...i'll be calling art carr for my needs.thanks to all....paul

 

I agree with the theory of the forward drum living in a turbo car, verses a "lotsa torque NOW" engine. I'm guessing the turbo spooling up helps ease the shock load on the shaft. Sounds reasonable to me!