clwz28

I am having a trans built for my car,z-pack or bw 3-4 clutch pack,I am having hd 700 sprags put in and a beast sun-shell,my builder wants to install the z-pack or bw high energy,he built a trans for a 02 6.0 1/2 ton with a 150 shot with the z-pack, 20,000 miles still runs 7.90s 1/8 mile,he wants me to go with the z-pack,but says the bw is really good?

performabuilt

iTrader: (25)

Its all a matter of opinion we have cars and trucks with the zpack running 10s and 5000 plus pound trucks in 11s with the zpack but another builder will give a different opinion

JUNK

My z-pak built unit will get 200+ passes well into the 9s in a 3400lb car. I just took it apart to freshen it up and my only disposables were the 3/4 pack, band and rev drum. Make sure the clearance is checked using 2 feeler gauges 180* apart and shoot for .070 clearance, Then, put some street miles on it shifting many times from 2-3rd to seat the clutches w/o glazing them. The Z-pak is the best u will get, and they are the reason I still run a 4L65 and not a 4L80. I have a butt-load of units out there, and everyone in a racecar or truck has the Z-pak, worth the couple bucks it adds to the build. I also never use a corvette or any other GM servo, A solid, billet 2/4 servo assembly is a must and it eliminates the accumulator for 3rd gear. This and the Z-pak are 2 of the 5 things u need to make this unit live and come back to fight another day

clwz28

I just want to do it up right,I am planning on le heads soon,and 7s in the the 1/8,I will probably be in the 7s with a tranny that will hold,and some tires.(p.s has anyone ran the raysbestis hi-energy 8 clutch set up?my friend says its alot bettr than the z-pack

performabuilt

iTrader: (25)

I have used both but preferr the zpack over it. As I said it is builder preference. While I can show you ZPACKS with 100s of 10 second passes that look great other can show you the same with the high energy set and the borg set. At the same time can show you some that are fried to. Generally though no matter what set you use if there is a failure its related to hydraulic issue not the clutch set itself.
Many people assume a trans build is just about the parts but a whole lot more goes into it than that.

clwz28

Well said,I guess if someone can set up right I have no worrys.

PedaltoMetal

Holy crap. .070? I set mine a .022 Am I too tight? Frank, I'm talking to you.

performabuilt

iTrader: (25)

IMO no we set around .020 to .030 and have had good service. Not to say that his does not work well for him too. Its a little more than I like but as I always say to each his own. It seems that there are indeed multiple combinations that work well. Its the combo that counts and how everything works together.

JUNK

The recommended spec on the Z-pak from the manufacturer is .050-.070, if they are too tight they will drag hard at high-rpm in 1st and 2nd, as the drum speeds past 6krpm, the 3/4 pack tries to apply from centrifugal force. This is what the 5 "helper" 3/4 return springs in the factory builds (that everyone throws away) are there for. Many discussions on this, but the proof is in the pudding. Put a couple units together using tight clearance in 1, and loose 3/4 pack in the other. Make the shifts at 7k or better and start counting how many passes u get b4 u have no 3rd gear. The tight one will be gone and u will still be counting passes on the loose one. Heavy-@$$ caged f-bodies have provided me with all the data I need.

performabuilt

iTrader: (25)

As I said to each his own , I have been setting them up that way for a few years now. We have cars that have run 100s of passes 1/4 in the 10 second range. In fact I was just into one the other day a guy had for two years. He sent in because hes making up a new engine and doing and upgrade to a level 3 from a level 2 . We tore down and in fact I posted a pic of his zpack it was good as new. Visibly perfect. The clearance had opened up to about .040 but that would be expected. There we no signs of heating or anything unusual Which has been typical of the ones I have been back into.

built408

iTrader: (10)

blue plates, with kollene steels set up tight, shoot for .020

jakeshoe

iTrader: (14)

I prefer to set them up relatively tight also.
I however think that the blue plates and Kolene steels are pure marketing. This opinion is based on years of playing with other units.

I prefer the High Energy frictions and thick steels in the 700-R4's and 4L60E's that I do.

I've used the Z-Pack, I just don't like it, no problems with it that I've seen. I've installed a couple of them in towing applications to test both are still out there working great with 10's of thousands of miles on them.