Jerico trans in my sn95

[Guest]

[ram360]

I'm looking to get my sn95 mustang project on the road again.  I made the decision a few years ago to make it more or a drag car. It currently has all team z susp, relocated uppers, all solid bushings, arb. It really doesn't make much of a street car at this point. It has an h/c/I 351 based engine makes around 450 on motor, and I might spray 125 shot. It was an auto with a built 4r70w but for some reason a swapped it to a 5 spd.  At any rate I'm looking to put more of a drag race trans in this car. I've been considering a jerico dr4? any thoughts?

[Briansshop]

A lot more fun than an auto for sure. I've got a G Force GF4A 4sp in my foxbody.

[347HO]

Clutchless Jerico?
Yeah...  You're gonna have fun!

[dennis112]

Although a clutched Jerico drag race transmission works well on the street once you get the hang of double clutching, one with road race sliders would be a better choice in a street/strip car.  A clutchless Jerico would limit you to only strip duty.  On the street you would have to hold the tranny in any gear (if that's possible) and you are more apt to damage it in that scenario.  A clutched Jerico can be shifted clutchless, BUT you must interrupt the acceleration in someway to make it work without damage (IE hit the rev limiter.)

No matter what, if your current 5 speed is a street box, you're probably missing out on a lot more fun and consistency at the strip.  

On a side note, some street trannies can be modified to work similar to the Jerico.  I went through a couple of renditions of the toploader, first using a stock synchro'd one, later adding Pro Shift lugs and finally went to the best choice of faceplating.  Irregardless, none of those mods acted as smooth as the clutched drag race Jerico I've rowed for a few years now.  I use an H pattern shifter, but an inline would be the tits for a mostly strip oriented car.  

Watch getting used Jericos as they have gone through an evolution throughout the years and parts are non-existent for early models.  To make things worse, the current generation DR4-4 which is supported by Jerico has very few parts that are common to the previous generations.  Their supply of the previous generation of parts are slowly being depleted off the shelves.  

[dennis112]

I also should add that once you consider an aftermarket transmission for racing, you should also be looking for a modern racing clutch (also know as a slipper clutch.)  There are various ones available on the market, but the one you choose a pressure plate that offers base pressure adjustments and have provisions for counterweights.  McLeod calls their complete clutch assembly a Softloc and Ram likes to tote theirs as Sinterned iron, which refers to the makeup of the disc material.  Most, if not all, good racing clutch discs are made up of a similar sinterned iron material.  
The sinterned iron material has properties that are different from common organic based clutch discs.  Although heat is the enemy of all clutches, a sinterned iron disc likes a little induced heat from slippage--They actually lockup from some additional heat.  When properly adjusted they will slip a little during launch and then will fully lock up in less than a second from the heat created by the slippage.  This cuts down on initial wheel spin plus keeps the motor in its power band without bog.  In this respect these clutches somewhat serve the same purpose as an automatic's racing converter, but the slipper clutch lockup range is adjustable.  

Another benefits is that the slippage takes much of the load off drivetrain which helps prevent parts breakage.  Further, the pedal pressure is practically non-existent when on the lower side of base pressure.  An old school racing clutch was very stiff having 3000+lb of non-adjustable base pressure.  I race my sinterned iron adjustable clutch with at around 500lbs base and one can easily push the pedal to the floor with 2 fingers.  We're talking about a car with nearly 700hp with 3550lbs race weight. 

You do not need to have high HP to see the benefits I have stated.