Jmod with 1-2 accumulator spring left in place

[lifespeed]

Has anybody done this? My experience with my 4R70W in a Crown Vic was that the 1-2 shift was too harsh, even with a soft accumulator spring installed.

Based on that experience, were I to do this again I would drill the 1-2 accumulator hole smaller and leave the stock springs in place. The harshness arrived after the PCM was tuned and the trans pressure increased.

Does anybody else have experience getting a firm, but not neck-snapping, shift by tuning 1 - 2 separator plate hole size, computer-controlled line pressure and accumulator springs? I am somewhat reluctant to remove the accumulator springs based on past experience. It would be really cool if I could get it correct the first time into the trans fluid bath. :P

[Darrin]

You can definitely leave both springs in place. But I would drill the hole size out close to a 7/64 or .109 and call it good. The springs more control the feel on firmness and the hole size is more of the quickness of the shift.

Now, on tuning you can firm it up or soften it up through shift pressure. So I think the proper combination of both is the way to do it.

Darrin

[Green96]

I left my springs in when I had my t-bird j-modded. I love it. I did exactly as Darrin said and firmed it up a little with a tune. Firming with a tune also allows you to firm it up at heavy throttle, but leave it closer to stock at light throttle.

[mrogerc]

I am thinking of reinstalling my springs. I don't like the 1-2 feel at low speeds. Anyone know if you need to take the valve body off to replace the springs?



I left my springs in when I had my t-bird j-modded. I love it. I did exactly as Darrin said and firmed it up a little with a tune. Firming with a tune also allows you to firm it up at heavy throttle, but leave it closer to stock at light throttle.

[Darrin]

You don't need to remove the valve body to get to the 1-2 accumulator. I also sell a nice spring setup for the 1-2 if you are interested. It is firmer than stock, but not nearly as stupid as no bottom spring.

Darrin

[mrogerc]

Darrin,

Let's talk. Please PM me the best way to reach you, or should I just call the BC Automotive number during business hours?

[justbob]

My springs are now on my desk and my line pressure is turned down too far, this equalls a very mild shift. It shifts quicker but there is zero whiplash, I'll be looking to swap my chip over to my xcal so i can up the line pressure a notch. I was expecting a serious shift having listened to so people and mine is still soft.