WHERE AND THE HELL CAN I GET THE JMOD SHIFT KIT?? every forum ive been to recommends this kit of everyother shift kit on the market but i cant seem to find a place to purchase it
The tuner puts up the pressure. This firms up the shift (a good thing) but can make the shift a little harsh. The pump operates along a curve (flow vs. pressure). The tuner increases pressure so the capacity is reduced. This means that when putting more fluid to the accumulator (higher pressure) then fluid is taken from elsewhere. With the J-mod, the holes in the separator plate are enlarged so that less pressure is required to move more fluid to an accumulator. This makes the shift quicker so there is less friction in the transmission, less heat, longer life and more flow (total) is available. The accumulators get the fluid in a hurry without reducing flow to any other part of the transmission.
A tuner is a good first step and will make the shifts feel better but they can feel harsh. To make the shifts occur quicker, the holes need to be opened up to improve the hydraulics and no parts of the trans will starve for fluid (which is the coolant and lubricant).
fastford03:
Go to TCCoA.com. Find the Tech Articles. Go to Transmissions. You want "Transmissions 101" plus the two how-to articles by A-Train. I don't recall the exact chapters but there are two for the J-mod. Read, read, and re-read until you have a good understanding of how it works and what needs to be done. Get the tools together, including a quality inch-pound torque wrench, and get to work. I can tell you that I had never taken the drain pan off an auto prior to my '98 and I got the J-mod done and it all went very nicely. Take digital pictures as you go along and bag-and-tag your parts (if you want). Keep everything clean. Take your time. You can do it.
Call Darrin at BC-Automotive.com. He is top-notch and has separator plates ready to go and he can help out with an SCT XCal, if you want, to get the shift schedules, pressures, and lock schedules tweaked.
ive done the J-Mod on two of my stangs. On another i had a tuner. the J-Mod was worth the effort. It wasnt a hard mod to complete. on the first stang, i had ZERO tranny experience and completed the mod with no issues. It has been the most fun "seat of the pants" mod i have ever done!
The MAIN reason to do the J-mod is that it is actually better for your transmission. Larger holes = more rapidly filled accumulators = faster shifts = cooler fluid and transmission components.
As far as the shift firmness is confirmed, the J-mod is still better than a programmer. Been there, done that. It firmed the shifts up more than a programmer ever did on my car, and actually made the part throttle shifts better as well, unlike a programmer. There is a reason why Jerry Wroblewski, the engineer of the 4R70W, recommends the J-mod: because it is better.
If you are nervous about tearing into your transmission, don't be. I had never touched my transmission before I did the J-mod. It was very easy and straightforward, and it only took a few hours total on my first time. If you want to get picky about the time, you can go out RIGHT NOW and buy the tranny fluid, drill bits, and any tools you may need, and DO the J-mod before your programmer comes in the mail. And it's $300+ cheaper as well.
Oh, and also. Late '01-'04 cars don't need the J-mod nearly as bad as pre '01 cars. The newer cars already came with slightly modified valvebody separator plates and accumulators. So while there still will be a difference, it won't be nearly as pronounced as on a car like mine.
The MAIN reason to do the J-mod is that it is actually better for your transmission. Larger holes = more rapidly filled accumulators = faster shifts = cooler fluid and transmission components.
As far as the shift firmness is confirmed, the J-mod is still better than a programmer. Been there, done that. It firmed the shifts up more than a programmer ever did on my car, and actually made the part throttle shifts better as well, unlike a programmer. There is a reason why Jerry Wroblewski, the engineer of the 4R70W, recommends the J-mod: because it is better.
If you are nervous about tearing into your transmission, don't be. I had never touched my transmission before I did the J-mod. It was very easy and straightforward, and it only took a few hours total on my first time. If you want to get picky about the time, you can go out RIGHT NOW and buy the tranny fluid, drill bits, and any tools you may need, and DO the J-mod before your programmer comes in the mail. And it's $300+ cheaper as well.
Oh, and also. Late '01-'04 cars don't need the J-mod nearly as bad as pre '01 cars. The newer cars already came with slightly modified valvebody separator plates and accumulators. So while there still will be a difference, it won't be nearly as pronounced as on a car like mine.