J-mod Plus Electronic Tune, Too Much For 4r70w? Consensus Sought.

[fastcar]

Hi guys,

I've been scouring threads on the j-mod, but needed to open a new one to specifically answer this question. Logan mentioned the shifts being too hard when using the J-MOD (jerry's mod) in conjunction with a tune.

My tune is by Lidio. He improved my shift A LOT. Sometimes it even squeeks 2nd gear.

The thing is, I want to have the fluids changed to synthetic, and thought I should do this upgrade while I'm at it.

My objective is to improve transmission life, and firm things up just a little bit more.

1. Does this mod lengthen tranny life. Mine is N/A, probably 335 crank horsepower. It's not likely to get above 360 anytime in the near future.

2. Will it shift obnoxiously hard with both mods? I'm looking for more input.

I hate the idea of losing a mod that's good for tranny life, because of my tune. I don't know how to modify the tune myself to adjust the shifts back down.

Any meaningful input would be much appreciated. Thanks.

fastcar:burnout:

[Bradley G]

Depends on your preference, I read the same thing. Both will net you, uncomfortably hard shifts. Might not be at WOT, but going through the church parking lot, may be a little harsh. If you have an adjustable tuning device, you can find out where to back off, shift pressures.

[Dennis Reinhart]

Hi guys,

I've been scouring threads on the j-mod, but needed to open a new one to specifically answer this question. Logan mentioned the shifts being too hard when using the J-MOD (jerry's mod) in conjunction with a tune.

My tune is by Lidio. He improved my shift A LOT. Sometimes it even squeeks 2nd gear.

The thing is, I want to have the fluids changed to synthetic, and thought I should do this upgrade while I'm at it.

My objective is to improve transmission life, and firm things up just a little bit more.

1. Does this mod lengthen tranny life. Mine is N/A, probably 335 crank horsepower. It's not likely to get above 360 anytime in the near future.

2. Will it shift obnoxiously hard with both mods? I'm looking for more input.

I hate the idea of losing a mod that's good for tranny life, because of my tune. I don't know how to modify the tune myself to adjust the shifts back down.

Any meaningful input would be much appreciated. Thanks.

fastcar:burnout:

All I would recomend is lower the line pressure.

[fastcar]

All I would recomend is lower the line pressure.

Hi Dennis,

Thanks for your input. I take it you are suggesting to USE THE J-MOD and then lower line pressure electronically, or do you mean physically in the transmission? Is the J-MOD good for the transmission? Thanks,

fastcar:burnout:

[Dennis Reinhart]

Hi Dennis,

Thanks for your input. I take it you are suggesting to USE THE J-MOD and then lower line pressure electronically, or do you mean physically in the transmission? Is the J-MOD good for the transmission? Thanks,

fastcar:burnout:


Lower it electrinicly

[RoyLPita]

Your MM should have Mercon 5 which is a full synthetic fluid. So there is no real need to change it again unless you have many miles on it since the last time.

[CRZYBIKER]

I just had my transmission rebuilt and I already had the Lidio tune. I requested the 'J' mod done while it was apart since i do plan on supercharging the car eventually. The best way I can explain it is it now shifts like Lidios tune times 3, it is very crisp. I like it and do not mind it, but everyone has different comfort levels. at less than quarter throttle it will now chirp the tires on the 1-2 shift. At 1/2 throttle it hits hard enough to make it sound like the dash is being shifted. At wide open throttle the tires break loose freely on the 1-2 shift. If you ever plan on driving on icy roads it would be a very bad idea I believe.

[fastcar]

Your MM should have Mercon 5 which is a full synthetic fluid. So there is no real need to change it again unless you have many miles on it since the last time.

Think it's time with 100K? :D

Thanks for the input, though. That was a good point...

fastcar :burnout:

[fastcar]

I just had my transmission rebuilt and I already had the Lidio tune. I requested the 'J' mod done while it was apart since i do plan on supercharging the car eventually. The best way I can explain it is it now shifts like Lidios tune times 3, it is very crisp. I like it and do not mind it, but everyone has different comfort levels. at less than quarter throttle it will now chirp the tires on the 1-2 shift. At 1/2 throttle it hits hard enough to make it sound like the dash is being shifted. At wide open throttle the tires break loose freely on the 1-2 shift. If you ever plan on driving on icy roads it would be a very bad idea I believe.

This is exactly the kind of input I was hoping for. OK, that gives me something to think about... Based on your experience, and one other, it sounds pretty severe. I want it to shift firm and resolutely under part throttle, but not rattle things loose. When I floor it, I want it to bang the shift as hard as possible.

Sounds like the tune plus J-Mod will give me 'as hard as possible' all the time, which is not what I'm shooting for.

The question remains, then - is it worth doing it, and struggling with the electronics to get it back down to tamer levels? If the mod helps the transmission last longer, get better lubrication, etc. etc. Then maybe it would be worth it...

Any input on just how important the mod is to tranny longevity???

fastcar:burnout:

[CRZYBIKER]

I dunno about the mod and longevity, maybe a pro could chime in. I only have 300 miles on my newly modded transmission so,way too soon to tell.

[magindat]

This is exactly the kind of input I was hoping for. OK, that gives me something to think about... Based on your experience, and one other, it sounds pretty severe. I want it to shift firm and resolutely under part throttle, but not rattle things loose. When I floor it, I want it to bang the shift as hard as possible.

Sounds like the tune plus J-Mod will give me 'as hard as possible' all the time, which is not what I'm shooting for.

The question remains, then - is it worth doing it, and struggling with the electronics to get it back down to tamer levels? If the mod helps the transmission last longer, get better lubrication, etc. etc. Then maybe it would be worth it...

Any input on just how important the mod is to tranny longevity???

fastcar:burnout:

hmm, not entirely true. Lower you shift points under light throttle. As throttle increases, increase your shift points in reverse parabola (graphically). This will cause the tranny to shift harder and harder the deeper you get in the throttle. At least that's my expereience by playing with my own shift points.

[sailsmen]

I think you will only find the shifts uncomfortable if you have the line pressure in the tune set to the max and do the jmod.

Like Dennis said just tune down the line pressure.

I drove my car for 30K N/A this way and another 40K S/C this way.

The question is not about the trans but about what you want.

Want good mileage and a smooth ride drive a Buick Parisienne.

I get a real kick out of people more worried about a stiffer ride or losing 1-2 mpg than how much a performance increase will result. Did they by a $35K Muscle car or a Hyandi?

[MarauderSM]

I would like an answer. How much power can the j-mod hold. I read built up the trans can handle about 700 crank hp. Is this true?

[fastcar]

I think you will only find the shifts uncomfortable if you have the line pressure in the tune set to the max and do the jmod.

Like Dennis said just tune down the line pressure.

I drove my car for 30K N/A this way and another 40K S/C this way.

The question is not about the trans but about what you want.

Want good mileage and a smooth ride drive a Buick Parisienne.

I get a real kick out of people more worried about a stiffer ride or losing 1-2 mpg than how much a performance increase will result. Did they by a $35K Muscle car or a Hyandi?

Who said anything about gas mileage? I just don't want to choke on my bubble gum every time it shifts. I had a 88 LTD PI car with a shift kit, and it was obnoxious. It sounded like it was tearing spot welds just cruising around town. If you like that, great. I don't. I want a reasonable positive shift under part throttle, and a hammer under full throttle. If you like a hammer all the time, good for you. But, I don't enjoy it, and don't particularly feel it's the best thing for the car, either.

I think the idea of turning down the line pressure makes sense, but the question is any of this worth it? Does the J-Mod make the transmission last longer, or is it just for increased performance? This is the unanswered question...

fastcar:burnout:

[fastcar]

hmm, not entirely true. Lower you shift points under light throttle. As throttle increases, increase your shift points in reverse parabola (graphically). This will cause the tranny to shift harder and harder the deeper you get in the throttle. At least that's my expereience by playing with my own shift points.

Thanks for the suggestion. If I ever find out that the j-mod is good for the transmission, I will pursue this.

fastcar:burnout:

[sailsmen]

Firming the shifts does make the trans cluthes last longer.

This can be done electronically via a tune.

If I was going to keep my car w/ stock hp then the tune is fine and the jmod is not needed.

Either way it is not going to break any welds or cause any bubble gum to be swallowed.

When my car was N/A it had the jmod and max line pressure. Occasionaly the 1-2 shift would be hard under lite throttle.

I don't know about the previous trans u have driven. This trans is electronic. Most agree that a shift kit is not the way to go.

With a tuner u can have the shift and line pressure adj to your individual taste wether it be Double Bubble, Bazooka or Orbit.

[magindat]

Get the jmod AND and SCT tuner from DR. Download Extreme Tune from SCT. Start playing. Leave the engine parameters (timing, lean/rich etc) alone and play with the shifting until you like it. That way, you'll teach yourself about it, end up with what you like and stop speculating and asking opinions, cuz everyone will have a different opinion.

The j mod quickens the 'shift' to the point that it's more of a 'switch'. This causes less wear on the clutches since there is less time relieving pressure then re-applying pressure.

For firmness, you can adjust line pressure in Extreme tune and you can adjust shift point. The higher the RPM vs. Throttle position, the harder it'll shift due to the higher pump pressure.

So, make your light throttle shifts low in RPM. Let the tranny climb the gears quick at light throttle.

Get the xcal and j-mod kit from DR, then I'll send you a copy of one of my trans schedules I was playing with, then customize it to your own liking. Heck, you may just love DR's tune with the jmod right out of the box!!!!

[Darrin]

Yes, the hardware modifications are good for the transmission and no, jacking the line pressures through the roof at all times is not good for the transmission. You would be surprised at how many tuners have the pressures too high at all times.

To do it right you get the modifications done to the transmission and then get the drivability tuned for the way you want it to shift. It's all up to the tuner and their abilities at that point. You can tame the wildest of beasts with proper tuning. No need for harsh jerky shifts at part throttle.

Darrin

[fastcar]

Get the xcal and j-mod kit from DR, then I'll send you a copy of one of my trans schedules I was playing with, then customize it to your own liking. Heck, you may just love DR's tune with the jmod right out of the box!!!!

Thanks magindat. I appreciate the offer.

I read Lidio's thread at this forum on transmissions and have decided to leave it be for now. I'm simply going to change the fluid. I don't have the time right now to mess with learning more software. I'm up to my eyeballs with everything else right now.

It shifts close to how I want it, and I think it should last even without the j-mod. If I get more time next summer, I will look into a j-mod and cooler, when I do the PI 3500 RPM converter :)

Thanks to everyone for their kind assistance.


fastcar:burnout:

[Tom Kuznicki]

I think you will only find the shifts uncomfortable if you have the line pressure in the tune set to the max and do the jmod.

Like Dennis said just tune down the line pressure.

I drove my car for 30K N/A this way and another 40K S/C this way.

The question is not about the trans but about what you want.

Want good mileage and a smooth ride drive a Buick Parisienne.

I get a real kick out of people more worried about a stiffer ride or losing 1-2 mpg than how much a performance increase will result. Did they by a $35K Muscle car or a Hyandi?

just get the shift tune changed electronically. And c'mon now, in pure stock tune, a good running hyundai could probably keep up for a while. Owning one myself I can honestly say that is not really a muscle car in the truest sense but I would say that it is a fast Luxury car instead.