I have the sniper box as well (split the cost with a buddy too lol) and I like it alright.

Watch out with the shift firmness settings though... I had mine set to firm as well, and my stock tranny held up to that for around a year. Then one day I hammered it, the tranny downshifted fine.. but the upshift made a loud clunk and my tranny neutralled out. So I'm currently rebuilding it lol... Just letting you know that the tuner makes the shifts firmer by increasing line pressure in the tranny, but the tranny in stock form isn't always up for that.

The sniper tuning software wont let you tune your truck as well as lets say a professional tuners' software, but it'll let you tweak the fuel mixtures enough for you to pretty much get any setup going with a base tune. Just be careful messing with the mixtures as you can cause a lean condition and hurt your motor.

It's a pretty decent setup overall. Definitely woke my truck up a bit.

- Erik

 

How many miles on tranny? What about a mild shift? Do you know how much the line pressure is raised?
thanks

 

I thought firmer shifts were better for the tranny? I guess there are pros and cons like anything.

 

My theory was a firmer shift is easier on the clutches.

 

Ah...that makes sense.

 

There are at least three parameters in play here, and I don't have any idea which one the Sniper actually modifies.

Increasing the line pressure is one strategy, but if you increase it too much, you run the risk of increased transmission temperatures, which, of course, causes damage. Bill Cohron, at PHP says line pressure increases (both main and shift pressures) in the 15-50 psi range fall into this category.

The next modification is torque reduction, which causes a "dive" in the feeling of power during a shift. Reducing the torque reduction can improve the shift feel, but again, too much of this is not good for the machinery, because an abrupt torque change puts stress on components.

Finally, and this is what "shift firmness" is all about in the Edge and Gryphon, you can reduce the time interval between clutch release and clutch lockup during shifts. Again, if you take this to extremes, you put stress on the mechanical components, but, if done properly, it can reduce "slippage" wear on the clutch bands.

All of what I just said, I learned from Bill Cohron. I am not a tuner, but I am an engineer and it all makes sense to me.

The key here is, you've got to have some knowledge of the effect of changing these parameters, or you can get into trouble. This is why we rely on competent tuners to create tunes. If you play with these settings yourself, I'd recommend not going to extremes.

- Jack

 

Well the tranny did have 130K original miles. So this might have played into it a bit. But the tranny operated perfectly its whole life until that one shift that broke the sun gear shell inside the tranny. If that metal part hadn't failed the tranny would probably still be going now.

Either way, increasing line pressure inside the tranny isn't the ideal way to increase the firmness of the shift really. Shift firmness is controlled by accumulators in the tranny that fill with fluid to slow down the engagement of the clutches. So the faster the accumulator fills, the faster the shift. So increasing the line pressure forces the fluid into the accumulator faster by increasing pressure.

The proper way is to make certain fluid passage holes bigger in the separator plate and to change the springs in the accumulator to allow the normal fluid pressure to be able to fill it faster. This doesn't create any extra heat, and definitely increases clutch life in the transmission. So thats why on the rebuild I'm going with the line pressure at stock, and installing a Trans-go shift kit instead. Should make the shifts nice and tight, without the need for higher line pressure.

I don't know any specifics on the line pressure that each setting on the Sniper software is set to, but I do know that if you have questions about it you should check out the Sniper Tuning forum. The guys there should be able to answer the questions you have. I'm pretty sure they say that running anything higher than "mild" on a stock transmission is a bad idea. But go you should go there and confirm.

www.snipertuningforums.com

- Erik

 

But does the mild setting make much of a difference?

 

Ive got a sniper tuner with the custom Delta Forces tune. I like it.

 

If I remember correctly, yeah it makes a difference over stock. Can't say how much it would on your truck. You should just try it out as it only takes around 10 min to make another tune and load it into your truck.

Like I said, you should ask on the sniper forum and see what they say about running it on firm on a stock trans. I'm just posting what happened to mine, I don't wanna scare you from using the "firm" setting if you like it, but I don't want you to ruin your tranny either lol.

- Erik

 

my tranny let loose at 137,000 miles. so its rebuild and under 20,000 miles. The firm seems to get rid of that laggyness between shifts. it used to go to 5,000rpm then slowly shift into 2nd. now it gets to 2nd in a hurry.

Yes i know messing with the A/F ratios and adding more fuel and taking fuel away can be bad if you dont know what your doing.

Well we wrote a tune for my buddys expy. runs alot better than it did when he had the superchips in it. Last night when he left work we raced. 1st gear he pulled me 2nd gear around 50-60 i started to pull him and by 80+ he was at my back bumper....i was suprised by this i thought for sure he was going to take me.

So far im loving this. need to increase my shift points to 5,300. havnt wrote a tune with race shifting on it. ill let my buddy do that one lol.

Anyone use the data logging yet? were you have the laptop in the truck and pluged into the truck? looks kinda cool but have yet to use it.

Cant wait to write a tune for 93oct

 

Yeah yeah, that is all great, but with the newer transmission controls in the PowerPC PCMs it is worthless as the strategy will correct, and after some driving cycles you are back to almost stock shifting.

 

And that was my next question!

 

So I got the template for my box code today, and guess what, the version they sent me still doesn't tune my tranny. They said to call early next week and they should have any another version ready that will tune 04+ trucks.

We will see...

 

Hmm, yeah don't know about the newer PCM's, so that might be true. Not sure. Either way, my 2000 doesn't have the newer pcm, so it'll work for me atleast.

Can't say about the new trucks. If it has a 4R70W I don't see how the PCM would "learn" that the transmission has a shift kit. Theres no sensor for that in a 4R70W, and I'm not sure but the 4R75 doesn't either. So no idea how that would work.

- Erik