Hey guys, I've been running my XCal3 on 87 Performance tunes with my shift pressures bumped up to +10%, +10%, +5% but wanted more firmness so just changed to +15%, +15%, +10%. I tool around in it but don't race it to extremes, and I do tow our dragster and trailer that's about 4500lb (soon to be 30ft enclosed 5000-6000lb trailer) about every other weekend, and occasional towing and hauling in between.

My concern is that I need to upgrade to a shift kit, but I've only seen the kits listed for 4R70Ws, not mine. Are there any kits available for my transmission? Should I be concerned running this much pressure?

 

OOPS!
I thought I was still on the last website I posted on. I didn't mean to break any rules here in any way. Dinner, wife, kids = confusion.

Sorry.

Darrin

 

troyer makes a shift kit (exchange actually) for the 4R75W

 

What all does it exchange? I've just seen their VB for $300 that has the $100 core charge on top of it. I'd like to keep my OEM parts around for spare so $400 doesn't seem to much of a deal...I could be wrong, though.

Any other options available?

 

Not if you want quality. What's yer tranny worth to you?

By the way - you do know that limited towing only, is usually allowed ( ~2000-2500 Lbs) on perf tunes, unless specifically stated otherwise by yer tuner ( who is ...?)

A tow-specific tune lowers shift points and softens the shifts among other things (like TC lock strategies to help lower fluid temps) in support of safe towing that is also easier on the tranny. By firming it up like that, on a Perf tune that already has firmer shifting, you are not doing the tranny or driveline any favours.

Call yer tuner to discuss to get the full poop on this. and get a 87 max tow tune while yer at it.

If you do decide on a VB, ensure the tuner factors this into the revised tuning - which will need to be done as this mechanical change requires shift pressure downward adjustments as a new 'baseline'.

MGD

 

Sorry about that MGD, I do have a towing tune as well - all from VMP. I run the performance (without trailering a heavy load) at +15/15/10% and the towing at baseline or +10/10/5%. My father just bought the 30ft trailer this morning and it was quite a bit of pull for the truck, but not as bad as I originally thought it would be. Now, once a 235" dragster and parts, tools and equipment are loaded in it, that could be another story...

I'm wondering if using a towing tune, with shift pressures pushed up, will be too much of a strain on it or if I can get away with it (even if temporarily)? Or should I keep the pressures at baseline on the tow tune? Or with this much weight, would it be in my best interest to upgrade as soon as possible? I've heard that the 4r75e can take quite a bit of punishment, but don't want to push it too hard.

I have no problem putting out $200 or so for a valve body or shift kit that will ensure I don't overwork the tranny, but I don't have the time at the moment to do it myself and would like to make it another month or two (end of racing season) to work on it. My tranny is running strong at 150k+ but it doesn't take much to change that, but if anyone thinks that I should be worried and/or not run with it like that for the next two months please let me know.

 

I recently talked to Darrin myself about my trans. I am at 128K on mine and it has seen its fair share of hardwork. I was going to add the VB but he said that with that many miles that I should really rebuild the trans. So that is what I am saving up for. Just call him up he is a really good guy.

 

Who's Darrin? I'm looking to do the valve body from Troyer when I get my 4r75w rebuilt here in the next month or so.

 

NTXRockr,
If you decide to add a shift kit with your tuner I would suggest custom tunes for that. I had a shift kit installed when I had my tranny rebuilt (4r75w) after about 50000 it had to be rebulit again clutches were fine in it but from the harsh shifts everything else was shot I now run with the tuner off and truck is alot smoother but shifts are still firm compared to a stock truck. Just my two cents on this subject.

 

Darrin Burch from BC Automotive.