General Supercharger Thread

I’m fairly certain that is the case for Drive but not for S-Mode or Tow/Haul (maybe not for both, but for I thinks so). I know for certain that my truck will lock in 4th when I tow; but I RARELY tow in Drive and use S-Mode I stead to drop a gear before getting part way up a hill, or downshift to scrub some speed for going down hills. So I honestly don’t recall if it’s Tow/Haul or SMode that changes the 4th gear lock, but RPM’s drop, trans temp drops, and I’ve watched it show Locked while data logging via HP Tuners.

All this talk of roasted transmissions is pushing up my want/need for an IPT valve body. It’s been on the list since looong before the SC, but I was thinking ‘why mess with a good thing’ and just made sure to go with 30k transmissions OCI’s. Now the VB is on the short list. I just need to figure out when I can afford the down time.

 

Must be cause when I’m watching it like a hawk I have it in S mode for towing. I don’t usually monitor lockup as much when not towing, and it doesn’t sit in 4th that long in D for me to notice. Either way, I’m pleased with the towing lockup!

 

My bad was just saying about normal mode...yes s mode tow haul ai cruise it will lock. Forgot about towing and putting it in s mode. You can view your trans settings to check em out.

 

My hypothesis is that it may simply be just too much for the clutches to handle under WOT. The scenario doesn't, or hasn't in my case, presented itself for 2nd and 4th. 2nd, because it doesn't lock up, 4th because at WOT I'd potentially be going too fast for my driver's license (CDL) should I be "observed". Not too long ago, I was looking at a chart that showed the maximum speeds for each gear, but now for the life of me, I can't find it. If I do, I'll share it here. It might be a different situation though if you were to already be in lock up and then go WOT because the clutches are already engaged. I think of it like the difference between doing no-lift shifts with a manual transmission versus lifting, allowing the clutch to engage, and then reapplying the throttle....if I'm explaining that correctly.

Like in this situation, where you're more likely to go "easy" on it until it's locked up, then really lean on the throttle.

 

No worries. I assumed you were talking about Drive; wasn't trying to be a know it all.. And Sniv beat me to it anyways. Ha. But I do notice a huge difference in towing with the converter locked vs unlocked in 4th and 5th so I've aimed for 4th gear locked under load or even 5th gear locked if on the flats and NOT pulling one of my enclosed trailers. I've done this since before the the SC to keep temps down. Now I really need it cuz those pan temps will jump fast.

I'm just hoping that my choice of stock tire size and a limited number for full throttle runs through the gears helps the transmission survive, despite the portly showing at the scales. I guess it helps that I know the gear in the bed will slide to tailgate if I floor it, so I try to keep the throttle juuuuuust under that point. Until I get Gforce drunk and pedal the thing.

 

6375rpm is default disable from my stock tune. Bad pic from my cheap tune computer... one could set tow haul to lock up 4th for those hill climbs. Other stock tunes can vary since mine is 2007.

 

I remember coming across the same chart once upon a time. IIRC, 5900 RPM in 4th gear with stock tires and gears would be over 130 MPH. I'm pretty sure I saw 4800 RPM the other day while passing some jack wagons.. on a back road in Mexico, of course...

I am very curious about the clutch load capacity like you are talking about. I was under the impression that under heavy load in the lower gears 1-3, it's best to keep the TC unlocked to use as a buffer, so to speak, between the clutches and the engine power due to the gear reduction, torque multiplication, and physical size/clutch surface. But by the time you get to fourth, the shaft speeds and torque transfer is such (being 1 to 1 obviously) that the clutches are no longer an issue and heat becomes the problem.

As a sideways example, I believe my source is actually Jon at IPT on this, the TC clutches are physically big enough and robust enough, that locking and unlocking them isn't ever an issue as far as holding the gear lock; it's just the heat that causes them to warp which then causes failure. Wearas, the lower gears can actually slip and disintegrate themselves. But that's coming from the mothballs somewhere. I'll have to dig up the reference for it.

 

Found these two nuggets:

 

On the earlier years the flex lock and weak damper in the torque converter were causing shudder and p2757 code. Toyota made the TC have a heavier damper and I think a thicker lining in the tc to deal with excess heat from the tc flex lock engaging/disengaging so many times a second. I dealt with this overcthe years but since disabling flex lock I haven't had any issues.

 

And all y'all don't be calling John at IPT and distracting him with your questions while they're building me a transmission.

 

Any benefit to keep flexlock for our applications (looks like purely for mpg) or recommend tune it out with HPT?

 

Disabled it on mine. Truck drives a lot better and the rpm isnt constantly changing from it locking/unlocking, which I found extremely annoying. No noticeable difference in trans temps or mpg.

 

Oh, I wouldn't dream of it. I was planning on waiting at least a few days to call him and pester him with all of my inquiries...

 

As a follow up question, why not just disable it and set the converter to lock in 4th normally? Or does that disable it in cruise - not just flex lock but normal lockup in cruise?

 

When I spoke with John he was interested in disabling flex lock especially those that experience shudder. I did have 4th lock up at 2300rpm in normal and disable at 2100rpm but he said there really is no need in normal mode. So I just set it back to normal.
Cruise is already set to lock you would have to set each mode up individually. Changing one does not affect the others.
Flex apply release is independent of the regular torque converter apply release settings.

 

I looked at it as less heat being generated in the torque converter and longevity being supercharged.
I too haven't noticed any loss in mpg and seemed there was better shifting. Definitely can tell when it locks and unlocks.
You can test it out and always revert it to the original flex apply release settings if you don't like it.

 

Stock yeah but for backup I threw my 17g fuel cell in the bed just incase since we are going up threw BFE nevada lol

 

Decent areas I was able to run in 5th as ling as I could get the comverter to lock. Was , from the screen, getting 10mpg

 

It haa to lock in gears above 4th because when mine isnt itll start to climb in temp until it locks then itll cool right away

 

that sounds about right. 100-125 miles if you're towing heavy on the stock 26gal tank. that's why I just upgraded to the 46!
You should be OK at 5th gear so long as you're not hunting. with the blower you should have plenty of power without needed to change gears every other second.

 

I was going to say, it def locks 4th in S mode. I can see it when doing DYNO runs (and on the road), you get a shift to 4th and then a small drop in RPMs and an audible load change. I am super aware of this, as I listen for it and know that's when to start the DYNO run.

 

I only drive in s4-s5 and as mentioned trans temps stay happy

 

for the last week. I've driven in S5.

truck is noticeably happier.

I'll bump it to S6 when I get situated on the hwy.


for the record...I still don't like that I can hit 6lbs of boost w/o going into PE.
I'm considering taking it back to Peitz Performance to have finagle the PE thing.

 

Same ive been getting 6psi +- and still see my afr in 13/14s.
Hell ive been driving and showing maybe 3psi but with normal driving afrs

 

Do you have HP tuners? It's simple to do and you can adjust it multiple times while testing, probably in the amount of time it takes to call and sched and appointment

Some of it is personal preference and driving style and without the person who drives it all the time making the adjustments. You can go round and round with a tuner to dial it in, or it could be done in the truck with a few revisions.

 

You can have them adjust TPS when PE comes on or bump PE in the lower rpms.

 

yes.

but you and I don't want me doing that kind of shit.

and it's probably locked by Peitz, right?

 

If you can. Try and get it into the mid 10's to low 11's by adjust PE and when it enables. There is a trade off as it will lower mpg's a little bit as @snivilous stated a few pages ago.

 

I mean, if you are lean and are making adjustments to the richen it up, not really any risk IMO. It would be the other way around where you could get into trouble. Trying to lean up a rich spot.

 

I wish there was a way to switch to speed density without the cost and complexity of a standalone. Imagine being able to tune based solely on pressure, no more messing with larger MAF tubes and scaling... Curse you Toyota for not having a backup MAP sensor on the motor like almost all other MAF motors! LOL