The 5.29 Mega Thread!!

Unless your a manual in which case the speedo is off the transmission not the wheel sensors.

 

ahh touché good point!

 

Hey guys this has probably been covered already but I don't have the inclination to scour 3,500 posts for the info. I just got off the phone with ECGS about getting 5.29's installed and the guy helping me mentioned that they've had a few customers get 5.29's on 33's with the AT have their top speed limited to 83mph, and they don't have a solid explanation or fix for it. It only happens in a very small minority of customers, so I'm wondering if this group has come across the reason this happens and hopefully a solution.

My guess is that I can go into my ECU tune on VFTuner and change the gear ratio and/or speed limiter to fix this if it were to happen on my truck. Can anyone confirm this is the case?

And yes I realize I won't often be going >83mph but all the same I don't want the fucking computer telling me what I can and can't do.

 

I can confirm that with 5.29s/AT you can physically exceed 83 mph. (I think I was on 35s at the time, but no reason it wouldn't work on 33s as well.)

 

Thanks for the reply but that was not the question at all. I'm well aware that at 83mph I'd be nowhere near the rev limiter.

 

It's talked about in the OVTune threads. Not sure if they got it resolved or not but they were working on it. @tonered might be able to shed some light on it.

 

I mean, I can clarify that I was on stock tuning -- you could try to mess around with VFTuner to see what the issue is, but I have not run into it. I also have not actually heard of anyone having that mentioned issue, it seems to be kind of a boogeyman post. Everyone has a friend of a friend who knows a guy that had it happen.

 

Did you read my post? I was talking to a very reputable gear shop, East Coast Gear Supply, who gave me this as a warning. They have seen this happen in a small minority of their customers. This isn't hearsay it's a fact coming from people who professionally install gears for a living.

 

Yeah. There is either the 5.29 tune that gets folks back to Stock, about 108mph, or just a quick edit of the tune to remove the speed limiter.


I recently saw a steady 117 on GPS and backed off as my Softopper didn't look too happy. There would be more to give if it wasn't on there.

 

Folks that I have tuned ran into the speed limiter issue. Super easy to fix, depending on their preferences.

 

Thanks Tony! As usual you come to my rescue with some super helpful info. Much appreciated brother I'm feeling more confident now.

 

You're welcome!

If you need anything after the gear install, lemme know. Everyone that got them seems to love them. From my perspective, it makes the gearing as good as it can get for the 3rd Gen not to mention a lusty 1st gear crawl ratio.

 

alright, i'll shut up. It seems highly unlikely that there are so many variables that would cause a discrepancy between the trucks where only a small portion of them are having an issue. I'd personally wait and see if it affects you, and then tune from there. sounds like it's an easy fix with a tune though.

FWIW I ran 5.29s with a variety of tire sizes (including stock, just for fun) and had no speed/rev limits aside from those imposed upon me by nature/the dash.

 

the speed limiter is more like 89mph. It’s supposedly fixable in vftuner.

 

ECGS said it moves to ~89mph on 35's

 

It's all good.

Supposedly, the speed limiter senses the AT output shaft speed which is why this comes up with a diff gear swap.

I agree that it is weird if it only happens on some Tacos. Tire sizes have some effect, just like the gears, but it should be consistent. Good for folks that it doesn't affect though.

 

I wonder if its something regarding the version of the TCU/ECU, as I have an early 16 and never updated any of that until I tuned it with OVTuned last summer/fall. I am just surprised to hear it be an issue -- I ran (radar confirmed lmao 90+) on 5.29s with 35s and the truck seemed happy to keep going, aside from pushing air out of the way.

 

I’m on 5.29 on 33’s and have tested this and my truck hits the limiter at 89mph. My Speedo is corrected for tire size tho.

 

Interesting. Thanks for the info bro

 

It might be? I have only one person on my list with a 2016 / 2017 with 5.29s. Five others that are 2018+. I know that the 2016s and 2017s have a smaller ECU memory compared to the 2018+. 1.5mb versus 2.0mb.

I had never tested mine prior to the recent run. Only saw about 100 a few times. On the recent trip with some 75mph and 80mph speed limits, I was getting passed by semis and just about everyone else. The speed run was the only time I went more than five over. Considering that I got a cracked out windshield on the trip, I didn't want any other rewards or commendations. Haha!