Initial Development And Prototyping Of A 102 mm GM LS Throttle Body On A Supercharged Tundra

I'm not sure how it would work on mine. I have the valve body accumulators (C2, B3, C3) locked up where they only move about 1/4 to 1/2 inch. It creates a direct shift with no clutch overlap for 2-3-4 (poor mans shift kit or 1970's muscle car shift kit). So it is a harsh shift in its self for those gears.

 

That's a good question

 

@ViktorG or anyone in the know. Im testing different throttle position angles and shift rpms.
If I have tow/haul setup for one throttle position and lower rpm than my main tune will that be an issue. Just trying to make it easy to be able to test different parameters. But don't want to brick anything. Thoughts?

 

I can't see any way for that to be an issue.

 

I adjust the throttle position angle to a reduction by 40% and shifting rpm's by 200 for shift speed. Reduced tcc setting a little too much as it shifts from 3-4 pretty quickly and will lock in 4th gear. I believe the cold settings are ok but once at 185-195 deg the hot settings need to be increased from where i reduced them. Shifting to 6th needs a bit of adjustment still. A work in progress for sure. Submitted a ticket to hptuners to be able to do inverse tables for torque load and desired air load as hpt for GM has that function.

 

@armyoffoo anyway to let hpt know that the adaptive reset is not coming up on the beta version?

 

I emailed them back, waiting on a reply.

 

@armyoffoo Appreciate it!

 

Getting closer to decent shifting. Got 6th gear back where it won't down shift at the slightest grade. Still haven't gone WOT! I'm inching closer got to 78% in 4th gear.

 

Hopefully have the new intake setup soon with the 5” and 103. See how it all works out

 

This was interesting. Today I received a response from hpt stating that doing an inverse table is not applicable to Toyota. They were going to close my request when I replied with a picture that they offer it for Ford and GM plus that I was following slownstock's advice to have the desired air-load be an inverse of optimum torque load, they escalated it to their engineers.
Not sure if it can be done for Toyota though...
It is shifting better without the airload adjusted but it could be better.

 

And that's not the only inverse table. Transmission optimum and inverse are explicitly called that.

 

It'll be a start if they can bring this to Toyota's editor as it seems like we are the bastard that is forgotten. They to respond with Toyota is archaic in their programming of ecu's.
When I read the Ford hpt forum they asked for an inverse function in 2018 and they got it on Dec 2023 but I believe only for 4th gen on up.
Then after they do all the math/conversions/table adjustments....the final dialing in is based on how it feels/responds to adjustments that deviate from the tables.
And here I am trying this out when I could hardly understand adjusting my ltft's.
But a hearty thanks for your guidance!

 

Can you download one of the files for a vehicle that has the inverse converter working and use that?

Considering it's just interpolating and flipping data I would think it'd be a generic tool

 

I tried a few from the GM but were older files and not available and hpt kept redirecting my sign in so I gave up. I saved a few posts that have the info. Will try and see. Plus I always seem to mess up excel files.

 

Lots of info to digest and see what applies to Toyoya. https://forum.hptuners.com/showthread.php?66263-Whats-the-torque-inverse-calculation/page6

 

I just got @reywcms new TB from @ViktorG and it's gorgeous!



But this got me thinking (and coincidentally I had read about someone making their own TBs the other day but didn't put 2 and 2 together), why don't I just design us a TB that uses the Tundra electronics? Sell it as a kit where you get the billet TB and plate and shaft, and then take your stock TB and swap the electrics over and voila. Bolt up to the Tundra bolt pattern, no need for the signal converter, would effectively be a stock unit.

Did we already talk about this and I forgot and that's why no one has looked into it? I would probably need to machine it overseas to keep the price in reason (like sub-$300?). Would anyone be interested in that?

 

Hell yes! Put me down for one.

 

Yes lol

 

I just looked at my stock TB, the electronics hold down plate is riveted, so I'm definitely not taking my apart that I need Rey is trying to get his hands on a stock one to send me.

 

Do you want a stock one, or a RCF? I have both that I can send.

 

I'd rather a stock one, in the event the RCF internals are different. I want to be able to use as much stock hardware as possible.

If you have it on hand and can send it that'd be awesome! I'll pay for it and shipping too.

 

PM me your address and I'll drop it off at UPS today. Consider it credit towards whatever you come up with.

 

That works out! And what I'll do actually is build one here with the parts from yours, and then I'll just send you the whole thing already assembled plus the remains of the stock throttle body. So you'll just end up paying for material cost (assuming it all works out and is an acceptable price) and you'll end up with an already assembled billet throttle body.

 

Shit yes

 

Perfeck!

 

The tuning will still be the final hurdle but can be done. When I ran the GM 103mm (a crappy friends one) it acted like a on/off switch. But when it was in the range it was gobbling the air and scooted big time! Using the GM 95mm, its not perfectly tuned on the shifts and is 90% better than before. After I changed my shift rpms, throttle position angle (reduced by 45%) torque and air loads I was hitting my Rev limiter. Hopefully after @snivilous suggestion to change it up it should be sweet!!
**I did encounter a hard start situation when I reduced the throttle angle by 50% but it did start after a cool down. I believe it was truck related as I tried 40% then 45% and 50% again and it ran and started fine. I just settled on 45% for now as is close to the stock increase TB from 76mm to gm 95mm TB.
Good times!

 

My hope is going with the Tundra body will remove the variable of "throttle body quality" as well as the multiple adapters and configuring needed to make the GM one respond correctly. Maybe even make tuning easier since the TB control isn't running through the wiring adapter.

If I get it to work I'll install one on my own truck so I can help you guys figure it out too.

 

YES! A project I too have wondered about. One hurdle will be the motor, as it is directly in the way of expanding the throttle plate diameter too much, less so on the RC-F. If you find a work around, do post about it! Flopping the motor over 180 is a possible solution, but one of the sensors is in the plastic cover. The other 1/2 of the sensor is built into the end of the throttle shaft with a gear on it.

They open up easily…

 

Looks like an additional idler gear could be added to offset the motor more?

EDIT: Or just upsize the idler gear in there actually