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

If you find it, let me know. All I could find was a idle relearn, it's idling fine though.

 

I think you can tinker with the throttle tip in in your tune if it doesn't settle to something you're okay with.

 

Do you happen to know the area/section that is found? If not, no big deal, I can dig through my tune file. I was thinking this may require a follow-up tune...ProSpeed has my latest file, but I have an older revision I can look at and the base tune to compare. Latest logging shows that everything appears to be checking out voltage-wise and throttle commanded/actual are lining up, and no DTCs.

 

Do a power drain and it should trigger a relearn. Disconnect battery and touch Positive and Negative terminals for 30 seconds or so. I also leave battery disconnected for about 20 minutes

 

I can't recall off the top of my head, the only thing I can is that when you hover over the icon for the correct one, at the bottom of the window that give the definition, it say something like, "ALTER AT YOUR OWN RISK".

 

Already did that Sunday night, I think it's been relearning since it's gradually gotten better.

I forgot I had a Foxwell scanner that can access special functions. I performed the "learned value reset" and "TCU reset" since I never did that after I got my IPT valve body installed way back in 2021. Going to drive it around a bit so it can relearn...again.

 

2 options I see, see if you can get a "smoother" or more gradual TB/angle map tuned into the convertor to use as a baseline. Or adjust the "desired throttle angle" table in HPT to lag the TB response a bit.

https://forum.hptuners.com/showthre...-Haul-sensitivity-in-Drive&highlight=throttle

 

After performing the learned values reset yesterday, and 3 x 0-100% pedal pushes with key-on, it's running perfect today!

I was able to feather the throttle to avoid the IPT shift harshness, shifts were smooth, response was spot-on and I swear it pulls harder off the line. It was a blast to drive today, got home with a smile on my face!

I'm going to keep the unit installed, obviously, so if there are any issues I will report back.

 

Dammit, that means it's time for me to spend some more money.

What TB are you running?

 

Details in this post...I updated it today to make sure it includes everything I had to do to get to this point

https://www.tundras.com/threads/ini...supercharged-tundra.75732/page-3#post-3398107

 

I wanted to clarify that any TB should work, now that this is working on the 90mm, there should be nothing preventing anyone from trying with a 102mm or 110mm, or a non-GM TB. Once I've run it a while, I plan on getting the Harrop FDFI snout that has the 110mm GM throttle body built-in with a custom 5" intake.

 

Absolutely. I'm looking at using a takeoff LT4/LSA 87mm or similar.

 

Yes!!

 

They can make the harness with the Toyota connector on the engine harness-side, but if they don't have them, it's not hard to do. Get this

$14 Godaca 1x Black PVC Male Connector 6-way for Throttle Body Sensor 90980-11858

https://www.amazon.com/gp/product/B078CK2R3C?ie=UTF8 and use the pinout below:

Toyota Engine Harness / D2A engine connector
Pin 1 (Green) / Brown
Pin 2 (Red) / Yellow
Pin 3 (Blue) / Black & White
Pin 4 (Yellow-Black) / Purple
Pin 5 (Yellow) / Blue
Pin 6 (Yellow-Red) / Green

Here is mine...pay no attention to the colors I used, the wires at the top are from the D2A harness, the wires at the bottom are the stock Tundra TB connector

 

For anyone looking into this, here is a cheaper TB with a larger blade that will also work...here's the email I got from TorqueRush.

The GM LT5 95mm digital TB(12669871) is also an option with the D2A as it can convert the digital signal to analog. https://www.rockauto.com/en/parts/acdelco,12669871,throttle+body,6472

 

Awesome, I’ll need to confirm if the Fast 103 is the same which I think it is

 

We are going to see a few RC F's going up for sale. I can see a 90 or 95 in the future! Thanks @armyoffoo !

 

I'll take an RC F when one does!

 

Now that they have the values recorded from the RCF TB I was using previously, any TB should work. Whether it sends an analog signal like the one I bought (LS3), or a digital signal like the one I just linked (LT5).

RE:LT5 TB digital signal vs. LS3 TB analog signal
"Yes both signals are digitally encoded and transmitted on a single wire using the SENT protocol. Ford and GM both use this now, although the Ford data messages are in a somewhat different format.The D2A can decode such data into the respective TPS1 and TPS2 values.

You should be able run almost any TB with the D2A."

 

Is the 90mm length, back to front, similar to the rcf?

 

The RCF TB from mounting surface to where the silicone coupler sits is 1 7/8", the GM TB from mounting surface to where the silicone coupler sits is 2". The ProSpeed RCF TB adapter is 1/2", where Snivilous' GM TB adapter is 1" thick.

So, I added 5/8" to my air intake length. I didn't have to modify anything on my intake.

 

It should be noted the 1" I did was arbitrary and meant to try and subtly transition the diameters between the two sides. It could be made a lot thinner, but there was no thickness requirement.

 

Like when we do the 102 to 103 lol

 

Well we talked about how we thought the Whipple bolt pattern is inherently a GM pattern, so if that's the case at most I'd say like a .060" thin plate to smooth it out, probably be better to just sand it slightly larger for the transition though.

 

Yea I’ll have to see the pattern when I get the 103. Not much room for sanding but it’s not needed

 

I saw SCOL used to offer a TVS1900 snout for the GM 102mm TB. Was the snout opening on th GM TVS larger than the Tundra? A quick glance appears it could fit with a lot of porting. But is it too much over the 95mm for a stock motor? Read a few GM forums using 1900 with 102mm...

 

Try searching for "magnuson 1900 ported ls2 snout"...it looks like there is a LS2 snout that might work, and can be opened up with porting. Double-check with SCOL or Magnuson on whether the snout will swap over (snout and housing line up, coupler engagement/clearance, pulley lines up). Harrop said their GM snout (linked below) on the 2650 will work on the 3UR 2650, essentially only the snout and intake plenum changes, so chances are good Mag has a similar setup.
https://www.harrop.com.au/110mm-integrated-throttle-body-ls-engines

 

What are some reputable shops to pickup a TB. Looking at a 102mm but may settle on 95mm.

 

so the one to have is the Nick Williams 103. Some of the 102s didn’t like boost so they changed the motors etc and updated it to the 103. This only applies to the 102-103

 

Thanks. I did look at those NW ones. Good and cheap...really don't go together.