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

Wooo!

 

Update: I'll have my Toyota connector, terminals and seals on Friday so I can re-pin the harness to suite a Tundra. Should be able to get everything tested this weekend, and get some measurements for a TB adapter.

 

Sweet!!! How much did the harness run? If yours works out I may need to have you re pin mine etc aha

 

The harness was $80, a bit overpriced for what it is, but saves time figuring out the wiring yourself. I plan to cut the 7 wires off at the GM connector, and re-pin to the layout below on the 6-pin Toyota connector.

Toyota Connector pins / D2A harness wires

1 - Green - Motor - / Brown
2 - Red - Motor + / Yellow
3 - Blue - Ground/Low Ref / Black and White wires
4 - Yellow-Black - TPS2 / Purple
5 - Yellow - 5v Ref / Blue
6 - Red-Yellow - TPS1 / Green

 

Trying to confirm the TB part number might be this SD103LTXB

 

I received the Toyota 6-pin adapter today and it looks like it will work...it physically mates with the plug that normally connects to the Toyota throttle body. Link is below, I'll get it wired up later and tested.

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

https://www.amazon.com/dp/B078CK2R3C?ref=ppx_yo2ov_dt_b_product_details

 

Awesome!

 

I may have a brand new rcf for sale asap if this pans out lol

 

yeah, and silicone reducer, and mounting adapter...I'm in the same boat, and once I get this tuned with the 90mm GM TB, I'm gonna turn around and start planning for the new Harrop snout with the 110mm.

 

If anyone else wants to run the GM throttle body, @snivilous designed a mounting adapter made for the 90mm to Harrop:

https://www.tundras.com/threads/general-supercharger-thread.85513/page-305#post-3231180

 

Because I don’t know, when does the stock throttle body become a bottleneck? And what about the RCF one?

 

Here is the PS testing on the RCF, really only an issue if you are maxing out the MAF so the larger tube lets it be rescaled:
https://www.tundras.com/threads/general-supercharger-thread.85513/page-221#post-3121010

 

The throttle body doesn't become the issue with the MAF, it's the diameter of the intake tube that requires it to be rescaled. If you read that article, it actually says the last mod they did after the intake scaling was switching to the RCF throttle body for a gain of 30HP. A larger throttle body allows for more air flow through the mouth of the supercharger, which usually increases boost. This will only help boosted engines. Check out this article for details:

https://www.motortrend.com/how-to/1306-boosting-your-horsepower-gettin-air/

 

Richard holdner? I believe is his name but he has a ton of data and engine testing that you can see on the YouTube. His data shows you absolutely want the biggest TB and intake you can fit on a positive displacement blower. Bigger is better

 

Based on the Holdener article

So am I misunderstanding something where you wouldn't want to upgrade TBs until you've reached and cleared other constraints first? If your current CFM capability sufficiently meets your HP needs folks would have little to gain from a larger TB upgrade.

Article also eludes to other factors playing a role aside from diameter. I would expect such a big difference of diameter would offset any other negatives this throttle body may have.

 

It allows more volume for the SC to compress and shove through the engine, reducing the amount the intake has to neck down to the TB and from the TB to the intake mouth.

For instance, when I get the 90mm going, it will be a 4.5" intake to 4" TB to ~3.3" intake opening into the Harrop, rather than the 4.5" intake to 3" stock Tundra TB to ~3.3" intake opening.

I wish I had a before and after with mine, because I installed the RCF at the same time as the Harrop and got 588whp on the stock 85mm pulley.

 

I'm essentially revisiting the question earlier of when a TB is beneficial.

So this reads to me gains are to be had when the TB is "the" restriction and the manifold or other parts are not a restriction. How does one determine that?

The only tests I've seen to determine this is by measuring pressure before and after the TB or dynos before and after air mods.

Listening to a long form Holdener video on this and reading the shared Holdener article, draw throughs boost application can always benefit from a larger TB but up to a limit and as long as there aren't other restrictions.

Sound like we are about to find out how much is left on the table with the 90 vs RCF vs Stock.

 

I think it's beneficial as soon as you install the blower. I'd imagine the stock head becomes the restriction before the throttle body would, that would probably be the limiting factor for CFM. But that's just a guess.

 

And a 103. The inlet of the whipple is 102 so I’ll be going back to the 103 if it all works out

 

This changes the test parameters since @armyoffoo is running a Harrop unless you have the other TBs to test and compare. It will tell us if a restriction is removed but not when you hit the "limit"

But you are answering the question from what I could find.

Matching the TB size to the inlet as closely as possible seems to be the correct answer of "when do I benefit from a TB upgrade?" Too small and you may still have a restriction (though it may be minimal at small HP goals), too big and you potentially run into turbulence issues if the inlet isn't ported. This is assuming other restrictions have been removed first, starting with the filter and moving back to the TB.

 

Any updates on getting the TB controller working?

 

I hooked it all up for a test-fit, but it isn't configured out of the box, so it didn't work. I read the instructions and configured the converter to use the GM TB that they have pre-programmed, but still need to test it. If that doesn't work, I will have to use the converter to record the GM TB blade movements and apply those values and test again.

If I stay home this weekend I should have time swap it all back and test it.

 

***Update 11/29/2023***
These were the steps required to get the unit working on my truck
Manual firmware update
--custom firmware provided by TorqueRush
Configure Unit with steps outlined below
Key-on, Reset "Learned Values" via Foxwell NT510elite, Key-off
Key-on, 3 x 0-100% throttle pedal pushes, Key-off
Start truck

TorqueRush said they have Toyota connectors and can make harnesses ready to go, but you will need to contact them as they are not an option on the website. The throttle body I bought required the motor wires to be swapped on the D2A Harness GM Throttle Body connector.

Controller and Harness: http://www.torquerush.com/d2a.html
Throttle Body: https://www.summitracing.com/parts/ado-19420707
Throttle Body Adapter: @snivilous

Wiring:
Unit's 12V needs to be 12V constant power with a 2 AMP fuse

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

D2A Harness GM Throttle Body Connector (Yellow and Brown may need to be swapped, depending on TB)
A - Yellow
B - Brown
C - White
D - Grey
E - Pink
F - Orange

Configuration steps:
Program D2A:
Connect Unit to vehicle
Key on
connect to PC with USB
Click Find Device
Select 12V Constant check-box
Set Mode A to A
Set Emulation to Custom and enter the values below
-TPS1 690 , 4060
-TPS2 2250 , 6463
Set TB Type to Record Direct
Click Record and move the blade by hand from resting to fully closed and back to and HOLD at fully open
Click Stop before releasing blade
Click Program and wait for confirmation
Disconnect PC, remove USB cable
Key off, unplug unit for 30-60 seconds to clear any current faults in the vehicle ECU
Plug unit back in
key on/engine off to test throttle operation via the pedal

Record TB log:
Key on
connect to PC with USB
Click Find Device
Click Record and move the blade by hand from resting to fully closed and back to and HOLD at fully open
Click Stop before releasing blade
Click Save, name file
Disconnect PC, remove USB cable
Key off

Manual Firmware Update:
Remove Unit from Vehicle
connect to PC with USB
Click Find Device
Click Update, Manual Update
Browse to select File
Click Update Module Firmware, wait for confirmation
Disconnect PC, remove USB cable
Connect unit to vehicle

 

Awesome!

 

Awesome work! I’ll have to keep an eye out for reliability long term.

 

Yeah, still working out the kinks like I said. I actually drove it to an exhaust shop this morning with the GM throttle body installed, it wasn't fun...need to get more logs to the TorqueRush guy. I imagine once he gets it working on mine, it should be fairly easy for everyone else.

 

I miss the old days of cable driven TB’s lol

 

Not to detract but I always wondered if Joe Drifter ever got that 5.7 with the cable operated 90mm TB on the 1900 going...

 

Update:
I drove the truck to drop off the kids this morning and it's behaving better...still not like before, but easier to manage the low throttle take offs. I was able to do a nice throttle pull. It felt great! I'm going to give it a few more driving cycles to "relearn".

I'm not sure if there is a Tundra-specific throttle relearning procedure, I couldn't find one, but I did key-on 0-100% pedal pushes 3 times, then started it up. Maybe this is why it was a little smoother this morning, or maybe it was just the driving I did yesterday on the way back from getting my exhaust fixed up.

 

I believe there is a throttle relearn. I saw it somewhere but you’re not far off I think