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

@armyoffoo I will get another adapter that will work with my original and I ordered the straight 6 pin TB adapter and will re pin when I get it next week or so. I looked at the 95mm TB and it has a strong stepper motor and is a genuine GM.
The reset values did seem to work but I had to rescale again as the TB I had would randomly throw codes for high voltage. Some TB's cant handle the constant voltage from the Toyota side. I read the same concerning drivability issues with the 102/103mm TB's and seemed they gave up early on. Mine idled fine and except for the shifting relearn drove alright. The larger TB's need to be tuned and dialed in. But they are used for drag applications. You see them on the dyno/drag strip but I think they can have issues with drivability if not tuned properly. Some seem to be finicky at the lower rpm's from what I read.
Grant at TRP said a lot of lower and mid grade TB's are just rebranded and sold at different price points. The motors can be smaller combine with misadjusted throttle blades. Even some of the larger companies are Chinese TB's that will port, thin the shafts and new throttle blades. He didn't have a list but he recommended staying with the NW 103's and GM products(ford, etc). You can send him information the type of TB you want to use and will give you an honest answer. Grant has helped a lot in troubleshooting as well as @snivilous reviewing my logs.

 

@ViktorG snout swap:
https://youtu.be/Q6R8Vo5txiM?si=c8vCaw1sVyUz8Kne

 

If you got the Harrop or Whipple it makes it easier to go big! Nice NW 103mm TB and intake.

 

The new Maggie 2650 has got some inlet girth too.

 

Nice! I was able to port the tvs1900 to 94mm. So the 95mm TB should be plenty for me.

 

Here's the repy from HPT for the learning reset.

 

I'm still trying to get my current tune file from ProSpeed so I can send it on...

 

I got the same canned response...fingers crossed

 

@armyoffoo Hpt replied and stated that Toyota ecu technology is old school and not much they can do compared to GM and others. All they gave me was the idle relearn by disconnecting battery and do Toyota's idle relearn procedure.
Ask them for at least reset transmission shift learned values. It would be something for those that don't have tech stream or better scanners.

 

That's odd, unless the Foxwell scanner's function didn't actually do anything, nor the Snap-on tool? That seemed to be the key for me, not likely a placebo effect. Unless it was just a coincidence, or the 3 x 0-100% pedal pushes did it? I tried the idle relearn procedure on a Monday morning and didn't notice any difference immediately afterwards. I did the learned value reset the next day, so either the idle relearn might have needed another engine cycle, more time...or the learned value reset did something? I don't know, too many variables.

When I put in the ticket with HPT I specified that I was able to perform this function with the Foxwell Elite scanner, so we'll see what response I get, if it differs at all.

 

Yes, I had to do the same and explain we know of the idle relearn but having the transmission reset would be beneficial as other scanners have the function to reset it.
It does take a few cycles and varied throttle positions.

 

Last week I removed the 102mm TB and re-installed the RCF TB. Since I ported the snout to 94mm the prospeed o-ring doesnt seal. A little FIPG did the trick. Did a idle relearn and idle normalized in a day shifts are just getting back to normal from grandpa mode...haha
Received my 95mm adapter plate today and 95mm TB will be showing up tomorrow. I have a adapter for my snout to the 102mm and will stack plates using the 95mm to 102mm ict adapter. Later in the week my gm adapter for the digital signal TB should be here by Friday. Still no word from HPt for the transmission relearn reset. Hopefull they come through.

 

Finally installed the 95mm TB. Getting the Wiring sorted out...man it's cold outside!

 

I waited until it hit a nice 20degrees before finishing up the install. Started up and purred like butter(haha). Did a idle relearn and it settled out. Shifting is not like the 102mm TB. 1-2 shifts happened around 2500rpm, 2-3 was about 3000rpm and 3-4 about 3-3500rpm. Throttle response is a lot better in the part throttle area below 3000rpm too. It settled into 5th and 6th gear. The 102mm never went into 6th. I still would like to be able to reset the learn shifting. I don't feel like shelling out more $ for the shops scanner. Will keep a eye out for someone with tech stream or a top end scanner.
The delay was fine tuning the digital signal as the GM 95mm TB is digital and Toyota is analog. Grant at Torque Rush helped with fine tuning the code. Also my laptop had an old version of Java script so needed to update that. Would of been done yesterday but the laptop threw us for a loop but Grant figured it out.
Will keep letting the transmission relearn...

 

That's great news that the 95mm is working out, but sucks that the 102mm was essentially a waste of time and money...there goes my plan for that 110mm Harrop snout. I'm not dropping that kind of cash on a gamble that my daily driver will be undriveable as a daily. I wonder if @ViktorG encountered these shifting issues with the PerfectLambda convertor...I would imagine it only does voltage scaling like the D2A.

 

I did use a POS 102mm TB. The NW 103mm TB should be good and other top end models. Grant at TRP was saying that it takes a little bit of patience to get it tuned. Even reading on the vette,, ls1 and other GM forums there are some issues but most are able to be fine tuned for drivability. I know the hpt for Toyota lacks certain functions but should be doable. Definitely a @ViktorG question!

 

I originally used a cheap 102 mm eBay throttle body and it was having all sorts of issues. I then went with the Nick Williams and Perfect Lambda. I had one Nick Williams TB fail after a while, it would not stay open at full throttle. Replaced it with another NW one and it was fine.
As far as shifting, that is where tuning is required. You will have to make a lot of adjustments if you want the truck to drive like stock with that large of a throttle body and shifts properly etc. Mine is not perfect, but I don't daily drive the truck anymore, so it drives well enough to get it to the track and back. I would have to spend more time on it to perfect the tune, will hopefully be able to do it in the future.

 

It was suggested to increase the torque values for the command throttle and trans input rpm. Is that a good start.

 

Thank you for clarifying, I figured additional tuning may be required, but I didn't recall you mentioning it in your videos or posts.

Grant sent me this, saying basically the same thing, that Commanded Throttle * will need to be adjusted/tweaked to get it responding more like stock:

"I noticed that this table will be off due to the larger TB. If your shifting is still off, you can try shifting the columns left by one or two columns and see if that makes a difference. Here I have selected all columns starting from the 21.5% TP column, copied and pasted to the 12.9% column. I would try just 1 column for a 90mm. 2 for a 102mm."




Unfortunately I still don't have the file that is currently flashed to my truck, so I can't modify it. I will probably end up getting another tune from scratch once I get my Five-O injectors back...need to call the cleaner place to see what the hold up is.

Also, I never heard back from HPTuners about my case since they escalated to Engineering, so hopefully that's still moving forward.

 

Ah well if that’s the case I’ll probably stick with the RCF then for reliability for how I wheel especially.

 

He sent me the same table and suggestions. Ill try and shift the table and see how it goes.

 

I think of we can dial it in it will be pretty awesome! We are relying on Toyota technology to use larger TB's. I think once we get the torque pressures figured out for the Toyota platform we will be on to something, hopefully! It seems all platforms have this issue and just need some fine tuning.

 

I am not an "expert" in this, but what you want to try to do is replicate the stock driving behavior with the much larger throttle plate by accounting for the increase in that area.
The very first table to work with would probably be the throttle opening angle VS accelerator pedal position table.
If you don't convert this one, the truck will be extremely jumpy at low/part throttle.
With the new throttle plate area being around 80% larger than stock, you want to try to calculate the opening area of the new throttle plate at various throttle plate opening angles vs the old throttle plate opening area.
Then try to extrapolate that over the throttle opening angle tables in all gears.
Afterwards, you will likely have to play with the the torque tables since the engine will be making a lot more torque at the same throttle opening angle VS before.
That's why your tuner was recommending to shift the torque table to the left to try to (very approximately) adjust for the increase in torque at the same opening angle.
Lastly, you will probably still have to work with more tables such at the transmission shift points etc. if you want it to be perfect.
It will take a fair bit of tuning time to make a rowdy pulleyed supercharged truck with a massive TB drive and shift similar to stock.

 

Thank you. Yes it was also mentioned to adjust throttle blade position in relation to pedal position, torque and shifting tables. I figured with my tvs 1900 supercharger and setup the 95mm seemed like a good fit. The GM built 95mm TB should be more stable and shifting is about 1000rpm lower than the 102mm TB. Will see if @snivilous can help with my math skills...

 

I could model the stock and upsized throttle bodies in CAD and look at various angles for how much the area changes, and maybe use that scale to apply to each column. I'm sure there's some math that could be applied, but math is hard and CAD is easy

 

That would be a great place to start! If you could calculate the intake opening area for stock TB and 103 TB at various opening angles, we could then alter the tables to hopefully get us closer to proper drive ability.

 

I shifted the torque table 2 cells over and went for a cruise. Shifting was still high, 2800-3500rpm in the 1-3 shifts and to 4th was a little better at 1/8 to 1/4 pedal. Not sure if the trans will relearn as I haven't reset the transmission learned values.

 

In my understanding, transmission learned values reset mostly affects shift quality, it will not affect shift RPM much if any.

 

Good to know. I wanted to see if it would alter anything. @snivilous @ViktorG @armyoffoo I'm up for testing and running any tunes to get this further along.