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

It's when it's about 10-20% throttle where the 1-2-3 shifts at the higher rpm range will take a little bit to upshift. And the highway speed down shifts 6-5-4 under slight load. On a level straight away it's good, just needs some fine tuning. When I had the 102mm TB it was more pronounced but with a quality TB and fine tuning is doable.

 

I downloaded the beta version and didn't see the reset it in editor. I hooked the computer up to verify vehicle then took it inside to adjust pedal vs tb angle. Trying it 5% at a time. Will load later on.

 

It should be in the scanner utility, not the editor, but I'm not sure where though. I'll admit, I didn't verify, I just posted what they emailed me. I should be able to try it in a couple of days though.

 

I did see a tab in beta scanner for special features but when I opened the feature it was blank. Also the beta canner didn't save a log file, was a good run, and wouldn't show my fuel trims...guess it why it is a beta version.

Don't mind the glare.

 

Curious to see how Viks TB and cable will do on mine and how much tweaking it’s going to take

 

A few pages back he stated he was dealing with the high/flared shifting rpm. He didn't mess with it as he was just driving to the track.
Here is what he posted.

 

@snivilous fyi

 

Sniv correlated the change in plane for the TB's. 76mm,84mm, 90mm and 103mm.
From what I've read they always don't follow an exact formula for increasing or decreasing throttle and TB. Gotta play to get it close. But I'm sure using a formula will get you in the ballpark. Plus from what I gather you can't change the throttle vs TB angle too much as it could brick the ecu.
I've been playing with 5% at a time. Also shifting for trans output rpm... will put them all together and see what happens. Been testing individually to see if it messes with the ecu.

 

Post #252

 

Is there evidence of this? And does it mean to change a bit at a time but you can do it forever to get to the point you need, ie don't do a big jump from tune to tune? Or there's a hard cliff that if you set it too far it bricks?

 

I'm not 100% sure. Grant at TRP said that changing more than 10% "could" cause issues and brick the ecu. But he's never encountered it. Was just a warning. He ran dual 90mm TB's on his GM and changed the TB airflow planes without issue, more than 50%. He probably was just giving a heads up of what could happen.
Crap picture but he warning from hpt too. I'll keep changing it and see what happens.

 

I guess that I interpreted that warning differently. It made me think that if one were to have the throttle angle set too great at, oh say, zero pedal position, it might result in kind of a runaway situation where you wouldn't be able to "close the throttle" and the engine could be unintentionally run up to the rev limiter. Or, the ratio of pedal input to throttle angle could be too aggressive and during a test drive a small input could result in the TB opening WAY too much and put you through the back of the garage, or into a cement mixer or something. But I might just have an overactive imagination....

 

Yea I thought there were a handful of tables with that warning. If it was me I would just yeet to the value. But I'm also not doing it and no one warned me

 

I added the shot about the warning. Wasn't sure what that was about. Grant has worked with people on different vehicles and just something he mentioned. So I was just proceeding cautiously.
I'll try and find the email to re-read it. I tend to delete old stuff.

 

I'll probably follow your advice when I try to dial in Rey. Last thing I need is to brick someone's ECU

 

I know you helped out a lot dialing my tune in and have been a bit frustrated with hpt. I'm just bad at excel type functions.

You'll probably get it dialed in before me!

 

@snivilous
Ok, had the email mixed up as he was warning about the GM's...his response.

Has anyone tried reducing the throttle vs pedal table? It seems that would be the logical thing to do. Just don't know if the PCM will like that. I know GM has failsafes that kill the PCM if there is a large discrepancy between what the tune is doing and some secondary monitor. HPT and EFILive warn not to modify these tables by more than 5%, but what people are usually doing is increasing the throttle response, not decreasing it like you would want to do.

Regards,
Grant@
Torque Rush Performance Inc.

 

@snivilous I cycled through the circle green parameter and now it's gone. Do I just reload as it changed chart?

 

I don't quite follow your question. You changed units and now can't change back?

 

Yes. I changed the units. Its in another torque based chart but had this pic for reference.

 

So the units completely disappeared? I still don't follow what the actual issue is

 

Also when I spoke with Trp he stated the perfect lambda can be TB specific. So it may only work with the NW 103.

 

What table is it and I'll recreate it

 

Ok... I made 3 different tunes to test. Maybe test on Friday.
I'm using the GM 95mm TB which is about 50% more air than 76mm.
1. Moved optimum torque load 3 cells to the left.
2. Reduced electronic throttle desired angle by 50% to 39 deg then smoothed to 100%.
"Hopefully this one doesn't mess with my ecu!"
3. Reduced shift scheduling by 200RPM in the 20-50% range. Did a little less at 60-85% and left 100% alone.
Each one is an add on to the previous to see how they interact.

shift point adjustment for tires/gears...

 

This is getting exciting!! Fingers are crossed!

 

So... I am happy to report that reducing throttle angle by 50% did not brick my ecu. Shifts from 1-2 at part throttle are under the previous 2800rpm and down to 1500. 2-3 shifts are a little higher but not in the 3000rpm range. Shift into 4th and 5th need a little tweaking but are way better. Will work on 5-6 as it stays in 5th longer but does shift into 6th. It will downshift 6-5 when encountering a increase in grade. I still have to adjust the torque converter lockup rpm as @snivilous reminded me. The tune for shifting is kinda rough but will keep fine tuning it. Just happy it's better and will keep at it. Grant at TRP was helpful in laying out a game.

 

@helidave and I have been messing with Ignition Efficiency parameters to try and smooth out some of his shifting. Still a work in progress but Dave said the results as of this morning were improved. We may want to incorporate those same tweaks into your tune to see if the shifting can get smoothed out. Dave can comment on how much of an improvement it did/didn't make.

 

Well not to burst the bubble. I went to the store and it was running like before. I came out to start and it catches for a second then stalls out. I reloaded the older tune and same thing. It wrote to the ecu. Will keep you posted. And of course it starts raining!

***edit: I'm up and running. Not sure what went on. I may bring the throttle down to 40% and see about other solutions like @snivilous suggested.

Actually thec50% reduction doesn't happen at startup. So it could of been just my truck having an issue.

 

Definitely softened the harsh 2-3 shift quite a bit. Still shifts harder than the other gears, sometimes, but even when it does it's not as jarring as before.