BBK 95 mm throttle body Tuning 2013 Camaro SS Auto - barely starts then stalls.

[DaveGuy]

A buddy of mine installed a BBK 95 mm throttle body on his 418 LS3 Automatic (VVT/DOD delete). Tuned and runs perfect on the stock 90 mm TB. I have run a BBK 95 & 102 on my 2010 Camaro SS Automatic without any issues with a Whipple Supercharger.
I changed in the tune (95mm):
B1650: 5636 to 6350
C0803 , C0804, C0805, & C0806 to the same values I used in my 2010 supercharged Camaro SS.
Is there something I'm missing? It works in the 2010 any thoughts?
Thank You

[joecar]

What is the cam specs on the 418...?

[DaveGuy]

It's a small Comp Grind: 219/235 .624/.624 113+4.

[joecar]

Is this with the same ECM that came in the car (2013 Camaro SS)...?

Does it stall within 2-3 seconds of starting...? Log the pid GM.VTD to see if VATS is preventing fuel.


edit: fixed typo.

[DaveGuy]

I have had it run for more than 30-45 seconds by giving the car a little throttle. When I let off the TB seems un-responsive and the car stalls out. It is the same E38 ECM that was stock with the car. The car runs and was tuned with the stock 90 mm without any issues. This throttle body came off my car and works perfectly on my 2010. I put a 102 on my car without an issue. I don't have the car with me right now. I can log GM.VYD the next time he is around.

[joecar]

...

I can log GM.VYD the next time he is around.sorry, I misspelled it, it should have said GM.VTD...

if the engine runs more than 2-3 seconds, then VATS is not what is shutting it off, so there is no further need to log GM.VTD.

[DaveGuy]

Do you see anything in the tune file that might be causing the issue?

[joecar]

You may need to increase idle desired air...

but typically something like this (displacement/cam) usually starts and idles on the stock tune.

[DaveGuy]

I played with the minimum idle air and put some pretty big numbers in there and it no response or change. It really makes no sense. In my 2010, I swapped it in and it just worked. I'm just wondering if the 2013's have some additional parameter that I am missing.

[joecar]

I'm looking thru your files...

you may have to do idle tuning, see here: E38-idle-tuning (https://forum.efilive.com/showthread.php?9740-E38-idle-tuning)

[DaveGuy]

I would actually agree with you, but the car idles perfect with the stock 90mm. The throttle body isn't responding at all. Minimum Air doesn't seem to do anything. If the car ran with the 95mm and hunted I would agree with you. Could one of the airflow tables be causing this issue or run away throttle tables? I upped them to the same values in my car.

[joecar]

Ok, I've run into this before... aftermarket throttle body, and not responding to IAC commands... turned out TB gasket (flat paper style) was missing a hole for the IAC air passage.

[DaveGuy]

Yea, no IAC on this car. Throttle by wire. IAC intergrated into the throttle body blade position.

[joecar]

Ah, DBW, what was I thinking :doh::chair: (I was in a hurry, sorry)...

[joecar]

How did you calculate B1650...?

Should B1651 and B1652 change also...?

[DaveGuy]

To calculate B1650. I took a percentage increase of the stock TB calculation on 5636. 90*90=8100, 95*95=9025, 9025/8100=1.12. 1.12*5636=6312. I rounded it up to 6350. I works on my 2010 without any issue. I didn't adjust B1651 or B1652, i'm using the stock values.

[joecar]

What happens if you make B1650 10% smaller, and then 10% larger...?

[DaveGuy]

I didn't try that. I should have time with the car this weekend. I can bolt the thing on for the 5th time and give it a try.lol

[Tre-Cool]

cars with blowers tend to get away with lower airflow numbers as the compressor helps draw in the air. which is why on yours is probably worked fine.

I reakon you have simply gone too far in your adjustment for the n/a motor and the larger number is giving you less throttle blade movement for cold starts/idle etc.

put it back to stock and see what it does, if it idles too high and pulls timing then bump the numbers up more.

[DaveGuy]

So you want me to try to reduce B1650 to the stock 5636. I'll try it.