ETC area scalar

[Sébast19X]

Why ??? Because it have some confusion between you and greg.

You multiply by 0.88 and do not substract the shaft area
And greg substract the shaft area and did'nt multiply by 0.88

In my sens that make a bigger difference than +-200

90mmTB: (3.1416*45*45)=6361.74
90mmTB shaft 10mm assumed : (90*10)=900
So 90mmTB :6361.74-900 *88%=4806
ETC=4806 vs my Hp tuner value at 4725 are pretty close

For the 2009 TB I did'nt think that GM put a bigger TB. What do you think If they put 5636 just because they assume that the 88% is in reality 100%
That would give:
90mmTB: (3.1416*45*45 ) =6361.74
90mmTB shaft 10mm assumed ( 90*10)=900
So 90mmTB :6361.74-900=5462 for 100% opening
ETC=5462 vs Hp tuner value at 5636 are also pretty close.


102mmTB: (3.1416*51*51)=8171.3
102mmTB shaft 10mm assumed102*10)=1020
So 102mmTB: 8171.3-1020=7151.3

As for the NW 102mm TB I think that the correct value should be for C6 Z06 2008: 7151.3*88%= 6293

For 2009 car's: 7151.3*100%= 7151.3
Let me know what do you think,
Later,
Sébast

[Amric]

I don't see any need to over complicate this whole topic.

Stock Value * New Area / Stock Area = New Value

Using your estimate for the shaft size of 10mm:
5636 * 7151.3 / 5462 = 7379 for a 2009
4725 * 7151.3 / 5462 = 6186 for a 2008

[DSteck]

You shouldn't use a different value based on what year the car is. If a 2009 throttle body is in fact larger, then that explains why the value in the calibration is higher FOR A STOCK THROTTLE BODY.

For ANY year Z06, you should use the 7000+ value. A 2006-2008 throttle body probably has a true size somewhere around 86mm. If you want to split hairs, measure the inside diameter of the stock throttle body, run your calculations, then measure the inside diameter of the NW 102mm throttle body, run your calculations, find a ratio, and multiply whatever is in your stock calibration.



To Sebast19X... The reason one person multiplies by 88% and another subtracts the area of the rod is just preference. When the blade hits about 88% rotation, it is still blocking some area of the throttle body bore. That area is roughly equal to the area of the rod. You shouldn't multiply by 88% in addition to subtracting the rod area... Just do one or the other.

Hell, maybe I'll just take my stupid throttle body off when I get home and measure it out to give everyone a warm fuzzy feeling.

[Sébast19X]

You shouldn't use a different value based on what year the car is. If a 2009 throttle body is in fact larger, then that explains why the value in the calibration is higher FOR A STOCK THROTTLE BODY.

For ANY year Z06, you should use the 7000+ value. A 2006-2008 throttle body probably has a true size somewhere around 86mm. If you want to split hairs, measure the inside diameter of the stock throttle body, run your calculations, then measure the inside diameter of the NW 102mm throttle body, run your calculations, find a ratio, and multiply whatever is in your stock calibration.



To Sebast19X... The reason one person multiplies by 88% and another subtracts the area of the rod is just preference. When the blade hits about 88% rotation, it is still blocking some area of the throttle body bore. That area is roughly equal to the area of the rod. You shouldn't multiply by 88% in addition to subtracting the rod area... Just do one or the other.

Hell, maybe I'll just take my stupid throttle body off when I get home and measure it out to give everyone a warm fuzzy feeling.

Good idea that would be great to know . Take that measure and let us know.
Thank you sir,
Sébastien

[RWTD]

I still don't understand why my original post, which explained everything in detail, nor why Greg's, which was even easier to fathom, is so difficult to comprehend. DSteck's post hopefully cleared up the confusion.

Sebastien, this is what it boils down to: On any vehicle using the 102mm TB, just use the final value I gave, or the one Greg gave. This doesn't need to be complicated.

[carlrx7]

On my TB the shaft is shaved, hmmm, now what?

[Amric]

Just measure the shaft area and take that off the total area of the throttle body for the actual area at WOT.

[LSX378]

Because, as I stated, your '08 TB has a smaller effective area than the '09 TB.

Why don't you just try the value I gave in my post, or the one Greg gave in his post. They are within 200 of each other.

Any chance this improves the ability of a GM '09 TB to work without raising faults on an OS expecting an '08 or earlier TB? (apart from moving to an '09 ECM & OS with the right pedal).

Thankyou RWTD!

[RWTD]

LSX378, it *should*, yeah buddy.

[ayousef]

Ok guys, another question. What are the drawbacks, as in what is it possibly doing wrong if you have 08 TB parameters in an 09 Z06?

Can it hurt performance?

[RWTD]

I wouldn't say it could hurt performance, BUT that is one of the key components of a quality idle (having the correct ETC Area Scalar).

Any reason why you have the '08 stuff in your '09 Z06? I know that Andy of A&A swaps in the '08 TB into the '09 vehicles, due to fitment issues with his SC kits. In that case, YES!, you should put the correct ETC area scalar for the TB you're using. I made a comment to him about that on these forums not so long ago.

[trompazo]

I just bought a Nick Williams 102mm TB to add to my setup. (LS7/QM600 cam/ported heads/Fast intake).

I was thinking that all I had to do was change the ETC area scalar which seems simple, but now the place I bought it from is telling me I need to adust:

TPS allowed air.
Grams/sec in MAF vs RPM.
Airflow Estimate: Max Airflow WOT by RPM

Has everyone who installed these played with all these settings, or just the area scalar? This is way beyong my tuning ability and I have no one local that can tune the car adequately.

I was given some numbers for these parameters, but it was off a completely different car using 13:1 compression and a different cam so they likely are not applicable.

[RWTD]

Just change the ETC Area Scalar. As for the other parameters mentioned, those are generally modified anyway when enough airflow is increased through the engine that would exceed the factory values. Many just max those out on vehicles that will exceed the factory values that run those tests, whether or not that is the proper thing to do. However, in stating that, you're only disabling the diagnostic tests. It will not affect anything else, in reality.

[04colyZQ8]

help with switching 90mm LS2 trailblazer throttle body to 78mm throttle body E40 PCM

PCM wired to control 8 wire throttle body low and hi refs joined together TPs and TPs2 wired to sweep in opposite directions, like the PCM wants to see.

He was getting lean codes and had to use the pedal to get the truck to start

I noticed that the idle scalar was never changed from the larger throttle body so I calculated the ETC scalar for the 78mm and came up with;

78mm calculate area divide by 2 =39mm (39mm x 39mm x 3.141592653589793= 4778.3623mm) subtract throttle shaft area 10mm x 78mm =780mm so 4778.3623mm- 780mm = 3998.3623mm x 90% max throttle opening = 3598.5261mm rounded to 3598.5mm

I am 90% sure this is calculated right, I had him change his etc scalar to this, he then tried it and it would not start to easy, he leaned it way out and now it starts 2nd to 3rd crank, but set code P0121 throttle position circuit.

I think the tables below the etc scalar need to be changed as well?

like the Effective area, max, min fail, etc..

wild guess at hoe effective are max is calculated?? stock is 8192 is this kind of like 90mm x 90mm ? = 8100?? sort of close should I change this to 78 * 78= 6084??

any other settings need to be changed?

[driver240]

hi... i don t change the value in the area scalar and my trottle is opening 115% so it s like the blade is closing.....how can i set the aarea scalar for my nw etc 102mm

[2003 venomous]

First off, I realize this thread is old; however I believe it has the data I need in order to get my 05 CTS V running right. Car has stock short block with Stage 1 ported heads, TSP V4 cam, Headers, 90mm Intake and TB mod by TPIS and stock MAF with a stock fuel system, those are the major end items changed. A friend and myself have been tuning it; he is experienced, I am learning. I would like to modify the ETC Scalar area (ECM 2154), but mine is in a small decimal number and many are saying the have theirs set to 4500, 5000, 5500, etc. as posted above. Question is why is mine so low, field shows a range from 0.0000 to 1.0000. Am i looking in the wrong spot to modify this calibration? Any help is appreciated. Let me know what other data is needed.
HP Tuners.jpg

[LS3SS]

I have searched high and low to try and fix the idle dip, and the proclaimed smart people telling each other clearly have no idea what their doing . But "Kelp" was right!!!! The Effective area min is your min throttle open!!!! So 50 commanded 6.7 TPS which was perfect. Idle doesn't dip past my target idle!! Why has no one spoken about this to fix, blows my mind. I might have to make youtube video about this.

[RobZL1]

I mean, that's one way to fix an idle dip.

I think this is the best first post ever. In one post you managed to say that both Greg Banish and Dave Steck are clueless. Hmmmmmm...

[LS3SS]

I'm not referring to them nor did I mention any from here. But if they didn't know what the "Effective area min" does then, guess they learned something too. Life's all about learning, I will share this knowledge. Tunning a 102 is a pain and I'm happy I figured it out. Oh and it's ebay 102 , not an over priced NW102.