View Full Version : Relative Throttle Position


pgrothe
05-23-2009, 10:59 AM
Hey guys,

Here is a quicky. I was looking at my datalogs for full throttle runs and noticed that my relative throttle position top at 66.69%. I was expecting to see 83.95% as specified in the ECU.
I also notice that my pedal position top at 99%.

Can someone help me this ? Is this normal ? What are your readings from your car ?

dannobre
05-23-2009, 12:10 PM
Can't do much about it anyway :) There is no adjustment on the OEM throttle body, or PCM

If you have a buddy that will let you swap out the Throttle body to try another...

Otherwise it isn't really an issue

pgrothe
05-23-2009, 01:17 PM
I would just like to compare with others to see if it's normal. It's much quicker to ask on the forum than swaping TB from car to car to compare.
I know that I can't adjust it, but it would be a good indicator for me, that way I would know if I have to inspect mine or simply buy a new one.

If I can't find my answer here, I will try to swap it with one of my friend but I will take time and that would be in a few weeks.

Thanks anyway.

dannobre
05-23-2009, 01:22 PM
I went looking for some old logs..but I don't have any relevant ones to help you

Hell...at this point I'd be happy with throttle opening above 10% :)

There are so many parameters that the PCM uses to tell the TB how far to open the throttle that unless your car is running poorly, or idling really crappy you are likely fine

ZumnRx8
05-23-2009, 01:24 PM
when my car is off i realized after taking off my whole intake box (stock intake) that my throttle stays about 5% open...wtf? i can literallly push it fully closed with one finger. Can that explain that when i turn it on, the high idling for about two minutes and slowly fallls.....thank you.;

dannobre
05-23-2009, 01:50 PM
That's normal...the throttle body is also the idle air system. It uses TB opening to control the idle

There have been a few instances of the TB not working properly...PM Technics about it...I think he has dealt with this problem

pgrothe
05-23-2009, 02:29 PM
My run were at full throttle with engine load at 95% in third gear at around 8000RPM. I got the same on fourt with 87% engine load. It really seems that the ECU doesn't want to open it up more than 66.69% at any time. Would I get a CEL if the TB had a trouble ? If it was blocked by something.

My car seems to run fine anyway. The idle is perfect and the acceleration is ok. I can even manage to get 221 g/s at the MAF. I just find that 66,69% number very strange and would like to compare my number with anyone with a similar setup.

I went looking for some old logs..but I don't have any relevant ones to help you

Hell...at this point I'd be happy with throttle opening above 10% :)

There are so many parameters that the PCM uses to tell the TB how far to open the throttle that unless your car is running poorly, or idling really crappy you are likely fine

rotarenvy
05-23-2009, 06:43 PM
mine only logs ~78% but when I take the throttle off and look it is wide open. when traction control kicks in it will be ~66%.
try with your DSC button off.

pgrothe
05-23-2009, 07:05 PM
Thanks for your help, I will try with the DSC off. I don't understand why the DSC would affect the throttle when I'm not loosing traction.

When I recorded my logs I was on the highway in third and in forth with a completely dry asphalt so there is no chance the the DSC would have kicked in.

I will try with a couple more runs when I have time next week.

pgrothe
05-25-2009, 08:38 PM
Did a few runs today with the stock map and even tried with DSC off as suggested... nothing changed... I got the same constant (66.69%).
I overused my "ticket free" luck today :)

pgrothe
06-04-2009, 07:37 PM
A member of the club was kind enough to lend me two of his TB for the testing. I thought it would be interesting to take a video of the test.

From the video we can clearly see that the TB is totally opened and that there is no way it could be opened more. So apparently on my car the relative throttle position of 67% = absolute position of 100%.

All the TB that I have tested gave me the same results... BTW the one from the video is not mine. Mine is all shiny because I almost lick my car during the long winter months :uhh:.

So the conclusion... my car is just fine.

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