When fixing up my gas pedal I noticed that Full Throttle never reads more than 87.8% on my OBD2 Logger and then I stumbled on this device:

http://www.jscspeed.com/universal/el...controller.htm

Just some of the text that doesn't full make sense to me... wouldn't this just make the throttle more sensitive and then feel like it's doing very little difference the farther you push down the gas pedal? I've already driven cars that seem to speed up as you let off the gas where the 85%-90% throttle position seems to be faster than WOT which always struck me as odd.

It says you won't gain HP but you will now be able to use all of the power the engine is capable of...

Could it be that the reason the X starts off so slow is that we are missing 12.2% of our Throttle Opening? That would be pretty damn funny... I guess I'll remove my Lower IC pipe and have some one go WOT and verify that sucker is opening to 100%. Speak up if you have already checked into this!

 

I'm using a DrewTech dashdaq to log the X now, and I agree on the never 100% WOT readings. I've tried relative, and absolute-and I cant get either to go above about 91%...my guess is that it may read off the TB not the pedal, and the ECU may limit the opening of the TB in lower gears-my mazdaspeed 3 did sorta the same thing-it limited the boost in 1-3 gears so you didnt roach the trans and tires.

 

I member after our own heart.

Zeitronix / Dashdaq for the win

 

Yeah I've been doing some reading and the Blitz device just makes the pedal more sensitive which seems like a Placebo effect if anything. What I'm not sure about is if the drive by wire is intentionally not opening the throttle plate to 100% for a performance reason. I also read that in some cars it will not open the throttle as far once it reaches certain speeds so logging this the next time I can do a high speed run has peaked my interest, like through the traps at the drag strip. It very well could be that angling the throttle plate at less than 100% is more power at certain engine speeds and that is why they are doing it that way.

Then again... it could be holding us back a little too!

 

Just using the free ScanTool.net v1.13 software here, forgot to get 25% values oops!

Estimated Throttle Position ...... 0% ........... 50% ...... 75% ..... 100%

Absolute Throttle ..................... 14.5 ......... 50.2 ...... 70.6 ...... 87.8
Relative Throttle Position .......... 6.7 .......... 50.2 ...... 75.3 ...... 95.7
Absolute Throttle Position B .... 14.5 ......... 50.2 ...... 71.0 ...... 88.2
Accelerator Pedal Position D .... 19.6 ......... 51.4 ...... 69.4 ...... 89.8
Accelerator Pedal Position E ...... 9.4 ......... 25.5 ...... 34.5 ...... 44.7
Comm. Throttle Actuator Cntrl ....6.7 ......... 49.8 ...... 75.3 ...... 95.7

I have no idea why there are so many different numbers and what they all do. Seems like 95.7 is the highest any of them get at full throttle.

 

Another thing for you guys to look at, is what happens when you shift.

I remember when the new mustangs came out the computer would shut the throhtle body and would not open it right away when quick shifting for emision pourposes. That's something that could be happening to our cars, and something that might give it a bit more better engine response.

And about this, well maybe something ECUtek guys can look at fixing with the tuning software. Good job Hiboost.

 

When I tuned my car on EcuTeK, it never showed higher than 87% either. Its normal.

 

I'm curious if the drive by wire cars are set up to fun full throttle mapping at 87 % to give better partial throttle response. I'm willing to bet that that's the case, but it would be nice if someone could find out for sure because I have a hard time believing that any auto manufacturer would purposely handicap their cars, especially their flagship performance car.

 

so the reason the X responds better to partial throttle than WOT is because of throttle limiting and not running super rich when stock or is it really both?

 

I hate electronic throttle control. Someone fix this if this is true and post the fix please!

 

just for your guys info when i tune a subaru their boost control maps stop at 80% theres no 100%

the other maps are load based like the evo.

 

That stinks

 

mmmmmmm Good find.

 

I'm not sure it necesarrily means we are getting reduced performance, but it wouldn't hurt to verify that it stays at max opening position at all speeds. I'll report back after some datalogging and also verify with the lower IC pipe off what angles it sits at for the 95.7 number. Likely it's the best it can be now, but if it's pulling some tricks without us knowing since it's electronically controlled, that would be Eeeeevil.

 

The STIs always had a poor throttle map from the factory not allowing the TB to fully open. I know a lot of people tune this out on the STIs and it looks like it will be another tuning variable on these as well.