E63 Tony

anyone notice a difference? i use a obd2 app when driving in mexico and this weekend i noticed at 80% throttle the car feels and makes more boost at the same gear/rpm/speed than it does when you flat out punch the gas.

Try this in manual mode; at 3400 rpm 3rd gear, punch it 100% WOT... Go back to 3400 ish rpm and then only punch to 80% of WOT. My butt tells me I'm accelerating faster at 80%, also the boost is 2 psi more than at full WOT according to my obd2 screen.

i saw on a different forum with turbo cars this little comment: "As I'm writing this, I think I'm starting to understand what you're saying. If I punch it, the turbo reaches overboost and has to be brought back down by the ECU. It's this taming process that fells like lag/loss of power. If on the other hand, I only go to 80% the turbo reaches max. allowable boost without going over. There's no "taming of the lion" and I get more power, faster. Am I making sense?"

anyone else feel the difference?

Astolfo

what app and obd2 transmitter do you use? I do not get boost on my transmitter or Garmin.

E63 Tony

The app I use is obd2 fusion on iPhone. It's like a $10 app. And the Bluetooth adaptor is $35 off amazon.
Lelink Bluetooth low energy ble OBD-II OBD2 car diagnostic tool for iPhone/iPad/

LELink Bluetooth Low Energy BLE https://www.amazon.com/dp/B00QJRYMFC..._B7yJyb0DD7M74

Wickdwagon

First of all thank you. That OBDII scanner was very cool so one of those is now coming my way via amazon. Not wanting to mix apples and mangos. But does the TCU and throttle response reset that people talk about have any affect on this?

Luke-BITURBO

Did I read something the other day that resets something on these cars and gives more throttle percentage?

CarHopper

My guess is that at 80% throttle you'd be in gear longer (because you were actually accelerating at a slower rate initially) allowing the car to generate those extra couple pounds of boost so that once you hit the top end your butt dyno is telling you you're accelerating quicker, but, it took longer to get there.

Next time you're in Mexico () try your same test in higher gears. The longer the gear the more boost you'll end up making, to a certain point limited by the car. Or, do your same tests but time how long you are in each gear.

At 100% throttle in low gears there just isn't the time to generate boost, you rip through those gears.

This is just the way my mind worked out how this could be possible and I don't have facts to back it up, just years of experience driving turbo cars. Similar situation in my Sti once I went with a large turbo in that if I babied the throttle low and allowed for boost to build then hit it by the top end I'm flying. Kind of like brake boost almost but instead of using brakes to build boost you're deliberately accelerating slower.

Astolfo

+1 I believe your theory is correct.

Wickdwagon

Sort of related where is the OBDII port and can you leave the BlueTooth OBDII reader plugged in all the time?

Astolfo

Between the driver's door and steering wheel. near the bonnet opener. I would not leave the bridge/reader all the time, although they draw very little they can drain the tiny battery these cars have. But maybe if you drive every day it is ok.

PeterUbers

80% of the time it works everytime...

10speed

Tiny battery? The car has two batteries 1 under the hood on passenger side against firewall and a smaller one in the trunk.

Astolfo

I would say tiny for the drain the car imposes on them when there isn't an alternator or trickle charger maintaining them.
Try to leave your OBDII bridge connected for a month without riding your car or having it in trickle charger, then get back to me...

Wickdwagon

Sounds good it more or less a daily driver so it should be fine. But point very well taken.