mild hesitation issue when tracking

Alchemis · 05-30-2023, 07:56 AM

hi guys,

i have a question here.. i need some ideas to start where to look.
i have below configuration
- stage 2 custom mapping
- catless downpipe, catless midpipe
- Xhp stage 3 default configuration
- stock air intake, mann oem air filter
- running 5w40 due to tracking (air temp 30 degrees celcius)

after i got the car fully warmed up, hours into the track. i noticed at the front straights where i'm pushing 5k rpm onwards 5th gear and 6th gear. the car had a loss of power. and when revving at that time, the power comes and goes like hesitation oscilating feeling. feels like the waste gate opens and closes. but the speed is still climbing but slower than normal. max speed when not hesitating, it's 230km/h, but when the hesitation happens, it's 217km/h

so i cooled down the car. for around 30 minutes. hit back out the track, the hesitation is gone on my out lap, and 1st lap, then end of 2nd lap it comes back.. 3rd lap same. felt like temperature related.

no CEL, no intermitent errors recorded in my ECU as well. all clean
oil temp i wasn't paying attention. but it's a valvoline european 5W40 BMW LL01 approved oil. running slightly thicker due to hot temp and tracking.

fuel filter ?
fuel pump ?
intake insufficient ?
tuning related ?
oil temp related ?
traction related ?

Tommix · 05-31-2023, 01:18 AM

My guess is that IAT was too high.

Doctor X · 05-31-2023, 03:41 PM

Run some data logs and see how high your IATs are hitting.

It wouldn't be a bad Idea to run some front mount intakes for spirited track days (+induction noise haha)

Alchemis · 12-15-2023, 05:46 PM

Confirmed with tuning issue. The tuner went to track with me and gave me some new maps and the issue went away. It was the way the boost regulates.

05-30-2023, 07:56 AM	#1
Alchemis New Member 5 Rep 29 Posts Drives: Bmw f82 Join Date: Dec 2022 Location: Malaysia iTrader: (0)	mild hesitation issue when tracking hi guys, i have a question here.. i need some ideas to start where to look. i have below configuration - stage 2 custom mapping - catless downpipe, catless midpipe - Xhp stage 3 default configuration - stock air intake, mann oem air filter - running 5w40 due to tracking (air temp 30 degrees celcius) after i got the car fully warmed up, hours into the track. i noticed at the front straights where i'm pushing 5k rpm onwards 5th gear and 6th gear. the car had a loss of power. and when revving at that time, the power comes and goes like hesitation oscilating feeling. feels like the waste gate opens and closes. but the speed is still climbing but slower than normal. max speed when not hesitating, it's 230km/h, but when the hesitation happens, it's 217km/h so i cooled down the car. for around 30 minutes. hit back out the track, the hesitation is gone on my out lap, and 1st lap, then end of 2nd lap it comes back.. 3rd lap same. felt like temperature related. no CEL, no intermitent errors recorded in my ECU as well. all clean oil temp i wasn't paying attention. but it's a valvoline european 5W40 BMW LL01 approved oil. running slightly thicker due to hot temp and tracking. fuel filter ? fuel pump ? intake insufficient ? tuning related ? oil temp related ? traction related ?
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05-31-2023, 01:18 AM	#2
Tommix Private First Class 42 Rep 129 Posts Drives: F82 M4 Join Date: Sep 2013 Location: Finland iTrader: (0)	My guess is that IAT was too high. __________________ 530e xDrive LCI and DCT, MHD Stage 2+ E30, xHP Stage 3, catless DP:s, NGK F8S Previous: F20 M135 AWD AT 445 bhp, E93 335iA 450 bhp, E92 335iA 650 bhp, E60 535DA, E61 535DA, E34 530iA
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05-31-2023, 03:41 PM	#3
Doctor X Second Lieutenant 78 Rep 202 Posts Drives: B58 Join Date: Dec 2022 Location: Los Angeles iTrader: (0)	Run some data logs and see how high your IATs are hitting. It wouldn't be a bad Idea to run some front mount intakes for spirited track days (+induction noise haha)
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12-15-2023, 05:46 PM	#4
Alchemis New Member 5 Rep 29 Posts Drives: Bmw f82 Join Date: Dec 2022 Location: Malaysia iTrader: (0)	Confirmed with tuning issue. The tuner went to track with me and gave me some new maps and the issue went away. It was the way the boost regulates.
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