Choke with Edlebrock SC on E85 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

gt86yasss · 03-09-2019, 11:30 PM

I had my car remote tuned and it gets a choke occasionally around 3k rpm when accelerating after shifting gear. For instance, shift gear, engine speed drops to 2500 rpm, accelerate smoothly until 3000~3500 rpm, choke, back to normal. I tried to switch to 91 map, still happened. Just wonder if it happened to you guys as well and seeking for a solution.

Specs:
2017 BRZ manual on pure E85
Edlebrock SC
Delicious Tuning Dbox
Openflash Catless header
Greddy Supreme SP catback
No fuel mod

https://drive.google.com/file/d/1jdF...ew?usp=sharing
https://drive.google.com/file/d/1Xqd...ew?usp=sharing
https://drive.google.com/file/d/1D3i...ew?usp=sharing

Kodename47 · 03-10-2019, 06:03 AM

Looks a bit fuelling related to me - goes too lean to make power. MAF appears to spike as well in that region, not sure why though.

tomm.brz · 03-10-2019, 06:25 AM

you really need to change PI injectors if you keep using e85 with that boost
DI opening time is too high over 7ms and you are getting spark just 0.5ms after end of injection. That's very dangerous
i would upgrade fuel pump also just for safety

the spike doesn't seem to happen to MAF voltage, so it must be maf scaling related, like as the tuner bumped up the scaling in that voltage zone

gt86yasss · 03-10-2019, 05:12 PM

Thank you so much for your responses. I'm not a car guy but let me give you guys some more background. The dyno was done approximately 2 weeks after the car was tuned, and during the dyno session the shop owner told me the car was running lean in high rpm, but base on the reading he believed the injectors still have room to play with. I spoke with the tuner and he suspected the AFR reading on the dyno machine was not calibrated right and he also suggested me to get the dbox to smooth out the power curve.
I was suspecting it was fuel related too but my confusion is why it only happened in the 3-4k rpm range. If it was a fuel supply problem shouldn't it be more observable in high rpm? I'm going to do some more logging today and post it.

tomm.brz · 03-10-2019, 05:32 PM

well, 0.5 ms end of DI to spark is totally dangerous, if your tuner is ok with that, i don't know what else to say

Grady · 03-10-2019, 06:03 PM

Get larger injectors and better fuel pump. You can do boost or E85 on stock injectors. Not both.

CSG Mike · 03-11-2019, 03:57 PM

I would talk to your tuner.

gt86yasss · 03-13-2019, 02:18 AM

My tuner is quite responsive and ask me to provide log when it happens, but I wasn't able to duplicate the problem in the past few days. However, I did a 4th gear pull tonight and below is the log, if possible can you guys please enlight me on to read those data and what shows the sign of problem? Much appreciated!
https://drive.google.com/file/d/1lO5...ew?usp=sharing

03-09-2019, 11:30 PM	#1
gt86yasss Member Join Date: Jul 2017 Drives: White 86 Location: Orange County Posts: 40 Thanks: 3 Thanked 3 Times in 3 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Choke with Edlebrock SC on E85 I had my car remote tuned and it gets a choke occasionally around 3k rpm when accelerating after shifting gear. For instance, shift gear, engine speed drops to 2500 rpm, accelerate smoothly until 3000~3500 rpm, choke, back to normal. I tried to switch to 91 map, still happened. Just wonder if it happened to you guys as well and seeking for a solution. Specs: 2017 BRZ manual on pure E85 Edlebrock SC Delicious Tuning Dbox Openflash Catless header Greddy Supreme SP catback No fuel mod https://drive.google.com/file/d/1jdF...ew?usp=sharing https://drive.google.com/file/d/1Xqd...ew?usp=sharing https://drive.google.com/file/d/1D3i...ew?usp=sharing

03-10-2019, 06:03 AM	#2
Kodename47 Senior Member Join Date: Oct 2012 Drives: UK GT86 Location: UK Posts: 3,040 Thanks: 185 Thanked 1,629 Times in 1,112 Posts Mentioned: 155 Post(s) Tagged: 1 Thread(s)	Looks a bit fuelling related to me - goes too lean to make power. MAF appears to spike as well in that region, not sure why though. __________________ .: Stealth 86 :. Abbey Motorsport/K47 Tuned Sprintex 210 Supercharger Kodename 47 DJ: Soundcloud / Instagram / Facebook

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03-10-2019, 06:25 AM	#3
tomm.brz Senior Member Join Date: Jan 2017 Drives: brz 2017 hksv2 Location: italy Posts: 2,196 Thanks: 500 Thanked 1,067 Times in 775 Posts Mentioned: 65 Post(s) Tagged: 0 Thread(s)	you really need to change PI injectors if you keep using e85 with that boost DI opening time is too high over 7ms and you are getting spark just 0.5ms after end of injection. That's very dangerous i would upgrade fuel pump also just for safety the spike doesn't seem to happen to MAF voltage, so it must be maf scaling related, like as the tuner bumped up the scaling in that voltage zone

03-10-2019, 05:12 PM	#4
gt86yasss Member Join Date: Jul 2017 Drives: White 86 Location: Orange County Posts: 40 Thanks: 3 Thanked 3 Times in 3 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Thank you so much for your responses. I'm not a car guy but let me give you guys some more background. The dyno was done approximately 2 weeks after the car was tuned, and during the dyno session the shop owner told me the car was running lean in high rpm, but base on the reading he believed the injectors still have room to play with. I spoke with the tuner and he suspected the AFR reading on the dyno machine was not calibrated right and he also suggested me to get the dbox to smooth out the power curve. I was suspecting it was fuel related too but my confusion is why it only happened in the 3-4k rpm range. If it was a fuel supply problem shouldn't it be more observable in high rpm? I'm going to do some more logging today and post it.

03-10-2019, 05:32 PM	#5
tomm.brz Senior Member Join Date: Jan 2017 Drives: brz 2017 hksv2 Location: italy Posts: 2,196 Thanks: 500 Thanked 1,067 Times in 775 Posts Mentioned: 65 Post(s) Tagged: 0 Thread(s)	well, 0.5 ms end of DI to spark is totally dangerous, if your tuner is ok with that, i don't know what else to say

03-11-2019, 03:57 PM	#7
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,530 Thanks: 8,920 Thanked 14,177 Times in 6,835 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	I would talk to your tuner.

03-13-2019, 02:18 AM	#8
gt86yasss Member Join Date: Jul 2017 Drives: White 86 Location: Orange County Posts: 40 Thanks: 3 Thanked 3 Times in 3 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	My tuner is quite responsive and ask me to provide log when it happens, but I wasn't able to duplicate the problem in the past few days. However, I did a 4th gear pull tonight and below is the log, if possible can you guys please enlight me on to read those data and what shows the sign of problem? Much appreciated! https://drive.google.com/file/d/1lO5...ew?usp=sharing

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