JRSC and octane at the track - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

gshopper · 02-13-2021, 03:58 PM

(this is crossposted to the forced induction forum, so sorry about the redundancy)

I have a 2019 BRZ which has been the track a few times (JR oil cooler, camber bolts, brakes and tires...otherwise stock). While I love the way the car handles, I wish it had a few more horsepower; I think around 250 would probably be the sweet spot for me. I don't need to be the fastest, but there are a lot of fast cars in my group, and it would be good to keep up with the pack. I do mostly HPDE's and a few days of open track. No racing, but I usually drive in the advanced groups.

I am thinking of getting a Jackson Racing supercharger. The instructions "REQUIRE a minimum of 50% 100 octane fuel" at the track. 75 to 100% 100 octane is recommended.

Some of the tracks I would be going to may not have 100 octane. Also, while I recognize that going to the track is not cheap, when I can get it, it is over three times the price of 93 octane.

Can a JRSC run 93 a the track? I don't need crazy horsepower, and I would be happy to sacrifice some power for a 93 octane track tune, if one exists.

What is everybody doing?

Thanks.

Glenn

rice_classic · 02-13-2021, 04:24 PM

Do you still have your catalytic converters? If not, one option is to use Boostane to cost effectively raise your octane to 100 at the track.

Alternatively, buy some gas cans and purchase your 100octane before going to the track and take your track fuel with you.

gshopper · 02-13-2021, 04:26 PM

Still got the cats... but

"Jackson Racing supercharger systems require Premium grade (91 Octane or greater) gasoline, as does a stock FR-S/86/BRZ. Fuel quality is very important with a high performance application, so remember to only use a “Top Tier” gasoline. Do NOT use Octane Boosters in your fuel system. Octane Boosters will damage your spark plugs and your oxygen sensors when mixed incorrectly."

quote from JR installation manual

Purist · 02-13-2021, 04:32 PM

E85?

Sent from my SM-G973F using Tapatalk

gshopper · 02-13-2021, 06:53 PM

e85? Not really interested. Can’t get it where I am.
Need to focus on 93 octane gas.

ML · 02-15-2021, 01:38 PM

I have never ran more than 93 with the 12-10psi pulley, and have not had any knock issues. the base pulley should be even safer.

gshopper · 02-15-2021, 04:13 PM

ML,
Is that for the street or track?

My car is my daily, but it would see track duty a few times a year.

ninjan00dles · 02-15-2021, 04:48 PM

Get a custom tune from a reputable shop and tell them to build you a conservative tune for track use

ML · 02-15-2021, 06:08 PM

Quote:

Originally Posted by gshopper

ML,
Is that for the street or track?

My car is my daily, but it would see track duty a few times a year.

Track use only, but like ninjanoodles said you should get a good tune to be safe.

CSG Mike · 02-15-2021, 06:48 PM

The higher octane is safety margin. If you choose to roll the dice, you can do so, and many do successfully, but in the case of an engine failure due to knock/detonation, know that higher octane could have prevented that.

Race fuel, Race pads, Race maintence, makes sense, for a car being driven at a Race track.

DarkSunrise · 02-15-2021, 07:03 PM

The easiest way to tell is to datalog at the track and see how much knock you're getting on 93, and figure out how much knock you're comfortable with.

CSG Mike · 02-15-2021, 08:28 PM

I'm not comfortable with any knock at all!

Remember, track driving will load the intercooler far more than street driving, which means higher intake temps, which means higher risk of knock/predet. Higher octane fuel means higher knock resistance.

It has nothing to do with the tune, and everything to do with the driving conditions.

02-13-2021, 03:58 PM	#1
gshopper Member Join Date: Sep 2018 Drives: 2003 330i, 2019 BRZ (blue, with PP) Location: Philadelphia Posts: 40 Thanks: 0 Thanked 8 Times in 6 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	JRSC and octane at the track (this is crossposted to the forced induction forum, so sorry about the redundancy) I have a 2019 BRZ which has been the track a few times (JR oil cooler, camber bolts, brakes and tires...otherwise stock). While I love the way the car handles, I wish it had a few more horsepower; I think around 250 would probably be the sweet spot for me. I don't need to be the fastest, but there are a lot of fast cars in my group, and it would be good to keep up with the pack. I do mostly HPDE's and a few days of open track. No racing, but I usually drive in the advanced groups. I am thinking of getting a Jackson Racing supercharger. The instructions "REQUIRE a minimum of 50% 100 octane fuel" at the track. 75 to 100% 100 octane is recommended. Some of the tracks I would be going to may not have 100 octane. Also, while I recognize that going to the track is not cheap, when I can get it, it is over three times the price of 93 octane. Can a JRSC run 93 a the track? I don't need crazy horsepower, and I would be happy to sacrifice some power for a 93 octane track tune, if one exists. What is everybody doing? Thanks. Glenn

02-13-2021, 04:24 PM	#2
rice_classic Senior Member Join Date: Jun 2012 Drives: Nevermorange FRS Location: Seattle, WA Posts: 4,160 Thanks: 755 Thanked 4,200 Times in 1,803 Posts Mentioned: 77 Post(s) Tagged: 1 Thread(s)	Do you still have your catalytic converters? If not, one option is to use Boostane to cost effectively raise your octane to 100 at the track. Alternatively, buy some gas cans and purchase your 100octane before going to the track and take your track fuel with you. __________________ SCCA T4 - FRS

02-13-2021, 04:32 PM	#4
Purist Senior Member Join Date: May 2017 Drives: Subaru BRZ Location: Australia Posts: 349 Thanks: 125 Thanked 261 Times in 145 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	E85? Sent from my SM-G973F using Tapatalk __________________ Less More

02-15-2021, 07:03 PM	#11
DarkSunrise Senior Member Join Date: Apr 2012 Drives: 22 BRZ (Previously 13 FR-S) Location: USA Posts: 5,794 Thanks: 2,164 Thanked 4,242 Times in 2,220 Posts Mentioned: 48 Post(s) Tagged: 2 Thread(s)	The easiest way to tell is to datalog at the track and see how much knock you're getting on 93, and figure out how much knock you're comfortable with. __________________ "Never run out of real estate, traction, and ideas at the same time." 2022 BRZ Build 2013 FR-S Build

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02-13-2021, 04:26 PM	#3
gshopper Member Join Date: Sep 2018 Drives: 2003 330i, 2019 BRZ (blue, with PP) Location: Philadelphia Posts: 40 Thanks: 0 Thanked 8 Times in 6 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Still got the cats... but "Jackson Racing supercharger systems require Premium grade (91 Octane or greater) gasoline, as does a stock FR-S/86/BRZ. Fuel quality is very important with a high performance application, so remember to only use a “Top Tier” gasoline. Do NOT use Octane Boosters in your fuel system. Octane Boosters will damage your spark plugs and your oxygen sensors when mixed incorrectly." quote from JR installation manual

02-13-2021, 06:53 PM	#5
gshopper Member Join Date: Sep 2018 Drives: 2003 330i, 2019 BRZ (blue, with PP) Location: Philadelphia Posts: 40 Thanks: 0 Thanked 8 Times in 6 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	e85? Not really interested. Can’t get it where I am. Need to focus on 93 octane gas.

02-15-2021, 04:13 PM	#7
gshopper Member Join Date: Sep 2018 Drives: 2003 330i, 2019 BRZ (blue, with PP) Location: Philadelphia Posts: 40 Thanks: 0 Thanked 8 Times in 6 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	ML, Is that for the street or track? My car is my daily, but it would see track duty a few times a year.

02-15-2021, 04:48 PM	#8
ninjan00dles Member Join Date: Oct 2020 Drives: 2015 FRS Location: Bay Area California Posts: 91 Thanks: 48 Thanked 67 Times in 35 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Get a custom tune from a reputable shop and tell them to build you a conservative tune for track use

02-15-2021, 06:48 PM	#10
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,530 Thanks: 8,918 Thanked 14,175 Times in 6,834 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	The higher octane is safety margin. If you choose to roll the dice, you can do so, and many do successfully, but in the case of an engine failure due to knock/detonation, know that higher octane could have prevented that. Race fuel, Race pads, Race maintence, makes sense, for a car being driven at a Race track.

02-15-2021, 08:28 PM	#12
CSG Mike Join Date: Jul 2012 Drives: S2000 CR Location: Orange County Posts: 14,530 Thanks: 8,918 Thanked 14,175 Times in 6,834 Posts Mentioned: 966 Post(s) Tagged: 14 Thread(s)	I'm not comfortable with any knock at all! Remember, track driving will load the intercooler far more than street driving, which means higher intake temps, which means higher risk of knock/predet. Higher octane fuel means higher knock resistance. It has nothing to do with the tune, and everything to do with the driving conditions.

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