Thoughts on mixing your own race fuel. - Subaru Impreza WRX STI Forums: IWSTI.com
STI Forum
Join
Start New Thread Create Account Advertise FAQ Members List Contact
Thoughts on mixing your own race fuel.
Thoughts on mixing your own race fuel.
Go Back   STI Forums > > > Thoughts on mixing your own race fuel.
Reply
 
Thread Tools
Old 07-15-17, 04:27 AM   #1
yebokmj
Becoming A Contributor
Feedback Score: 0 reviews
 
Fav Mod: Coming Soon
My Threads
Posts: 23
My Subaru Parts for sale

Join Date: Mar 2012
yebokmj is an unknown quantity at this point
Default Thoughts on mixing your own race fuel.

So I just got my setup tuned. 416 whp and 373 tq on 93 on a Mustang Dyno at BrenTuning. They also did a more conservative map for track 373 whp 358 tq. So I went and did a Track Night right after and it was pulling timing like crazy on the conservative map so they told me to add a few gallons of race fuel under track conditions . Next run problem solved. Now Thompson has fuel on site but some of the venues do not. I am thinking of either bringing some with from some place or making my own and wanted some input. I've done some internet reading on making your own but didn't find much directly relating to Subaru.
Note: catted down pipe.
yebokmj is online now  
Likes 0 Dislikes 0
 
Reply With Quote
Sponsored Links
Advertisement
 
Old 07-15-17, 04:43 AM   #2
Cake Eater
Advanced Contributor Level 4
Feedback Score: 0 reviews
 
Car: 15 STI
Fav Mod: All of them
My Threads
Posts: 420
My Subaru Parts for sale

Join Date: May 2016
Location: Sydney, Australia
Cake Eater will become famous soon enough
Default Re: Thoughts on mixing your own race fuel.

Are you sure about the fuel you put in, it wouldnt be the first time a station has sold lower octane fuel out of the higher octane pump.

If the fuel was good, adding extra octane is a bandaid fix at best, maybe even the chance of a lunched motor.

Next step would be looking at your tune.
Cake Eater is offline  
Likes 1 Dislikes 0
 
Reply With Quote
Old 07-15-17, 06:06 AM   #3
Jay11STI
Advanced Mastery Level I
Feedback Score: 2 reviews
 
Car: 2011 SWP STi Sedan
Fav Mod: EWG & The Look On Your Face
My Subaru Parts for sale

Join Date: May 2011
Location: North Jersey
Jay11STI will become famous soon enoughJay11STI will become famous soon enough
Default Re: Thoughts on mixing your own race fuel.

How was your DAM during your track event? Did it fall below 1? I agree with Cake Eater above. Its possible you got some crappy fuel. Either it was contaminated or could have just been lower octane fuel. If this continues to happen often after you have changed your fuels, then it might be time to look into this deeper.

I dont really know much about making your own race fuel using additives/octane booster and stuff like that. I honestly wouldn't bother with that. If your going for race fuels, Sunoco does sell canned unleaded race fuel. 94-104oct unleaded which will be fine for cats and oxygen sensors. Im sure VP does something similar. Be forewarned, its expensive, roughly $10/gal. Im not sure where your located but some gas stations may even have 100oct at the pump but im sure quality may be questionable along with price lol.

Sunoco Race Fuels.
http://www.sunocoracefuels.com/fuels
Jay11STI is offline  
Likes 0 Dislikes 0
 
Reply With Quote
Sponsored Links
Advertisement
 
Old 07-15-17, 12:54 PM   #4
yebokmj
Becoming A Contributor
Feedback Score: 0 reviews
 
Fav Mod: Coming Soon
My Threads
Posts: 23
My Subaru Parts for sale

Join Date: Mar 2012
yebokmj is an unknown quantity at this point
Default Re: Thoughts on mixing your own race fuel.

I usually fill up at the same Shell Station every time. Because I picked up my car from BrenTuning and went right to the track, I stopped at an unknown Shell station I filled up with 1/2 of a tank of 93 there. They said on the dyno my car was rock solid no timing issues even with 88 degrees and 95% humidity. So my DAM went to .93 after a couple laps then .832 I think then eventualy the last few laps .32. After talking to them I added 3 gallons of 98 at $10.50 to the 3/4 tank and ran with the DAM staying at 1. I logged everything and sent them to BrenTuning.

Now why would race fuel be a band-aid if the car runs great on the street? On a road course for 20-30 minutes it's seeing extreme temperatures so it seems normal it would need more overhead. If it requires the race mix on the street then it would seem that the tune is off, though I have yet to really run it on the street. I drove home from the event and just to and from work since and I'm still on the mixed tank.
yebokmj is online now  
Likes 0 Dislikes 0
 
Reply With Quote
Old 07-15-17, 02:53 PM   #5
Cake Eater
Advanced Contributor Level 4
Feedback Score: 0 reviews
 
Car: 15 STI
Fav Mod: All of them
My Threads
Posts: 420
My Subaru Parts for sale

Join Date: May 2016
Location: Sydney, Australia
Cake Eater will become famous soon enough
Default Re: Thoughts on mixing your own race fuel.

Because, by rights, if the tune and fuel quality/octane which it is tuned for, runs well on the street it should run well at the track.

If it happens again take a fuel sample and get it tested.

I have never had a car that required an octane booster for track use when the car had a tank of fuel with the same RON it was tuned for.

I have though, picked up bad fuel, when I do I drain the tank.

I only fill up at CALTEX now with their Vortex premium 98 RON, I have found this product varies the least.

If it's not bad fuel, what else could cause these issues you have?

Overheating? To much timing? Injectors maxing out? Fuel pump? Going past the efficient max PSI on your turbo?

You stated it happened on the "low boost" setting, I would hate to think what your "high boost" setting would be doing under load.

I would have the car put back on and see what the issue or issues are, fault finding to diagnose and fix a know issue is always better than trying to bandaid something.

Finally, what are your specs, fueling, internals, bolt ons, low/high psi, cooling.

Last edited by Cake Eater; 07-15-17 at 02:58 PM.
Cake Eater is offline  
Likes 0 Dislikes 0
 
Reply With Quote
Old 07-15-17, 02:54 PM   #6
mheyman
Silver Member
Feedback Score: 4 reviews
 
Fav Mod: Nomal wear & tear
My Subaru Parts for sale

Join Date: Feb 2012
Location: SJ USA
mheyman is just really nicemheyman is just really nicemheyman is just really nicemheyman is just really nice
Default Re: Thoughts on mixing your own race fuel.

if you tuned for 93, then it should run on 93 or the tune isn't right.
But there is always the question about whether there was 93 in the tank at the time.
__________________
If someone's description of a mod sounds to good to be true, it probably is !!!

If you think you should have lower r's at cruise you're in the wrong car

I become a more loyal IAG customer every time I drive my STI
mheyman is offline  
Likes 0 Dislikes 0
 
Reply With Quote
Old 07-16-17, 10:55 AM   #7
Jay11STI
Advanced Mastery Level I
Feedback Score: 2 reviews
 
Car: 2011 SWP STi Sedan
Fav Mod: EWG & The Look On Your Face
My Subaru Parts for sale

Join Date: May 2011
Location: North Jersey
Jay11STI will become famous soon enoughJay11STI will become famous soon enough
Default Re: Thoughts on mixing your own race fuel.

Quote:
Originally Posted by yebokmj View Post
I usually fill up at the same Shell Station every time. Because I picked up my car from BrenTuning and went right to the track, I stopped at an unknown Shell station I filled up with 1/2 of a tank of 93 there. They said on the dyno my car was rock solid no timing issues even with 88 degrees and 95% humidity. So my DAM went to .93 after a couple laps then .832 I think then eventualy the last few laps .32. After talking to them I added 3 gallons of 98 at $10.50 to the 3/4 tank and ran with the DAM staying at 1. I logged everything and sent them to BrenTuning.

Now why would race fuel be a band-aid if the car runs great on the street? On a road course for 20-30 minutes it's seeing extreme temperatures so it seems normal it would need more overhead. If it requires the race mix on the street then it would seem that the tune is off, though I have yet to really run it on the street. I drove home from the event and just to and from work since and I'm still on the mixed tank.
I dont have any track experience myself so maybe take this with some salt. I believe the 93oct tune you have on the car should run perfectly on the street and on the track. You cant say it runs perfectly on the street just yet because you currently have mixed fuels. You just got this car tuned, you should give it some time before you decided how good your tune is. I think its kinda ballsy taking the car off to the track right after it got tuned.

For all we know, the car could have been pulling timing for multiple reasons. Track events are tough on our cars especially on hot summer days. If you continue to suspect something after you have drained your current tank, i would suggest getting a fuel sample and checking for contamination.

Its simple, disconnect a main fuel line, turn the key/try starting it and let it pour into a clear glass bottle. Snapple bottles work good for me, just make sure you wash them out completely. Close up the bottle and let it sit somewhere for like 10-20mins. If its contaminated you should be able to see stuff floating around and even settle at the bottom. If theres water in the fuel, you should be able to see it separate and see a visibly noticeable color difference between the fuel and water. After the water has separated from the fuel, it will settle at the bottom.
Jay11STI is offline  
Likes 0 Dislikes 0
 
Reply With Quote
Old 07-17-17, 07:53 AM   #8
yebokmj
Becoming A Contributor
Feedback Score: 0 reviews
 
Fav Mod: Coming Soon
My Threads
Posts: 23
My Subaru Parts for sale

Join Date: Mar 2012
yebokmj is an unknown quantity at this point
Default Re: Thoughts on mixing your own race fuel.

Here is my current setup:
MY08 STI
Killer B Holly Header w/V-band up-pipe DEI Titanium Wrapped
Grimmspeed Catted Limited downpipe
Grimmspeed Turbo Heat Shield
Prosport T3 Titanium Turbo Heat Shield Blanket
Cobb Catback exhaust
IAG TGV deletes w/phenolic spacers
KSTech air injection deletes
ETS TMIC
DW 65C Fuel pump
Cobb Fuel Pressure Regulator Kit
Iag V2 fuel rails run parallel
Grimmspeed 3-Port boost solenoid
Perrin Turbo 2.4 inlet
Grimmspeed Cold air intake
IAG Stage 2 Tuff short block
ARP head studs
OEM Engine Gasket kit
ID 1000cc injectors
Group N motor Mounts
Circuit Motorsports Clutch Master Cylinder Brace and pitch stop mount
Killer B oil pickup and Baffle
Factory water pump
Gates Racing Timing Belt Kit
Blouch Dominator 1.5XT-R 8cm
ACT clutch kit Heavy w/factory flywheel.
IAG Street AOS
Koyo Aluminum Racing Radiator
Motul 300v 5-40w

My gas light just came on so I'm going to run it low and refuel from my regular station. Unfortunately it's impossible/really bad idea to duplicate track driving one street so I won't truly know anything till my next event. I have yet to hear back from the tuner on my logs.
yebokmj is online now  
Likes 0 Dislikes 0
 
Reply With Quote
Old 07-17-17, 12:54 PM   #9
TimM
Becoming A Master Contributor
Feedback Score: 0 reviews
 
Car: 2004 WRX STI
My Threads
Posts: 635
My Subaru Parts for sale

Join Date: Jul 2003
Location: Florida
TimM will become famous soon enough
Default Re: Thoughts on mixing your own race fuel.

I'd disagree with most on here.

Circuit driving is far different than street driving. Heat is the issue. Your car will never see the heat load on the street that it will see on a road course. Brakes, power steering, engine included.

I never exceed 140 degrees intercooler temps on the street...at Daytona, I was hitting 198 degrees! Coolant starts to go up, etc. My car could be overbuilt to deal with the heat, but I have not done so...I'm convinced a top-mounted intercooler will saturate on a track.

Why not add high octane fuel to the mix. If its available-I'd do it in a heart beat to avoid any 'issues.' Daytona was $450 entry fee...80 bucks in 100 unleaded fuel is insurance.
__________________
153 MPH STI
Autobahn!
Stage II: 262 WHP / 270 WTQ / 12.84 @ 105.3 MPH
Stage III: 327 WHP / 12.73 @ 106 MPH
Stage IV: 412 WHP / 367 WTQ / 12.28 @ 112 MPH
TimM is offline  
Likes 0 Dislikes 0
 
Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


New To Site? Need Help? More

All times are GMT -8. The time now is 05:24 PM.


Powered by vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Designed & Powered by Domain Architect