My BRZ ST* Autocross build

[MarkRacerX]

REPRESENT!!

Congrats, way to go !!!!

Thanks for sharing,

[Getagrip]

Nice run. I wish our courses would allow us to get into a solid third gear.

[xwd]

Can you run E85 in STX? Pretty incredible gains with a re-tune running E85. This is with a catless header and the rest of the intake/exhaust stock, but some previous tuning showed adding the tune plus header didn't make any more power than just the tune.

[-max-]

You can run e85 in STX. But is the stock fuel system up to it.

[xwd]

Yes this is all on the stock fuel system and it has shown to be okay with regards to flow. As far as the system components they should be okay with E85, the other Subarus are.

The turbo car running on E85 ran out of fuel around 320WHP.

[Sccabrz192]

I wouldn't want to run E85 on a still-streetable car which isn't OE flex fuel capable. Pump E85 is wildly inconsistent in it's blend quantity/quality. Most people I know who run E85 in their SP vehicles have a few pumps they always go to and always check the blend to make sure it is proper for their tune. These cars are autocross trailer queens and wont get in a bind stuck in the middle of BFE without proper fuel. At a minimum you will need to be able to switch between multiple maps, and exhaust the one type of fuel in the tank before switching over.

2 of the SP Kappas tried running it last year and in addition to the vehicles not taking to the tune well (they started breaking up around 6200RPM due to lack of fuel flow) and they were both driven to/from events. IMO it seemed like much more trouble than it's worth. We make sufficient power and torque on 100 octane compared to where they were at on the E85.

[xwd]

With FI, you can make way more power on E85 than 100 octane but obviously you need the fueling modifications which is substantial.

I think you would need a couple maps. I wouldn't necessarily want to drive around on E85 all the time, although people have being doing it in WRX/STIs for a long time now.

I used to bring fuel with me to events.

[Guff]

Can't a Pro-EFI or similar setup do on the fly Ethanol percentage readings and do automatic map adjustments depending on how much ethanol is currently in your gas tank? That would certainly reduce much of the hassle created with running ethanol.

Looks pricey though...

[Sccabrz192]

Originally Posted by dwx

With FI, you can make way more power on E85 than 100 octane but obviously you need the fueling modifications which is substantial.

I think you would need a couple maps. I wouldn't necessarily want to drive around on E85 all the time, although people have being doing it in WRX/STIs for a long time now.

I used to bring fuel with me to events.

That statement is assuming combustion chamber temps and knock are your limiting factor to upping the boost. In the Kappa, the stock turbo is very near out of breath at high RPMs with a 100 octane tune. So switching over to E85, assuming you can flow the necessary extra fuel (since ethanol has lower specific energy than gasoline) there isn't much more you are going to get in the useful autocross powerband range, especially since the Kappa is second gear challenged.

Getting back on topic... I'd want to see what he can do about improving the curve up near redline before I entertain an E85 BRZ tune based on that graph. The taper off on the E85 tune above 7200 RPM is pretty significant compared to the 93 tune. I would suspect a 100 oct tune would land somewhere between 93 and E85 tunes with the +7200 RPM characteristics more resembling the 93 octane tune. That would be my choice. Flat power curve near redline rather than peaky power at 7200 with a quick taper off. I understand this is his first revision of this BRZ on E85 so there could be ways around it, but until it goes flat I'd wait.

[Scooby South]

More mild Power mods today...
K&N panel Filter with sound Generator Delete..and a Kartboy Prototype Lightweight Pulley...= better power and noticeable torque gain coming off the corner... ME LIKEY

[Scooby South]

Ok..Quick review of Current ST legal mods implemented so far:
2013 BRZ limited
KW Variant 3 Coilovers with RS camber plates.
17x9 Rota DPT 42 offset
Hankook RS-3 245/40/17
Kartboy Rear Endlinks on Stock Rear Sway Bar
Stock Front Sway Bar
Kartboy Differential Bushings
Kartboy knuckleball
Kartboy Oil Cap
JW2 Muffler Delete turn-down
9lb DEKA battery
K&N Panel filter
Custom Intake tube with Sound Generator Delete
Kartboy LW Crank Pully
P&L Motorsports Stainless Brake lines
Motul Dot 5.1 Fluid

Current weight 2634...fighting weight...with 1/4 tank of gas..


Future:
Titanium catback Exhaust (Weight)
Header with hi-flo Cat
Tune
Sparco/Recaro Light-weight seats

more later...

Bill

[iLuveKetchup]

^ That's a great weight for a full interior car. Nice!!

[Sccabrz192]

Bill, I'd highly suggest forgoing the Titanium cat-back unless someone is going to give you one. The $$ to weight/performance gain just isn't there if you have to go buy one yourself. Buy a small SS muffler, add on a turn down and terminate it under the car

[mrazny]

Originally Posted by Scooby South

Ok..Quick review of Current ST legal mods implemented so far:
2013 BRZ limited
KW Variant 3 Coilovers with RS camber plates.
17x9 Rota DPT 42 offset
Hankook RS-3 245/40/17
Kartboy Rear Endlinks on Stock Rear Sway Bar
Stock Front Sway Bar
Kartboy Differential Bushings
Kartboy knuckleball
Kartboy Oil Cap
JW2 Muffler Delete turn-down
9lb DEKA battery
K&N Panel filter
Custom Intake tube with Sound Generator Delete
Kartboy LW Crank Pully
P&L Motorsports Stainless Brake lines
Motul Dot 5.1 Fluid

Current weight 2634...fighting weight...with 1/4 tank of gas..


Future:
Titanium catback Exhaust (Weight)
Header with hi-flo Cat
Tune
Sparco/Recaro Light-weight seats

more later...

Bill

It wouldn't be a fast comparo, or neccesarily easy, but on paper I'd think that it'd be cheaper to have the catless-header with a Race Cat in the overpipe/joint pipe/downpipe [depending on whose describing it]. I'm sure the header having the cat would get that cat hotter and more efficient than in the overpipe as far as sniffer tests, but OBD based stuff shouldn't be an issue. If I did my Bimmer right for STU, I should've down catless downpipes and race cat midpipes, though that's a turbo powertrain.

From a total knowledge standpoint, that'd be a great delta comparison on dyno...