Pure Motorsport: JDL Turbo BRZ Track Build

[ATL BRZ]

Originally Posted by mission2toilet

Ian, any chance of you going FI? I am leaning toward to KW. Any advise? My goal is 350hp on E85(btw sorry that I came out of no where to ask, this is totally not this topic but your opinion is greatly helpful) thank you.

There's always a chance

I am a fan of the Jackson Racing Rotrex kit over KW for many reasons. JR and CSG did lots and lots of testing on and off track prior to releasing their kit and it shows. The JR kit is a more simple design with less parts overall, and it exclusively offers a plug and play thermostatic oil cooler kit to make it the best solution for a car that will be tracked and street driven through all seasons and climates. I appreciate the minor details in the JR kit like the easy air filter change, the simple bracketry and belt drive, the Mocal thermostatic sandwich plate compatibility, and not having to replace the OEM washer tank to clear the charge piping. Also with the oil cooler kit you get the biggest capacity core available from any Rotrex kit which will provide the best cooling, and it all mounts on a nice bracket which puts both the SC fluid cooler and engine oil cooler cores right next to each other, protected by the intercooler in front.

Based on what I've seen so far with the current JRSC kit, you can expect 300hp/230tq (280whp/220wtq) on E85 with the included pulley, stock fueling and a catless header. With the upcoming, soon to be released JRSC upgrades that are currently finishing up testing you may be able to get the C30-94 to move enough air to get close to your 350hp on E85 goal with a port injector, fuel pump, and clutch upgrade.

I'm well aware that KW offer a C38 upgrade but in my opinion that's too big for the car and tuning out the tip-in knock has proven to be a pain for some of this platform's most experienced tuners. I'm a fan of keeping things simple and reliable. I like the idea of keeping the stock fueling and clutch, maybe even the stock cooling system and running a rock-solid reliable kit that has been tested for thousands of miles to ensure it will perform without any issues. Shit can happen with any kit but the failure/issue rate with the JR kit has remained relatively low and that gives me confidence as a potential buyer.

The KW kit has had it's share of issues including fitment, missing parts and broken belts (ironically since the separate belt system is supposed to be more reliable). There is also this weird situation KW is in with lots of no-shows at the track days out in SoCal where KW should be out testing the kit and proving its worthiness. Perhaps it's because the kit is still not CARB approved but who knows. I'd expect KW/Skunk2 to have a trailer and tow rig to get their car out to WSIR and other 86 Cup events but based on what I've seen they are pretty reclusive.

Either way they are both good kits, I just prefer the one with the simpler design, more compatibility and best track record in development and post-release. Upgrade-ability should not be a concern in your choice as both kits will soon be upgradeable.

If you want to hear this with some more debating mixed in from KW owners and reps, head on over to this thread: http://www.ft86club.com/forums/showthread.php?t=74774

[enivid]

And gmsii is a shady character.

[vutall]

Excellent build thread, reminds me a ton of when I have my EVO X SE.

I have a question for you however. I read through this whole thread and when the comments go to FI startd coming in, I found your answers quite robust and well thought out. There was something that was never mentioned though and I haven't quite figured it out. It's something I see many people in the auto world "forget" exists.

If a turbo generates too much heat, and a SC has too many replacement consumables (plus a bit of heat generation)...

Why not water meth injection? You could see some very significant gains and when done correctly, it runs much cooler.

I'm not sure on how well it plays with E-85 however...

[ATL BRZ]

Originally Posted by vutall

Excellent build thread, reminds me a ton of when I have my EVO X SE.

Thanks!

Originally Posted by vutall

I have a question for you however. I read through this whole thread and when the comments go to FI startd coming in, I found your answers quite robust and well thought out. There was something that was never mentioned though and I haven't quite figured it out. It's something I see many people in the auto world "forget" exists.

If a turbo generates too much heat, and a SC has too many replacement consumables (plus a bit of heat generation)...

Why not water meth injection? You could see some very significant gains and when done correctly, it runs much cooler.

I'm not sure on how well it plays with E-85 however...

Specifically for a track application, depending on the kit design and presence of supplemental cooling modifications, yes, a turbo FA20 can heat soak to the point of noticeable performance degradation and risking the motor. This is most prominent in the front mount turbo kits where a big radiator, vented hood, and lots of heat wrap are needed to control it. The same can be true for twin screw SC's and helical gear-driven centrifugal SC's if you push them hard enough on a track. There is an excellent thread on combating the heat here in the FI subforum: http://www.ft86club.com/forums/showthread.php?t=53580

I'm not sure what you mean when you said SC's have too many replacement consumables, though. The only consumables on a SC I'm aware of are gear oil/traction fluid and the drive belt; both of which are supposed to be consumed in tens of thousands of mile long intervals.

I think that Rotrex SC's are an exceptional option because they have proven to be the best at handling the heat from track abuse. @CSG Mike has measured intake air temperatures lower than stock in SoCal on a Jackson Racing kit. Heat is not an issue on track either, thanks to the Rotrex internal traction drive system which transmits power through friction forces between its rolling elements. The traction fluid momentarily increases viscosity under high surface pressure, enhancing the traction drive performance by securing the optimum friction between rolling elements while cooling and protecting the system. With this you get excellent transient response and the ability to spin the impeller pretty fast- nearly as fast as some turbochargers, and characterized by high adiabatic efficiency and low noise.

[ame]http://youtu.be/eQDbk8CJya0[/ame]



The kit keeps the traction fluid cool with a cooler and reservoir which the SC naturally pumps through it.




What I'm getting at is that with a Rotrex SC specifically, there is no need for WMI when you can just run E85 and get gains through tuning, while also cooling the combustion temperatures and resisting detonation by nature of burning 105 octane ethanol. The intake air temperatures still stay low because the compressor is efficient and the intercooler is able to do its job in all climates and applications. WMI would just be an unnecessary complexity IMO since you'd have to put in a tank, lines, port adapter, and spray/trigger mechanism and tie all that in seamlessly. Think of it as a crutch rather than a true solution to the problem. I've seen WMI setups on twin screws that were deemed necessary because the twin screws heat soak like a mofo on track in warm climates and the goal is to use the water's cooling and octane of the methanol to provide power consistency and prevent detonation due to high cylinder temps. E85 does essentially the same thing on its own and paired up with a SC that doesn't overheat in the first place...

[ATL BRZ]

First set of photos from Road Atlanta October 25/26 with Peachstate PCA.

Photographer: Juha Lievonen

[ATL BRZ]

Second set of photos from Road Atlanta with Peachstate PCA 10/25 and 10/26

[DocWalt]

With your upgraded brakes, how do you find heel-toe? I've noticed that I really have to be careful to not clip the throttle in heavy braking, and I can't seem to roll my foot easily between brake and gas and stay smooth on the brakes.

[ATL BRZ]

Originally Posted by DocWalt

With your upgraded brakes, how do you find heel-toe? I've noticed that I really have to be careful to not clip the throttle in heavy braking, and I can't seem to roll my foot easily between brake and gas and stay smooth on the brakes.

I actually don't heel-toe. I just have quick feet. I'd recommend you get a SRP gas pedal to help out: http://www.srpracing.com/pd-brz-fr-s...pedal-only.cfm

[DocWalt]

Originally Posted by ATL BRZ

I actually don't heel-toe. I just have quick feet. I'd recommend you get a SRP gas pedal to help out: http://www.srpracing.com/pd-brz-fr-s...pedal-only.cfm

Ah, fair enough, lol. I was looking at that pedal, Cusco's and the Camry pedal mod. I'm going to try some things before I resort to spending money, but we'll see. To be honest though my issue isn't so much the gap between pedals, my GTI is just as wide... My issue is that the gas pedal is a touch higher than I'd like.

[vutall]

when you are on the track, before you do a run what do you have your TCS/VSC set at? Do you do the "Pedal Dance" as well?

Also, what would you say your average speed is on your local track and the top speed you have hit?

[CSG Mike]

Originally Posted by DocWalt

With your upgraded brakes, how do you find heel-toe? I've noticed that I really have to be careful to not clip the throttle in heavy braking, and I can't seem to roll my foot easily between brake and gas and stay smooth on the brakes.

Practice makes perfect.

I used to struggle with this, until I sat with a pro driver friend, and witnessed him do a 6 -> 5 -> 4 -> 3 with zero lurching or weight shifting, letting the clutch out in every gear, rapid fire.

I Resolved to master the technique, and focused on that specifically for a while, until I got it down. You can do it too!

[DocWalt]

Originally Posted by CSG Mike

Practice makes perfect.

I used to struggle with this, until I sat with a pro driver friend, and witnessed him do a 6 -> 5 -> 4 -> 3 with zero lurching or weight shifting, letting the clutch out in every gear, rapid fire.

I Resolved to master the technique, and focused on that specifically for a while, until I got it down. You can do it too!

It's not an issue in my GTI and I can crack 'em off smooth in that, the BRZ's gas pedal is a touch too high for me to use the same technique Trying to practice it on the street is just asking for trouble so I'll wait to try if the BRZ ever hits the track.

Any suggestions on technique with the BRZ's pedal layout?

Sorry to thread jack a bit!

[ATL BRZ]

Originally Posted by vutall

when you are on the track, before you do a run what do you have your TCS/VSC set at? Do you do the "Pedal Dance" as well?

I hold down the left button down until both lights come on the dash.




I don't do the pedal dance, although I probably should, but I'm always too busy rushing down to the grid, getting my HANS, harnesses, GoPro, lap timer all ready to go.

I also don't trail brake much so that's probably why I haven't needed the pedal dance. The stability/traction/braking control systems don't ever intervene so I'm good with the button hold for now.

Originally Posted by vutall

Also, what would you say your average speed is on your local track and the top speed you have hit?

Around Road Atlanta when the car is running E85 I average 90mph on a hot lap. Top speed before braking into turn 10 after the long back straight is 125mph, redlining 5th gear.

With pump gas my lap times are consistently about 5 seconds slower and my top speed is around 115.

[vutall]

That is impressive. Both on the car and the driver. Ever thought to try and get sponsored to go race for a team? You seem to have the ability