Pure Motorsport: JDL Turbo BRZ Track Build

[Sportsguy83]

Originally Posted by phastafrican

I'd like to see how that works in a 48 minute race at Road Atlanta where you're full throttle for nearly 75% of the lap.

I wasn't srs

[King Tut]

Originally Posted by phastafrican

Hell, even using regular pump gas in the GTI, I had that happen at Roebling. (there's no gas at the track for those that don't know, and the gate is closed when there's a session running). Left to go get gas and something happened on track so the session before the race got ended early and race started 5 minutes early. Got back as the pace car was released. Can all be mitigated, but I like sharing my mistakes if someone learns anything at all from it.

I had a similar thing happen to me at my first race weekend at Roebling with NASA. I made it back during the session before my race after getting some lunch and had to sit there and watch as all the SpecE30s headed to the grid. I had to wait till that session was done then rush across the track and get in my suit and get the car out on track. I think I started 2 laps down, haha. I told myself I would never leave the track for lunch again, and I haven't missed a race start since.

[ATL BRZ]

They need to dig at least a pedestrian tunnel under the front straight at Roebling

[phastafrican]

Originally Posted by King Tut

I told myself I would never leave the track for lunch again, and I haven't missed a race start since.

Words of wisdom to live by. But nice to know I'm not the only one who's screwed up there!

Originally Posted by ATL BRZ

They need to dig at least a pedestrian tunnel under the front straight at Roebling

Actually, a pedestrian overhead bridge between the entry and exit roads would be fairly easy and inexpensive. Plus a great place to take photos/videos of cars on the front straight too.

[DAEMANO]

Originally Posted by ATL BRZ

ESC Controller would be toast assuming the dump batteries lasted even 20 minutes

Methinks you may have missed a few developments over the last couple of months. Since I've been running my AUX charger (second charger to the primary in the controller), I haven't had any heat issues. The recharge load is now spread across the two chargers. This is without extra ducting (because it hasn't been necessary). If needed I have another option for that. Battery recharge rate is nearly double as well. Data coming soon.

[ATL BRZ]

Originally Posted by DAEMANO

Methinks you may have missed a few developments over the last couple of months. Since I've been running my AUX charger (second charger to the primary in the controller), I haven't had any heat issues. The recharge load is now spread across the two chargers. This is without extra ducting (because it hasn't been necessary). If needed I have another option for that. Battery recharge rate is nearly double as well. Data coming soon.

Good news, thanks for the update. I have missed the newest developments past the first few data points that came in from the first round of track testing with the overheating controllers. I like the ESC concept and design but in execution, specifically for a road course application, the boost curve leaves a lot to be desired even if the charger and controller are working fine. I understand that every PSI counts even if its 1psi at redline because its non-parasitic! I'd love to see the TQ250 with a motor that spins the compressor fast enough to make more than a few PSI of boost in the upper rpm range, but that may be hitting load limits down low pretty easily. I hope they figure out how to build ESC boost progressively like a full time SC.

[Xero-Limit]

Interesting discussion...here's what we've seen and why @ATL BRZ has stayed NA for so long.

NA, 200hp, great consistent power. Won't get you around the vette on the straights, but you can have fun on most tracks when properly set up.

Using tires to go faster: works well, expensive lap after lap when buying slicks. Will need a dry sump if you get real slicks. Boxers really suck at this as oil pools in the heads.

So next step is FI. Turbo: heat, stress, heat....unless you get a super efficient garrett 25 series or small EFR, you'll be churning way too much power. 300whp is too much IMO. Find me a semi-prepped 300whp BRZ or FR-S that churns lap after lap at 300whp--and does a whole season. I bet you that race team has much more money than most. Or isn't running anything near the stock engine/trans.

Not just tires, brakes, cooling...but the wear and tear that comes from pushing 300whp with skill on the track. Won't be doing that with stock gears for long, or driveshafts, or stock oiling once you move to slicks.

SC is a better solution, and why the rotrex stuff works well. They make good consistent power, shed heat pretty well, but their area under the curve is actually somewhat limited. This keeps torque down, power is there when you absolutely need it (just wind out that gear a bit longer) and weight gain is minimal. Power is easy to keep to under 225 ft/lbs. Just keep spare belts. Wear is RAPIDLY accelerated with track use due to the time at WOT.

My take on it at least. For every high powered modded street car on track, there's a miata driver the following season

[ATL BRZ]

Originally Posted by moto-mike

For every high powered modded street car on track, there's a miata driver the following season

I've seen this first hand just recently with a previous student of mine who had a monster built-motor, Cobb tuned STI hatchback which ended up blowing the welds clean off the turbo downpipe flange exiting turn 5 at Road Atlanta when we hit full boost after several hot laps.

He just bought a spec-Miata

[gramicci101]

@moto-mike,

So, turbo = too much heat in a confined space, potentially melting wires and belts and cars after long term high rpm usage.

Supercharger = ok if you have to, but track usage tends to wear them down too.

NA is best for track, but we're kind of limited with that. Even if he did a full NA build with ported and polished heads, valve work, lightened and balanced crank, etc..., could he really approach the power levels of a supercharger? And if so, at what monetary cost?

[Xero-Limit]

Originally Posted by gramicci101

@moto-mike,

So, turbo = too much heat in a confined space, potentially melting wires and belts and cars after long term high rpm usage.

Supercharger = ok if you have to, but track usage tends to wear them down too.

NA is best for track, but we're kind of limited with that. Even if he did a full NA build with ported and polished heads, valve work, lightened and balanced crank, etc..., could he really approach the power levels of a supercharger? And if so, at what monetary cost?

None knows as to what the NA limit will be. People are just starting to develop that. What we're seeing now is just the beginning.

The SC doesn't wear the down nearly as much. You just need to understand that belts are wear items and expect to replace them a season or two. A very minor thing when you consider the brake bleeds, tire changes, general maintenance with a track car.

Turbo isn't just heat in a confined space, it is the power output. More power means bigger radiator, oil cooler, venting etc...

[King Tut]

Originally Posted by ATL BRZ

I've seen this first hand just recently with a previous student of mine who had a monster built-motor, Cobb tuned STI hatchback which ended up blowing the welds clean off the turbo downpipe flange exiting turn 5 at Road Atlanta when we hit full boost after several hot laps.

He just bought a spec-Miata

He bought the wrong car then. SpecE30 is where it is at in the Southeast. There will be 40 plus cars at the East Coast Championships in a couple weeks.

[King Tut]

Originally Posted by moto-mike

My take on it at least. For every high powered modded street car on track, there's a miata driver the following season

What if you are already a SpecE30 driver? I want to see someone with a BRZ/FR-S prove the turbo track car doubters wrong.

[ATL BRZ]

Originally Posted by moto-mike

Will need a dry sump if you get real slicks. Boxers really suck at this as oil pools in the heads.

This seems to be a controversial topic for our cars. Some say we have "enough" baffling from the factory.

I am seriously looking into the Racer X baffled oil pan as I'm a safety nut and really want to prevent oil starvation any way I can even if my car isn't pulling over 1G in the corners. I'm actually going to borrow a friends TrackMate for my next event to see where the cornering loads are at.

Mike have you looked into oil accumulators for the FA20?

Phil at Element Tuning has got some great info and an amazing 9k rpm turbo build using an accumulator. Ive been wondering if a plebe like me with a N/A or even a low boost, 7k rpm SC build could benefit from running slicks with an accumulator in tandem with a baffled pan.

Originally Posted by King Tut

I want to see someone with a BRZ/FR-S prove the turbo track car doubters wrong.

See the link above to Phil's build (and watch this video) as it looks to be a serious contender for what you're looking for, although it's a very pricy build.

[King Tut]

Originally Posted by ATL BRZ

See the link above to Phil's build (and watch this video) as it looks to be a serious contender for what you're looking for, although it's a very pricy build.

I have been following Phil and Element Tuning since they first got their FA20Club turbo kit.