That's why I also mentioned alignment. Rear camber/toe can play a big factor in straight line traction. Anyways, we've beat the horse to death. Sorry :bellyroll:

My experience is a 2018 BRZ tS with 2600 miles on it. I am running a stock 95 mm pulley on a Harrop installation. The initial plan on the install was to go with a 90 mm pulley. Consultation with Neal at Racer's Line, who did the installation said that it was Zach's from Delicious Tuning, and his opinion that the 2017+ engine's compression ratio was a bit higher than stated by the factory. They came to this conclusion empirically from data that they were both compiling. So we kept with the factory pulley for reliability concerns on the stock engine.

With E85 I will get the traction light illuminating just even pulling out from a stop to a intersecting road in first or second gear. The tail will get a little light and start swerving a little bit. That is not even punching it all that hard. I will occasionally get the light come on and the tail moving a bit on some of the move curvy roads that I drive, but to be honest I could get that with the car totally stock as well. With the added power from the SC, it a greater possibility.

Not expecting changes in handling of the car when putting over a 100+ more horsepower to the wheels is a ludicrous assumption.

Most importantly traction issues can be easily controlled with the position/movement of your foot on the accelerator pedal. Don't want to break traction on the rear? Stop putting so much of your foot into it.

My bigger concern than traction issues with pulleys smaller than 90 mm is that you can start breaking internal engine components on stock engines.

Running E85 and the Harrop, as I have it set up I am happy with the way the car runs. It now has plenty of power and that is not an issue anymore. I am not looking at many other mods. Being that the car is a tS, for the most part I see no need to change much on the suspension. The only mods that I am looking at doing further would be a lightweight battery, CF driveshaft, and maybe an STI tower brace and TRD door shims.

There will ALWAYS be faster, better cars on the road, so unless you have a built McLaren, why bother. Enjoy what you have and realize that your happiness does not have to be derived by being faster than the other guy. The reality is there will always be someone faster.

How are you finding under hood temps with the harrop? Any need for ugly hood vents, or bigger fans? I live about 5 miles from Harrop HQ. Looks like I'm going to have to drop in and get some info.. Has to be the best looking and setup SC out there for these cars and Harrop, in Australia anyway, are renowned for quality in the performance area.

For daily spirited driving and canyon carving you will be fine. All I have is an OEM oil cooler/regulator. An upgrade to a better oil cooleris commonly recommended for more aggressive driving, but I think for auto crossing you coukd be fine, yet it doesn’t hurt to go with an oil cooler to be safe. Tracking/time attack/etc will most definitely require an oil cooler. Vents would depend on ambient temps, boost/hp, event duration, e85 use for a given hp, etc.

What will the car be seeing?

I have done 12 86Drive Challenge track events on the 12-13psi pulley and a stock FA20. Another competitor just switched to 13psi pulley as well. A 3rd competitor is on the stock pulley. All cars running strong within the challenge.

For a stock motor I wouldn't go any higher than this just for longevity of the motor and more so the transmission if doing any high performance driving. For pure street, I wouldn't worry about 13+ psi.

I went to a Jackson Racing dual radiator cooler and experience extremely solid values from IAT sensor, OTS, and CTS. It has been a functional upgrade for driving in both cold and heat in a high desert environment. Everything, from IC to AC radiator bolt to the radiator. There is no thermostatic control of oil flow, so one less failure point too.

Probably little track work but spirited country driving. May not be available in US but I’m pretty sure Harrop make a specific oil cooler for the 86.

They do make one and you can get it here, but it doesn't include a thermostatic oil sandwich plate so it's no good for the street.

Just took a look at the Harrop oil cooler for our car: https://www.harrop.com.au/shop/engin...h=oil%20cooler

Ouch! About the same price and no mention of thermostatic control.

My personal take is that with the JR Radiator, you have faster warmup of oil and more stability of both oil and coolant temperatures. It's at 1.4 bar pressure and larger volume capacity over stock, but doesn't require any modifications or aftermarket fans as it does not intrude into the engine bay.

I'm running the JR Radiator with the Harrop. Both coolant and oil run a little over 190F most of the time. This is notably lower than stock readings. The only time I have seen these values creep up higher is during really hot days, going up steep hills (11% grade) and stuck behind someone going slow, so higher revs and not much forward movement.

Looking to move forward with the Harrop kit in the near-future. Curious as to how many Harrop supercharger owners got a local dynotune? It seems like everyone is doing e-tunes from DT/Moto East.

@johan

Some others have too. Maximizing power on a dyno or taking a risk on a local tuner who may not have a rep to their abilities may not be worth it for most.

The guy who tuned my car doesn't tune anything but MoTeC now. He was so good they hired him out of the market as their lead tuner.

Well Jay, we can’t all be so lucky finding tuners :-p

I can’t remember anyone else who dyno tuned their car, but I can recall someone saying the did a DT then did a dyno tune. I don’t know if they were happy or not. I haven’t heard anyone breaking engines on the dyno or having horror stories in this thread, but that doesn’t mean there aren’t people who had issues.