Level of prep needed for occasional HPDE use: ND2 vs NC2 vs BRZ

As my search for a California DD/weekend 7/10ths HPDE car continues I am now considering what kind of prep is needed for the various options out there.

Obviously the convertibles need a roll bar, but after that it gets shaky. I know the stock NC2 suspension sucks and all that but I'm more worried about stuff it would need to not blow up or otherwise fail. I am presuming all new fluids (particularly brake fluid) for all three, with performance brake pads at a minimum.

I see statements that the BRZ needs an oil cooler. Anything similar needed for the ND2 or NC2? What else should I be looking at and thinking about?

I had a ND for a while and I never heard of anything needed for a stock one and HPDE use, outside of nice fresh fluids. My understanding was they were pretty good for use in stock form and when you started adding stuff you needed to beef other things up.

Im sure Keith will chime in though and give you actual first hand experience.

Depending on the frequency and severity of use, a trans cooler isn't out of the question for the ND2. It's definitely not a guaranteed failure but that's the fluid that takes the most abuse. But yeah, they don't need a lot of special equipment to survive.

The NC2 will be at least a decade old, so I'd definitely be looking at maintenance items.

Brake pads and fluid on the NC and possibly tires depending on what is currently installed. For 7/10th, going to be able to abuse the heck out of it for quite a while as long as preventative maintenance is kept in check.

A set of upgraded sway bars are a cost effective way to improve the ROLLLLLLL of the stock suspension and a hard dog roll bar seems like the easy button for the vert safety aspect.

I tracked my FR-S for the first time last weekend. Without (GASP!) an oil cooler.  Air temps were in the mid-90's.  I ran 0w-40 oil as I had heard all about the high temps causing low oil pressure with the 0w-20 oil and I don't have an oil pressure gauge.  Anyway, my oil temperature peaked at 294F.  From what I understand modern synthetics are good for well over 300F.  I did five 20 minute sessions.  Didn't use any oil and when I changed it yesterday all seemed fine.  YMMV.

parker said:

I tracked my FR-S for the first time last weekend. Without (GASP!) an oil cooler.  Air temps were in the mid-90's.  I ran 0w-40 oil as I had heard all about the high temps causing low oil pressure with the 0w-20 oil and I don't have an oil pressure gauge.  Anyway, my oil temperature peaked at 294F.  From what I understand modern synthetics are good for well over 300F.  I did five 20 minute sessions.  Didn't use any oil and when I changed it yesterday all seemed fine.  YMMV.

The issue isn't oil breaking down though.. The issue is that viscosity changes with temperatures. As oils warm up dynamic viscosity decreases which means the oil may become too "thin" to protect and lubricate parts such as bearings. I'd highly recommend an oil cooler if you're running temps over 260F in the BRZ/FRS. 

In reply to parker :

The oils may be good for over 300F but the bearing materials start to bubble and flake at around that temperature.

Also to be noted is that a lot of heat in the oil is generated in the rod and main bearings, and the reason why we have pressure feed is not to force oil in to wedge the surfaces apart, but to flush oil through to cool the bearings.  Point is, if the oil is 294F, the bearing surfaces are probably a lot hotter than that.

BRZ might need a couple of spare engines - OK, I'm a bit annoyed at mine for blowing up very quickly, so take this with a pinch of salt.

Oil cooler is pretty much a definite need on a Frisbie, even when running top level synthetic oils. Not quite at the same level, but close are an oil pan baffle and an unpgraded oil pickup - supposedly the stock oil pickup is a restriction that causes issues and can contribute to the engine going bang.

Stock radiator is supposed to be good enough at least until you go FI as they're supposedly very efficient.

Outside of CA I would add a header and overpipe to the list, but ideally you want a tune with the header and that might cause CA smog issues.

Compared to a Miata, there is hardly any adjustment in the Toyobaru suspension, although the aftermarket has you covered there. There isn't much camber stock, so at least some camber bolts in the front and maybe adjustable lower arms in the rear help.

Like with the Miata, there is a lot of cheap E36 M3 around when it comes to suspension,  but you can get good stuff as well. I run Konis on stock springs and think that the car would benefit from more sway bar.  I don't think the ride needs firming up if the car is not exclusively a track weapon - from memory the ride on my ND1 was more comfortable than on the BRZ.

In reply to goingnowherefast :

There's a line of thought that thinner is better because it flushes more oil through the system at a given amount of pressure, as long as the oil pump is keeping up. You've got to be running good tolerances on the bearings, though, old timey .003" clearance isn't going to like 0W20 too much.

I have "heard" that NASCAR runs thin oil, at pressures as low as 20psi, but LOTS of volume...

Radiator is fine with a stock engine.  Water temp never exceeded 200F.  Suspension is fine for fun use.  At this point I'll take my chances with the oil.  If I was running FI then yes I'd want a cooler.  With a stock engine I'm not convinced.  Hell I can hit 250F oil temps on the highway and I have 103,000 miles on the thing.  I never took oil temps on my Cobalt SS turbo but it would hit 250F water temps on track.  I sold it with 250,000 miles on it and it didn't use any oil.

In reply to parker :

Some of this depends on where you are - the OP is looking for something to track in CA, and some tracks there (like Thunderhill) can get stupidly hot in summer. BTDT.

I'm in central Texas.  This year has been uncommonly cool with highs only in the mid 90's.  Typical highs are low 100's from June to September.

https://www.nedautoparts.com/products/ned-oil-cooler-kit-factory-oem-subaru-brz

Suffice to say, the factory Subaru oil cooler retrofit kit that's beloved by BRZ guys is cheap and easy enough to install that I would just do it for peace of mind if I end up with a BRZ.

I don't think I've ever seen or heard of a catastrophic engine failure of a non-boosted Miata at the track.  I've seen an awful lot of stock Miatas of all generations out there, and many of them doing way more than 7/10ths.  Spec Miatas are a great test case because additional coolers are prohibited and they do a lot of their racing bumper to bumper with little airflow through the radiator; even with those, engine failures are pretty rare.  Maybe not representive of NC's or ND's, but even in Spec MX-5 or the newer MX-5 Cup cars I don't recall ever hearing about an engine failure.

Catastrophic failures do happen to NCs at least. Maybe not "parts all over the track" catastrophic, but major rod knock. Usually the reaction of the owner is "yay, now I get to do a 2.5!" :) There were also a rash of failures on...2007s? back in the early days before they went to forged internals. NAs and NBs can also lose engines but they're getting a little old so it's hard to identify a common cause.

I don't know about failures in the pro series but they do happen on track days.

For an NC consider an aluminum coolant expansion tank.  The stock plastic ones tend to fail with age.

Decent pads and a fluid change/bleed should take care of the brakes.

We had Konis, FM springs and Progess sways on our NC3, and it was a really nice street/ mild HPDE setup.  Don't forget a good alignment.

You'll need a fender roll with 17x9s and 245s.

I finished my last session this past Wednesday evening in my friend's BRZ and I was really impressed doing about 7-9/10 (I backed off as they weren't my tires but put in a few hot laps and then brought the pace down). His car is pretty much stock at this point with 75,000 km on it, just some aftermarket 17 x 8 wheels with 225 RS4's on it with the very affordable (I won't call them cheap because they work well) powerstop track day pads available from rock auto (my experience with these is they'll handle the track and autocross duty well but the dust might be a bit much for you on the street).

The car was planted everywhere on a bumpy former airstrip with great brakes and just enough power to be interesting, even the tire temps with a stock alignment weren't too bad (perfect in the back, not quite as good up front). I'd do an oil cooler for piece of mind and go have fun, for occasional fun like this or an autocross you don't need to spend much beyond what comes stock (less than a roll bar for a Miata). If you want a roof this is the way to go, just find a nice stock car that has been taken care of to start with.

In reply to ShinnyGroove (Forum Supporter) :

I wonder, too, if the spec tires limit how far the oil pan baffling, or lack thereof, gets stressed.  Vintage racers on modern tires began running into this almost as soon as vintage racing became a thing - they worked fine on 50s/60s bias plies, but newer, grippier rubber made new limitations apparent.

Pete. (l33t FS) said:

In reply to ShinnyGroove (Forum Supporter) :

I wonder, too, if the spec tires limit how far the oil pan baffling, or lack thereof, gets stressed.  Vintage racers on modern tires began running into this almost as soon as vintage racing became a thing - they worked fine on 50s/60s bias plies, but newer, grippier rubber made new limitations apparent.

The Hoosier SM spec tire is pretty darned sticky compared to a typical 200tw track day tire. I don't think they're quite as fast an an R7 but they're not far off. 

In reply to ShinnyGroove (Forum Supporter) :

So they're not running on RA1 "grippy enough to be fun but you might get a full season out of them" tires anymore? 

Pete. (l33t FS) said:

So they're not running on RA1 "grippy enough to be fun but you might get a full season out of them" tires anymore? 

IIRC NASA spec miatas run Toyos while SCCA has both a Toyo and a Hoosier version of the class (or maybe I've got that backwards).  The dry weather Toyos are RRs, I believe the RA1s are only used as rain tires now.

I had always read that the SM7 was just an R7 with different sidewall markings that was only available in the spec miata size (and was thus discounted).  Never used one though.

Pete. (l33t FS) said:

In reply to ShinnyGroove (Forum Supporter) :

I wonder, too, if the spec tires limit how far the oil pan baffling, or lack thereof, gets stressed.  Vintage racers on modern tires began running into this almost as soon as vintage racing became a thing - they worked fine on 50s/60s bias plies, but newer, grippier rubber made new limitations apparent.

Worked fine is a bit bold.  Periodic engine tear downs were common because oil pressure is dropping. 
     They'd look at the oil pressure gauge  on the straight and it would be right up there. But they never watched it under heavy braking going into corners. ( little busy ). 
     Oil slosh would fill up the timing chain area and be away from the oil pickup.  Run without oil even a few revolutions and bearings wear quickly.

The oil is hot not because you're going fast. The oil is hot because the bearings don't have oil under hard braking.  ( because you're going fast) 

 Go ahead buy the accusumps, baffles oil pans, suplimental pressurized oil,  etc. I know I did. 
     In 1953 testing their new disk Brakes the factory racing team discovered the problem.  Those racing tires were designed to last 24 hours+ at racing speed. The oil sump held 22 quarts, plus filter and oil cooler. fully baffled. Etc. the only solution that lasted was a dry sump system. Since 1954 every Jaguar race car has used a dry sump system.