I think the "if we don't say you can, you can't" rules are a bit lazy and boring.

Oh well...

Someone should give it a shot on a street car then...


So which rule set are you favouring, right now?

Play with a calculator a bit. If you can keep the torque output at high rpm, you get good hp numbers. That chart earlier showed 160tq to the wheels.

HP = TQ x 5252.

228hp = 160 x 7500rpm
248hp = 160 x 8000rpm
273hp = 160 x 9000rpm

I'm sorry Dimman... once I got rolling I just couldn't stop myself.
The reply:

Maybe so but it allows the GCR (General Competition Rules) to be a 700 page document instead of a 7000 page document. I can't imagine how screwed up grassroots racing would be without that little caveat.

NASA, SCCA and even Conference (ICSCC) all sort of approach rules in a similar fashion and many classes are pretty similar and some are even recognized by other clubs. For instance, Improved Touring, is an SCCA class but it was also adopted by ICSCC so I race in ITA in ICSCC because ICSCC is a much bigger, more populated organization than SCCA in the PacNW. I do favor the IT ruleset because it works well in helping racers self police and police each other and it's simple.

I'm also considering the PT NASA class which has a very different formula compared to IT but allows more "creativity" with the build but it seems like a more difficult formula for self policing and policing each other, primarily because there's "math" involved (sort of joking).

IT = You can modify to what's listed in the ruleset.
PT = You can modify at your discretion but each modification represents a certain "point" value and if your total accrued points exceeds a certain number it's bumps you into another class. (like adding mods to a car in Forza. Start with a C-class car, and mod it to a B500 car... similar idea).

Higher on the alphabet is faster the class (PTD is faster than PTE). PTA>PTB>PTC>PTD>PTE and so on and so forth.

Example:
The CRX Si starts of with a base class at the top of PTF and after adding up what's done the car with my ITA setup it fits right at the top of PTE. The FRS might start at the top of PTE and with suspension/brakes/tires end up in PTD, but with some changes to clutch/diff/power mods etc find itself in PTC. Do cams, porting, standalone, BBK, really big tires and end up really high up. You can see how attractive this structure is to someone building their car specifically to a class. Lots of freedom to "maximize".

Everybody wants to go faster and many folks new to road racing think that you have to go faster (aka: go fast bits) to go racing and that's not the case.

Two things that correlate to exponential increase in racing costs in motorsports, as I've come to understand.. (remember, building the car is the cheap part)

1: The more restrictive a class the less expensive and the more open the ruleset of a class (more things "unrestricted") the more it costs to compete in on an exponential growth curve. It could be the difference of spending $10k for a years worth of racing or spending $150k. :D

2: The more popular and competitive a class is, the cost to be competitive grows exponentially, even on restrictive ruleset classes like Spec Miata. The cost to go play up front is pretty cheap, until there's 40 guys that are all serious about running up front.. then the men get separated from the boys and everyone gets separated from their wallets. :D

Put 1 and 2 together and well... there's no finer mechanism for the disposal of money.

:party0030::burnrubber:

I know that was a long post but it does offer some insight into why developing N/A power is important and also making power effectively (low hanging fruit) as keeping the costs down is vastly important.

PT sounds more intellectually challenging (interesting) from a development point, to me at least. The balancing of doing what you can to find speed, but not to the point of getting bumped up to a more challenging class of racing. Interesting.

But I can see people going overboard. 'Just one more mod...', then getting bumped up a class and starting more mods since they are all of a sudden less competitive. Could get expensive so the 'mostly stock' class makes a lot of sense.

Keep us updated.

There is no denying FI power is cheaper. Of course the Twins can also be HP-Monsters, but that is not in the budget of everybody. I'm interested in NA mods for, the strenght of this car is the balance and preciseness. My goal with NA mods is not daily drivability, but track usability, and I don't want turbo or compressor. I'd like to stay at the limited 2.0l, 86x86, as I'm not interested in torque or hp wars, but in maximum output of the engine, satisfaction comes from the fact that there is no improvement possible. FA20 from a conceptual perspective has alot of potential, more than other I4 engines. And I don't think NA rebuild is that expensive, if that is what you are looking for. I could justify the price Autodelta is asking for Alfa Romeo engine rebuilds from the Busso and TS engines. All 2.0l I4 race engines are making 270-280 PS, be it the Alfa Romeo 2.0l TS, BMW 2.0l I4, Mazda MX-5 GT4 etc.

Could somebody who has relation contact Cosworth?

Great post #45 rice classic.

I think Cosworth are announcing something at SEMA?

Considering this boxer is running 86mm square, I would think that pushing the redline up would have limited detriment to reliability. Obviously pushing the rpm's will increase strain on the engine, but I think that the 7300rpm fuel cutoff is VERY conservative.

A k20z3 revs to 8300 rpm reliably(stock) and it has similar specs to the fa20. 86mm square with an 11:1 CR. Those push 9k rpm with ease. I'm not saying that the fa20 is a honda engine, but as a ballpark to compare to I think the k20 is similar.

That 86mm square setup keeps piston speeds low enough to really open up the top end. If you are going full out race car, I would think that upgraded rods and valve springs should be enough to handle a 9k fuel cutoff. You would probably need to upgrade the oil pump as well to support those rpms. But I think that the reason for our low redline is simply that engineers decided that a torquey cam profile suited the platform better and didn't want to sacrifice mid/low torque for a fast top end. As a result, we get power loss above 7k rpm, not physical damage to the engine.

Then again, I'm no engineer.

If its a race engine, get a custom set of pulleys made, and get them massively underdriven.

The accesories are getting far too much drive at high revs.

The Toda kit picks up 10hp just from the fact its underdriven. And they still made it so its streetable.

Do you need power steering? 86 is pretty light. I ripped out the PS out of my ae86 when it was NA. I didn't miss it.

What kind of racing are we talking? There's some nice race/track specced GT86 race cars out there (which you probably know about already but still useful):

TR86 spec race car (New Zealand):
http://the86.co.nz/TR86/

GT86 Cup/VLN race series eligible car (Europe):
http://www.toyota-motorsport.com/mot...p/tmg-gt86-cup

And of course, the TRD Griffon concept:
http://www.speedhunters.com/2013/02/...ned-eight-six/


Power is one thing, and I think you could indeed push some good power numbers N/A if you went balls out (and spent a whole lot of $$$) on the motor. I'm guessing that you'd hit a 'wall' somewhere slightly above 200whp on pump gas though. Thing is, those extra few HP would be relatively expensive and would it be worth the possible reliability hit?

If I were building a GT86 race car I'd choose a class very carefully based on what power output I think I could reliably and consistently maintain and then focus on stuff weight savings, aero, suspension, rubber, final gearing and brake combos to make it quick. Basically, a strategy of winning through consistent quickness as opposed to on the edge power. A strategy focusing on consistency and end of season Championship end results as opposed to being 1st in every single race, etc.

To put it another way, focusing on making the best of what power you DO have reliability could perhaps help to keep your running costs under control as well as your build costs.

Would give you some time to gradually R&D stuff to build up your power levels reliably as well.

Still, class rules could be a killer. Ballast rules killing your lighter weight and then there's those absurdly lightweight, cheap and cheerful Hondas out there to deal with.

Endurance racing could be particularly fun in a well built GT86 race car though - Thunderhill and all that. :)

Only someone who has been racing understands this.

That's why I'm considering selling my 400hp ae86 and buying a rc86 as a track car.

Interesting fact, my ae86 with all the driveline upgraded to support this power has increased the weight to 1050kg. It's fully stripped, with a cage.

My gt86 is 1150kg with only a partial interior strip. I'm confident I can get a rc86 to 1050kg with full glass. Get near 1000kg with plastic windows.

Driveline keep near stock to keep weight down, running costs down, and retain (if not better) oem reliability.

200whp will be very fun in a 1000kg 86. Focus on weight more than power. I'm sure you already no dis.

I appreciate a cage is (relatively) weighty but why doe the VLN 86 weigh so much at 1204kg wet?
http://www.toyota-motorsport.com/mot...s_2013_car.pdf

It's hard for me to thoroughly comment as not all specs are known. But it does seem heavy.

My 86 (Base 86 in NZ) was 1198kg with a quarter tank of gas, so 1180kg. I've then taken out 20kg of interior, swapped a 20kg seat for a 5kg Bride, and have a track pipe, swapped the front brakes for Wilwoods, and use se37k's on the track, (which are basically the same as the stock 16" enkeis) So I'm confident I'm below 1150kg. Taking the rest of the interior out, (remember the other 20kg seat is still in there) Replace battery, flywheel, remove crash beams, window washer bottle, and you're under 1100kgs in my eyes.

I think there is too much focus with these cars that bigger is better. For example, why run 17's or 18's on a track car. Why not 16's? Because of the brakes. Well, there are plenty of cars at the race track that weigh around 1000kg running 15's that brake really well (outbraking me with BBK and semis) Theres also cars that are on the better side of a tonne, running 13's.

If I end up building an 86 race car, I'll be focussing on this area first. Trying to put together a package that works under a 16, or even better a 15 inch wheel. Then you have a MUCH lighter wheel/tyre combo, shorter gearing, arguably better braking, and its significantly lowered your COG without touching suspension geometry.