BRZ vs. Prelude Si vs. S2000. . . Initial Thoughts

[InvalidJohnny5]

AVO proved a simple EL header and tune drastically improved torque and peak whp I'll try to find a dyno sheet. But it went damn near 200rwhp with just the HKS headers.

[regal]

Originally Posted by InvalidJohnny5

AVO proved a simple EL header and tune drastically improved torque and peak whp I'll try to find a dyno sheet. But it went damn near 200rwhp with just the HKS headers.

Yes I've seen that a a thousand other dyno charts posted on this forum. Dynos don't tell the whole story. quarter mile trap speeds tell a lot about performance upgrades (with a competent driver.) Its data that this forum is seriously lacking. One guy with a $5k Votech supercharger trapped 100 mph with a 2" 60ft launch, so I am still skeptical about moddying this car until we start getting real information.

[InvalidJohnny5]

Meh that's true.

[CSG Mike]

Originally Posted by Jawnathin

Not sure I follow berating a BRZ for wear after track use. Track use will inevitably wear out components of a vehicle, and the BRZ nor S2000 are an exception.

IIRC, on an S2000, there was an issue with the front control arms detaching from the frame, oil starvation, rear axles, CVs, and wheel bearings failing, and brake rotors cracking during track use. Maybe other things too, but that's what I remember reading when I was researching them.

I'll address these individually, since I have firsthand experience.

Front upper A-arm: AP1 issue. Spot welded. Seam welded on AP2. Fix: reweld or reinforce.

oil starvation: owner error

rear axles: only if you're making big torque (it's a honda)

CV: result of change in right height (because you dropped the car). Fix: Swap CV cups left/right or get axle spacers.

Wheel bearings: wear and tear items on track cars ONLY (once a year item, if that. Costs $30/bearing).

Brake rotors: Car is over 15 years old in design. Today's tires didn't exist when it was made. It was also released with a 205 front tire. We all run 255 now, in way stickier compounds. Fix: $30 rotors or BBK.

[CSG Mike]

Originally Posted by Jawnathin

Wow, pretty excellent driving by both. Buttonwillow is a fun track, I just wish the surface was a little cleaner.

Normally I'm dismissive of these videos, as its almost always the driver that is the limiting factor here, but both were well driven. Thanks for sharing.

The driver in front is holding up the BRZ; the BRZ's cornering is THAT much faster.

But, to be fair, that's due to a setup error on the S2000 (I don't agree with how that s2k is set up), and the s2k driver's experience.

At the time the video was shot, the lap pace in that video was about 2.5 seconds slower than my hot lap pace with the stock BRZ.

[CSG Mike]

Originally Posted by fatoni

do the brzs handling advantages remain advantages after a decent track suspension/tire is used? i feel like most of the brzs charm comes from it being awesome right out of the box but i have a hard time believing that it has the same headroom as an s2000

At a bolt-on level? yes.

Most suspensions for the BRZ/FRS make the car understeer like a FWD. Understandable, since most people going to this platform come from FWD, and are used to FWD push, and freak out at the slightest amount of rear twitch.

I've thought about it, and virtually everyone who regularly tracks a FRS/BRZ comes from AWD/RWD backgrounds. The FWD guys all do one or two days, scare themselves, and generally don't come back...

[CSG Mike]

Originally Posted by regal

So I think it is fair to compare a stock ap1 to a Twin with a header+tune, question is would it out pull an S2k? Would it match the S2k 0-60 mph? Would it trap 100 mph? Amazes me that such simple questions hasn't been answered yet. A million dynos posted on this forum but so few 1/4 mile and 0-60 times posted.

Nope. Simply nope. It's not posted because bolt-on FR-S/BRZ don't see the gains claimed by the manufacturers/shops trying to make a quick buck.

Think of it this way.

This is a VERY crude way of thinking about it, but the S2k has 17% more RPM, so the FRS/BRZ would need to make 17% more torque, to have equal output at the wheels. Has anyone increased output with the FA20 that much? Nope. It's just not possible.

[CSG Mike]

Originally Posted by DAEMANO

Love this video. The BRZ is doing so much more with so much less. The '86 has a better chassis with better aero and much less tire than that S2k. Give it minor upgrades and that more aggressively tired S2k woulda had nothing on it.

To be fair, I can run faster times than that lead s2k in a less modded s2k.

The video is strictly to showcase the major differences.

[CSG Mike]

Originally Posted by Suberman

Not sure what he means but it is important to be definite and throw some exact numbers in. How he explains the specific torque output of, say a Porsche 911 at around 86 lb ft per litre is an interesting speculation.

It is odd that this misconception about the importance of power to weight is so widespread.

Torque is not a function of displacement other than bigger engines generally produce more torque but it is almost always non-linear and entirely unpredictable except that it is more difficult to extract the same specific torque from a larger engine. The reason for this is the fact that gasoline and air combust at a fairly fixed rate. The smaller the combustion chamber the higher compression and more advanced timing will be achieved before detonation sets in. It is, frankly laughable to imply that a F1 engine develops the same specific torque as a BRZ.

So, specific torque is dependent primarily upon combustion efficiency: which in turn is dependent upon volumetric efficiency and resistance to detonation. Indeed, the only reason to bench test any given engine on a dyno is to measure specific torque. If all you want is more torque (or power if you prefer) regardless of efficiency then of course just fit a bigger engine. That's one of many bone headed ideas that put the American car industry behind the 8 ball. You will note that specific torque and power declined precipitously in particularly American engines during the implementation of emissions regulation. Specific torque improvements have been driven entirely by fuel economy considerations or limited displacement racing formulae.

What's missing from the peak power to weight ratio is the curve. Only torque can explain that. Two cars of the same weight and same power can have radically different 1/4 mile times depending upon specific torque, whether the gearing is optimized for acceleration rather than fuel economy (the two transmissions in the BRZ rather neatly prove that point) and most importantly where in the rpm range that torque is delivered. This works for all forms of intake supply and varies according to the type of fuel used, I.e. flame front speed and octane rating.

If power to weight mattered American muscle cars should have been bog slow.

I concede I have never seen a direct to engine dynamometer in operation but my understanding is that it measures the force required to brake the engine to a constant speed, revealing the net useable torque generated by the engine at that speed. This force is plotted for the useful rpm range of the engine and bhp derived from that. If instead it measures the power consumed by the brake in order to maintain the engine at the desired rpm then that is a distinction without a difference, the object of the exercise is to derive the available force to accelerate anything attached to the engine. Bhp and torque at any given rpm are related by a constant for the simple reason that Watt wanted a constant unit of measurement.

So are you saying they are or are not correlated?

Increase the number of cylinders

[CSG Mike]

Originally Posted by iLuveKetchup

<---- elitist snob

What is the video suppose to prove? All I see is that particular BRZ/driver is keeping up with that s2k. I really want to like the twins, but the reliability, no ice mode braking, & double wishbone suspension of the s2k keeps me from getting one. I don't even mind the lack of power. Waiting for a BRZ STi that is 2500lbs 240hp & double wishbone suspension. I'll keep dreaming.

You really need to drive a car that we've set up. They universally corner faster than S2000s at a bolt-on level.

Lack of horsepower is really what's holding them back, but for under 10k, you can make a DEADLY car.

BRZ/FRS
CSG spec Tein SRC
RPF1 + RS3
Innovate supercharger

Just imagine the possibilities...

[CSG Mike]

holy hell i'm spamming. hahahaha

[DAEMANO]

Originally Posted by CSG Mike

To be fair, I can run faster times than that lead s2k in a less modded s2k.

The video is strictly to showcase the major differences.

but to be even more fair, the S2K was a much more expensive car to start, right? (in 2013 dollars over $12k more than a base FRS). That value is part of what makes the '86 so damn cool. Like you said, put $10k of bolt-ons into an '86 and it will fly.

Originally Posted by CSG Mike

You really need to drive a car that we've set up. They universally corner faster than S2000s at a bolt-on level.

Lack of horsepower is really what's holding them back, but for under 10k, you can make a DEADLY car.

BRZ/FRS
CSG spec Tein SRC
RPF1 + RS3
Innovate supercharger

Just imagine the possibilities...

[CSG Mike]

Originally Posted by DAEMANO

but to be even more fair, the S2K was a much more expensive car (in 2013 dollars) to start, right?

Sure, lets give it a 2013 chassis and engine while we're at it

[DAEMANO]

Originally Posted by CSG Mike

Sure, lets give it a 2013 chassis and engine while we're at it

We could build a time machine for a gazillion dollars or buy an FRS+bolt ons for $35k. Looks like we've both chosen the latter. :happy0180: