johnc

If your build goal is ultimate horsepower then yes, I agree that boost is the way to go. But there are many, many reasons to not build a boosted engine especially if you're building a competition engine that has to meet a set of rules. I think that's where the disconnect is in this thread. On a boosted engine the little grooves probably don't matter one way or another. You can always turn up the boost. On a NA engine the grooves kill compression and quench which is critical to getting power.

I ran Outlaw 2800s on my racing 240Z and won NASA's OTC Unlimited 3 two years in a row. Then I sold the complete brake setup to another 240Z racer who went on to win VARA's CP3 championship with the same brake setup. Lighter then the Wilwoods especially with 11.5 x .81" vented Coleman front rotors and 11" solid rear Brembo rotors.

Search the Suspension forums. Lots and lots of information there from dozens of guys who road race their cars.

Great! That's a good time for a FWD Maxima. What was its times or mph before you did the headwork?

All of that data is publicly available and an aggregator just needs to match things up. Everyone that has a web site can use any number of tools to monitor traffic. Those tools don't produce demographic (gender, income, status) data but that can be inferred using IP addresses. None of this is new or evil, you guys are just becoming aware of it. Google probably also collects data about their ad serving and then makes that available to aggregators.

Spares! You are planning on keeping an extra set of pads and rotors in your spares box right? Also keep brake fluid, bleeder bottles, bleeding wrenches, bleeder screws, and two complete caliper rebuild and pad hardware sets for each type of caliper you have.

I'm not bashing you. I'm just asking the advocates of combustion chamber grooves to do a test. Since you claim that this works for you, please let me know: 1. What were you're 1/4 mile times on either of your engines (Maxima, Camaro) immediately before you cut the grooves in the head? 2. What were you're 1/4 mile times on the same same engine immediately after you cut the grooves? 3. Did anything else get modified (besides the groove cutting) between step 1 and 2 above and if so, what were those mods? This includes simple things like timing AFR, plug gap, boost psi, etc. These changes don't necessarily invalidate the test but its something that needs to be taken into account when looking at your 1/4 mile improvements. Again, I'm not bashing you, I would just like to see some data. Thanks.

If that's true then we know that the engine is losing A LOT of compression if you have to open up the piston to head clearance that much.

Yup. And its up to the optimists to prove their theory. We don't use the Bermuda Triangle Scientific Method, where a person can state, "Grooves in the cylinder head make more power, reduce fuel consumption, and reduce emissions and no one has proved me wrong, so it must be true." That's BS. So far I haven't seen anything other then anecdotal evidence citing: Smoother idle. Cooler engine compartment. Reduced detonation. Someone prove me wrong with a true test.

Yes but make sure your specific shock is designed to function this way. Some shocks are not designed to be repeatedly topped out.

There are rumors that an OS Giken LSD for a Subaru STi application fits very well in the R180 case. I have one behind my 350Z (R200) and I love it. Let me check on part numbers, etc.

http://www.sae.org

The current research direction is away from spark ignition and more towards Controlled Auto Ignition (or CAI), Homogeneous Charge Compression Ignition (HCCI) at least for steady state cruise. This should push the thermodynamic efficiency of normally aspirated gasoline engines close to or beyond the current F1 level of efficiency. And we'll be seeing combustion chamber designs very different then what we're used to looking at now.

Assuming same pad material/co-efficient of friction, same wheels and tires, same brake fluid, same brake lines, etc. then your stopping limit is determined by the grip of the tires. Both setups when properly installed and tuned will lock up all four wheels any time you want. What you gain with the Wilwood setup over the Toyota 4 piston setup is less unsprung weight and more time before the brake system is heat soaked. How much additional heat soak time do you need? Lots of VARA 240Z racers run the Toyota 4 piston setup because that's what the rules require. They can run a one hour race without running into a heat soak problem. At the Cal Speedway Roval they do one big stop from 140 mph down to 50 mph every lap. At Buttonwillow they do three stops from over 100 mph to about 50 every lap (depending on the configuration).

Vizard is behind the curve. For cutting edge combustion chamber design you need to look at F1 and MotoGP where they are getting around 35% thermodynamic efficiency from a normally aspirated gasoline powered ICE.

Check the inner and outer lower control arm bushings, front diff crossmember mounting, and rear control arm mounting.

Exactly!

Maybe we like little pink ponies and maybe others here will the taught how to love the pony.

http://jalopnik.com/5176055/30-epic-do+it+yourself-automotive-fabrication-failures

I think the grooves do induce some kind of turbulence in the combustion chamber. So what? If you take a properly tuned and optimized engine and cut grooves in the combustion chamber, how will that increase horsepower? Probably not because you've reduced the compression ratio. If you take a poorly tuned and non-optimized engine and cut grooves in the combustion chamber, how will that increase horsepower? Probably so by inducing enough extra turbulence to burn a little more of the fuel that isn't getting burned before the grooves were cut. So, if you've got a poor running car, pull the head and cut grooves in the combustion chamber!

All the replacement bushing kits I've used included a new sleeve.

Except compression.

He should mount the siren and generator on his autocross car.

I'm skeptical. I've never seen them on any professional race team engine from drag to road racing. This is an old idea that's been around at least 70 years (In my Miller book there's a picture of a machine turned combustion chamber on a Miller Marine 220). Modern combustion chamber design with a good quench does everything claimed for the grooves (or dimples, or hexagons, or swirls, or whatever). Its not snake oil, but its a band-aid for poor combustion chamber design. If you do things right to begin with, you don't need to do this extra work and lose compression in the process.

The picture I linked to was 225/50-14s on 14 x 7 wheels.