johnc

First, get the rule book for whomever you are going to race with. That book will determine material selection and cage design.

Huh? OEMs can't get good squish and swirl in their combustion chambers? What about the Honda F20C engine - 120 hp per liter and meets Bin2 emisisons standards? Maybe the Honda B16 engine - 100 hp per liter and meets PLEV standards? Or how about Ford's new EcoBoost 3.5L V6 - direct injection which is the ultimate in swirl technology? Nissan's VQ and VK engine series...

V8.

I don't have a set of the headers or an engine to put them on right now. EDIT: Keep in mind bellhousing and trans clearance.

What Leon said... The cone or megaphone is after (really part of) the final merge collector. A final collector with a straight extension off the minor throat is leaving a little on the table. Cone shape and length are used to tune for a specific rpm band. For most of the L6 street installs a 2.5" minor throat (assuming each of the two collectors off the header are 2.5") with a 7 degree cone to 3" will help mid-range power. For high rpm power (as on my old race engine) I went with a 2.75" minor throat and a 7 degree cone merge to 3". That moved everything up about 1,000 rpm. The cone also makes the exhaust louder. Keep that in mind when building for a street car. I measured a 3db increase with no other change on a customer's autocross E36.

As I said back in March and April, take it up with the seller, contact your local district attorney, or file a civil suit. We are not the police, a judge, or a jury.

From the test conclusions in the first .pdf: The engine was more efficient at moderate loads in the higher rpm ranges. Improved highway cruise is my interpretation. No increase in horsepower or torque at high loads but a slight increase in NOx and CO at higher loads and rpms. Could that have been achieved without the groove via some other kind of combustion chamber reshaping, a compression ratio increase, or maybe something as simple as projector tip spark plugs and indexing the spark plugs? Maybe.

You will need a jig to make sure the completed header hasn't moved out of position due to welding distortion. That parts may all fit together just fine and only go together one way, but the collector outlets could be out of position by inches after everything is welded together. That header is a fairly tight fit near the steering shaft and at the collector outlets near the floor pan. If the outlets are pointed the wrong way or moved outwards you may not be able to get a "Y" on it.

How did I miss all these updates? Congratulations and the car looks fantastic! Its an ever greater accomplishment when you look at everything else you started during that same time period. I have the same starting and running a business 50 lbs. on me. I think its a given. Look forward to the track day video.

Running to the top of the strut tower should give you a 35 to 40 degree angle.

What about a slight bore decrease for the VK45DE engine (93mm bore 82.7mm stroke)? This engine was run in Japan in the Super GT races and, in restricted form, made 490hp. Unrestricted it made close to 750hp. Flat plane cranks and other performance parts are available for it here and over in Japan. This engine was used here in the US in the Q45, FX45, and M45 from 2002 through 2008. That engine is currently being used in various ALMS LMP2 cars and makes around 450hp in restricted form. As Tony suggests, contact Frank or Ed.

An old set of Koni reds. D-Spec is a Tokico marketing term. Probably too long for your shortened strut tubes.

If we're here to discuss flatheads and side valve engines then I concede that there might be some benefit to cutting grooves in the cylinder head. I still doubt it, but hey, those engines were designed for 70 octane fuel and, with today's fuel, its hard to a compression ratio much above 10 to 1 without a lot of detonation. Maybe cutting grooves will help. Either way, IMHO, its of no benefit to any of the engines that are installed in the HybridZ member cars, unless someone I don't know is running a flathead.

Yup. Got it.

As you point out, there's a lot more involved in the installation then most folks realize. All the issues have to do with fitting new, straight parts to a 40+ year old car.

If everything is square then I wouldn't worry about different thread counts on each side.

ARP 100-7708 12mm x 1.5p .508 knurle.

What's important is that the alignment is square. I suggest you string the car if you have time and make sure the back tracks the front. Pull the steering wheel off before you start so it doesn't give any preconceived idea about where the steering center is. Then put the tie rod ends an equal distance out from the groove for the outer rack boot lip.

You have to pay more attention to the A6 when using it on the track. As JT1 mentions above its pretty easy to overheat them. Shock damping, suspension settings, alignment, and a smooth driving style are more critical. The A6 is successful in road racing because its fast on the first lap of the race. It really helps the "get out front and stay there no matter what" race strategy. Remember, its much harder to pass someone then to catch them.

1. You never measure from anything made of rubber. 2. Did you lock the steering wheel in place when you adjusted toe?

That's kind of a misnomer. The A6 is a softer compound so it provides more grip at lower temps then the R6, but like the R6 its best grip comes at 190 to 200F. All DOT race tires and most race slicks provide their best grip around 200F, that's just the nature of the rubber compounds used in their manufacture. Softer compound tires will generate heat quicker (due to increased elastic hysteresis) and will overheat quicker, but the operating temp range is the same as a harder compound tire.

A6s have noticeably more grip then the R6s. For 30 minutes of circuit racing they are fine. You can do that about 4 times before there's significant loss in grip. With practice, qualifying, and a race they are essentially good for one race day if you've only got one set. Most of the bucks up guys will bring three sets to a weekend race. One set for practice, one set for qualifying, and one set for racing. The practice set is usually the previous race weekend's qualifying set. The two new sets are used for qualifying and the races. The race sets are always retired after the weekend.

Let me know. Need pictures and price.

Dang! I'm surprised that Miller, Offenhauser, Chevrolet, Ford, Cosworth, Rolls Royce, Jaguar, Ferrari, Maserati, Porsche, Bugatti, Mercedes, Lamborghini, BMW, Audi, Oldsmobile, Toyota, Buick, Nissan, Mazda, and Pontiac never sold their production or race engines with grooved combustion chambers in the 100+ years the car has been around. Image getting 20% from just a casting change. How dumb can their engineers be? Can i really take my old 325hp N42 head L6, groove the combustion chambers and now make 390hp? No. Never. Not in a million years. Now if I add a Vornado and magnets to my fuel line...

Those collectors are worth $150 each by themselves. Nice design and the minor throat at 2.5" will work well for most any L6 application. If you add a 7 or 14 degree cone out to 3" they will work even better. 28 to 32" total length to the final point where all the tube come together into the single exhaust. That's hard to do with a 6-2-1 design due to packaging requirements so most folks shoot for 28 to 32" at the 2 point and then run 2.5" tubes as short as possible to the final merge collector.