Tuning Updates : Air-Fuel Mixture

Cleaning the spark plugs early in the morning. I inspected the plugs for signs of fouling, but all the plugs showed clean burning.

The spark plugs are still in good condition after repeated high engine revs. Modified the tip for better spark and burn. I'm currently looking for gold plated tipped contact points. I saw one a few weeks ago. It might enhance the spark for a better burn. I'm also looking for a new old stock Bosch ignition coil to replace the one I'm using in the roadster...quite rare nowadays.

Tan to light brown color on the plugs indicating a balanced air-fuel mixture on the Mikuni PHH40 Type T's. I noticed an improvement in torque and acceleration.

Plans:

1. Repipe exhaust system - 2 inch diameter, stainless steel mandrel bent tubing

2. Stainless steel free flow resonator

3. Stainless steel flex pipe

4. Stainless steel megaphone tip

5. Custom aluminum heat shield for twin Mikuni carburetors

6. Re-jet and re-balance PHH40 Type T Mikuni carburetors

Stainless Steel Exhaust System Project - Custom Built by Titan Works

Stainless steel Flexible Pipe installed, note the stainless steel mounting bracket, TIG weld quality is superior. Stainless piping is 1 3/4" from flex pipe to resonator and 2" from resonator to exhaust tip

Custom built stainless steel 20" x 6" x 3" free flow resonator

Custom built stainless steel megaphone tip 2" (inlet) to 2.5" (outlet) being fitted

Finally finished! Looks and sounds great! Low frequency rumble at idle is solid...unlike those that sound like a tin can! Driving experience is definitely much more exciting! Better still, torque didn't decrease at the low rpm range. Next is to have the carburetors re-jetted! Now, I've got to schedule a tuning session with twin carb guru Fil Gulfin!

I recently installed a new accelerator cable with a thicker stainless steel strand for better durability during racing. I'm planning to go to Batangas Race Circuit in May to tune the engine. Custom made steel brackets.

Update photo of the engine with the new accelerator cable installed. (April, 2009) Been running the engine up to 6,000 rpm. Acceleration is just awesome even when the twin carbs haven't been tuned yet. Hopefully, by this month I'll be able to dial it in. The exhaust note and induction noise are really something! It's freakin' addictive!

Also just bought (May,2009) Goodyear Eagle NCT5 (185/70/R14) tires to replace the old and cracking Dunlop rear tires.

I finally received the 52.5 Pilot Jets from Rodger of RM Carburetors in Australia. He even added Mikuni stickers...which will be a nice touch on my racing helmet (planning on entering the vintage racing series)! I can't wait to have the twin carbs tweaked by tuning guru Fil Gulfin!

Replaced the old radiator cap with a Raybrig cap with a pressure release valve. Looks much better as well.

Finally, tuning begins!

Finally, I had the Mikuni carburetors and engine tuned at Fil Gulfin's shop! The difference is incredible! Throttle response is crisp, acceleration is so much improved, torque is evenly spread over the power band, and the induction noise is such an awesome sound to hear!

The pilot jets are now 52.5 and the main air jets are 170. The pilot screws have been replaced with the correct ones and the leak has been fixed by replacing the diaphragm cover at the bottom of the left carburetor.

Here's a short film I made about a Sunday fun run with the Fairlady:

http://www.youtube.com/watch?v=5Pky9u4IErE

New Goodies from eBay!

New filler neck grommet

New Nissan shift boot to keep those hot exhaust gases out! Finally!

Another Gift from Dave (East Coast Roadster)

New Carolprene spark plug wires - OEM look, taylored to fit the roadster's engine perfectly. I can't wait to install these! Thanks so much, Dave!