LeonV

Well keep up the awesome work! Fortunately, both the 260s have triple Webers.

Two very important things need to be mentioned here: 1. There is no specific compression ratio-to octane conversion, since knock-resistance is dependent upon much more than just static compression. Some key factors are combustion chamber design (including spark plug location), RPM, AFR, and valve timing profile. 2. Max timing DOES NOT equal max power. The optimal timing map for an engine is found during controlled dyno testing. There are a many reasons that can cause engine knock, as well as different types of knock. Fundamentally, knock is when a part of the mixture ignites before the flame front from the spark plug gets there. In your case, I'd be thinking about things getting too hot in the combustion chamber. This usually comes from three things: spark plug, exhaust valve, glowing deposits. Going to a cooler plug and/or dropping coolant temperatures could help, but not guaranteed. Spark plugs are easy enough to try out. However, if I were you, I'd pour in some 100 octane fuel and go to the dyno to see what YOUR engine really needs as far as timing goes. Come up with a "good" dyno testing strategy, i.e. minimize variables. Just keep in mind, knock happens for many reasons and is also dependent on ambient conditions. This is why there's a safety net built in on factory spark maps.

Very cool project! I haven't really been following as I don't have a 280Z but sounds like you've put forth a TON of effort and research. If I owned a 280Z or ZX with stock EFI, I'd be pretty damn excited! Are you designing and coding the tuning software/interface as well?

Saw two yesterday. One was an orange 240Z in the Sunset, parked a block from 19th Ave in the morning. The other was a brown 280Z traveling on 19th Ave in the evening. Nice to see Zs out and about!

That would be Matsuo-san.

AWESOME photos Blue, thank you!

Rubber hangers are used for NVH reasons, as well as introducing some extra compliance to the exhaust system. Both are good things, especially the latter.

Seriously? Holy hell, that's a terrible idea! That's a lot of bending load placed on that joint, which is also transferred to your header primaries and exhaust manifold studs. I wouldn't be surprised to see pipes getting warped and/or cracks developing. At the very least, put a support at the muffler...

Great project, love the green/butterscotch!

Since we're being pedantic, I'll make a few comments about performance effects of EGR... EGR does not "allow" increased spark advance, it DEMANDS it. EGR dilutes the fresh air/fuel mixture which slows the burn rate of the entire charge. Because of the slower burn rate, spark timing MUST be advanced in order to maintain performance. Thus, spark timing is increased to sustain performance, not increase it. On the pumping loss point, it's not the decrease in exhaust pressure that reduces pumping losses, or at least that's not the main driving factor. The increase in intake pressure (holding load constant) is what boosts performance, as the intake has a throttle valve to deal with. There's also another important factor in the performance bump and that's reduced heat loss to the cylinder and combustion chamber walls because of the lower flame temperature dictated by EGR. This means more of the fuel's energy is transferred to the piston and not lost as heat. Agreed. You're right. If you're talking about a diesel engine. A spark-ignited internal combustion engine has a throttle, which throttles the amount of air that enters the cylinder (where's Captain Obvious? )! Volumetric efficiency is the key word here, and it's drastically different from easy cruise and WOT. This is a very basic, yet important fundamental concept of SI (spark-ignition) engines. This is the whole reason for multiple-circuit carburetors!

You're thinking too hard. Two guys can push a Z up onto a dolly/trailer easily, especially one without an engine. It helps to have someone in the car in case steering adjustment is needed.

A good target would be as lean as you can go while keeping the engine running smoothly. That might be 12-13:1 on a cold start. If you're at 14:1 at cold idle without start enrichment, then I bet you're too rich when the car is fully warm.

Not sure what you mean by the suspension being "a bit bouncier" but removing the rear ARB should not be detrimental to around-town driving. It will only be noticeable when the car is driven harder, as an increase in steady-state understeer. The ARB does nothing if both wheels are in jounce/rebound.

Welcome Theron! Cool to a member from Dorrington. We've been regularly staying there for YEARS during our winter ski trips. Love that place.

Nope, same exact part. Never had an issue in my old 240Z either. Come to think of it, I still have my old 240Z mirror. Wanna buy it?

Cool. It's definitely rare to see a Mk1 in such great and original shape!

I don't think you understand, John sells ST ARBs which mount to the rear transverse link supports and not the frame. It all comes down to what you want. Do you WANT stiffer ARBs? If the answer is no, then go with the weld-it-back-up idea. Might as well do bushings and end-links at the same time...

Yup... Fairlady Z Mesh Grill - Reproduction Thead - Vendor's Forum - HybridZ

I've never had an issue...

Hi Rob! Any pics of the Supra?

Saw a great looking (and sounding) black 240Z on 25th Ave and Fulton around 7pm last Friday, if my memory serves me right.

Ouch is right!

You "know" the starter has a relay inside the car? If it does, it's not stock. The starter solenoid is the SOLE relay in the stock starting system. I added a $5 relay to trigger the solenoid directly from the battery (using the ignition switch to trigger the relay coil) and haven't had issues since.

What do you mean by the "factory installed relay"? The starter solenoid?

Hi Gordon, were you at the ZONC show earlier today? There were a few original owners there with some fantastic looking (and very original) Z-cars! As far as worth, put up some good pictures and you should be able to get some close, credible estimates.