LeonV

Stock flywheels are single mass, dual mass flywheels were not around when these cars were built. A light one won't be any more noisy than OEM.

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Nice project! Gotta love starting with a solid base.

I don't have any issues in the hills of San Francisco with a 10lb flywheel. The stock pressure plate and disk allow for easy engagement and an L28 with a 3.9 is plenty torquey. You're overthinking it.

Doubt you can discern any meaning from those numbers. The ratio will be in xx:xx format, e.g. 39:10 which means a 3.9 ratio. Take another look at the ring gear.

Porterfield can provide that information. https://www.porterfield-brakes.com/

One is a 27 and the other two are 18's. Someone took a matched pair and added a third.

I ran the close ratio box with a 3.54 and it really fit the GT feel of the car. I've since swapped to a 3.9 LSD and while it's turned into a more spirited drive, it's definitely buzzier on the freeway. I seem to settle into a natural cruising speed closer to 70 rather than 80mph with the 3.54. There are merits to both but if you're doing a lot of cruising, the 3.54 is the way to go. I run an L28/P90 combo with a decent cam and 10lb flywheel and have no issues with hill starts with the amount of torque the motor puts out.

This is not complicated, Captain Obvious is correct. The sprocket connects to the cam and the cam is free to spin. The sprocket's clocking doesn't change chain tension, outside of the fact that the valve springs can statically load the sprocket to favor a direction. When the sprocket is removed and set to various positions, it can feel as if it's altering chain tension. With the engine running, chain tension is the unchanged although cam timing would be different.

Nice work, Jim! It's nice to see someone running the heritage bodies, I've been admiring them from a distance for a while. I did the same on my Z, made the exhaust as quiet as possible so that I could hear the DCOE's roar. I like your style. Now post some videos!

I run a 10lb Fidanza flywheel on an OEM clutch. It has stock-like tractability but revs much quicker. The car dynoed at 195whp and 180ftlb, the clutch holds just fine. I run an 8lb flywheel with OEM clutch in my S2000 which made a more notable change in tractability as it doesn't have nearly the low-end torque of the Z. Still much better than the 23-pounder it came with. Both cars are driven in SF Bay Area traffic without issue.

Absolutely not. The seats need pass-throughs that capture the sub and shoulder belts. Otherwise, your harness will not function as intended and you're going to have a bad time. I'm assuming (hoping) this is a race car that doesn't see the street. A roll cage and race harnesses are not fun nor safe on the street (unless you're wearing a helmet and HANS device at all times).

The compression rod controls longitudinal toe compliance. Are you sure the nuts on the body-side compression rod attachment are torqued?

What's the state of your compression rod bushings and all associated fasteners (at body and control arm)?

Looking good! What do you think of the BFG SC2 so far?

Hi Nick, I usually measure from the rocker or pinch seam to make sure there's some rake in the body for aero purposes. These are measured before, during, and after the corner balance on a leveled-out 4-post alignment rack. Make sure the car is level when doing the corner balancing and the wheels are allowed to settle after lowering from the jacks or else you'll be chasing a moving target.

Nothing weird going on here. You have adjustable spring perches so you just need to corner balance the car, preferably laden to race spec. Looks like it has a 49% front and 51% left distribution as it sits so you should be able to get within 18kg at 50.0% corner balance. Either raise the RF and LR, lower the LF and RR, or a combination of both. Note: you can't adjust Left % or Front % when corner balancing, that's based on the CG of the car, but you can change the diagonals. The diagonals in your measurements are off by 5% which tips off that a corner balance will take care of most of your worries.

Did you check your actual timing after you installed the 123? First thing I did after install was make a "setup map" with timing at 10° everywhere and put a timing gun on the pulley. Timing was substantially off so I clocked the distributor until the gun showed 10°. I can post my timing curve when I'm on my tuning computer.

The P90 should already have the hole for a mechanical pump, it's covered by a bolt-in blanking plate. Now is a good time to install a 10lb flywheel, you won't regret it. ?

No Calagarians that I know are heading down my way any time soon so let me know if you're ever in the SF area! No worries if someone else buys it, I'm just being opportunistic. ?

Ah, bummer. Let me know next time you're in the area, always good to meet like-minded people. I'll let you know if I can arrange pickup!

Jim, I'd love to take that off your hands but shipping would be a killer. Although, I do know some people that go between Calgary and SF once in a while...

Nice find! I have the same one although it has some battle scars. Not a lot of them around, especially NOS!

You are correct, thanks for catching that. Everything else I said stands. ?