Discussion and questions related to the course Road Tuning
I replaced the clutch/flywheel in my 2015 Camaro SS with a lightweight aluminum flywheel. I have a large N/A cam with lots of overlap (which also hurts torque down low). As expected, starting from a stoplight in traffic requires feathering the pedal (due to the lower mass of the new flywheel). I have 4.10 gears and a 6 speed manual, so it is not horrible; but it's definitely not as easy to get rolling as before, especially when loaded with fuel and passengers.
So I'm wondering, would it be better to either tweak my timing to add a little advance down low, or tweak the fuel to get it in Power Enrichment just during launch, or something else? Either way, I am looking for a solution that would not interfere with idle or cruise conditions, and would want it back to normal by 1500 rpm.
you will struggle to make a good compensation for a heavier flywheel
what was you reason for doing this ?
You 'should' already have the timing optimised, with any further advancement causing light detonation - what you could do is back the timing off a little at the idle rpm and a little above it while keeping the timing fully advanced below that - it will need a little more throttle to hold idle but it will be a little more resistant to dropping below idle as the clutch engages.
Some friction plates have more Marcel spring take up than others, and some friction materials are less 'grabby' than others - you may be able to find something that gives a smoother transition/take-up, but that can be a little $$$ive.
However, it's really just something you're going to have to live with if you want the response, or refit the OEM one for more inertia. Swings and round-abouts...
You cant tune mechanical rotational mass. This is the results of the lighter flywheel and rather than messing your tune up to make it work should you not be asking yourself is a practical choice to have in a car where your carrying passengers or a daily driver. This something best suited to motorsport applications.
Thanks for the replies!
Ross - The reason for the lighter flywheel was purely the performance of the lower rotational mass; and it absolutely made a significant difference. If you 'blip' the throttle now, it revs like a racecar and I'm super happy with it. Someone had mentioned to me casually before that I'd want to tweak the tune with the lighter flywheel. That's really what made me question if there was a way to help that situation.
Gord - I did already go through the tune and optimize the fuel and spark as done in the LS3 Worked Examples, and it runs great in all other scenarios. I was just looking for some way to smooth it out in that specific condition.
Marty - it's not a daily driver so I really don't mind it; it primarily goes to car shows and the drag strip. I was definitely aware of the limitation of the lower mass, but the trade off of the quick rev is totally worth it :-)