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Anyone have info on lightening the forward side of the stock flywheel outer-ring for engine performance without adding significant risk of part failure?
I don't do any clutch dumps and no revs near redline. My highway rpms at 85mph are the most I rev it, somewhere around 4000rpm if I remember correctly.
I can get my flywheel milled, but I just don't know how much people have shaved off and had no part failure, what they found to be a good result.
1/4 inch?
more?
Jay Johnson
You'll get a while lot more performance by revving near redline...
Allow me to clarify, I really want to eliminate less parasitic drag from the heavy flywheel.
It will show up as engine performance, but I mostly just want the free gas mileage.
Jay Johnson
With a light flywheel you're going to want to rev higher. Went with a 7lb flywheel and my gas mileage went down since I was revving the shit out of it everywhere I went, lol.
Doubt you'll see any gas mileage with a shaved wheel. Do go with a lighter wheel though if you have the clutch out. Either way you'll wish you did, hell I still wish I went with a lighter clutch with my fidanza.
Edit: There are a tons of info/argument threads on the lightening topic on Miata.net. I read all through that before I scored my fidanza a few years ago, but you should be able to get good enough info to take to the machine shop. In all my readings I never came across one that grenaded (on a miata anyway) so I wouldn't say it's less safe than an aluminum as long as a competent machine shop balanced it afterwards.
More is better. Start with 1/2" and maybe go up from there. You're parasitic drag analogy is spot-on.
Whatever floats yer boat, but f I were going to do it I wouldn't take off less than 15mm.
IIRC. you have been experiencing some sort of engine problems? You might want to stay focused on that first. From my experience, trying to loop in unrelated engine upgrades to a repair can sometimes lead to problems that can be difficult to identify the source of. Is that vibration from the broken part I replaced, or the new performance part I installed at the same time?
The original engine would only be worth fixing if I could aquire a good cylinder head for cheap. I'm sure at some point I'll get a low-buck cylinder head and put it on the short block. The short block will eventually get dropped into a 1959 Nash Metropolitan, for a basket-case runner on the cheap.
I have a spare Miata chassis with a motor(mated to automatic transmission) that I can swap, to replace my motor with the cracked head.
So, I'm looking to do the mods that will be presently available while the motor is out.
Jay Johnson
You should start a Nash thread, and also one for the auto chassis, to avoid confusion.