OEM Flywheel Questions - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 11-06-2007, 08:35 PM   #1
Junior Member
Thread Starter
 
Join Date: Jul 2006
Location: Huntsville/Auburn, AL
Posts: 114
Total Cats: 0
Default OEM Flywheel Questions

I spoke with a local racing/machine shop today about getting my spare OEM 1.8 flywheel lightened, balanced and resurfaced and was asked a couple questions I was unsure of. He asked if the flywheel is forged or cast and if it can be balanced statically since I don't have a spare crankshaft to mount it on.
RickA is offline   Reply With Quote
Old 11-10-2007, 09:47 PM   #2
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,797
Total Cats: 248
Default

I would think it is cast, not forged. I would think the engine is internally balanced, so you would not have to bolt it to the crank to balance it.

Edit: I searched Wiki and Yahoo and can't find a anwer. All I found was the car was a well balanced machine, balanced weight distribution, balanced bla bla bla

Last edited by patsmx5; 11-10-2007 at 10:00 PM.
patsmx5 is offline   Reply With Quote
Old 11-10-2007, 10:24 PM   #3
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Its 100% cast, lightening beyond removing the inertia ring on the back is highly UNRECOMMENDED if you enjoy having your legs. It can be balanced separately. Common practice is to balance all components separately and then as a unit.
neogenesis2004 is offline   Reply With Quote
Old 11-10-2007, 10:33 PM   #4
Junior Member
Thread Starter
 
Join Date: Jul 2006
Location: Huntsville/Auburn, AL
Posts: 114
Total Cats: 0
Default

The shop I talked to told me the same thing. I told him I only want ~4 lb taken off so he told me it SHOULDN'T take out my legs since it's not a major reduction. When I brought him the flywheel he reassured me that there's plenty of material to take off 4 or 5 lb and still keep my legs.
RickA is offline   Reply With Quote
Old 11-10-2007, 10:36 PM   #5
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

Pretty sure Ben had this done.

*looking for thread. Found it.
https://www.miataturbo.net/showthrea...=cost+flywheel
cjernigan is offline   Reply With Quote
Old 11-10-2007, 10:45 PM   #6
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

The ring on the back isn't structural, so removing it is ok. Its only there specifically to add weight.
neogenesis2004 is offline   Reply With Quote
Old 11-10-2007, 10:53 PM   #7
Junior Member
Thread Starter
 
Join Date: Jul 2006
Location: Huntsville/Auburn, AL
Posts: 114
Total Cats: 0
Default

So when people talk about a lightened cast flywheel exploding, what part of the flywheel's mass do you remove to make something like that happen?

Quote:
Originally Posted by cjernigan View Post
Pretty sure Ben had this done.

*looking for thread. Found it.
https://www.miataturbo.net/showthrea...=cost+flywheel
Yeah I had read that thread previously, but nothing was spoken of manufacturing process or how it can be balanced, both were questions the machine shop here asked me.
RickA is offline   Reply With Quote
Old 11-10-2007, 10:55 PM   #8
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

Personally, i would buy the ACT steel replacement flywheel. Atleast you know it won't explode. Atleast not as likely.
cjernigan is offline   Reply With Quote
Old 11-10-2007, 10:59 PM   #9
Junior Member
Thread Starter
 
Join Date: Jul 2006
Location: Huntsville/Auburn, AL
Posts: 114
Total Cats: 0
Default

Quote:
Originally Posted by cjernigan View Post
Personally, i would buy the ACT steel replacement flywheel. Atleast you know it won't explode. Atleast not as likely.
Well, I was reassured by the machinist who also builds track cars so i saved myself a few bucks... Flywheel was $45 shipped and the resurface, lighten, and balance was estimated at $100
RickA is offline   Reply With Quote
Old 11-11-2007, 12:15 PM   #10
Junior Member
 
Join Date: May 2007
Location: Mountain View, CA
Posts: 220
Total Cats: 0
Default

I took the lip off the back and I still have my legs...it did not make a HUGE difference but is noticeable. I just balanced it separately and put it back on...hopefully it is all good.
kylelind is offline   Reply With Quote
Old 11-11-2007, 12:17 PM   #11
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

Quote:
Originally Posted by cjernigan View Post
Pretty sure Ben had this done.
Yeah, the machine shop took 5 lbs off of mine to about 14 lbs total. Which was quick and easy for them. It was one of those while you wait type jobs. It was like $100 and I'd recommend it. A good shop should be able to get it down to 12-13 if you wanted them to. Another option is FM's 10 lb flywheel is on sale at $250 right now, brand new.
Ben is offline   Reply With Quote
Old 11-11-2007, 04:09 PM   #12
Senior Member
 
Join Date: Sep 2007
Location: Alamo City, Tejas
Posts: 774
Total Cats: 1
Default

Another option, if your build and budget permits, is to knife-edge the crank instead. You'll still lose rotating mass, but also gain the benefit of reduced drag on internal components.
l_bader is offline   Reply With Quote
Old 11-11-2007, 04:23 PM   #13
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

Did you nitride your crank after shaving it? If you don't mind, what did that uber-light crank cost?
Ben is offline   Reply With Quote
Old 11-11-2007, 08:41 PM   #14
Senior Member
 
Join Date: Sep 2007
Location: Alamo City, Tejas
Posts: 774
Total Cats: 1
Default

Quote:
Originally Posted by Ben View Post
Did you nitride your crank after shaving it? If you don't mind, what did that uber-light crank cost?
Ben -

No, I didn't think to have it treated after getting it machined. - Hopefully it won't turn out to be a mistake.

Profiling, lightening and knife-edging the crank and then balancing the crank, flywheel and pressure plate individually and as a single unit was a touch over $800.

Total cost on all the machine work done on the block before taking up to Corky's was about $1700.

- L
l_bader is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 12-15-2017 09:00 PM
Garrett Turbo, 1.8 Oil Pan, & Misc. Stuff nbdooey Miata parts for sale/trade 9 08-30-2017 10:50 PM
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
ACT race clutch and AASCO 7lb. aluminum flywheel graexodus Miata parts for sale/trade 5 10-26-2015 02:48 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:01 AM.