It's not so much what we've learned about stock limits as how bad the pump gas has become. 91 octane cars couldn't approach those timing numbers nowadays without water/meth injection or drowning them in fuel.
Bill Cardell TurboDog's Dad Flyin' Miata 1-800-359-6967 (sales) 970-464-5600 (tech support) www.flyinmiata.com www.fmwestfield.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, July 27, 2010 11:42 PM To: Jeff Abrams Cc: [email protected] Subject: Re: Stock 1.6l w/FM2 kit,mechanical limits with regard to boost and advance? I was under the impression that by specifying which kit it supposedly was, that would include which turbocharger I am running. Perhaps that is a flawed assumption, I don't know that much about the flyin miata kits of the past. All I'm looking for is a ballpark figure where things get dicey for the bottom end, now that I'm running enough octane that the knock sensor isn't going nuts well before I approach any conrod limits these things matter. I saw in the FM Link manual stuff like: There are limits to the amount of ignition advance run on a stock bottom end. In the 400 row the timing should not be set more advanced than the timing in the 300 row, and the timing at torque peak for turbo cars should not exceed 88 (22 degrees). In the 500 and 600 rows on turbo cars, each having less timing than the previous, the timing at torque peak should not exceed 80 (20 degrees). Exceeding these values can put too much pressure in the combustion chamber for the stock rods and pistons to handle, causing a failure. We are currently pushing this limit on supercharged cars (less backpressure), and a limit has yet to be determined. For N/A cars, ignition advance at torque peak in row 6 is usually good around 108 (27 degrees). Does this still hold true or have we learned more about the 1.6l stock limits since this manual was written? Regards, Vito Caputo On Tue, Jul 27, 2010 at 09:27:57PM -0700, Jeff Abrams wrote: > I can???t help but chuckle whenever I see people use ???limit??? and unqualified ???boost??? in the same sentence. Then again, these are often the same people that believe that detonation is somehow directly tied to manifold pressure. > > ???Boost??? is a symptom, not a cause. > > Hopefully, Corky will chime in here about flow. > > > > - Jeff Abrams > > - [email protected] > > - www.mazdamaniac.com > > > > > > > > From: [email protected] [mailto:[email protected]] > Sent: Tuesday, July 27, 2010 9:02 PM > To: MataPowerList > Subject: RE: Stock 1.6l w/FM2 kit, mechanical limits with regard to boost and advance? > > > > i been following this since Christ was a corporal, and a properly tuned 15psi has always been the safe limit that I have heard of. on a 1.6 thats about 220rwhp. > > > > these normally durable engines are very unforgiving of detonation under boost. > > > > a set of low comp pistons and better rods really pays off if you can sustain the cost of those and a rebuild. > > > > > > > > On Jul 27, 2010 [email protected] wrote: > >> My question is what are the safe limits of boost and ignition > >> advance one can run when there's enough octane to not knock? When > >> do the rods and/or pistons give up on the stock 1.6l? > > > > The general feeling seems to be that once you start exceeding 250 > > rwhp (at stock rev limit) you should worry about the life of your rods. > > > > Not sure about pistons -- most failures of those that I've seen on > > the net seem to be head/detonation-related, rather than power. > > > > --Ian > > _______________________________________________ > > > > _______________________________________________ > Miatapower mailing list > [email protected] > http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
