on the syncrotech website they have rebuild kits with the stock (brass?) syncros or carbon syncros and i was just wondering the pros and cons of each? seems like carbon would wear out faster? thanks in advance

 

The carbon-moly synchros are brass sprayed with carbon-moly. They generally last longer than all brass synchros and allow the synchro to bite the gear more effectively. The new carbon synchros (carbon matrix lining that is not sprayed on) will last even longer and work better, which is why the carbon-moly synchros are being phased out.

 

hmm interesting, where might i find these carbon matrix syncronizers? also, there don't seem to be offers for any kind of carbon syncro for 1st or 2nd.. is that not a practical application?

 

I actually have a concern about those carbon synchros too.

Since the carbon coating will wear out ..
the tolerance of the synchro will become loose...

 

The problem I have found is that the coating is not always true and consistent, causing them to not have a lot of surface area to "bite" onto the cone. I tried a set of the carbon matrix ones during prototyping and they have been holding up perfect on a gsr transmission for quite some time and abuse now. Talk to David at Synchrotech, he is a great person to deal with.

 

OEM > all imo
Ive had carbon syncs in my s80 and my 1st, 2nd, and 4th all grind after 5000 miles.

 

You might have a different problem. Not just the synchros.

 

I have synchro-tech carbon 3rd 4th and 5th synchros. No problems even sometimes down shifting at very high rpm.

 

Thank you for your input. What trans are you using?

 

The Carbon coated synchros are no longer on offer. All synchros offered by Synchrotech and MFactory are carbon-lined, similar to the oem K-Series synchros. Unlike oem though, our engagement angle is more aggressive, which helps slow the gear down even faster.