Transmission fluid swap?
 

Has anybody thought of doing this yet. My recent dealings with new cars have shown that factory fluid blows. I've put royal purple synchromax in my last 3 cars with great results. I think there is a little room for improvement in this great gearbox, but I don't want to screw up either. I've noticed a moderate notchiness at below 3k rpm and when not completely up to temperature. I realize this is common in a manual tranny but would like to slick things up if I could.

Just brainstorming...feel free to chime in.

IMHO, RicerPurple is garbage that is only sold due target demographic marketing.

Use Amsoil gear lube and you'll probably never switch back to anything else. The main thing to note is what type of Gear Lube you need and get the correct stuff. Some are harsh on yellow metals and will deteriorate your synchros. I don't know the specifics of the FR-S trans at this moment or I'd suggest a specific one. But Amsoil makes really good fluids.

I'm going to let other people experiment first. My personal experience has been with Subaru transmission and I've found that the Subaru Extra-S is fantastic for daily-driving and occasional AutoX. But it doesn't hold up to heat all that well. I'm currently running Motul 300 in my RallyX car with much better results.

But I would be curious as to what the Miata and S2000 guys have found to work. The BRZ/FR-S transmission is same with just small tweaks.

Like lord Taku said...

Me it goes like this

Motul/Redline

Amsoil

Castrol/mobil1/penzoil

Really make sure components won't be harmed due to detergents and added synthetics :) Most lubricants are made to manufacturers specs.

Amsoil
Torco
Old GM SM was great. Ford has one that supposed to be great too.
Redline is ok, depends on the car.. it SUCKED in the S2K IMO, felt very notchy.

I've run the ford stuff and wasn't impressed at all...switched to royal purple and it was much better. It may not be the niche brand but I've had good luck. I've always wanted to try redline too but never have. And I hear good things about Amsoil. I'm not a brand loyal kind of guy, so whoever supports this car and gets some good reviews is who I will go with.

Taken from advice by friends at S2Ki, I've always used GM Synchromesh Friction Modified; worked perfectly in my RSX-S tranny, & I plan to use it for the FR-S once I put a few more miles on =D

The S2K tranny doesn't use yellow metal in its syncros? I'll have to dig for it, but I thought the cutaway of the BRZ transmission used brass syncros. If so, GM SM is bad for longevity.

So what all is good for brass parts?

Or better yet...what chemical or substance in these fluids is bad for the yellow stuff?

I found the following article that says most modern transmission oils are not harmful to yellow metals, given that they are GL-4 oils; I was trying to look up the GL number for GM SM Friction Modified, but can't track it down as of yet;

http://www.bobistheoilguy.com/forums...1231273&page=1

The following 2 links are personal accounts of the fluid; one for regular use, the second from S2Ki w/ track useage =D

http://honda-tech.com/showthread.php?t=2184992

http://www.s2ki.com/s2000/topic/1824...tion-modified/

I will continue to look into this; OP, but if you are considering to use this please note that Friction Modified is different from regular GM SM fluid; as noted in the personal accounts =D

Sulphur, but in my first link up there it gives a better explanation than that =P

+1 Subaru extra-s. You will find that teams support it for track use, its even more livable for the street.

I think the BRZ calls for a GL-3 fluid which is not even a current spec any longer. I would say that GL-4 is probably the best fit.

AWD Subarus use a GL-5 fluid, which is what is not particularly compatible with the soft metals. So I'm not so sure Subaru Extra-S will be the best solution for this particular transmission.

Redline MT90.
On a side note I love all these threads that i used to read on NICO 10 years ago lol. It's starting all over again.