Murray Posted July 30, 2022 Report Share Posted July 30, 2022 I have yet to change the trans fluid in our new-to-us car. I'm curious what fluids people recommend for our kind of racing? In the past I've had good luck with GM Synchromesh, Redline (what's it called mt90?), even some royal purple. However for all of those cars they were street cars or mixed duty street/HPDE cars. What does everyone run? I remember reading good things somewhere on here about Motorcraft syn something or other I think. For what it's worth the car is a 87 supra with the 1uz swap (IPF racing's old car). It uses the weaker non-turbo transmission (Toyota W58) to keep the points down. Quote Link to comment Share on other sites More sharing options...
mender Posted July 30, 2022 Report Share Posted July 30, 2022 I run Redline MT85 or MT90 in my endurance cars, no issues. Fiero with Getrag 282 and Civic with a B series transaxle w/ helical LSD. Quote Link to comment Share on other sites More sharing options...
Hugh Jass Posted July 30, 2022 Report Share Posted July 30, 2022 MT-90 in a Miata Quote Link to comment Share on other sites More sharing options...
MichaelPal Posted July 30, 2022 Report Share Posted July 30, 2022 Motul 75w90 300v Quote Link to comment Share on other sites More sharing options...
Ian Posted July 30, 2022 Report Share Posted July 30, 2022 We run a Liqui Moly brand GL4 Manual gearbox oil in the G. We tried running GL5 and other gear oils, but find the synchros feel a bit crunchy. True GL4 MT oil is getting tough to find. 1 Quote Link to comment Share on other sites More sharing options...
Hugh Jass Posted July 31, 2022 Report Share Posted July 31, 2022 8 hours ago, Ian said: We run a Liqui Moly brand GL4 Manual gearbox oil in the G. We tried running GL5 and other gear oils, but find the synchros feel a bit crunchy. True GL4 MT oil is getting tough to find. MT-90 is GL4 Quote Link to comment Share on other sites More sharing options...
Ian Posted July 31, 2022 Report Share Posted July 31, 2022 8 hours ago, Hugh Jass said: MT-90 is GL4 Correct, but nobody round these parts stocks redline products. Quote Link to comment Share on other sites More sharing options...
obscene Posted July 31, 2022 Report Share Posted July 31, 2022 MT90 Quote Link to comment Share on other sites More sharing options...
Murray Posted July 31, 2022 Author Report Share Posted July 31, 2022 Thanks for all the input! So sounds like MT90 is a safe bet, I believe the local race shops stock it so a great option. Quote Link to comment Share on other sites More sharing options...
Todd K Posted August 1, 2022 Report Share Posted August 1, 2022 We run Torco MTF in our Integra - holds up well but we also make sure to change it out after every race weekend. I pay $70 / 5 liters with free shipping - gets me 2 changes. Quote Link to comment Share on other sites More sharing options...
Black Magic Posted August 1, 2022 Report Share Posted August 1, 2022 We use the same motor oil for the engine and trans in the neons, Mobil 1 0w 40 euro formula. Factory used either ATF or a fairly thin mopar version of syncromesh. Use a higher temp range oil of the viscosity the oem called for. Quote Link to comment Share on other sites More sharing options...
MMiskoe Posted August 1, 2022 Report Share Posted August 1, 2022 Synthetic ATF. Changed after every race. Don't know the science behind it, but 20 years worth of Nissan/Mazda transmissions later I don't question it too much. Quote Link to comment Share on other sites More sharing options...
ross2004 Posted August 3, 2022 Report Share Posted August 3, 2022 We have an old Honda trans and they work well on motor oil (some synthetics are too slippery, though). Rotella T6 5w-40 in the engine and trans. It's JASO MA rated and the synchro's are happy. Quote Link to comment Share on other sites More sharing options...
RandomTask Posted August 3, 2022 Report Share Posted August 3, 2022 On 7/30/2022 at 12:08 PM, MichaelPal said: Motul 75w90 300v You fancy. 1 Quote Link to comment Share on other sites More sharing options...
wvumtnbkr Posted August 3, 2022 Report Share Posted August 3, 2022 I had many issues with manual Trans over the years. I finally talked to ALL of the people... For mazda transmissions, idemitsu is the best in my opinion. It made our rx7 Trans go from lasting 2 or 3 races to like 5 or 6 years before synchro crunch. For tremec T5 WC Trans, I talked with the guy who literally wrote the book on rebuilding and doing performance upgrades on the t5 (Paul C.). He recommended royal purple syncromesh. It has worked wonderfully for us for years. 1 Quote Link to comment Share on other sites More sharing options...
Timothy G. Elliott Posted August 3, 2022 Report Share Posted August 3, 2022 (edited) BG syncro shift II. Edited August 9, 2022 by Timothy G. Elliott Corrected Quote Link to comment Share on other sites More sharing options...
ETR Posted August 3, 2022 Report Share Posted August 3, 2022 2 hours ago, wvumtnbkr said: For mazda transmissions, idemitsu is the best in my opinion. It made our rx7 Trans go from lasting 2 or 3 races to like 5 or 6 years before synchro crunch. I've flip flopped between the Motorcraft/Amsoil sauces in our nb 5spd's and have always stressed to my drivers not to shift fast (the classic miata synchro killer), but I still feel like 3rd gets crunchy earlier than it should. Have sent a few samples to Blackstone over the years and everything always "looks good". Which Idemitsu are you using? I'm interested and seeing ATF and CVTF but not a manual-specific formula. Quote Link to comment Share on other sites More sharing options...
wvumtnbkr Posted August 3, 2022 Report Share Posted August 3, 2022 I was using the idemitsu like this.... https://mazdatrix.com/product/oil-gear-synthetic-idemitsu-75w-90-case/ 2 Quote Link to comment Share on other sites More sharing options...
Gkuhn41 Posted August 8, 2022 Report Share Posted August 8, 2022 Redline MTL Quote Link to comment Share on other sites More sharing options...
MBMEngineering Posted August 8, 2022 Report Share Posted August 8, 2022 Schaefer’s 75W-90. We do sell it in bulk 5gal buckets if anyone is interested. Quote Link to comment Share on other sites More sharing options...
takjak2 Posted August 8, 2022 Report Share Posted August 8, 2022 Ford XT-M5-QS (it's a 75W-90) goes into our Miata. Quote Link to comment Share on other sites More sharing options...
mindspin311 Posted August 8, 2022 Report Share Posted August 8, 2022 MT85 per Redline's website for the Mini Quote Link to comment Share on other sites More sharing options...
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