6 speed transmission #4 go boom.
#23
Supporting Vendor
iTrader: (3)
Join Date: Jul 2006
Location: San Diego
Posts: 3,303
Total Cats: 1,216
Is it naiive of me to think it's absurd that a solution can't be found to handle 400 whp?? It's monster power to us miata guys but it's really not that much in the bigger picture. This whole $12k to get a transmission that doesn't implode from <400 ft-lbs seems ridiculous. There has to be a solution.
-Ryan
-Ryan
#24
If you don't care about ratios there are several that just need fabbing (mounts, adapters/bellhouse) to get in there.
A contributing problem is that the stock ratios are really good and if you do something why make it worse.
PAR gears seems to be the cheapest/convenient "solution", currently. But no one here knows how long it will hold (it will fail for someone for some reason at some time of course).
A contributing problem is that the stock ratios are really good and if you do something why make it worse.
PAR gears seems to be the cheapest/convenient "solution", currently. But no one here knows how long it will hold (it will fail for someone for some reason at some time of course).
#28
Is there a reason why you track guys are against 4 speed, with the quicktime bell housing and something like this
G-Force Transmissions and Long Shifters
i would think that its a far cheaper option then custom gear sets or sequential gear boxes. I find it hard to believe you can't get ratios to work with the amount of custom ratios for 4 speeds and rear ratios for our diffs.
G-Force Transmissions and Long Shifters
i would think that its a far cheaper option then custom gear sets or sequential gear boxes. I find it hard to believe you can't get ratios to work with the amount of custom ratios for 4 speeds and rear ratios for our diffs.
#31
Elite Member
Thread Starter
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
I could definitely make a box with fewer gears work for either track or autocross but not both from anything I have seen. Autocross is easy you only need two gears one low gear to launch and one that will hit right around to 70Mph with an elevated rev limit.
#32
Elite Member
Thread Starter
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
interesting I think you could build one with good ratios. why have I not seen that before?
http://www.richmondgear.com/pdf/RG21.pdf
#33
Elite Member
Thread Starter
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
interesting I think you could build one with good ratios. why have I not seen that before?
http://www.richmondgear.com/pdf/RG21.pdf
http://www.richmondgear.com/pdf/RG21.pdf
Richmond ROD 6 speed
Gear ratio Mainshaft countershaft
Drive - 22 37
1st 3.043 38 21
2nd 1.993 32 27
3rd 1.570 28 30
4th 1.237 25 34
5th 1.000 - -
6th 0.857 26 51
looks like it might be about 50-60 lbs heavier than an AZ6 by the time you get the bellhousing and taileshaft mounting setup.
#35
Elite Member
Thread Starter
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
Sorry to hear about your trans problems. Subed for more info.
Is the RX-7 turbo 2 trans too much fab work to mess with? Bad gearing choices?
Any potential advantages to cryo treating if your building another 6 speed?
What are you currently using for rear end and half shafts?
-Jeff
Is the RX-7 turbo 2 trans too much fab work to mess with? Bad gearing choices?
Any potential advantages to cryo treating if your building another 6 speed?
What are you currently using for rear end and half shafts?
-Jeff
#37
Elite Member
Thread Starter
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
If picked right a 6 speed will have 2 useful gears for autocross and 4 useful gears for the track. A 5 or a 4 speed can be optimized for one or the other but not both. The stock gearing in the 6 speed is Ok but I think it would be improved if it were closer ratios still. Second gear needs to be slightly taller for autocross and I think slightly less rpm drop between shifts 3-4, 4-5, and 5-6 would be faster on the track. On the track you really sort of want it to where being in any of two different gears at critical points will keep you on the power curve so you can adjust shift points to match for both the track layout and speed while staying at RPM’s that have the most throttle response and power.
#38
Elite Member
Thread Starter
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,478
Total Cats: 144
Pretty crummy jump between 4th and 5th. still looks bad to me with a 4.10 or 3.909. Best 5 speed gearing speed seems to be the Quafe wide but even that I think can be optimized for the track or for autocross but not both with the same rear end ratio. I just get enough speed out of second with the 6 speed 3.636 combo for autocross by turning up the rev limit to 8600 rpm Im not quite sure how much taller I can go before loosing power and throttle response for slower corners cost significantly. My guess is not much like 5mph more max. I have been over geared with the 5 speed for autocross before and it was an eye opening experiance with lower gears and a higher rev limit. Top speed is not important enough to sacrafice power and throttle response on the rest of the course but shifting to 3rd sucks.
Last edited by bbundy; 06-16-2014 at 01:21 PM.
#39
Former Vendor
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,100
Perfect, except 5th is a little deep as Bob said.
Read this thread, especially from post ~125 onwards, for a lengthy discussion of what gear ratios are ideal and why they are ideal.
https://www.miataturbo.net/suspensio...es-dust-75506/
Read this thread, especially from post ~125 onwards, for a lengthy discussion of what gear ratios are ideal and why they are ideal.
https://www.miataturbo.net/suspensio...es-dust-75506/
#40
Perfect, except 5th is a little deep as Bob said.
Read this thread, especially from post ~125 onwards, for a lengthy discussion of what gear ratios are ideal and why they are ideal.
https://www.miataturbo.net/suspensio...es-dust-75506/
Read this thread, especially from post ~125 onwards, for a lengthy discussion of what gear ratios are ideal and why they are ideal.
https://www.miataturbo.net/suspensio...es-dust-75506/
G-Force Transmissions GFT5242-93S G-Force T5 Transmission Gears And Mainshaft Upgrade Kits - Free Shipping on All Orders @ JEGS
you can also get a 0.82 fifth gear which should work better than 0.75
G-Force Transmissions GFT82 G-Force T5 Transmission Gears And Mainshaft Upgrade Kits - Free Shipping on All Orders @ JEGS