Arca's Time Attack Build Thread (13b-REW Swap)
#301
Still trying to find a stupid 5 speed. I've been in contact with some JDM engine/trans importer in New Jersey, he says he has them in stock, sent me an invoice on Paypal but when I asked to see pictures of the transmission he just keeps stalling so I haven't sent payment.
#303
Registered
iTrader: (25)
sorry, my bad on the original post, it was recently sold
This one is a bit steep
http://www.ebay.com/itm/JDM-04-08-MA...04479c&vxp=mtr
.
This one is a bit steep
http://www.ebay.com/itm/JDM-04-08-MA...04479c&vxp=mtr
.
Last edited by TeamRX8; 01-21-2015 at 02:41 AM.
#305
sorry, my bad on the original post, it was recently sold This one is a bit steep http://www.ebay.com/itm/JDM-04-08-MA...04479c&vxp=mtr .
#307
sorry, my bad on the original post, it was recently sold
This one is a bit steep
JDM 04 08 Mazda RX8 RX 8 SE3P 5 Speed Transmission Japan Euro Spec Very RARE | eBay
.
This one is a bit steep
JDM 04 08 Mazda RX8 RX 8 SE3P 5 Speed Transmission Japan Euro Spec Very RARE | eBay
.
That bozo has had that thing listed for like a month at just under $1000, looks like he relisted it as an auction. It used to be a "Buy It Now" button and a "Submit Offer" button. I offered $350, then $450, then $600 and he declined all of them. Shipping for him would be cheap too, only one state away and I have a business address with a forklift it can go to if necessary.
#309
Well, turns out the JDM importer I was talking to had sent the pictures like a week after I requested them, but didn't really mention it in the email that they were attached so I missed them. So, good to go. Trans looks clean and supposedly has about 40,000 miles on it but who knows. The pictures showed it still attached to a low power 4 port, and the engine had an R Magic oil filter on it which is common in Japan, so it's highly likely that it's the JDM version that I would prefer and not the EUDM version.
Yay.
Also I picked up a wiring board from Leash Electronics that I'll be using to wire the car from scratch.
Mad JDM tyte busted up shift **** because pictures are fun...
![Name: IMG_1192_zps8dtgdskw.jpg
Views: 341
Size: 53.5 KB](https://www.rx8club.com/attachments/rotary-swaps-217/220154d1501207062-arcas-time-attack-build-thread-13b-rew-swap-img_1192_zps8dtgdskw.jpg)
Yay.
Also I picked up a wiring board from Leash Electronics that I'll be using to wire the car from scratch.
Mad JDM tyte busted up shift **** because pictures are fun...
![Name: IMG_1192_zps8dtgdskw.jpg
Views: 341
Size: 53.5 KB](https://www.rx8club.com/attachments/rotary-swaps-217/220154d1501207062-arcas-time-attack-build-thread-13b-rew-swap-img_1192_zps8dtgdskw.jpg)
![Name: 10924821_10153072457452533_7409315533614051321_n_zpsggqueg07.jpg
Views: 356
Size: 132.7 KB](https://www.rx8club.com/attachments/rotary-swaps-217/220155d1501207062-arcas-time-attack-build-thread-13b-rew-swap-10924821_10153072457452533_7409315533614051321_n_zpsggqueg07.jpg)
#310
So in this post I wanted to explain the differences between gear ratio differences between the JDM and the EUDM 5 speed manuals and why I prefer the JDM version for my application.
The JDM RX8 5 speed gear set is identical to the JDM RX-7 FD ratios. The EUDM gear set has a 3rd gear ratio that I don't really see used in any other RX or Miata gear boxes, but the 5th gear ratio is identical to a Turbo II.
Gear Ratios:
Gear -- JDM -- EUDM
1 ----- 3.483 -- 3.483
2 ----- 2.015 -- 2.015
3 ----- 1.391 -- 1.484
4 ----- 1.000 -- 1.000
5 ----- 0.806 -- 0.762
R ----- 3.288 -- 3.288
Now the reason I like the JDM version better is because the RPM drop from 3rd to 4th isn't as big and disproportionate as the EUDM box, and the 4th to 5th gear RPM drop is almost 400RPM less as well.
I will still be able to get up to about 165MPH at the rev limiter with the stock diff and 275/30R18 tires. I might be able to get close to that on only a handful of tracks and is dependent on a lot of things but I don't think I'll ever be able to top out the car on a road course. But who knows.
Also, playing around with the MFactory Ratio Calculator is always fun. This will help you see the differences in RPM drop when you shift gears.
The JDM RX8 5 speed gear set is identical to the JDM RX-7 FD ratios. The EUDM gear set has a 3rd gear ratio that I don't really see used in any other RX or Miata gear boxes, but the 5th gear ratio is identical to a Turbo II.
Gear Ratios:
Gear -- JDM -- EUDM
1 ----- 3.483 -- 3.483
2 ----- 2.015 -- 2.015
3 ----- 1.391 -- 1.484
4 ----- 1.000 -- 1.000
5 ----- 0.806 -- 0.762
R ----- 3.288 -- 3.288
Now the reason I like the JDM version better is because the RPM drop from 3rd to 4th isn't as big and disproportionate as the EUDM box, and the 4th to 5th gear RPM drop is almost 400RPM less as well.
I will still be able to get up to about 165MPH at the rev limiter with the stock diff and 275/30R18 tires. I might be able to get close to that on only a handful of tracks and is dependent on a lot of things but I don't think I'll ever be able to top out the car on a road course. But who knows.
Also, playing around with the MFactory Ratio Calculator is always fun. This will help you see the differences in RPM drop when you shift gears.
![Name: mfactory%20jdm%20vs%20eudm_zpsqe44qtwh.jpg
Views: 349
Size: 63.3 KB](https://www.rx8club.com/attachments/rotary-swaps-217/220153d1501207062-arcas-time-attack-build-thread-13b-rew-swap-mfactory%2520jdm%2520vs%2520eudm_zpsqe44qtwh.jpg)
Last edited by Arca_ex; 01-24-2015 at 01:33 AM.
#315
My end game is to get a GForce GF5r dog box with straight cut gears into the car which is loosely based on a T5 design. This 5 speed is just something to hold me over until then.
#316
Modulated Moderator
iTrader: (3)
I have a FD Dog box in another car...It shifts great racing...but driving it around slowly at all is a PIA
The T56 dog box is unnecessary for the power levels we are running. The gears are wide and heavy and the tranny shifts like that. Same with the T5 Variant that you are talking about.
I am going to run a 5 speed stock for a bit...if it hold up like I hope..I m going to build one with REM'd gears and tapered roller bearings and that should work well. I just want to run it stock first before I spend a grand or so upgrading it before I know it will work
The T56 dog box is unnecessary for the power levels we are running. The gears are wide and heavy and the tranny shifts like that. Same with the T5 Variant that you are talking about.
I am going to run a 5 speed stock for a bit...if it hold up like I hope..I m going to build one with REM'd gears and tapered roller bearings and that should work well. I just want to run it stock first before I spend a grand or so upgrading it before I know it will work
#322
This a fun thread to read man. Really cool to see your progress as a driver! If you were to participate on a Nasa TT event, after you complete your swap, what class would it be? I have the intention of doing HDPE events with the goal of participating at TT events later. The whole TTU~3/TTB~F classing can get pretty confusing.
#323
This a fun thread to read man. Really cool to see your progress as a driver! If you were to participate on a Nasa TT event, after you complete your swap, what class would it be? I have the intention of doing HDPE events with the goal of participating at TT events later. The whole TTU~3/TTB~F classing can get pretty confusing.
I'm planning on doing TT1 with it. It would normally be a TTU (unlimited) car but with electronic boost control I can dial it back for TT1 or TT2 as well. Maybe even TT3 but I might make too much power on wastegate spring to fit into TT3.
The classing isn't too bad it just takes some time to thoroughly read them. If you ever need any help with classing your car you can just PM me.
#324
Thanks man.
I'm planning on doing TT1 with it. It would normally be a TTU (unlimited) car but with electronic boost control I can dial it back for TT1 or TT2 as well. Maybe even TT3 but I might make too much power on wastegate spring to fit into TT3.
The classing isn't too bad it just takes some time to thoroughly read them. If you ever need any help with classing your car you can just PM me.
I'm planning on doing TT1 with it. It would normally be a TTU (unlimited) car but with electronic boost control I can dial it back for TT1 or TT2 as well. Maybe even TT3 but I might make too much power on wastegate spring to fit into TT3.
The classing isn't too bad it just takes some time to thoroughly read them. If you ever need any help with classing your car you can just PM me.
Thanks man. I'll take my time and try to understand it a little better. One of my main questions is about the cage. Do I need a 6 point cage for TT123? I have built a cage before for my S14 drift car and wouldn't mind building another one. But if I can save the weight and cost of materials to spend else where, I would.
#325
Thanks man. I'll take my time and try to understand it a little better. One of my main questions is about the cage. Do I need a 6 point cage for TT123? I have built a cage before for my S14 drift car and wouldn't mind building another one. But if I can save the weight and cost of materials to spend else where, I would.
Did you do an engine swap as well to get up into those classes?