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Few questions FD, NA 13B vs 20B

Old 06-18-10, 04:57 PM
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Few questions FD, NA 13B vs 20B

Didn't know where to put this as my questions are all over the map.

I might be getting back into the rotards as the things I am hearing about p-ports are really impressing me. I have a few general questions:

1)How much does a NA 13B weigh minus tranny?

2)How much does a NA 20B weigh minus tranny?

3)How simple/complicated is the physical aspects of installing a 20B in and FD? I know custom mounts are required, but is any hacking of the firewall and/or tranny tunnel necessary?

4)If a 20B is put in an FD without screwing with the firewall/tranny tunnel, how is the weight distribution of the car?

5)How light can a stripped race prepared FD get?

6)What amount of power can a NA 13B make while still being reliable for a full time circuit car (not drag)?

7)What amount of power can a NA 20B make while still being reliable for a full time circuit car (not drag)?

8)For the above two "motors", how often would a rebuild be necesary? And would would the rebuild consist of?

Please keep in mind these questions are for a full time track car, not a street car. Also, please spare the "do what's in your budget" answer, I am simply looking for some straight facts.
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Old 06-19-10, 12:38 PM
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Originally Posted by seakayracing View Post
Didn't know where to put this as my questions are all over the map.

I might be getting back into the rotards as the things I am hearing about p-ports are really impressing me. I have a few general questions:

1)How much does a NA 13B weigh minus tranny?

2)How much does a NA 20B weigh minus tranny?

3)How simple/complicated is the physical aspects of installing a 20B in and FD? I know custom mounts are required, but is any hacking of the firewall and/or tranny tunnel necessary?

4)If a 20B is put in an FD without screwing with the firewall/tranny tunnel, how is the weight distribution of the car?

5)How light can a stripped race prepared FD get?

6)What amount of power can a NA 13B make while still being reliable for a full time circuit car (not drag)?

7)What amount of power can a NA 20B make while still being reliable for a full time circuit car (not drag)?

8)For the above two "motors", how often would a rebuild be necesary? And would would the rebuild consist of?

Please keep in mind these questions are for a full time track car, not a street car. Also, please spare the "do what's in your budget" answer, I am simply looking for some straight facts.
1. something like 250lbs, probably with water pump/flywheel

2. not sure, maybe 300? 320?

3. depends, lately people have been moving the 20b as far back as they can without cutting the firewall.

4. depends on #3...

5. seems like people get to the 2350-2450 range, depends on the cage, and how nuts you get

6. a mazda MFR 13b with 48ida engine is [email protected] more to be had with efi, 2mm seals, the 9.7 rotors etc.

7. the MFR 20b/13G is [email protected]

8. depends on apex seal choice, the carbons need more frequent replacement than steel or ceramic. basically its not a rebuild so much as a tear down/ inspection. the re amemiya gt300 engine lasts about a full season, however long that is
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Old 06-19-10, 11:42 PM
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Thanks for the informative reply. Can FDs really get that light when stripped? Anyone on the board with stripped cars?

Can anyone confirm the weight of a 20B? How much does the 13B+FD tranny weigh?

what is mazda mfr? I find it really hard to believe that 450ps can be had with a 20B. Can only imagine an NA FD weighing 2300 pounds with 450ps....
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Old 06-20-10, 12:39 AM
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Originally Posted by seakayracing View Post
Thanks for the informative reply. Can FDs really get that light when stripped? Anyone on the board with stripped cars?

Can anyone confirm the weight of a 20B? How much does the 13B+FD tranny weigh?

what is mazda mfr? I find it really hard to believe that 450ps can be had with a 20B. Can only imagine an NA FD weighing 2300 pounds with 450ps....
MFR = mazda factory race, i took my numbers right out of the japanese mazdaspeed catalog

the weights are best guess...
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Old 06-20-10, 01:41 PM
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Why don't you take a look at some of threads in this section (like this one on the first page):

https://www.rx7club.com/race-car-tech-103/bigals-fd-20b-racecar-project-747809/
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Old 06-20-10, 01:48 PM
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Old 06-21-10, 06:56 PM
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theres a 13b single turbo fd in the uk running full cage as he races that weighs 1918lbs, thats the lightest fd ive seen
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