 Which is a better ratio for "first" in a V8?, A or F? |
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| bondo |
 Sep 19 2004, 10:43 PM
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#1
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Practicing my perpendicular parking  Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California  |
I have an A and an F (stock) mainshaft, which should I use for my V8 conversion? I think I know the answer, but I thought I'd get some confirmation. These are both ratios that would be in the second gear position, and not subject to the "cantilevered first gear" weakness. F is the stock second gear ratio, and is what most V8 conversions use. My gut feeling is that the A ratio (same as the stock 914 first gear) is way too low for a V8, but F seems a bit high (stock 914 second gear ratio)
I will be using an H flipped as "4th" gear (in place of 5th), and will be spacing out "2nd" and "3rd" based on the "1st" gear choice, using what gears I have. |
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Replies(1 - 5)
| smrz914 |
Sep 19 2004, 11:06 PM
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#2
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Soon to be brightening the life of the person behind you. Group: Members Posts: 456 Joined: 21-April 03 From: Pleasant Hill, CA or Chico, CA Member No.: 596 |
First gear in a 914 with a v8 is really low. Never used it never had a desire to. Not to mention you shouldn't use it. I think that the stock 2nd gear is a tad high but very usable. If your choices are to use a "1st" gear ratio vs "2nd" gear ratio i would go with the 2nd gear ratio. My engine has about 280 hp and 330 ft/lbs tq. I'm running a stock tranny (IMG:style_emoticons/default/sad.gif) . Use the second gear ratio.
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| ArtechnikA |
Sep 20 2004, 03:24 AM
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#3
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rich herzog Group: Members Posts: 7,390 Joined: 4-April 03 From: Salted Roads, PA Member No.: 513 Region Association: None |
or you could find an 'E' 2nd gear mainshaft ...
Charlie Davis' website shows the transmission type numbers that used the 'E' 2nd. cross-referencing those back to ccar models is left as an exercise to the student, but the information should be in Anderson, Barth's 'The Porsche Book' and 'Excellence was expected' ... |
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| propricer |
Sep 20 2004, 08:12 AM
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Member Group: Members Posts: 365 Joined: 16-April 04 From: Morgan Hill, CA Member No.: 1,938 |
1st is MUCH too low and will cause breakage.
Use 2nd ... MUCH smoother yet still allows burnouts, not that you would EVER do that !!! H conversion is also a GOOD idea. Good luck ... |
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| Andyrew |
Sep 20 2004, 09:31 AM
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#5
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Spooling.... Please wait Group: Members Posts: 13,378 Joined: 20-January 03 From: Riverbank, Ca Member No.: 172 Region Association: Northern California 
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Currently, I broke my throttle cable... Sooooooo Im using a 2k idle, and first and second to get around the block.. Then just coast around at 15...
ahh the joys!!! |
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| bondo |
Sep 20 2004, 10:04 AM
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#6
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Practicing my perpendicular parking Group: Members Posts: 4,277 Joined: 19-April 03 From: Los Osos, CA Member No.: 587 Region Association: Central California |
Cool, thanks. That's pretty much what I thought, just wanted to hear it from others (IMG:style_emoticons/default/smile.gif)
That makes these my chosen ratios: "1st" F 18:34 "2nd" V flipped 25:27 "3rd" ZD 31:22 "4th" H flipped 32:19 Which, if I'm not mistaken is what they say to do anyways, which means all my math effort was a waste of time (IMG:style_emoticons/default/smile.gif) Looks like all I can use from the 912 4 speed is the H gear (and the nifty magnetic drain plug) Does anyone know if the intermediate plate or differential cover are interchangable? They are both aluminum and should be stronger. |
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