-----Original Message-----
From: George Schiro [mailto:gschiro@lni.net]
That is quite a project!!!
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You're telling me! ;)
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Are you planning to keep the existing shock towers?
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No, the frame rails for the new chassis are in the same place as the
originals, but all of the suspension and it's mounting to it will be new in
the front and rear.
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Will the RX-7 tranny (I assume it is a 5 speed manual) handle the torque?
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It ought to. 400hp isn't that uncommon for an RX-7 motor, although the car
will almost certainly be heavier than most RX's. The big thing with that
tranny is that you've got to baby the synchros a bit - match the revs on
upshifts, heel-and-toe on downshifts, and it will be fine.
I know a guy who drag races a 550hp 2nd-gen with a full interior that weighs
in at almost 3000lbs - On one particularly hard launch with particularly
grippy tires, he sheared the lugs, but he's never had to change or fix his
tranny.
Not bad for a 75-pound unit. ;)
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Is there a 4 speed automatic that will fit the engine?
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Don't know, don't care. ;)
There was a 3-speed auto used in the RX-7, but apparently they're not very
good. The rotary shares a bellhousing bolt pattern with some other Mazda
motors, so there's a decent chance that if there's a 4-speed auto for a
B2000-series pickup, it might fit.
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With that much re-working, it might make sense to build an aluminum chassis
to replace the steel.
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If I was starting today, I'd seriously consider it. This all started when I
got the body off my frame and it turned out to be _totally pooched_. I
commissioned some race car guys I know to build me a near-stock replacement
(plus some extra gusseting, etc). The original plan was to just go with the
Lincoln Versailles rear end, a 4-point cage, and a strut brace and poly
bushings up front.
1. "Well, how hard would it be to go to coil springs in the back?"
2. "Hmmm... Maybe I should just put a Vette IRS in there..."
3. "If I'm going to do that, I guess I'm going to need some big wheels and
tires"
4. "With all the mods I'm doing, I really should widen the track to take
advantage of them"
5. "Boy, it sure would be a shame to have that recirculating ball steering
setup be the weak link in the chain - better go with a rack and pinion"
6. "Well, if I'm moving all the mount points anyhow and changing the
steering gear, why not just go with an all-custom setup?"
7. etc.
8. etc.
9. etc.
;)
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That way you could really increase torsional stiffness by adding a backbone
tunnel. Such a frame can get down to 200 pounds ( less the birdcage which
is probably too expensive to duplicate). The other nice thing about making
up a new frame is that you can add all the adjustments for camber, castor
and lateral weight transfer.
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Yes, all those adjustments will be there (front and rear) with my new setup.
But it won't be aluminum. :(
Oh well, maybe next time. :)
--
Phil Martin pmartin@surgnav.com
"I'm a Charger, charging through the night,
Like an orange bolt of lightning passing everything in sight"
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