caber
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| posted on 20/7/06 at 08:33 AM |
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Automatic?
HAs anyone looked at an auto box for a 7? I was reading about the Chapparall can am cars in the 70s that used torque converters and initially a single
speed box and latterly a three speed very successfully because the power to weight ratio was so high they gained more than they lost through using an
automatic on lap times.
I was wondering what auto boxes were used on Fords that have the same arrangement as the type 9 box.
TIA
Caber
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donut
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| posted on 20/7/06 at 09:03 AM |
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No reason why not although resale value will drop as no one wants an 7 auto (except me!!!!) as people see these cars are racers/sports cars. I have
seen 1 auto but the owner was disabled. I think it's a great idea..... but then i like left of center stuff!
Escort Mk2 would be ok with it's 1600cc Xflow.
[Edited on 20/7/06 by donut]
Andy
When I die, I want to go peacefully like my Grandfather did, in his sleep -- not screaming, like the passengers in his car.
http://www.flickr.com/photos/andywest1/
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smart51
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| posted on 20/7/06 at 09:31 AM |
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Was there ever a sierra auto? It seems likely. If the sierra auto box fitted in the same place in the sierra as the manual then it doesn't seem
unreasonable for the auto to fit in the seven.
The torque converter only idea is interesting. Torque converters have a torque multiplying range of between 2 and 3:1. When it is slipping, it
multiples the torque and as it reaches its normal speed, the torque multiplication reduces. If you had a fixed single gear of 15 MPH / 1000 RPM (a
bit like 3rd in a manual box) the torque converter would slip to as low as 5 MPH / 1000 RPM or 1st in a manual.
You would pull away in "1st" and gradually slip through "2nd" to you fixed 3rd. You'd have a top speed of 90 at 6000
RPM but the transmission would be very light.
[Edited on 20-7-2006 by smart51]
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smart51
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| posted on 20/7/06 at 09:58 AM |
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perhaps you could fit an overdrive as well so that you could have two ranges 1st to 3rd and 2nd to 5th.
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graememk
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| posted on 20/7/06 at 10:16 AM |
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i was thinking about auto at the start of my build due to lack of room in the footwell for my feet, i bought racing boots insted.
although i see alot of auto cobras around
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David Jenkins
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| posted on 20/7/06 at 10:23 AM |
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I don't believe that an auto box is truly in the spirit of a 7-style car, even though I like auto tin-tops.
However, I am a firm believer in people building whatever takes their fancy, so if it fits and appeals to you then go for it!
David
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Just
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| posted on 20/7/06 at 10:26 AM |
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There were definitely auto sierras - an entire section for the auto box is covered in the haynes manuals.
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Lawnmower
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| posted on 20/7/06 at 10:41 AM |
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My wifes got an auto mk1 Mazda MX5, with an over drive. It got the 1.6 engine, which when coupled with an auto, are made to be more torquey at lower
revs, bet less peak power. It nice to drive and fun, but it aint that quick, and will only just beat over cars away from the lights. When I buildi
mine, and if i do decide to use an max5 as a donor, I would go for the 1.8 engine couples to the 6 speed box.
Sithcing the OD on or off takes about a second...as does the kick down, shift down. etc. plus you it will change gear sometimes at random when you
dont want it too, ie you let off the gas for a corner, and it changes into a taller gear, then you it wont changes back down into the lower gear to
pull away. a bit annoying. may just be my driving style.
(would love to supercharge it, but on this car means losing the air con, and SWMBO wont let me)
IMO
to take full advantage of it, you need a more powerfull engine, more torquey at low revs , such as a v8!
or go for a bike engined car with paddle shifters!
[Edited on 20/7/06 by Lawnmower]
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asn163
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| posted on 20/7/06 at 11:23 AM |
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I know that last year MAC#1 supplied a chassis for use with an autobox, I think that the running gear was from a 1.8 Sierra.
Simon
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britishtrident
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| posted on 20/7/06 at 01:30 PM |
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Most automatics are a bit on the wide side because of the sump, however auto boxes have been fitted to MG Midgets and Lotus fitted one on some 70s/80s
Elites.
Best source would probably be a Mk1 Escort, Mk1 Capri or Mk 2 Cortina as they use the BW35 box --- very strong, the later Fords used the Ford C3 or
C4 boxes which don't take to hard use.
Which ever auto you use you will end up with a massive gap between the gear ratios.
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