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Registered
Join Date: Sep 2000
Location: Downingtown, PA
Posts: 138
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Converting auto to 5-speed
My son has a 78 924 with an automatic. The engine is a n/a with approx 75k on it. He is going to have to do several 10 hour drives (on interstates) over the next couple of years (going away to school). I am concerned about him running the automatic for that long as it doesn't really have an overdrive gear and the rev's at 60-65 mph are kind of high for cruising that long. I'm afraid he's going to beat the crap of the engine. Has anybody ever swapped an automatic for a 5-speed? Are there 4-speed automatics around that would fit?
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02-19-2001, 09:05 AM
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Join Date: Jul 2000
Location: Helena, MT, USA
Posts: 127
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What kind of RPM range are we talking about. Holding a constant RPM, even if its a little high, Is much better on an engine than stop and go driving. But their are limits. I used to road trip my 77 vette with a 3 speed auto. Aside from the crappy gas mileage the engine was fine.
------------------ If you drive it, Race it Dave '87 944 |
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02-19-2001, 04:35 PM
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Join Date: Sep 2000
Location: Downingtown, PA
Posts: 138
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He's probably turning 3500-3700 at cruising speed. I used to drive 3-speed (and even 2-speed) automatics back in the 60's and they were geared similar to my son's 924. It just seems to me that a lot of cars in the 60's and 70's only lasted 80k or so miles and I always felt gearing was a major contributor to early engine failures. Once 'overdrive' became standard, it seemed like engine life started to increase.
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02-20-2001, 03:37 AM
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Join Date: Feb 2000
Location: Athens Ga
Posts: 184
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Well I dont know about the 924 but my 85 944 auto has 180K+ on it original trans & motor. It's been from UCLA to Athens GA and back twice since I got it. I think it to be in good shape sinc eI just replaced the trns pan seal and I saw a minimal amout of shavings in the pan.
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02-20-2001, 05:06 AM
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Join Date: Sep 2000
Location: Downingtown, PA
Posts: 138
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Ven, just for a comparison, what rpm do you run at 60 and 70 mph?
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02-20-2001, 05:36 AM
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Join Date: Jul 2000
Location: bergen county
Posts: 459
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IMO..install an aftermarket transcooler...if i am not mistaken it is around 50.00 dollars...this should solve the ur problem...just my 0.02 cents
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02-20-2001, 07:00 AM
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Join Date: Jan 2001
Location: Laurel, MD, USA
Posts: 106
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I run my 88 3spd auto at about 3900 rpm at 75mph, and 4100 at 80. FYI: the 944 has an AT fluid cooler (lines run up to radiator and back). Is the 924 different?
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02-21-2001, 07:43 AM
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Registered
Join Date: Sep 2000
Location: Downingtown, PA
Posts: 138
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Tom, I don't know if it has a transmission cooler. I doubt if it does - they are kind of light weights... Your car does turn the same rpm's at speed as mine...
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02-21-2001, 11:23 AM
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Registered
Join Date: Feb 2000
Location: Athens Ga
Posts: 184
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4K @ 80 flat.
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02-21-2001, 02:32 PM
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