1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

RPM At Freeway Speeds

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Old Mar 29, 2002 | 10:39 PM
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Question RPM At Freeway Speeds

How fast is your engine spinning at freeway speeds in the different gears? (5th, 4th, 3rd?)
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Old Mar 29, 2002 | 10:57 PM
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From memory, its been since september when I drove my 85 last. But I think in 5th at 70mph it was 3100 rpm...
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Old Mar 29, 2002 | 11:12 PM
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yea in 5th doing 65-70 mph the engine is around 3000-3100. Something like that. Last time I was on the highway I kept it in 4th cause I was racing some homeboy in a lowrider truck (smoked his *** ). Goin 80 the tach was at 4300 rpm. hope that helps. Oh yea, in New Jersey they're called Highway's
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Old Mar 29, 2002 | 11:27 PM
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5-speed '84 GSL with 205/60/13 tires.
5th @ 70mph is 3500 rpm
3rd @ 70mph is ~6700 rpm
1st @ 60mph that blew last time
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Old Mar 30, 2002 | 01:57 AM
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5th @ 70 is about 3,500

my tach stays pointed in pretty much the same direction as my speedo on the freeway
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Old Mar 30, 2002 | 06:29 AM
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Mine is around 3,000 when doing 65 in 5th gear.
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Old Mar 30, 2002 | 10:21 AM
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at 60mph...
5th - about 3100
4th - about 3800-3900
3rd - don't drive it that fast in 3rd (no power up there, just noise)

Despite what the books say, my '85 seems to have a shorter 5th gear than the '80 did. The '80 was 3000 at 60mph in 5th. 3rd gear I think was something like 5000-5500, usually not paying attention to the speedometer if I'm winding it out like that
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Old Mar 30, 2002 | 10:28 AM
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That's about THE most nagging thing about first gens.

I HATE that the car is doing so many RPM to cruise on the highway. I *wish* they had a 6th gear, or a smaller 5th.

My Ford Screw is at like 1600 RPM at 70 mph on the highway. Barely feels like idle.

I am putting a TII tranny in my car as part of my project, but I recently read the gear ratios, and I don't think there was any real improvement for the 5th gear ratio.

Oh well.. short of changing the rear end to something smaller, anybody have any idea's?
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Old Mar 30, 2002 | 11:28 AM
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My beef is that 5th is TOO tall and I rarely use it...

One of my "evil ideas" is having new 5th/Reverse gears made, make 5th gear around 4.8:1 or so (need to do math) and change the positions of 5th and reverse, and then alter the shift fingers. Basically the old 5th gear would become the new 1st gear, Reverse would be to the left and up, 1st would be to the left and back (dogleg first! YES!) and 2nd to 5th would be the standard H pattern, and 5th gear would be 1:1. Then put something like 3.7 gears from an RX-3SP in it so 1st gear isn't too deep.

This is similar to the close-ratio 5-speeds used in some BMW's, with the dogleg First and 1:1 5th. Why go through all the trouble? Besides being cool as all time (which it would be) it would also greatly reduce driveshaft RPM. One problem with running deep gears (like 4.88's) is that the driveshaft wears the transmission's output bushing very rapidly because of all the extra RPM the driveshaft is turning.

Directfreak, if you REALLY want a TALLER 5th gear (well, i suppose there aren't too many hills in southern Florida) you could grab an FC transmission. They have stupid-tall 5th gears.
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Old Mar 30, 2002 | 11:52 AM
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I hear ya... those 2nd gen 5th gears are brutal. Great for highway fuel economy though .
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Old Mar 30, 2002 | 12:11 PM
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sounds like a hard job peejay
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Old Apr 1, 2002 | 02:34 PM
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Those 2nd genz gears are very usefull when you have power to go through them :]
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Old Apr 1, 2002 | 02:43 PM
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From: 3OH5
Originally posted by peejay
Directfreak, if you REALLY want a TALLER 5th gear (well, i suppose there aren't too many hills in southern Florida) you could grab an FC transmission. They have stupid-tall 5th gears.
Okay, next question. Who here as a 2nd Gen Tranny in their car (Turbo II preferred)? What kind of RPM are you at 65 MPH?

Thanks
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Old Apr 1, 2002 | 03:44 PM
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Y0u freak... I think 2nd is gear @ 7500 rpms is right about 65mph.. but then again.. if you have the time to look @ the speedo as it hits 65.. then you need more boost. :] ...
I wan't a rematch damnit.!!!!
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