5th gear RPM to vehicle speed

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thefultonhow
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5th gear RPM to vehicle speed

Post by thefultonhow »

So the VSS crapped out on me in South Dakota and I now have no speedometer. My tach still works though. Does anybody know what RPMs correspond to the following speeds?

65 mph
70 mph
75 mph
80 mph

Thanks.
-- David

1990 Subaru Legacy L+ 4WD Wagon 5MT, white with 66k miles -- SOLD
[url=http://www.g20.net/forum/showthread.php?t=66214]1992 Infiniti G20 5MT[/url], White Sandstone with 175k miles
wiscon_mark
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Post by wiscon_mark »

3.9 FD?

65=2775ish
70=3000 on the head

not sure about the others, don't drive at that speed.

I'd assume 80 is about 3500 though.
[url=http://www.sl-i.net/FORUM/viewtopic.php?t=486]1995 Legacy Outback 5MT[/url]
185,000 miles
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evolutionmovement
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Post by evolutionmovement »

If 70 = 3000, then 1000 rpm = 23.3 mph. Divide speed in question by 23.3 and multiply by 1000 and you have your rpm. However, I'm not sure 70=3000 is correct. I have a 3.7 and I do about 27 mph/1000 rpm. Seems like a larger difference than it should be to the 3.9. 5th gear is .7xxx. I'm too lazy to look it up.
Midnight in a Perfect World on Amazon or order anywhere. The first book in a quartet chronicling the rise of a man from angry criminal to philanthropist. Midnight... is a distopic noirish novel featuring 'Duchess', a modified 1990 Subaru Legacy wagon.
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