I have a 91 turbo auto car that I just swapped to a 5 speed. When i'm driving the rpms seem way higher then they should be? In 5th gear at 60mph i'm at like 3100rpm, 4th gear at 40mph is 3000rpm, does this seem high compared to cars that came 5 speed? Or maybe my auto tach doesn't register right? But if defiantly seems to be at 3k rpm at 60mph.
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- Thread starter CrazyInside
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You would be correct. The proper RPM for a 91 turbo with an R154 is 2272RPM's at 60MPH. A couple of questions.
How are you measuring MPH?
Where did you get the R154 from?
Are you running factory size tires?
Are you sure that the original diff is in the car?
How are you measuring MPH?
Where did you get the R154 from?
Are you running factory size tires?
Are you sure that the original diff is in the car?
The RPM measurement should not be affected. Your RPMs don't seem far off.
*What trans and diff do you have?
*What trans and diff do you have?
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Same thing happened to me. In my case the r154 came out of an early MKIII and I didn't know at the time to swap the little plastic speedo gear that goes in where the speedo cable connects into the trans. As a result, my speedometer is around 10% lower that what I'm actually doing. So the tach looks like it's reading higher than is should when in reality it's the speedo that's off. If I wasn't using my gps one day, I probably would have never noticed how much slower the speedometer was actually reading.
If he got the transmission from a 88-92 turbo car, it'll be set for the 3.73 rear gear speedo gear already. If he got the transmission from a 87-88 turbo car, it'll be setup for a 3.91 speedo. You'll need to swap over the entire speedo assembly IIRC because the gears from transmission to transmission have a different degree to the gears themselves.
But there is a lot of questions that need to be answered to accurately answer this question.
But there is a lot of questions that need to be answered to accurately answer this question.
Changing speedos won't make a difference, as most toyota speedos calculate speed based on 1026revs=1mile. So speedos from all years read the same unless they have worn out and are out of calibration. Which is a different story. Also speaking of the speedo gears in the transmission. There are two of them, a driven and a drive gear, and they both have to be changed to match whatever your final drive ratio is in your differential.
Ah, ok. When you said Speedo Assy. The actual speedometer assembly from the gauge cluster is what popped into my head.