Bernie
Full Version: Rear axle ratio?
It seems like my engine revs a lot at freeway speeds. The oil temp comes up to the danger level if I run at these speeds for any length of time. (3400 rpm at 70 mph) I have a 1.8 with FI and it runs normal to rich? cleaned the oil cooler put in new flaps thermo. what could be causing this problem.
Bernie
Bernie
What size tire Bern ??
3400 is a couple 100 rpm over what I think it should be.
B
3400 is a couple 100 rpm over what I think it should be.
B
B.
they are 195x60 15s hp4s
Bernie
they are 195x60 15s hp4s
Bernie
The problem is I installed the 911 guages so I have oil pressure and temp in the dash pod. so now I know. oil pressure drops to 1 duck when it comes to idle when hot.
Bernie
Bernie
Bernie,
when hot with regular oil the car might have 15lbs of oil pressure at idle. Synthetic could be a tad LOWER. Do you have the flaps under the firewall ??
All the teeth on the fan ??
Timing set correctly ??
B
when hot with regular oil the car might have 15lbs of oil pressure at idle. Synthetic could be a tad LOWER. Do you have the flaps under the firewall ??
All the teeth on the fan ??
Timing set correctly ??
B
clutch holding up?
Bern,
the other thing I see repeatedly: people replacing the oil cooler seals and pinching them half closed during reassembly.
B
the other thing I see repeatedly: people replacing the oil cooler seals and pinching them half closed during reassembly.
B
B
Timing is correct, have flaps, next change will be syn, clutch is good, haven't had motor out to check lines for crimping. have a 2L core engine that I will rebuild and install when I get rich. is a exterior cooler nessessary?
Bernie
Timing is correct, have flaps, next change will be syn, clutch is good, haven't had motor out to check lines for crimping. have a 2L core engine that I will rebuild and install when I get rich. is a exterior cooler nessessary?
Bernie
I think i get about 3100-3200 rpms maybe a tad lower in 5th gear while going ~about 70mph...w/ 165 r 15 cooper tires.
Bernie,
I assume you either calibrated your 911 guages to work with your engine's pressure and temp senders or you replaced the senders. If not, you'll get bad readings.
Douglas
I assume you either calibrated your 911 guages to work with your engine's pressure and temp senders or you replaced the senders. If not, you'll get bad readings.
Douglas
new senders to match.
Bernie
Bernie
"Druck" is German for "pressure".
1 on the gauge is 1 Bar, or one atmosphere. 1 Bar is about 14.5 PSI. Which is quite enough for your motor at idle--you don't start worrying until you see less than 10 PSI at warm idle.
--DD
1 on the gauge is 1 Bar, or one atmosphere. 1 Bar is about 14.5 PSI. Which is quite enough for your motor at idle--you don't start worrying until you see less than 10 PSI at warm idle.
--DD
Tire size has no bearing on rpm vs. odometer indicated speed, since both gauges are connected to the engine/gearbox.
There are only two final drive ratios, with the shorter one being about 10% under the stock one. That would put rpm up by more than 300 at 70mph if you had the short R&P installed. That is unlikely in a street car, since the alternate is somewhat rare.
I guess it's possible that one of your gauges is calibrated wrong. Perhaps the zero point of the tach is off. The easiest way to test would be to wire up a different tach.
There are only two final drive ratios, with the shorter one being about 10% under the stock one. That would put rpm up by more than 300 at 70mph if you had the short R&P installed. That is unlikely in a street car, since the alternate is somewhat rare.
I guess it's possible that one of your gauges is calibrated wrong. Perhaps the zero point of the tach is off. The easiest way to test would be to wire up a different tach.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.