Redline

[chitwnvw]

What's redline on a T4 1.7?

[bottomend]

5300 RPM? I'm probably wrong here.

[Amskeptic]

What's redline on a T4 1.7?

5,400 bus all 5,800 Porsche 1.7

Your #2 main bearing will be getting beaten oval above 5,000 rpm.

Redline operation is only useful if you do not have time to shift in an emergency. You can wing it up to 60 mph in 3rd early bus, 70 mph later bus. And if there were no air resistance, 102 mph in 4th.
Colin

[chitwnvw]

My bus seems to like 3-4000 rpm, just wanted to know what kind of headroom I had.

[Amskeptic]

My bus seems to like 3-4000 rpm, just wanted to know what kind of headroom I had.

Factory cruising rpm, the speed at which these engines were designed to operate indefinitely, is approximately 4,000 rpm for Type 1 engines and 4,300 rpm for Type 4 engines.
Colin

[Hippie]

... You can wing it up to 60 mph in 3rd early bus, ...
Colin

My 1600 torque curve slopes pretty sharply downward after 50 MPH in third though.
I gain more in a panic merge-scramble if I kick her on up to fourth after ~52 MPH...Maybe it's my tuning.


Rob

[Amskeptic]

My 1600 torque curve slopes pretty sharply downward after 50 MPH in third though.
I gain more in a panic merge-scramble if I kick her on up to fourth after ~52 MPH...Maybe it's my tuning.

Type 1 engines definitely get unhappy above 4,400. And yes, the state of tune can strangle an engine at high rpms. But remember, there are occasions where the time to shift is more of a dteriment than spinning that sucker up. Wheel torque goes down on each upshift even as the engine is returned to its torque peak by shifting up.
Colin arcane its all arcane

[Hippie]

... arcane its all arcane

Let me see if I got it right:
I don't maybe have time to play with that goddam-tranis-mission with JB Hunt ridin' my ass all the way up the ramp?



Rob