Am I losing it

[viceroy]

A while ago I posted that in 3rd I was reaching 150kph (93mph) @ 7000 rpm which seemed a tad high. I tested this a few times on the same night to make sure.

I was out last night and thought Id give the car a bit of a blast. To my suprise:


1st - hit the limiter just over 60kph (37mph)
2nd - hit limiter just over 100kph (62mph)
3rd - hit limiter at 145kph (90mph)
4th - hit the limiter at about 185kph (114mph)
How can the show such a difference from last week to this week? or am I just losing it???

At least these speeds seem consistant with other mk1 172s

 

[tonykart]

was the outside temprature the same ?

oil temperature ?

150 @ 3rd is normal for a 172

When mine was original Id dynod the acr. I did 148 Kmh in 3rd and 187 in 4th both till rev. limitter



Now its a bit faster

 

[viceroy]

outside temp was about 18 degrees

Oil temp, dont know for sure but the car was properly warmed up both times and the limiter kicked in at 7250 both times

I just think its strange that one night the car is doing over 150 in 3rd and another night the car hits the limiter at 145

 

[BigBoreBri]

I noticed on mine most days if it was warm n stuffy the car ran poor, in general my car did the following with a green induction kit and a K-Tec exhaust...

1st - about 40mph

2nd - about 65mph (wouldnt go above 60 till the zorst)

3rd - about 90mph

4th - nearly 120mph

5th - got to just over 140mph

 

[rt172]

1st about 40

2nd about 65

3rd about 89

4th about 120mph (goes to 121mph right on limiter)

5th 145 flat out (on private airstrip of course)