5th gear Why no power

[viceroy]

Alrighty I have a mk1 172 and live at high altitude which means I only make about 120hp @ wheels.

I dont really have a problem with the power, what I do have a problem with is my 5th gear...makes me wonder if everything is working as it should.

Ive taken the car on a high speed oval and couldnt manage more than 196kph (121mph), which is about 5600rpm in 5th.

Thing is Acceleration in 1st, 2nd, 3rd and 4th is strong and Im easily able to get to the limiter, but when it comes to 5th the car wont accelerate past 5600rpm, its like there isnt enough power to overcome the the drag...How can I not make it past this speed.

Could it be my 5th???? I have a hard time trying to out accelerate 1.6 cars in 5th I know the Clio lacks torque until about 4000rpm but even so I shouldnt have the problems Im having...should I?

Yet every other gear is great, put my foot down, even at 1500rpm and the car pulls cleanly and smoothly all the way to the limiter, yet in 5th I really struggle and only to 5600rpm.

Surely even with only 120bhp @ wheels I should have the power to go faster?

 

[viceroy]

No-one have any opinion?

 

[viceroy]

Guess no-one knows then

 

[Liam]

doesnt sound right does it, should still be pulling in 5th. Have you driven other 172s?

 

[dazraffan]

losing all that power becase of altitude were the f$*k do you live nepal?

 

[George16v]

You need to get a chip matey, makes a massive difference to the 5th gears torque

 

[James 182]

see the dealer mate

 

[Weeman]

South Africa, Joberg I believe, and yes the altitude saps loads of power.

 

[JayGTT]

What fuel you using? 172 you should really use 98 RON

 

[DAVE_RSi]

how many miles u done in the car??

trip to the dealer maybe??

 

[viceroy]

Yep, JHB, South Africa +- 1650m above sea-level

Car is chipped with a SMT6. Also got a decat and 63mm catback custom system

Fuel wise we ONLY get 93RON here...

Car has well over 30k miles on the clock so nicely run in.

I did low 16s 1/4 mile (before chip and zorst) and also do 7.9s 0-62mph which is quicker than my mates ex 172 which was always at least 0.2-0.5s slower on the strip. Ive gone up against other 172s on the street and track and mine has always proved to be quicker...hell even my mate who had a Golf VR6 which put down 155bhp @ wheels up here at altitude commented that my car is fuggen quick off the line so doesnt seem to be anything wrong with it...just cant get the damn thing quicker than 120mph (actual speed through a speed trap)...maybe it is just aerodynamics

Next time Ill lay the aerial flat on the roof and fold in the side mirrors to see if that helps.