Dyno test - weak results / engine compression

[lukasz]

Hi Guys,
Yesterday i made dyno test of my 2007 Clio (200k mileage) and results are weak - 173HP and 196Nm. Does anybody know, what should be the pressure in the cylinders?

 

[RSRowe]

That doesn’t seem too bad for an old engine.
The compression figure isn’t too important, but the difference between each cylinder.

 

[lukasz]

We already checked compression in three cylinders - 12 bar (174 psi) in each.
In the fourth we did not measure because we could not unscrew the spark plug.

I know that the engine isn't new but difference vs claimed power is quite big.
Any ideas what else should we check?

 

[RSRowe]

It's not that big. Not many 197's made the official quoted power figures.
~10% is well within the inaccuracy of chassis dyno's. My own car ran 193 stock. My friends 179.

Presuming you have no fault codes present, there's not much more you can do other than chucking parts at it.

 

[Dave W]

Most manufacturers design their systems to live for ten years/150k miles. Engines are no different. Performance is normally certified by Authorities of being able to make the claimed power for a given fuel. Once that is declared, you are then allowed a +/- 5% called COP (Conformity Of Production) to allow for tolerances in build etc. The industry authorities monitor the self certification of the manufacturers to make sure their audits fall within that tolerance band. The declared performance is PS rather than bhp. 197ps = 194bhp. Assume your engine new might have been at 194bhp less 5% and you're then at 184bhp from the factory.
So really, when you look at it like that, losing 9bhp over 200k when normally it could really do with a good check over isn't that bad. And 174psi is perfectly fine for compressions but get some WD40 down that remaining plug thread. Good luck.

 

[GeorgeG]

These engines are among the most inconsistent in producing their quoted horsepower.. mine made 202bhp at EFI with only a toyo manifold but others need cams to get above the 200 mark.

If your timing is correct and the engine feels healthy don't go down the rabbit hole of what is wrong with the engine.

if i was you i would potentially take it to another rolling road just to confirm the numbers

 

[Foxspeed]

200k mileage and your worrying about a few bhp!

some engines would be dead at that...

get the cam timing checked/dialled in new plugs and & quality oil in and enjoy it

 

[Abdulla Ali Al Ali]

Don't get bothered with dyno figures as long as the car drives smoothly and fault free

 

[HillclimbRS200]

Did you ever find your missing bhp? My RS 200 (with a much lower mileage) has just come back from its first RR run with virtually identical power and torque curves to yours.