What's your 5K kick like?

[7MAT]

Over on cliosport.net I have read many threads that describe the 182’s 5K kick.

I had often thought that these threads over hyped the kick as I can only just feel an increase at 5200 revs in my Trophy, but recently I drove Steve’s (sm wrc) 182 and his car really does kick, whereas my power delivery is much smoother?

Why is this?

 

[Cue]

is steve's standard?

 

[7MAT]

is steve's standard?

Steve's car has a custom 2.25" bore back box and centre pipe and std cat.

My car is running with Janspeeds 2.25" back box, centre pipe and sports cat.

I believe both cars are running with uprated panel filters, but thats it.

 

[drexel]

i wouldnt say mine was smoth. Violent i suppose

 

[fazedesign]

Mine's addictive!!! :twisted:

 

[OliS]

There really should not be any difference between the two, perhaps it is down to mileage and how run in the engine is? What's the mileage on the two cars?

 

[FunkyMunky]

i'd say mine is really noticeable, even now 2 and a half months later, agree with drexel in trying to find a word to desribe it - violent and a bit of a kick in the back

 

[Day]

I never notice mine any more - it's 5 years old now so fully run in.

Might go for a spirited drive later and rediscover it!

 

[Drew196]

The Trophy pulls a lot harder lower down the revs than my old 182 cup - there's still the kick at 5000 but it seems to be more gradual. The 182 cup didn't seem to have as much below 5000 then bang!!

 

[Steve]

After reading a little bit about it in this month's EVO, I have noticed that is just over 5000 revs but not 5500 as when the timing change is programmed to happen. I absolutely love it and if I increased my power output to 200bhp but lost the kick I have to say I would be really disappointed. I've got it absolutely down to a tee now, rolling along in fourth gear at 45mph, drop it into second, it dials up 4900rpm, foot down and you're right into the power band untill it hits the limiter (also fun). I did it this morning at before some traffic lights on a dual carraigeway (70mph) when three cars suddenly pulled over and I had a clear run through the lights, I was only doing 35-40 so it accelerated nicely to 5000rpm then really gave me a shove in the back, changed up to third and got it all over again, Brilliant!

If any technical gurus on here can explain EXACTLY what happens at these revs, it would be great, I've heard so many people (especially on cliosport) bullshit about 'coming on cam' and other crap, when we all know there is no secondary cam or profile change. The fact that it isn't so noticable when any modifications are done to the induction/exhaust systems is testiment to this.

 

[dcw@pr]

i get a pretty distinct kick, think its about 5.2 on my rev counter

http://auto.howstuffworks.com/question229.htm

 

[George K]

As far as I can gather the inlet cam is retarded until about 1,500 rpm and then advances fully (this helps stabilise the idle and town crawling with cam profiles which although modest are too extreme for a MAF system) - according ot Ben R of AWT, it also is retarded at 6,800 for reasons which are probably to do with longevity. What happens circa 5,000 is that the fuelling system changes from closed loop to open loop and thus can run a bit richer for max power. The relative kick will depend on how lean it was below 5,000. It does sound as though the Trophy may have been mapped for best performance throughout the range, hence less of a noticeable kick.

Going open loop is why modifed engines need re-mapping. What I now would like to know is whether it is feasible to stop the inlet cam retarding at the top end. Any takers!

 

[son of solo]

my trophy has a real kick at just over 5000rmp....this is mentioned in this months "evo" magazine page 133....apparently the variable timing switches 11 degrees at 5500 rpm thus giving the kick....the new 197 however changes continuously through out the rev range.... :shock:

 

[MickD]

Talking of the 5k kick, could one of you technically minded people clear something up for me?

I have been told that the ECU on these cars constantly re-programs itself to suit your driving style.

In other words, if you spend a few days doing nothing but trickling through traffic and going along single carriageways in heavy traffic then some of the 5k kick is lost and you get more torque lower down the range.

If you then get the chance to cane it a few times the ECU re-profiles and the 5k kick comes back to what it was and some torque lower down is lost.

This is the way mine seems to run, or is that just my imagination?

Is any of the above true or is it all bull :?:

Thanks

 

[7MAT]

^^^^^^^^^^^^^^^^^^
Not heard that one before.

Driving home from work today I could feel the car increase its pace at 5200 revs but its hardly an aggressive kick as in Steve's car. Not sure if its something to be worried about or just be happy my car is producing a bit more low/mid power.

I've wondered if its the sports cat? But I don't remember having an more agreesive kick before it was fitted. Guys with de-cats fitted do your cars still kick hard?

 

[son of solo]

its your imagination

 

[MickD]

its your imagination

Very probably :lol:

 

[7MAT]

its your imagination

Very probably :lol:

I just wish it was ......

 

[Steve]

Advanced valve timing in the F4R.

After reading a little bit about it in this month's EVO, I have noticed that is just over 5000 revs but not 5500 as when the timing change is programmed to happen. I absolutely love it and if I increased my power output to 200bhp but lost the kick I have to say I would be really disappointed. I've got it absolutely down to a tee now, rolling along in fourth gear at 45mph, drop it into second, it dials up 4900rpm, foot down and you're right into the power band untill it hits the limiter (also fun). I did it this morning at before some traffic lights on a dual carraigeway (70mph) when three cars suddenly pulled over and I had a clear run through the lights, I was only doing 35-40 so it accelerated nicely to 5000rpm then really gave me a shove in the back, changed up to third and got it all over again, Brilliant!

If any technical gurus on here can explain EXACTLY what happens at these revs, it would be great, I've heard so many people (especially on cliosport) bullshit about 'coming on cam' and other crap, when we all know there is no secondary cam or profile change. The fact that it isn't so noticable when any modifications are done to the induction/exhaust systems is testiment to this.

Well, I didn't get any answers, so I decided to do my own research and I know exactly what the 5K kick is now and it's very simple. I don't know what all the talk is of a butterfly valve in the cold air feed hose, this might be something else (which could explain the loss in torque at low revs when this original system is replaced by an aftermarket IK) but the 5K kick is simply an advance in valve timing.

Whereas a Honda VTEC (Variable Valve Timing and Lift Electronic Control) or a Toyota VVTL (they're the same idea) brings a secondary cam lobe profile into play by having a redundant rocker arm and extra intake cam that activates at high RPM to increase the duration of valve opening and degree of valve lift therefore increasing the amount of fuel and air entering the cylinders, the F4R engine in the Clio 182 simply advances the valve timing, so at high engine speeds (5500 RPM in the 182) the camshaft is rotated ahead 11 degrees, advancing the valve timing by making the intake valves open sooner but close sooner, this system is not as good as a variable timing and lift system because it doesn't increase the duration that the valves are open for or how much they lift, but is a simple and effective way of increasing the power at higher engine speeds without making the engine rough as arseholes at idle.

The new 197 incidentally, has variable valve timing, that rotates the camshaft gradually across the rev-range and up to as much as 45 degrees. So, it will have a stronger top-end but won't have the 5K kick caused by the on-off nature of the 182's timing advance.

An engine re-map would undoubtedly exploit this timing change to bring it on a bit sooner maybe, but it can't be advanced at too low RPM's or it won't increase power at all, just make the engine run rougher.

 

[George K]

Steve, if you go back to my post on page 1, you will see that my information is in conlfict with yours. I am lead to believe that at about 1,500 - 1,650 rpm the inlet cam is advanced by 15 degrees - and the Schrick valve timing data would confirm this amount of advance - apart from a possible retarding at 6,800 the inlet cam does not move again. The 5,000 kick is due ot the fuelling going open loop, i.e moving away from a self correcting lambda number.

You correctly state that the new 197 engien has a a fully variable inlet, which does enhance the benefits - possibly as much for emissions and economy as for outright power. The main top end power gain will come from the absolute valve timing and a more top end orientated inlet manifold (shorter), although to compensate for the weight increase, drivability is probably helped more by the fact that 6th gear is 10% shorter than 5th in the 182.

The butterfly valve in the inlet is quite interesting as it only acts in one of the two inlet pipes to the airbox. It is probably inteded to change the resonant length - although it is surprising that it can have this effect upstream of the air filter, i.e when one would expect the airfilter to act as a frequency damper. However other engines use a canister tee'd off the pipe between the AFM and the butterlfy to obtain a similar mid range boost - these are known as Heimholtz resonant chambers - but more understandably they are downstream of the air filter.

I will see if Ben Rushworth of AWT is willing to post a definitive answer to clarify the whole issue.