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can you lower the "5k kick" so it comes in earlier?



  2002 172
as above, and what mods can i do to my engine ive heard about the matched inlets and remap exhaust decat and filter but what about fuel pressure and bigger injectors and stuff like that? also at what stage would you add them?
 
  PH1 172 Sport
The 5k kick is only there because its where the cams become most agressive. All a remap does is smooth out the torque/power curve which will make the kick less pronounced.
 
  ValverInBits
No you cannot. The 5k is nothing to do with the VVT.

It's simply where the engine starts to become a little more efficient naturally.
 

The Boosh!

ClioSport Admin
  Elise, Duster
The 5k kick is only there because its where the cams become most agressive. All a remap does is smooth out the torque/power curve which will make the kick less pronounced.
Im sure its just Variable Valve timing...(or not lol)
Dont think it has anything to do with the cams... Massive thread on here a while back.

A remap wont make the "5k kick" come any earlyer as said, it just flattens out the power delivery.

Only way your going to get a kick earlyer is through ITBs or a turbo conversion

**Edit, i dont know anything :eek:**
 
Last edited:
  BMW M135i
Im sure its just Variable Valve timing...
Dont think it has anything to do with the cams... Massive thread on here a while back.

A remap wont make the "5k kick" come any earlyer as said, it just flattens out the power delivery.

Only way your going to get a kick earlyer is through ITBs or a turbo conversion

**Edit, i dont know anything :eek:**
Nothing to do with the VVT, just the cams coming into their optimum zone keep this for these occasions:

BenR said:
172 5k kick by BenR 2006

By no means is the 5k kick the result of any mechanical/electronic chance withing the engine system, whether that be mapping paremeters or valve timing.

I think to fully understand, a base understanding of the operating system of the vvt is needed. The vvt system employed on the clio is what we refer to as cam phasing, this is where the whole camshaft (inlet or exhaust or both) is advanced/retarded. This can be in a single step as it is in the clio (single stage 16 degree advance on the inlet), or variable. The camshaft is hollow and is used as a galley to feed the front pulley (called a phaser) with oil pressure, this pressure simply acts on vanes inside to rotate it in a desired direction, and returned under mechanical pressure. The cam does not always carry oil pressure, but a vvt switch is used, and is basically a plunder activated by 12 (grounded by the ecu (a lowside switch)) which allows the passing of oil from the lifter galley to an area of the cam bearings with holes that can feed the inside of the cam, which then passes through to the nose of the cam and into the pulley (phaser).

Variable setups (like the new 197) will use the same base components as what is used today, but instead of the vvt plunger being used as a switch, the same plunger has the ability to open and bypass oil to either side of the vanes in the phaser. By using a PWM signal, you can gain full control of the phaser to advance the cam in a near infinately variable curve vs rpm vs manifold pressure vs throttle angle etc.

Honda's Vtec system is a cam 'changing' system where the actual cam profile is changed in its entirety (hence the 3 lobes per cylinder), the actual 'timing' of the primary lobe remains the same at all times. And now with I-Vtec and VVTL-i the benefits of both phasing and changing is being used at the same time to build some monster VE (volumetric efficiency) curves.

Anyway, in the clio the cam sits in its dephased state until the required parameters are met. This is above 1450rpm and 800mb manifold pressure. When it is required though, the cam is phased and the cam timing effectively advances 16 degrees, at 6800rpm it is dephased again and power drops off like a stone. No official reason, but my thoughts are that they do it so you guys shift up once there is a loss of acceleration. The reason for that is because the stock pistons just fall apart with prolongned high rpm use.

The 5k kick is the result of a few natural phenomenons within the engine. At 5000-ish rpm VE suddenly reaches a higher %'age and the resultant torque increase gives you that wahey feeling. VE increases due to the cam comming 'on'. This term has nothing to do with VVT and is quite an old term, whereby the reference is to the rpm region that particualr engine/cam combo requires to process the valve timing events efficiently.

VE refers to volumetric efficiency, or the %'age of the cylinder that you can fill with fresh charge. For a 2ltr, thats 500cc per cylinder. If you can only fill that cylinder with 430cc's at peak efficiency (normally at peak torque point) thats 86% VE. The higher the VE on any engine, the higher the torque output at that specific RPM, and all engine tuning revolves around increasing or rather sustaining a good VE for as long as possible, and upto as high an rpm as possible.

Anyway, back on track. The clio with its advanced cam timing (phased) operates with an overlap value that is larger than when it is dephased (infact it has no overlap when depahsed). This overlap is part of cam design basics, and larger overlap periods are used to help generate higher VE's via scavenging and inertia ramming. At 5000 rpm the natural effects of the port velocity and pulse tuning al reach a level where they start to actively enhance the torque production with the valve timing it is running. Put in a wilder cam and it will push the 'kick' higher up if nothing else changes, but lower rpm efficiency will loose out, and peak power will be pushed up the rpm scale, along with a higher peak bhp figure. To an extent, there will be a point where you can go wilder on the cam and just loose out everywhere as the engine system as a whole does not work with the cam profile you are running.

Not very clear sorry, basis is that the 5k kick is the result of natural phenomenons within the engine, primarily port velocities and pulse tuning harmonics.
 
  Monaco 172
that big thread said the vvt is irelevant and actually comes into play at a little over 1k rpm, and its all to do with cams around 5k

EDIT:...thats the big thread i was on about.
 
  ITB'd MK1
it's actually where the emissions restrictions allow full opening of the throttle (on fly by wire cars) and the engine is also allowed more fuel. Quite strict emissions rules for manufacture mean the fueling is lean quite far up the rev range. The Throttle is only open 85% at 5k on FBW cars.
 
  LY 182
it's actually where the emissions restrictions allow full opening of the throttle (on fly by wire cars) and the engine is also allowed more fuel. Quite strict emissions rules for manufacture mean the fueling is lean quite far up the rev range. The Throttle is only open 85% at 5k on FBW cars.
dan whilst on the subject mate, looking at my rr graph the afr on my car is pretty much bang on 14.7/1 untill it hits 3500 rpm when it shoots right up to around 11.1???

this sound right to you, it dosn't really look right to me.
 
  ITB'd MK1
dan whilst on the subject mate, looking at my rr graph the afr on my car is pretty much bang on 14.7/1 untill it hits 3500 rpm when it shoots right up to around 11.1???

this sound right to you, it dosn't really look right to me.

something badly wrong there, you want 12.9 at peak on WOT
 
  LY 182
something badly wrong there, you want 12.9 at peak on WOT
i'll scan the graph and post in this thread tommorow..
i thought it looked wrong as soon as i watched it on the screen but the rr operator reckoned it was running spot on..

would you agree with me that it would be a map issue??

cheers
 
  ITB'd MK1
It's possible, but I'd be surprised if a generic map was that far out. A sensor fault sounds more likely to me.

Shocked the dyno operator said it was ok

Are you running a cat and where was the measurement taken from?
 
  Mk2 172
The 5k kick is only there because its where the cams become most agressive. All a remap does is smooth out the torque/power curve which will make the kick less pronounced.

Got absolutely nothing to do with the cams. its the ecu controlling the amount that the throttle butterfly opens. At 5k the butterfly opens all the way. Below that that, put simply it doesnt!
As sideways dan has explained above :)

Get throttle bodies. Only real way to get rid of the horrid 5k kick!
 
  PH1 172 Sport
What I meant is its the cam coming 'on'. It is to do with the cam profile and various other things in the engine. Its basically when the engine becomes its most effiecient and you get a nice boost in torque.

Most people know that the variable valve timing in the clio's is not like vtec.

And it can't be totally down to the throttle butterfly as PH1's have the 5k kick as well and they have a cable throttle.

bmh.01 has provided the best explaination.
 
  2005 Nissan Navara
Got absolutely nothing to do with the cams. its the ecu controlling the amount that the throttle butterfly opens. At 5k the butterfly opens all the way. Below that that, put simply it doesnt!
As sideways dan has explained above :)

Get throttle bodies. Only real way to get rid of the horrid 5k kick!

So how is it explained on the PH1's?

Its called volumetric efficiency :)
 
  ITB'd MK1
And it can't be totally down to the throttle butterfly as PH1's have the 5k kick as well and they have a cable throttle.

bmh.01 has provided the best explaination.

ph1 has a slightly less strict reg to adhere to, but still is not allowed much acceleration fueling and is kept generally lean and with tame ignition timing until higher up the revs
 
  2005 Nissan Navara
So how come its still present when "after-market" managment is utilised, and mapped open loop all the way through...
 
  GDI Demo 182, Rsi Spider
peak VE is about 5k on that engine, but on the stock ECU its kept lean for emisions until about then then fueled for max power hence the kick... AFR goes from circa lambda 1, to 12.9 and timing is brought in for power.

with std cams the kick is almost gone if you keep the top line at best fuel for power.. picks mid range torque up alot.

but it has nothing to do with cam phase shifting
 
  197
So how come its still present when "after-market" managment is utilised, and mapped open loop all the way through...

It's gone in open loop. Max VE is at 5500 rpm. CL/OL transition is the MAIN reason for the 'kick'
It's not that VE 'switches ON' all of a sudden.
For the 197 you are correct.
 
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  RSC 172
I must chime in here. I have virtually no kick these days. I have a full remapping with Fastchip via the fabled Innovate LC-1 fitted to an American..yes US of A Aero turbine system put together at a local exaust shop. The torque delivery is smooth. You can sense the intake cam phase shift as she ramps up but certainly no 'kick' as per the old days. Fueling is pretty well 'even stevens' thro the rev range between 13-12 afrs these days with specific 'icky' points with my RSC sorted with the wideband. If the RSC gets 'worried' it will sort the KC's via sensible fuel trims which in Aust is very important. She get's hot dwon here.

Being in Australia my main enemy is air temps which will kill the RSC quick smart re pwr/ torque. It is clear on the data logger when and why. I am very happy with the results. RSTuner gives 0-100 km/hr between 5.7 & 5.9 which seems about right on a cool to cold day with intake temps around 27 degs. Not good on the tyres though :) I envy you fellas with the icey English winters :)
 
  ITB'd Ph1 172
the phase shifter moves at 1600-1800 rpm

its also load based, (MAP sensor) but i have no idea at what kPA it triggers at
 


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