The 5000 rpm kick in a clio 182!

[Adam69]

Out of interest………………why is there only a kick ( cams lifting ) in 1st, 2nd and 3rd but not in 4th or 5th in a clio 182 cup. Just felt disappointed last night building up speed in 4th to 5000 rpm and then just no kick. Technical response required please. Thanks!

 

[Lee]

It's there in 4th and 5th, it's just not so noticable. The performance of Renaultsport engines varies massively.

My old 172 and 182 never felt anywhere near as lively as my Trophy does.

 

[Soulless]

It's there in 4th and 5th, it's just not so noticable. The performance of Renaultsport engines varies massively.

My old 172 and 182 never felt anywhere near as lively as my Trophy does.

n00b question,
but is that why after a K-Tec chip/map whatever they do, a 182 made 183bhp at the fly?
very minimal gain?

 

[Dan@SJM]

never 182 to start with!

 

[Lee]

It's there in 4th and 5th, it's just not so noticable. The performance of Renaultsport engines varies massively.

My old 172 and 182 never felt anywhere near as lively as my Trophy does.

n00b question,
but is that why after a K-Tec chip/map whatever they do, a 182 made 183bhp at the fly?
very minimal gain?

One of the more techical bods will have to answer that properly mate.

At various RR days the difference between standard engines has been seen to be massive. Some produce a lot less than they should, a few put out more. It appears that some of this is down to how good the inlet manifold (I think) is. Someone will come along with a more educated answer in a bit no doubt.

My old 172 produced 169bhp, my 182 172bhp!! Obviously that's dependant on the RR and weather conditions etc etc.

As for the remap, if their map is anything like the r sport one, then it will give a smoother torque curve, allow the engine to rev higher and only gain a few additional BHP. It's a decent improvement though.

 

[Soulless]

is there much point in raising the rev limiter on them though?
as tbh they peak before they limit.

 

[Lee]

is there much point in raising the rev limiter on them though?
as tbh they peak before they limit.

It depends I suppose.

Chris n nic has always found it helped, as did y0z when he had one years ago.

On track on Tuesday at Oulton Park it seemed to help Chris as he was able to hold onto third in a couple of places where I was into 4th for a very short period of time.

You're right though, power is on the decline at those sort of revs. Peak is around 6700 isn't it?

It scares me though to hear that poor engine squealing well into the red. lol

 

[Soulless]

haha

yeah ~ guess it could help in 1/4 mile, holding third instead of taking time to change into 4th..

(not sure on speeds of 3rd in a 182 though as I don't own one....yet.)

 

[Lee]

Chris's Cup was very rapid on the 1/4 mile considering the few simple mods it had.

 

[Graham Gooch]

is there much point in raising the rev limiter on them though?
as tbh they peak before they limit.

It depends I suppose.

Chris n nic has always found it helped, as did y0z when he had one years ago.

On track on Tuesday at Oulton Park it seemed to help Chris as he was able to hold onto third in a couple of places where I was into 4th for a very short period of time.

You're right though, power is on the decline at those sort of revs. Peak is around 6700 isn't it?

It scares me though to hear that poor engine squealing well into the red. lol

Aye from 7k onwards its sounds very strained. The vary rare occasions Ive been all the way to 7800 it sounded horrific

 

[graham_172]

if you fit cams then raising the rev limiter is a must.

 

[Soulless]

if you fit cams then raising the rev limiter is a must.

yeah ~
but you'd have a map for your modifications then, not just a chip which raises the limiter.

 

[A13EX F Trophy No70]

best bit of the remap is loosing the rev limit.

i usually change up at 7k if i'm having aplay agains civic type r's lol

 

[lewisniven]

they all vary like hell, my 172 cup used to pull away from 182 easily, im sure i had 'a quick one' as it were.

ive heard of 172's making 180bhp on RR's as standard.

 

[Wilkeh]

also with the throttle being electronicly controled when it opens up graduly and then fully opens before it gets on cam as it revs up, as for a good old valver which is cable throttle and therefore is fully open straight away

 

[bmh.01]

Eh? Can't see it working like that. It doesn't feel that different (5k kick wise) to the Ph1 afaik? (could be wrong) And thats cable throttled.

 

[Steve2004]

You should have a "5k kick" in every gear.

 

[Day]

.

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.

 

[theduck]

I love it when BenR gets techinal

 

[VIICarCare]

i wouldnt know,i dont like to rag my baby much,only now n again!

 

[RichMcc]

Mine doesn't have the 5k kick anymore it pulls from much lower down the rev range

 

[clio_luke]

yep its a good feeling around 5k
and yes it does it in every gear but because of the ratios in 4th and 5th its less noticable but you can feel it

 

[lasbazrre]

It's there in 4th and 5th, it's just not so noticable. The performance of Renaultsport engines varies massively.

My old 172 and 182 never felt anywhere near as lively as my Trophy does.

n00b question,
but is that why after a K-Tec chip/map whatever they do, a 182 made 183bhp at the fly?
very minimal gain?

Just get a remap anyway mate, it'll make the car drive better day to day , give you a far better mid range , and a few bhp top end, you can also have the limiter moved up if you wish, ive gone up to 7600, but ive never really used the extra!

RStuninng up north or k-tec down south , it's the same map!

leon

 

[Alan]

i wouldnt know,i dont like to rag my baby much,only now n again!

Get out at boot the arse out it...

 

[Soulless]

n00b question,
but is that why after a K-Tec chip/map whatever they do, a 182 made 183bhp at the fly?
very minimal gain?

Just get a remap anyway mate, it'll make the car drive better day to day , give you a far better mid range , and a few bhp top end, you can also have the limiter moved up if you wish, ive gone up to 7600, but ive never really used the extra!

RStuninng up north or k-tec down south , it's the same map!

leon

is there a difference between "superchipping" and mapping then, as i thought a superchip was non specific and a map was unique to your car.

 

[Gaz_]

best bit of the remap is loosing the rev limit.

i usually change up at 7k if i'm having aplay agains civic type r's lol

or black 182's

 

[mattsport182cup]

i have 182CUP and at4th and 5th hitting 5k revs and higher i feel extra kick 172bhp in 182??my one is original without mods and have exacly 182bhp at 6500rpm. Shame you have less

 

[Matt X2C]

how can people not like the sound at 7,800rpm? Are your cars standard?

My yozza and simota together sound incredible over 7k