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5000rpm why?
- Thread starter Stevehf2
- Start date
BMW M4; S1000 RR
That's not even true...
It's an NA car, it produces relatively steady torque across it's rev range and more revs with the same torque = more power.
I did read something about the lambda being ignored over 4800rpm but I don't know enough about engines and ECUs to know what that would do. The way people talk about the 5k kick makes me think mine is broken, but it's proven time and time again to perform on par or better than other 172/182s.
Knuckles
ClioSport Admin
Vtec y0!
That's what gearboxes are for, change down, revs go up, instant power.
Mine goes reasonably well for a 2.0 under 5k, but after that it really moves.
My understanding of variable valve timing systems like those on the clio is that they are there to make up for the loss of low and mid range torque which you would normally get due to the lumpy cams.
It isn't like on a Honda VTEC where a 3rd cam lobe effectively comes in at higher RPM giving extra valve lift and more power.
My understanding of variable valve timing systems like those on the clio is that they are there to make up for the loss of low and mid range torque which you would normally get due to the lumpy cams.
It isn't like on a Honda VTEC where a 3rd cam lobe effectively comes in at higher RPM giving extra valve lift and more power.
Ol’ Tarby
ClioSport Moderator
Clio 220 Trophy
VVT switching points are around 1700rpm and then 6800ish rpm I believe. Whatever happens in between is nothing to do with VVT
Pug 206 SW, 172 CUP
The engine has uprated cams over a shopping spec version of the engine. These are lairy enough to mess up the idle and very low end running. The VVT on the mk2 Clio is very simple in that all it does is make sure the car doesn't run like crap by moving the cam timing until things settle Down (a bit under 2000rpm) and then turns off again (over 6500rpm) to tail the power off at the top end.
Anything that happens between the two points is down to good old skool tuning and the mapping.
The mk2's inlet manifold is tuned to work with the choice of cams etc so the engine does have a noticeable gain in power after 5k as the cams really come into play . This can be felt as a real step in power as the Lambda which is setup for emissions and fuel economy is disregarded and a best power situation occurs at the same time.
The fuelling from people's experience actually goes a bit too lean just before the change with heavy throttle openings. So a 4.8K hole is quite accurate as someone previously mentioned.
The 182 added a 4-2-1 manifold instead of the previous 4-1 setup. The 4-2-1 manifolds tend to produce better mid-range but it depends on what it was tuned for.
The dephaser is purely there to make it usuable everyday. Anyone who's ran lairy cams on an old carb setup will know the joy of the hideously high idle and poor low end performance.
It is nothing like Honda's Vtec system.
The F4R engine in the MK3 has continously variable cam timing but still doesn't change to a different cam lobe like Honda's vtec.
Anything that happens between the two points is down to good old skool tuning and the mapping.
The mk2's inlet manifold is tuned to work with the choice of cams etc so the engine does have a noticeable gain in power after 5k as the cams really come into play . This can be felt as a real step in power as the Lambda which is setup for emissions and fuel economy is disregarded and a best power situation occurs at the same time.
The fuelling from people's experience actually goes a bit too lean just before the change with heavy throttle openings. So a 4.8K hole is quite accurate as someone previously mentioned.
The 182 added a 4-2-1 manifold instead of the previous 4-1 setup. The 4-2-1 manifolds tend to produce better mid-range but it depends on what it was tuned for.
The dephaser is purely there to make it usuable everyday. Anyone who's ran lairy cams on an old carb setup will know the joy of the hideously high idle and poor low end performance.
It is nothing like Honda's Vtec system.
The F4R engine in the MK3 has continously variable cam timing but still doesn't change to a different cam lobe like Honda's vtec.
Pug 206 SW, 172 CUP
The F4R is a long stroke engine and so makes good torque at the expense of top end power. Once you sort the fuelling out with an RS Tuner or similar and combine the F4R's grunt with a Clios low weight you get about as much grunt as your gonna get from an everyday 2.0 N/A hatchback.
Pug 206 SW, 172 CUP
Lastly the mk2 cylinder head is a bit pants despite the CNC porting from the factory. It will never flow hero spec amounts of air. Renault rectified this in the mk3.
dann2707
ClioSport Club Member
This, it was weird coming from diesels then to this.
It really is a petrol heads car driving a petrol (durrrrrrrrrrrrrr obvs) but when you get to a B-road, dropping it down a gear or two and thrashing it to the redline - the noise, the instant power, the smell is just something you don't get with a diesel imo and to be me is what makes the car/experience so enjoyable. I was giggling again tonight coming home from work on the roads I take. Nearly a year of ownership later and I still love it.
I know diesels are torquey and throw you back in yourseat with a shunt but watching the rev limiter to make sure you're in the powerband and not exhausting the turbo (yayapuns) just doesn't do it for me anymore.
Running a 2.0 on webbers producing just shy of 240bhp with a long first gearbox and you realise what hell trying to drive around town can be
Researc
Ol’ Tarby
ClioSport Moderator
Clio 220 Trophy
I think you need to research.
The VVT solenoid switches at two points only on the F4R. It may work in the way you describe on other applications, but not on this engine
Performance cams on any engine will give more bhp up top, but idle like a pig and not as good on low revs, there for a vvt puley is used, at what rev it opens and degrees i dont know, but i know how the system itself works... A 182 produces max torques at 5250rpm, i would think its when cams are fully advanced,...
Dude im not arguing, chill man if it works different on clio then cool, teach me
imprezaworks
ClioSport Club Member
Mk5 Golf GTI :)
Pug 206 SW, 172 CUP
Do a search regarding the MK3 head and you shall find. I can't remember if it's the port shape or a valve shrouding issue but the MK2 heads were not designed with big flow in mind. It is a breathed on Laguna engine after all!
Compare the power that's gained to similar 16v engines with just bolt on mods and it's not a front runner. Like the Vauxhall ecotec with it's narrow valve angle head the F4R's forte is grunt not fizzy power.
Ever wondered why they make such pants power!
Christ even Wikipedia knows more about VVT than most on here.
Compare the power that's gained to similar 16v engines with just bolt on mods and it's not a front runner. Like the Vauxhall ecotec with it's narrow valve angle head the F4R's forte is grunt not fizzy power.
Ever wondered why they make such pants power!
Christ even Wikipedia knows more about VVT than most on here.
imprezaworks
ClioSport Club Member
Mk5 Golf GTI :)
You remind me of a user that used to be on here, 'chip'. he was a very knowledgable guy too.
Pug 206 SW, 172 CUP
He knows far more than me about Clios! I just did a lot of reasearch into N/A tuning a while back.
An engine is a pump after all. If the head won't flow the air the way you want it to or the bottom end won't spin fast enough or isn't big enough to pump the air your on a hiding to nothing. You can stick what you like on it.
Years old engines with side valve heads, low compression and weak bottom ends would still be doing the rounds if flow wasn't the be all and end all.
Motorbike engines don't gain much in torque per litre over a good car engine but because they spin so fast and can produce their torque much higher up due to the way they are designed they make silly power.
It's a shame you have to have so much gadgetry to make an engine work well at a wide range of rpms. If it wasn't for the noise and the batteries being poo the electric motor would have won years ago.
An engine is a pump after all. If the head won't flow the air the way you want it to or the bottom end won't spin fast enough or isn't big enough to pump the air your on a hiding to nothing. You can stick what you like on it.
Years old engines with side valve heads, low compression and weak bottom ends would still be doing the rounds if flow wasn't the be all and end all.
Motorbike engines don't gain much in torque per litre over a good car engine but because they spin so fast and can produce their torque much higher up due to the way they are designed they make silly power.
It's a shame you have to have so much gadgetry to make an engine work well at a wide range of rpms. If it wasn't for the noise and the batteries being poo the electric motor would have won years ago.
I don't know why we aren't using ethanol to be honest. Oh actually yeah I do. The oil companies control the world. Funny how shell are now buying power companies. Ready for when the world goes electric. Its always been a sneaking suspicion if mine that battery technology has been purposefully held back. It wouldnt shock me if the technology exists to power a car for thousands if miles on a battery as big as a AA.
Course the same thing will happen like computers Pentium one million and ten.
Iphone two billion and two
Flastscreens, plasma, I don't buy in to the idea that companies develop better technology, I think they always know and just keep releasing better stuff to make money. After all if the iphone two billion and ten came out we woukdnt ever need touograde. Same with battery technology.
Iphone two billion and two
Flastscreens, plasma, I don't buy in to the idea that companies develop better technology, I think they always know and just keep releasing better stuff to make money. After all if the iphone two billion and ten came out we woukdnt ever need touograde. Same with battery technology.
So many wrong answers in here.....
VVT change over is at 1800 RPM. It's purpose if for a better valve timing for higher rev range whilst allowing the car to idle at a stable level.
The 5K kick you feel is all down to fueling. Anything below 5k the engine works out fueling using manifold pressure and a complicated algorithm, this is called closed loop.
Over 5k the car switches to what is called 'open loop', this is where the fueling is done based on the first lambda sensor.
VVT change over is at 1800 RPM. It's purpose if for a better valve timing for higher rev range whilst allowing the car to idle at a stable level.
The 5K kick you feel is all down to fueling. Anything below 5k the engine works out fueling using manifold pressure and a complicated algorithm, this is called closed loop.
Over 5k the car switches to what is called 'open loop', this is where the fueling is done based on the first lambda sensor.
dann2707
ClioSport Club Member
Out of interest, how come we experience poor running in general in every rpm range when the lambda sensor is kaput? Not just over 5k.
Not arguing with you, just wondering
Because the lambda still monitors the output in closed loop. Just doesn't have primary control
at 5K in open loop the ECU tells the MAP sensor to do one and let's the Lambda do what it wants....
Open loop is better but isn't great for fuel economy
BG Clio 182
So what effectively does the rs tuner do to sort this problem? It's all quite interesting
Interesting.
Pug 206 SW, 172 CUP
WTF?
Pug 206 SW, 172 CUP
Maybe it's me but the conditions It says in the Renault manual that the Injection computer ignores the upstream sensor seem to contradict what your saying and on the next page of the manual it's states that you do not exceed 4800rpm if you are testing mixture correction.
Pug 206 SW, 172 CUP
Pug 206 SW, 172 CUP
