ClioSport.net
This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
-
When you purchase through links on our site, we may earn an affiliate commission. Read more here.
more air!!!
- Thread starter tigerclio
- Start date
Well I wouldnt bother with an induction kit at all. Unless you have so little power anyway it doesnt matter if you lose a bit more!
The Viper is a good idea but very expensive. If you want to change the filter for something noisy then go for an induction kit and make sure you give it plenty of cold air. Will probably work ok as long as theres plenty of room under your bonnet.
I got a Viper and boy has it made a difference. Car performs very differently now, the valve timing change is very noticeable and it is definitely quicker.
Will hopefully RR it at Mowatts next time i am in Essex at my mums place.
Nick - will let you know in case you are interested to see the session.
Dave
nick i am intrested in knowing about ure bmc air fillter !!
Well Im just waiting for it to arrive at the moment, got that and a bit of Samco hose to hook it up to the throttle body; both on order. The one Im getting is definitely not the normal off the shelf model and its not the one for the 172 either. You know how little room there is in there, but it should work I reckon.
nick give me a call when u get it in
john
Yeah cant really remove fog light as its a lease car, but should be able to mod the front grille and also gain some space if i cut a few inches from the bit between the PiperX and the engine block air intake.
The part i am on about is just above the filter in the pic.
Dave
Its all to do with the amount of hot air there is under the bonnet of the performance Clios.
You need cold air thru the induction kit/airbox to increase performance, so if you put an induction kit in and no cold air feed your performance will suffer as it is sucking in hot air.
You cna get round this with good cold air feeds, heatshielding, or using a sealed induction kit with a good cold air feed (BMC/PiperX Viper).
Dave
The engine needs oxygen and fuel. Youve got enough fuel but the ECU will inject more (giving more power with the right mixture) if you can somehow get more oxygen in.
you dont have a turbo or supercharger so cant physically force more air in. but the density of air changes quite significantly with temperature. On a cold day there is more oxygen in a given volume of air than on a hot day.
Now if your induction kit is surrounded by under bonnet temperatures from the cylinder head, radiator, coolant pipes, exhaust manifold etc, its gonna be sucking in basically hot air, whatever the weather. Result - less oxygen, so the ECU puts in less fuel, so less power. (BTW The ECU knows how much oxygen is there by measuring the inlet air temp, manifold pressure and RPM of the engine.)
If you can get a big cold air feed to your induction kit then you might get colder air in there but there is still a lot of warm air surrounding it. At slow speeds, the cold air feed makes hardly any difference at all.
The simple solution is to seal the induction system so your cold air has no choice but to blow directly onto the filter, and also the heat from the engine bay is kept out. Thats what a factory airbox does, except it can only suck cold air through the filter, the air doesnt get forced through.
So you can have the best of both worlds by having an airbox with a performance element inside - with the air feed pipe coming from the front of the car, forward facing, so that air is rammed into it at higher pressure the faster you drive.
If you hook up a Viper or a CDA with a ramscoop this is how it will work,.
Beg to differ Nick..
The ram scoop is a load of tosh...
the car would NEVER get to speeds high enoug to enable ANY kind of forced induction. !
the radius on the end of the intake is purely the optimimum design for airflow INTO a pipe.
Joe
i beg to differ!!!!!! ive got my standard airbox on my valver, with 100mm diameter flexible tubing from the bumper grill to the airbox. it is sealed totally. the torque of the engine at speed has improved loads. ive had this setup on and off for the past year, as well as pooey induction kits. and by far the best setup is still the rammed airbox. put ur foot down at 80mph in 5th, and it really goes!! feels like uv dropped it into 4th. its probably the best mod ive made to the car,and it cost me 8 quid!
jimbo
This sounds pretty similar to the standard system, in that Ive got a pipe running straight from the airbox that buggers off into the front bumper somewhere.
Ive also got a flexible pipe that runs from the exhaust heat shied into the airbox. Would it be better to take this off and route a new pipe to behind the grille?
Cheers
Rick
Yep, there is NO ram induction.
take a piece of 3" pipe.. hold this out of the window
now measure the pressure at the closed end.. hmmmmmmm.. not a lot..
now deduct the flow that the engine requires in CFM.. ooooooops.. no pressure increase worth mentioning..
as I said, it dont work...
Its a good theory, but it doesnt relate to the real world.
Joe
Joe youve gone mental. The fact of the matter is that many people have tried it and it works, whatever boffin measurements you wanna take, you cannot deny that a front facing scoop will give a higher pressure to the intake air than if the pipe was just in the original position , behind the wheelarch where the air is relatively static and the engine just draws it out.
Contrary to what you think, the principle of ram induction is well documented and many race cars use ram induction of one kind or another, and were not talking Thrust SSC here.
At the end of the day it works, if you ever have a ride in my car Ill prove it, you can watch the air/fuel ratios at high speed to see the effect.
If Im correct ramair induction cant actually increase the pressure of the air the engine is sucking in above 1bar, just letting the engine suck the air in through a long tract means the resriction of the pipework prevents the engine drawing in air a 1bar, the ramair effect just boosts this back up to the full 1bar. I maybe talking crap though.
Hi Nick et al...
Nope, not mental at all LOL..
Air is drawn into the inlet tract in pulses. To obtain a benefit in what you term ram air you would need to have a pipe of a tuned length, even then it would only benefit one particular range.
there is no turbo effect, no boost effect. no nothing to speak of. on an F1 car at 150 mph then maybe the use of a large induction collector will benefit things............ but on a clio ???.. sorry no way ...
One could argue that the pressure under the bonnet will increase at speed.. all that lovely air going through the rad etc - into a cube with the bottom missing... errrrrr.. nope...
so, the only efect from moving the pipe is to feed cooler air into the system which is denser.
this is another classic example of an over rated and missunderstood non working tweak.....
Why not add a huge funnel to the fron to guide all this free power into a small pipe thereby gaining a free, even greater boost...
why not ??... cos it wont work.
Why not add a pipe directly from the throttle body, through the bonnet, to a K&N flat panel ???... why not ?, cos, it wont work... !!!
The effect of the inlet tract on a single inlet point system (Bikes n throttle bodies dont use this !) - ie, where the inlet air for ALL cylinders enters through a single opening ... is one of pulse progression, not constant stream. the effect of the exhaust adds to this too. If the pulse waves are upset, you will lose power due to overlap in the valves.
so Nick, no I am not going mental
Ak yourself a simple question.. why dont the manufacturers do this if it is so easy ???... simple.. again, it DONT WORK... measure the pressure at the inlet tract... hmmmm, may be lower ??.. why ??.. simple... pulse induction causes standing waves in the tract which can interfere with the next pulse.......
there ya go...
Joe
*lol* Well have to agree to disagree on this one then Joe!
I know what youre saying about inlet tract pulses etc and how this might be upset by pressurised air being rammed in constantly but this is a red herring IMHO. If engines were so easily upset that they had to be protected from the awful effects of pressurised air, rather than just sucking in the right amount of air through the inlet manifold, there would be no turbos or superchargers. These cause exactly the same effect, admittedly at a higher pressure.
If your argument is correct, you would see manufacturers using four separate blowers, one on each intake runner, precisely synchronised to feed in a pressurised charge to each cylinder at exactly the right time, and *also* having to vary their timing to compensate for different pulsing characteristics at different revs.
Please dont go down the route of worshipping F1 as if their technology and their engine design is so radically different from a fast road car, its not, they use internal combustion engines just the same as I do, and my car is capable of 140mph and a decent ram effect. I will concur that for the effect to work properly you need a relatively short induction tract from the scoop to the air filter and the filter to the throttle body. You also need a properly shaped ram-scoop, forward facing into the airflow where it is not affected by through the engine bay airflow issues. A bit of pipe sticking out at the bottom of the engine bay will not do it. That system I described is what I have, and I can guarantee it works. Obviously at 30mph it makes no difference but at 75mph and upwards you can clearly see the air/ fuel ratios going gradually leaner and leaner in direct relationship to the road speed. I compensated for this by adjusting my fuel pressure and having my fuelling reprogrammed.
In no way do I argue that air pressure will drastically increase at speed under the bonnet...of course it wont, there isnt a decent exhaust route there so why should it? This is the very reason why Ive always said that cold air feeds to induction kits dont work.
Contrary to what you say though, Im certain that if you connected a simple 90 degree elbow to the throttle body, with a funnel shaped inlet tract and then half way down it you put in a K&N flat filter and then at the end of it it opened out into a foot wide mouth, you *would* have a very noticeable ram-air effect. However on the front of the bonnet it would need to be a big collector. In another location, less impeded by the aerodynamics of the car, you could get away with a smaller inlet scoop - eg the one you can get for the Lotus 340 which sticks out into the airflow, or look at the Evo 6 Mak - ram scoop on the offside of the bumper - or my ram scoop right over in the furthest bottom corner of the bumper.
Finally Joe, the reason why it isnt used by manufacturers as standard is that its impractical for standard paper filters which arent tough enough to withstand the road muck and water that will be drawn in, and it would be a disaster if you drove through a ford. Its nothing to do with it not working. I have to clean my element every few thousand miles and it is pretty filthy every time. Most people just take their car to the garage and they replace the filter element for them. Thats why manufacturers of normal road cars dont use ram-effect induction.
Hi Nick,
*****"*lol* Well have to agree to disagree on this one then Joe!
"I know what youre saying about inlet tract pulses etc and how this might be upset by pressurised air being rammed in constantly but this is a red herring IMHO. If engines were so easily upset that they had to be protected from the awful effects of pressurised air, rather than just sucking in the right amount of air through the inlet manifold, there would be no turbos or superchargers. These cause exactly the same effect, admittedly at a higher pressure. " ********
This is an interesting analogy, but IMHO doesnt hold up. Its like comparing blowing by mouth into the pressure pipe to a commercial spray gun, as opposed to connecting it to a suitable pressurised supply. You appear to be overestimating the flow benefits.. A turbo engine DOES loose power at lower rpm conpared to a N/A engine, the design of the exhaust attempts to make up for the increased flow (Increased beyond all recognition compared to holding a pipe into the airstream....). The higher density of COLD air compared to underbonnet temp increased air is far greater and more tangible than the illustrious ram effect...
****"If your argument is correct, you would see manufacturers using four separate blowers, one on each intake runner, precisely synchronised to feed in a pressurised charge to each cylinder at exactly the right time, and *also* having to vary their timing to compensate for different pulsing characteristics at different revs." ********
Aha ! But they DO.. its called a pressure / pulse wave supercharger (Search for comprex).. this is often refered to as a turbo / supercharger.. it feeds the exhaust PULSES through a chamber on the manifold. The inlet assembly is rotated by a simple pully in direct rotational equilibriub with the engine rpm (Thereby varying the timing, as you mention above, to compensate for differing pulse lengths) the low rpm / high flow torque requirements are also compensated for by an increase in pulse pressure per cycle. There is NO lag with this system either.
Continued............
****"Please dont go down the route of worshipping F1 as if their technology and their engine design is so radically different from a fast road car, its not, they use internal combustion engines just the same as I do, and my car is capable of 140mph and a decent ram effect. I will concur that for the effect to work properly you need a relatively short induction tract from the scoop to the air filter and the filter to the throttle body. You also need a properly shaped ram-scoop, forward facing into the airflow where it is not affected by through the engine bay airflow issues. A bit of pipe sticking out at the bottom of the engine bay will not do it. That system I described is what I have, and I can guarantee it works. Obviously at 30mph it makes no difference but at 75mph and upwards you can clearly see the air/ fuel ratios going gradually leaner and leaner in direct relationship to the road speed. I compensated for this by adjusting my fuel pressure and having my fuelling reprogrammed." ******
Ok, the F1 bit first.. I dont worship (too much) their technology, but the induction / exhaust characteristics and design are NOWHERE near that of a humble clio on and EFI system.. ie - Slide / roller barrels on a tuned tract inlet optimised for the main power band - which is achieved at airflow rates that the clio couldnt even smile at The f1 units also live in the rear of the vehicle in turbulent air.
A modern f1 runs (usually) 10 cylinder units at 750-800 Bhp. this is supplied to open tract inlets (as I say above with tuned, individual tracts.. often the fuel injector is upstream of the tract depending on the power requirements and input tuned length) Here, a steady state flow is WHAT is required, not a misconstrued pressure increase, its a pressure STABILITY effect).. and agai, nope, that doesnt correspond to any normal clio in the wild....
******"In no way do I argue that air pressure will drastically increase at speed under the bonnet...of course it wont, there isnt a decent exhaust route there so why should it? This is the very reason why Ive always said that cold air feeds to induction kits dont work." *************
I actually DO believe that cold air feeds actually work PROVIDING the pipework does not upset the inlet tract.
*****"Contrary to what you say though, Im certain that if you connected a simple 90 degree elbow to the throttle body, with a funnel shaped inlet tract and then half way down it you put in a K&N flat filter and then at the end of it it opened out into a foot wide mouth, you *would* have a very noticeable ram-air effect. However on the front of the bonnet it would need to be a big collector. In another location, less impeded by the aerodynamics of the car, you could get away with a smaller inlet scoop - eg the one you can get for the Lotus 340 which sticks out into the airflow, or look at the Evo 6 Mak - ram scoop on the offside of the bumper - or my ram scoop right over in the furthest bottom corner of the bumper."**********
this is more for colder, denser air, as opposed to any ram effect.. although the customers like to see little wizzard bits on their exotic purchace
******"Finally Joe, the reason why it isnt used by manufacturers as standard is that its impractical for standard paper filters which arent tough enough to withstand the road muck and water that will be drawn in, and it would be a disaster if you drove through a ford. Its nothing to do with it not working. I have to clean my element every few thousand miles and it is pretty filthy every time. Most people just take their car to the garage and they replace the filter element for them. Thats why manufacturers of normal road cars dont use ram-effect induction." ***********
Continued again LOL.. wouldnt let me post - message too long
Hmmmmmm . the filter is a reasonable point, however, there is nothing to stop the manufacturer fitting K&N type elements.. apart from the fact that THEY DONT FILTER AS WELL as the paper ones... the engine longevity will suffer.. the airbox (or more correctly - RESONATOR) is designed as part of the induction system for overall power spread, yes, there IS a need to keep the tract clean, thats why its located in places like behind the headlight and other wonderful areas. You can always MOVE power within a certain range.. fitting a mega box and cold feed may well lean your mixture at the top indicating a gain in that area, but not overall, you dont often get anything for nothing..but, a power gain (From input restriction (designed in) removal - NOT from any ram air)) does not mean the car is any faster.. now, if you arranged a diverter flap at WOT above 4500, then you may get a worthwhile increase...
This discussion could go on for ever, the fact of the matter (IMHO) is that you are NOT seeing ANY ram effect.. you may well be seeing a false peak in the power band at the expense of other areas.. A clear route to the inlet tract can be worthwhile along with other engine changes.
Interesting topic though
ps, check out the comprex unit... good technology... highly patented.... commercial large capacity diesels are the main users, Mazda uses the system on its 626 though.. and the green piece twingo uses a 2 cylinder 4 stroke with pressure wave supercharging to achieve the same power as its 4 cylinder, twice the capacity, brother..
I have actually contemplated fitting one to a clio.. it would be interesting.. (I know of a complete unit locally for £100 !). the problem is the pulse tuning inside the unit, there is no data available to calculate the characteristics due to the patents.. and it would be a costly exercise to discover it dont work as you intended ... however, the thought of a turbo type system with no lag, and the superb instant supercharged effect with virtually NO power useage is a good one !. A wave device3 can operate from as little as a 2 bhp consumption.
http://www.pml.com.sg/glossary_image/glossary_c_5.jpg
Joe.
Similar threads
