Intake pipe wtf?

[Graeme GTR]

if its there to supply additional cold air when getting it up to speed, would it not be better to jam it open rather than closed to keep the maximum amount of cold air coming into the engine at all times? Can you ever have too much cold air? Would more air result in needing more fuel being pumped in?

 

[Ozi]

if its there to supply additional cold air when getting it up to speed, would it not be better to jam it open rather than closed to keep the maximum amount of cold air coming into the engine at all times? Can you ever have too much cold air? Would more air result in needing more fuel being pumped in?

It's just not that simple. If it would stay open all the time maybe it would suck in hot air from the engine bay (higher revs = heat) or maybe the turbulence caused by the auxiliary intake has good effects on airflow (performance at low revs actually) at lower revs and causes problems with higher revs cause the airflow is disturbed. Try to imagine a fluid flowing through a pipe and then another fluid coming from the side and disturbing the entire flow of the first one.

Maybe the intake of the Clio is a good combination for low and high revs. At low revs the engine needs the air as quickly as possible. If you look at different dynocharts you can see that short-ram intakes give good gains at low revs but don't really do much at high revs (actually they can even decrease the power). For high revs the best setup is almost always a cold-air-intake placed in the grill or bumper (except if you use ITBs). The stock setup of the Clio has both. If you consider this and the "disturbing" of the airflow if the auxiliary intake would stay open, I think it's really a good explanation for the stock setup.

Then there is also sound/resonance tuning etc. I think Renault really made a cracking job with the intake given the amount of space they had to work with. They surely tried different designs and benchflow tested them to get to the best one.

And forgot to add something to my previous post - now that I know what to watch (actually listen lol) for I know when the auxiliary intake is opened and closed I think it's not only based on the load on the engine at low revs. The ECU probably controls it based on the load on the engine (vacuum), throttle position, revs, airtemperature, maybe lambda readings,.....I can hear that the 2nd intake closes hmm around 3.5k rpm even if the throttle is pushed down to the end. From these revs to 5k rpm the Clio really doesn't feel that quick - think this is the rev-band about which many have complained. I presume that Renault maybe couldn't make an intake setup that would work well through the whole rev-band. I'm not saying that this causes the midrange torque (let's say) dilemma but in combination with the Euro 4 emissions (exhaust/cat), fairly wild cams, ECU programing,....it could have some effect on it. Some with the Clio Ph.2 V6 airbox do feel gains in mid-revs (maybe Renault didn't use this setup cause it would be too loud for a stock 197 or they couldn't get a decent air-feed to it - those with xenon headlamps know what I mean lol).

Personally I think that Renault really made a decent job with this engine. For a high revving engine it's really nice to drive in high gears and low revs and offers still some performance in these condition. It almost has a split personality - when driving normal it doesn't use much fuel, it's quiet and has some torque to cruise around - normal. Then after 5k rpm mental disorder begins :tongue_smilie:

Think there are better ways to improve the performance of the Clio than fiddling with the intake tbh

 

[Paul]

Craking post Ozi, once again! It makes a lot of sense what you are saying! I agree the engine is very useable and never really feels laboured, even in 6th it will pull uphill at 25-30mph. Gotta love it!

 

[Ozi]

Craking post Ozi, once again! It makes a lot of sense what you are saying! I agree the engine is very useable and never really feels laboured, even in 6th it will pull uphill at 25-30mph. Gotta love it!

Thanks m8 ;/:biggrin:

 

[J's RS]

i removed that pipe... loved the sound it caused... BUT i felt i lost some power...
now with it back on I will never take it off again! car runs 'smoother' with it on

 

[J's RS]

a couple of us here in SA might be on to something with the air setup and the temprature of the air... will post our findings here...

 

[patroklos]

nobody knows better than the ones that have design the engine!!!!!!!

 

[Dedespo]

nobody knows better than the ones that have design the engine!!!!!!!

I agree.

P.S. At last, a fellow Greek :thumbup1:

 

[Raptor6767]

nobody knows better than the ones that have design the engine!!!!!!!

That's true but they have to look after some things like: MPG, ecology, safety standards, economical reasons,...

 

[Foxspeed]

nobody knows better than the ones that have design the engine!!!!!!!

true.....but it is designed to meet noise and emission standards - and at times these are a trade off against engine power etc - so they are not always optimised and hence sometimes the easy gains from routing a pipe differently or a tweek to the engine map

you can only change the fuelling / timing / vvt on the 197 ecu - renault build in a safety margin for poor fuel / servicing / emissions etc - remaps push these limits to get the gains

same for the induction system - its homologated for world wide car markets but is not necessarily the "optimum" for power output

with the 197 being normally aspirated sometimes you have to rob from the lower rev range to get better power high up - the standard intake system will meet requirements over the entire rev range but will not nesscessarily be the optimum

 

[J's RS]

jip... best of both worlds are not always obtainable

 

[A2ON]

Is there a proper how to anywhere with pics and all of how to remove the piece of plastic blocking the air intake ?

 

[Ozi]

http://www.shrani.si/?3e/jb/2JCg4eDD/wrc-technical-aerodynami.avi

2:19 - look how tiny the intake whole in the grill for the WRC Focus is. I know they have tons of restrictions but imho this just shows that the stock intake of the Clio isn't that bad. The low/high rev setup is really a good solution. Anybody made the mod from page 1 and did a dyno run before/after?

 

[Bluetex]

if the Valve opens it will get hot air or what? wouldn´t it be better to fit a tube to it and connect this to the front? So the Engine would get cold air the whole time?

 

[Daverb]

I removed the bit plastic blocking the intake on my car after reading this thread. Did wonder about it before but I had poked a screw driver through the hole before and seen if from the grille so assumed it was ok. Much better now. Thanks guys. :thumbsup: