Crude air intake mod..i was curious.

Brumbrum · 23rd April 2015, 13:31

Thought I'd have a go at the infamous air intake and egr mod! I admit, it's very unfinished. But wow! I was surprised at the improvement to be honest. I never had much turbo lag before, but the engine is definitely more progressive from 1300 rpm upwards. It revs more freely, and doesn't feel as asthmatic over 3000 rpm either. I just need to devise a proper air feed. One drawback at the moment is the induction noise is pretty intrusive.

rich17865 · 23rd April 2015, 13:56

EGR bypassed in that manner is a great idea, refit the air intake though as it serves an important purpose!

Mickyboy · 23rd April 2015, 14:07

I wouldn't leave the intake like that, the hot air in the engine is not beneficial, the egr is a good idea

Jules · 23rd April 2015, 14:10

Bodge monkeys again

Brumbrum · 23rd April 2015, 15:03

I have no intention of leaving it like this! It was purely an experiment / 10 minute job after reading various topics on it, if i thought there would be potential gains from revising the oem intake. Idealy I'd like to keep it as original as possible. On an intercooled diesel, i wouldn't expect the heatsoak to make too much of a difference anyway, unlike say, a n/a petrol car. I've done rough calculations for this.

[QUOTE=Jules;1982587]Bodge monkeys again

[/QUOTE

Appears so. They get everywhere..

Johnny2R · 23rd April 2015, 15:30

The air intake question has been much discussed on here, and it would be worth your while searching through some of the threads. There was a fashion a while back to cut back the air intake to the bellows section, removing what was thought to be a serious restriction at the slam panel. This has now fallen rather out of favour and many, like myself, are reversing the mod, for two reasons. Firstly, it has been convincingly argued that having the intake like this is much more likely to lead to oil contamination of the MAF sensor, which you don't want. Secondly, though, T4 boffins on here such as marinabrian and bigruss have said that there is always enough air anyway on the diesel, and in effect the extra 'gape' is not needed anyway.

I have not tested it myself. These guys seem pretty well informed to me, though.

Brumbrum · 23rd April 2015, 16:05

Lookin at the complete ducting unit i removed, I'm not sure there would be a dramatic difference after chopping off the bellows anyway? Did you notice much difference? It's not a particularly smooth air path and without calculating the new intake area it might not of been a significant increase. There's a further restriction between that an the airbox also, as the pipe is smaller than the airbox opening as it's of a conical design. So, thinking aloud I think I'm going to try a straightish feed to fresh air

Totally agree on your maf point, this really isn't a good way to drive it long term.

I can't comment on others opinions, i can only say as i find. Obviously the car won't make anymore power with a better intake, as the fueling's unaltered. Be really interested to see difference in torque graphs though, if it's ever been tested on a rr.

marinabrian · 23rd April 2015, 19:49

Quote:

Originally Posted by Brumbrum

Lookin at the complete ducting unit i removed, I'm not sure there would be a dramatic difference after chopping off the bellows anyway? Did you notice much difference? It's not a particularly smooth air path and without calculating the new intake area it might not of been a significant increase. There's a further restriction between that an the airbox also, as the pipe is smaller than the airbox opening as it's of a conical design. So, thinking aloud I think I'm going to try a straightish feed to fresh air

Totally agree on your maf point, this really isn't a good way to drive it long term.

I can't comment on others opinions, i can only say as i find. Obviously the car won't make anymore power with a better intake, as the fueling's unaltered. Be really interested to see difference in torque graphs though, if it's ever been tested on a rr.

I've tested the combination of standard vs chopped air intake on a rolling road during the 160 development, and no difference in power output was found whatsoever.

What I will say is ducting fresh air directly into the aircleaner housing (experimental only) resulted in poor running on the car fitted with it.

My experience is the original setup is perfectly adequate, and won't cause power loss provided the rest of the intake system is in good order

Brian

RodgerD · 23rd April 2015, 20:50

Maintenance of the induction system is important, especially if you still have a working EGR valve. The amount of soot and crud in the EGR valve and plastic manifold can almost block the induction airways. This more than anything else will restrict flow.

Brumbrum · 23rd April 2015, 21:30

It doesn't surprise me that the chopped intake mod has much effect, due to the conical shaped section after it which ( i don't know this, as i haven't cut and measured it) could well be more restrictive than the hole left by the chopping. It's surprising that a cold air feed direct to filter housing had poor results though. If the original intake wasn't restricting, wouldn't the results of been the same?

Don't get me wrong, I'm not saying I've got more power from it, or it restricts top end power, but it's ability to 'breath' over 3200(ish) rpm is very much improved. The improvement lower down the range, could well be down to the egr vacuum hose plugged, but it could also be that's it easier for a slow spinning turbine to drag in air.

Honestly, I'm only speaking as i find. I wasn't expecting, and neither have i ever experienced such a notable difference from essentially, a simple airbox modification.

Totally agree, ive scraped the crud out of too many inlet manifolds. That's what taking over the maintenance of a Renault based taxi fleet does to you.

23rd April 2015, 13:31	#1
Brumbrum Newbie MGZT+ Join Date: Dec 2014 Location: South west Posts: 27 Thanks: 3 Thanked 1 Time in 1 Post	Crude air intake mod..i was curious. Thought I'd have a go at the infamous air intake and egr mod! I admit, it's very unfinished. But wow! I was surprised at the improvement to be honest. I never had much turbo lag before, but the engine is definitely more progressive from 1300 rpm upwards. It revs more freely, and doesn't feel as asthmatic over 3000 rpm either. I just need to devise a proper air feed. One drawback at the moment is the induction noise is pretty intrusive. __________________ [SIGPIC][/SIGPIC]

23rd April 2015, 14:07	#3
Mickyboy This is my second home MG ZT CDTI 135 + & MGZT CDTI AUTO 160 & ROVER 75 TOURER CDTI 160 TROPHY YELLOW Join Date: Aug 2013 Location: Hernebay Posts: 4,331 Thanks: 818 Thanked 2,414 Times in 1,141 Posts	I wouldn't leave the intake like that, the hot air in the engine is not beneficial, the egr is a good idea __________________ [SIGPIC][/SIGPIC] T4 Owner Jobs done : new UBP, Spy hole mod, Rear hub(wheel bearing),plenum cleaned and emptied, Inline thermostat fitted,Full service, In car Digital tv/DVD Bluetooth Satnav etc, Replaced UBP, Restored headlights,Fixed airbag connection.replaced HP pump,replaced rear light seals,changed intercooler O rings. Jobs to do: ,replace drivers lock,.[/SIZE]

23rd April 2015, 14:10	#4
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Bodge monkeys again __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block

23rd April 2015, 15:03	#5
Brumbrum Newbie MGZT+ Join Date: Dec 2014 Location: South west Posts: 27 Thanks: 3 Thanked 1 Time in 1 Post	I have no intention of leaving it like this! It was purely an experiment / 10 minute job after reading various topics on it, if i thought there would be potential gains from revising the oem intake. Idealy I'd like to keep it as original as possible. On an intercooled diesel, i wouldn't expect the heatsoak to make too much of a difference anyway, unlike say, a n/a petrol car. I've done rough calculations for this. [QUOTE=Jules;1982587]Bodge monkeys again [/QUOTE Appears so. They get everywhere.. __________________ [SIGPIC][/SIGPIC]

23rd April 2015, 16:05	#7
Brumbrum Newbie MGZT+ Join Date: Dec 2014 Location: South west Posts: 27 Thanks: 3 Thanked 1 Time in 1 Post	Lookin at the complete ducting unit i removed, I'm not sure there would be a dramatic difference after chopping off the bellows anyway? Did you notice much difference? It's not a particularly smooth air path and without calculating the new intake area it might not of been a significant increase. There's a further restriction between that an the airbox also, as the pipe is smaller than the airbox opening as it's of a conical design. So, thinking aloud I think I'm going to try a straightish feed to fresh air Totally agree on your maf point, this really isn't a good way to drive it long term. I can't comment on others opinions, i can only say as i find. Obviously the car won't make anymore power with a better intake, as the fueling's unaltered. Be really interested to see difference in torque graphs though, if it's ever been tested on a rr. __________________ [SIGPIC][/SIGPIC]

23rd April 2015, 13:56	#2
rich17865 This is my second home Transit Connect Join Date: Feb 2011 Location: Crewe Posts: 9,532 Thanks: 868 Thanked 1,619 Times in 1,095 Posts	EGR bypassed in that manner is a great idea, refit the air intake though as it serves an important purpose!

23rd April 2015, 15:30	#6
Johnny2R Gets stuck in Rover 75 CDT Club Tourer Join Date: Apr 2007 Location: Norwich Posts: 712 Thanks: 98 Thanked 47 Times in 24 Posts	The air intake question has been much discussed on here, and it would be worth your while searching through some of the threads. There was a fashion a while back to cut back the air intake to the bellows section, removing what was thought to be a serious restriction at the slam panel. This has now fallen rather out of favour and many, like myself, are reversing the mod, for two reasons. Firstly, it has been convincingly argued that having the intake like this is much more likely to lead to oil contamination of the MAF sensor, which you don't want. Secondly, though, T4 boffins on here such as marinabrian and bigruss have said that there is always enough air anyway on the diesel, and in effect the extra 'gape' is not needed anyway. I have not tested it myself. These guys seem pretty well informed to me, though.

23rd April 2015, 20:50	#9
RodgerD Rodger & Out Rover 75 Saloon Join Date: Nov 2014 Location: London Posts: 712 Thanks: 10 Thanked 159 Times in 141 Posts	Maintenance of the induction system is important, especially if you still have a working EGR valve. The amount of soot and crud in the EGR valve and plastic manifold can almost block the induction airways. This more than anything else will restrict flow.

23rd April 2015, 21:30	#10
Brumbrum Newbie MGZT+ Join Date: Dec 2014 Location: South west Posts: 27 Thanks: 3 Thanked 1 Time in 1 Post	It doesn't surprise me that the chopped intake mod has much effect, due to the conical shaped section after it which ( i don't know this, as i haven't cut and measured it) could well be more restrictive than the hole left by the chopping. It's surprising that a cold air feed direct to filter housing had poor results though. If the original intake wasn't restricting, wouldn't the results of been the same? Don't get me wrong, I'm not saying I've got more power from it, or it restricts top end power, but it's ability to 'breath' over 3200(ish) rpm is very much improved. The improvement lower down the range, could well be down to the egr vacuum hose plugged, but it could also be that's it easier for a slow spinning turbine to drag in air. Honestly, I'm only speaking as i find. I wasn't expecting, and neither have i ever experienced such a notable difference from essentially, a simple airbox modification. Totally agree, ive scraped the crud out of too many inlet manifolds. That's what taking over the maintenance of a Renault based taxi fleet does to you. __________________ [SIGPIC][/SIGPIC]