street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
|
|
May 17, 2006 19:54:00 GMT
|
I remember someone asking about drilling the airbox a few weeks back, so thought i'd put this in the general section as well as on the readers rides. My MG Mong-tego is a great example of a badly designed air intake, holding back some valuable horsies no doubt. It illustrates how restrictive manufacturers make their air intakes to keep their cars acceptably quiet. Basically, its sole air supply into the airbox is through this pipe.... ....Which draws air through this tiny little hole! The little shaft of light is the only gap from the front of the car into the engine! I'm suprised it can haul its own bodyweight, let alone return any decent performance. So, what it needs is some good cold air forced into the airbox ;D Most logical approach appered to be to enlarge the hole in the slam panel to accept some sort of pipework: Snip snip: But now it needs the pipework to pipe the cold air direct through the airbox. The obvious choice is, B&Q! And from my other favourite tuning shop, Homebase: Here it is fed through the new hole to the air box: But before it can be connected up, the air box is holding out on us: Looks normal enough.... ...But when I prized the box apart.... ....Inside was all this shizzle!: Great for quietness, but no good for optimum air scavenging. It all came out.... ....and was glued back together as an empty box with a filter on top. It will no doubt roar its man-boobs off when I mash the accelorator now! That useful bit of plastic pipe with a square flange on one end that came out of the airbox turned out to be just the sort of thing to bolt to the front panel.... ....Chop down and sit behind the grille holding the pipe facing forwards for some proper ram air technologeeee The finished article: If I didnt have a flat tyre tonight i'd tell you if it made any difference!
|
|
Last Edit: May 18, 2006 23:08:00 GMT by street
|
|
|
|
|
May 17, 2006 20:00:53 GMT
|
A marvelous example of ingenuity! And all that nice cool moist condensed air can race up to the engine. Question. Will the ribbed pipe (stop it!) create unwanted turbulance?
The airbox on the Volvo is similar, I can't even remember if I have a filter at the moment either. I ran a Westfield with twin 40's, trumpets and nothing but guaze trumpet covers to stop big stones and insects from being sucked in. It worked rather well.
|
|
Peugeot 307sw - Suzuki SV650S - MX5.
|
|
street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
|
|
May 17, 2006 20:05:50 GMT
|
A marvelous example of ingenuity! And all that nice cool moist condensed air can race up to the engine. Question. Will the ribbed pipe (stop it!) create unwanted turbulance? The airbox on the Volvo is similar, I can't even remember if I have a filter at the moment either. I ran a Westfield with twin 40's, trumpets and nothing but guaze trumpet covers to stop big stones and insects from being sucked in. It worked rather well. The pipe is smooth on the inside, so unfortunately we'll never know! Although I have seen some sort of air twirler things (yes thats their exact name) for use on trumpets, with some shpiel about how turbulent air is benificial somehow or other.... I dismissed it as a gimmick Edit: Sorry about some of the pic sizes guys, photobucket wont play nicely
|
|
Last Edit: May 17, 2006 20:07:45 GMT by street
|
|
|
|
May 17, 2006 21:03:46 GMT
|
Top modding Steve! Induction kit for £2.24p. Ave THAT Halfrauds!!! Hehe. It's amazing what gubbins the manufacturers chuck under the bonnet to make their engines more "polite". I can't wait to have a dig around the Volvo's engine bay!
|
|
|
|
|
|
May 17, 2006 21:14:22 GMT
|
good work that man!
|
|
|
|
|
|
May 17, 2006 21:18:29 GMT
|
thats good stuff. I'll be interested to know if you can tell a difference with it.
My mate had a Corrado with a 'Kekker + Nobrot' air filter, made a right load of racket so he bought an original airbox and stuck it back on, no difference in performance but much quieter.
I'll be surprised if you don't get a noticeable result with that set up.
|
|
1972 Fiat 130 1985 Talbot Alpine 1974 Lancia Beta Saloon 1975 + 1986 Mazda 929 Koop + Wagon 1982 Fiat Argenta 2.0 iniezione elettronica 1977 Toyota Carina TA14 BEST CAR EVER!!!!!!!! 1979 Datsun B310 Sunny 4-dr 1984 Audi 200 Quattro Turbo 1983 Honda Accord 1.6 DX GONE1989 Alfa 75 2.0 TS Mr T says: TREAT YO MOTHER RIGHT!
|
|
|
|
May 17, 2006 22:44:12 GMT
|
You are right they do have a very restrictive inlet system. But you have to be careful as they are set up to run like that and if they get too much air they can end up running too lean and loose a lot of bottom end torque and can miss a bit under load. An adjustable fuel regulator does help a bit with this.
|
|
|
|
street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
|
|
May 17, 2006 23:02:15 GMT
|
Cheers all! PhoenixC- Thanks for that, it did sort of cross my mind but couldnt see any obvious way to increase the fuelling, apart from bigger injectors. Adjusteable regulator sounds just the ticket, I will look into that. Does any car have such a thing as standard? Something I might find down the scrappers or Ebay perhaps?
|
|
|
|
|
|
May 17, 2006 23:04:35 GMT
|
Well that was a comical and interesting read, very proactive, keep us informed how it goes...
|
|
it doesn't matter if it's a Morris Marina or a Toyota Celica - it's what you do with it that counts
|
|
Jenn
Part of things
Posts: 929
|
|
May 17, 2006 23:08:48 GMT
|
Snip Snip, I love the DIY approach. My boyfriend has a dumb mate and they just wind him up by convincing him his car doesn't need certain components and you can remove them to save weight- air filter gone, not sure if he believed them on the glow plugs...?!
|
|
|
|
|
SkoCan
Posted a lot
Quando omni flunkus, mortati
Posts: 1,916
|
|
May 17, 2006 23:30:52 GMT
|
I wonder if this is what they mean when they say "I PLUMBED in a new intake"?
|
|
|
|
MWF
Posted a lot
Posts: 2,945
|
|
|
You are right they do have a very restrictive inlet system. But you have to be careful as they are set up to run like that and if they get too much air they can end up running too lean and loose a lot of bottom end torque and can miss a bit under load. An adjustable fuel regulator does help a bit with this. Not sure what engine management they run but I can see an air flow meter. The ECU should compensate for any extra airflow automatically.
|
|
|
|
|
|
May 18, 2006 10:37:00 GMT
|
On the Polo G40's (and possibly GT since they're MPi too) the airbox has a massive collar halfway down the intake, makes it less than half the diameter of the actual pipe. Removed it, probably no difference on paper but just felt a bit more perky mid-range.
One thing to note about drilling airboxes (i know you haven't, but it's a popular 'mod'), is that it lets the engine draw in hot air.... your approach of taking super-cool air from the front of the car is a lot more beneficial. My polo airbox was well and truly drilled, looked like swiss cheese - and it sat right next to the supercharger :roll:
|
|
Never trust a man Who names himself Trevor. Or one day you might find He's not a real drug dealer.
|
|
|
|
May 18, 2006 15:16:41 GMT
|
The pipe is smooth on the inside, so unfortunately we'll never know! Although I have seen some sort of air twirler things (yes thats their exact name) for use on trumpets, with some shpiel about how turbulent air is benificial somehow or other.... I dismissed it as a gimmick laminar flow (i.e. not turbulent) seperates a lot easier from a surface than turbulent flow, hence some manufacturers sometimes intentionally encourage a turbulent flow over the top of the car so as to reduce seperated wake behind. there's an interesting fact for you seems completely illogical but its true. i suspect however the main gain from turbulent flow in an inlet comes from better mixing of the fuel and air. i've been told a drilled airbox can give you some extra horses provided you don't drill any holes on the engine side. my intake hose runs into the rear of the headlight unit, which i'm sure doesn't actually have any flow in it. but hey, it seems to work so what the heck....
|
|
1986 Audi Coupe quattro
you need only two things in life: WD40 and duck tape. if it moves and it shouldn't use the duck tape, if it doesn't move but should then use the WD40. Genius!
|
|
|
|
May 18, 2006 15:55:54 GMT
|
home made induction systems FTW, lovely write up with images there on the montego
|
|
once again rocking with 1117cc and 4 gears!
|
|
|
|
May 18, 2006 18:38:59 GMT
|
I made an induction kit for my first car an 89 corolla 4wd out of gutter down pipe and a couple of bends, made loads of difference, then i found some ribbed flexible hosing at the side of the road, zip tied it in and I had a cold air feed whole lot (minus filter) cost about 7 or 8 squid.
|
|
|
|
|
|
May 18, 2006 20:04:39 GMT
|
An adjustable fuel regulator does help a bit with this. or, judging by the budget so far, put your current fuel pressure reg in the vice and give it a little squeeze. altho, if its fine, leave it as is. top modding, BTW
|
|
|
|
Reynolds501
Part of things
Volvos, they're boxy, but good.
Posts: 368
|
|
May 18, 2006 20:30:24 GMT
|
Nice work dude! I always thought those inlets were massively restrictive! the other type had a huge air inlet pipe that ran the length of the slam panel and sucked air from behind the R/H headlamp, gahh! The injection system on your car appears most likely to be the Lucas 12cu twin box system, the later cars had the MEMS system and did away with the airflow meter. The Lucas system is fairly sophisticated and will deal with your mods accordingly, though there is an airbleed screw on the throttle body housing for adjustment of base settings. It should sound pretty brutal aswell! I had the same injection system running an M16 in my old Maestro with a 'Green' cone filter directly fixed onto the airflow meter, it sounded great! Nice work again dude
|
|
|
|
street
Posted a lot
6.2 ft/lbs of talk
Posts: 4,662
|
|
May 18, 2006 23:04:22 GMT
|
Cheers again all I'd love to report that it is a vast improvement on performance, and it now takes off down the road like a raped ape, but at the moment its running rather badly! Gah! Its idling very low (although not stalling) and seems to be missing when revved, and generally down on performance. Its also smoking a bit too, so i'm guessing it needs some sort of adjustment? Snapdragon- This airbleed screw, would it help if it messed about with it do you think? Where is it on the car do you know? (M16 conversion sounds very interesting too! Wouldnt mind picking your brains about that once this little problem is sorted! ) Injection systems arent my specialty, i'm more a carbs kind of guy so this is all a bit puzzling for me! So if anyone can give any advice, its appreciated!
|
|
|
|
MWF
Posted a lot
Posts: 2,945
|
|
|
Was there an oil breather feed into the airbox?
|
|
|
|
|