Air box mod for 240's

[JW240]

Airbox mod for the 240

Why to remove the airbox restrictions and air preheat thermostat?
-more power, it made a noticeable difference on the butt-o-meter.
-better MPG (mine got a little jump better, but the thermostat in the airbox had failed on my 240 so it sucked hot air the whole time). I get 29 MPG now..
-If the engine gets hot air the AMM (Air Mass Meter) can be damaged and thats a very expensive part..

And on aside note, the engine has a bit more agressive sound when revving it :-P



http://img301.imageshack.us/img301/7493/p5170176k8no.jpg

You start with this... completely remove the airbox. this is done by removing the battery, the battery tray and disconnecting the 45 degrees elbow that goes from the air box to the rest of the engine (amm). Removing it takes maybe 10 minutes..

Tools required: 13 mm socket for battery tray, 10 mm wrench for battery cables (watch out not the short the + to the body, so disconnect negative first!) and a 7 mm socket or flat screwdriver to remove hoseclamps.



http://img221.imageshack.us/img221/1102/p5170187k7oc.jpg

To remove the thermostat flapper, there are 3 points where its held in place with little plastic thingies. They are visible when you look at the airbox from the air outlet side. Visible is one of the 3 mounting points. The thing releases when you press the 2 plastic tabs toward each other.

The next 2 steps can be left out if you completely remove the thermostat and valve. I didn't remove it because I didn't had a suitable way of closing the preheated air inlet and I wanted it to be reversible in case I would need it for a government emissions check. Untill now, this mod hasn't given any problems with emission checks.



http://img221.imageshack.us/img221/8512/p5170181k1nk.jpg

This is the removed thermostat with flapper. I added maybe 10 small stainless steel washers, so that no matter what the thermostat does (mine was broken, so my engine got preheated air all the time), its always stuck in fully cold air position.



http://img215.imageshack.us/img215/8121/p5170186k9qm.jpg

This is what it looks when fitted in the airbox again. It doesn't close all the way, so I added another washer to get it completely closed.

I still added a 50 mm cap on the hot air hose to prevent huge amounts water and dirt from getting in the airbox (the airbox has water drainage holes at the bottem so a bit water won't do much). Then, I connected the hot air hose again over the cap, so when I get a check, no one can see that it is not used..

http://img299.imageshack.us/img299/8933/p9090964k5yj.jpg

The preheat hose fitted but if you look carefully, you can see a small red edge where the hose connects to the airbox. The cap is between the hose and the inlet. So the hose has no function, but its still there so they won't whine about it when they chack your car for emissions..



http://img215.imageshack.us/img215/3171/p5170195k5tg.jpg

Here is a picture of the snorkel and 90 degree bend that volvo put in front of the air box. Notice the enormous decrease in diameter of the tube! the whole inlet system is at least 70-80 mm, and this is maybe 45 mm! so stupid. Only removing the snorkel gives some gain, but the bend is also very restricting.
The little piece of PVC tube next to it is what I replaced it with, but that was stupid. You have to replace the snorkle and bend with a single 90 degree PVC bend and a piece of pipe and point it upwards. a few water draining holes in the bend can be a good idea.
I want to point out that removing the snorkle and replacing it with a small pieze of tube is not smart! that way more dirt and water can be sucked into the air filter. not that that would hurt your engine immediately (well a lot of water would), but it reduces the lifetime of the air filter and it can damage it.
So a 90 degree bend should be used, but there isn't much space and when the airbox is back in place, its very very difficult to put the new bend in! I had to install the bend while the airbox was fitted and it was very difficult and it required some brute force... :roll:



http://img216.imageshack.us/img216/5975/p5170196k8fb.jpg

This is where the 90 degree bend is fitted.. It fits barely in the small space behind the headlight and its a PITA to install with the airbox fitted.. Some zip ties can be used to calmp everything firmly against the bodywork.



http://img274.imageshack.us/img274/8964/p9180906k2wv.jpg


http://img42.imageshack.us/img42/1200/p9180909k2fh.jpg

The piping I used as a replacement of the snorkel. Its 75 mm outside diameter. about 3".


The next step is to remove one or bothe of the screens of the AMM. I would leave the first one in place to prevent any debry's from entering the engine and damaging the AMM if the airfilter would fail or a hose break.

What I did soon after the aibox mod was to clean the Throttle body and I checked for leaks past the AMM, and I found one in the thick hose between the AMM and the TB, just after the AMM, there the hose rubs over the battery cables that run to the starter. The car drove better after cleaning the TB and injectors.
I get almost 29 MPG with my 240, and I don't drive slow at all.. so I recon the upgrades are good :)

JW

BTW: during the winter, i use a extra 90 degree bend on the intake that points a bit to the rear to prevent rain and snow from entering the airbox...

[JW240]

I would like to add for which years this mod works. I have a 1991 240, I believe all B2XX 240's from 1985 and on have it this way but i am not sure...

I did this mod in May 2005 and it hasn't given my any problems since then.

[volvostud]

removed

[BiG_BrIcK_240]

so what exactly do i need to drag out of there?

[JW240]

just rip out the snorkle, and bend, replace that for a 9- degree elbow sewer pipe fitting, and remove or block the thermostat....

[klr142]

I'd like to add that it's not so much improved sound when you rev it, but when you get on it under load. That's when you hear it the most, and it's yummy!

I think you could also adapt our pictures of the mod from the other post we have, where we cut out the front of the box on an '84 240.

[JW240]

OK I'll look at it

[240Psycho]

this was one of the first things i did when i got my car, about 4 years ago. Only i left the Volvo plastic snorkal, and cut a V out of the top to try and get more air flow into the box. I also used a cutting wheel to cut the hole in the air box that is shaped like a funnel so that it would be flat and that even more air would enter the box.

You can see the funnel shaped hole molded into the box that points right at the thermastat for the hot air hose assemblyhttp://img215.imageshack.us/img215/8121/p5170186k9qm.jpg

[Unregistered]

Don't do this in CA...My '84 240's preheat was stuck open, so I removed it and the smog inspection failed my for tampering with it.

[chunky]

anyone know if compleatly removing the thurmo will make you fail inspection in TX?


and couldn't you just clog the warm air hole, so that even if it opens no air would go into the box.

[dbh86]

They don't care in TX

[JW240]

....
and couldn't you just clog the warm air hole, so that even if it opens no air would go into the box.
if it would turn to preheating, your engine won't get any air or with a very high resistance...

[chunky]

ok, is the thurmo wired in at all? if i cut the wires and just pull the thurmo out is it going to throw codes or anything?

if i pull the thurmo out and then just put a cap over the hole will it still cause resistance?


as of now i just pulled the hose off so when the flapper opens it just pulls in air from under the car.

[243_Phantom]

ok, is the thurmo wired in at all? if i cut the wires and just pull the thurmo out is it going to throw codes or anything?

if i pull the thurmo out and then just put a cap over the hole will it still cause resistance?


as of now i just pulled the hose off so when the flapper opens it just pulls in air from under the car.
mechanical thermostat.

[JW240]

bump for adding some pictures!

[growley]

I think i'm gonna do this to my 240. I'll probably remove the headlight for easier access though. How exactly did you ziptie the bend down? Oh yea, I removed the thermostat assembly a while ago. I'm gonna have to saw off the rest of the preheat hose or something b/c it won't come off. And then i'll just cap off the preheat hole.

[NoSi1212ah]

nice write up and great pics.

[Dauntless]

I think i'm gonna do this to my 240. I'll probably remove the headlight for easier access though. How exactly did you ziptie the bend down? Oh yea, I removed the thermostat assembly a while ago. I'm gonna have to saw off the rest of the preheat hose or something b/c it won't come off. And then i'll just cap off the preheat hole.

I've done something similar on 2 of my 240's now. There's no need to remove the headlight, the battery, or the battery tray. Just put the 90 degree bend in first, then the snorkel you made, then finally hook it up to your airbox. I also removed the air heater from the exhaust pipe, and the brackets for the preheat hose, to save weight and tidy things up.

[growley]

I've done something similar on 2 of my 240's now. There's no need to remove the headlight, the battery, or the battery tray. Just put the 90 degree bend in first, then the snorkel you made, then finally hook it up to your airbox. I also removed the air heater from the exhaust pipe, and the brackets for the preheat hose, to save weight and tidy things up.
I was thinking the same thing. In fact, you probably wouldnt even have to remove the airbox...

[klr142]

My version is to cut out the front of the airbox, not all of it, but most of it, and then re route the preheat hose(after removing the T-stat) under the bumper to one of the holes down there. Leave the stock bendy elbow in place, but not have anything else in front of the support panel there, just the open elbow. Makes for a nice growl, and better performance than just putting some more restrictive stuff up front... And it's cheaper as well. FWIW.

[JW240]

I wanted to clamp the pipe with zip ties to the frame, but I never got around to do that. The pipe hasn't come off, it's still on there very good.
I mamaged to mount the bend behind the headlight without removing the airbox, but it was very difficult... I guess that 5 mm matters a lot, the bend was just a bit too big.

[brucepick]

Nice mod!
I'm seriously considering doing this.
It should be a good follow-up to my headlight mod (working on that now) - dual 6x8" sealed beams should leave room for some ductwork.

Can you confirm?
1) Original short hose goes from air box to existing hole in headlight/radiator support bracket.
2) New 90-degree bend goes on front side of bracket, points towards front of radiator area.
3) 30 or 45-degree bend points approximately towards the horns?

Thanks!

[JW240]

....
1) Original short hose goes from air box to existing hole in headlight/radiator support bracket.
2) New 90-degree bend goes on front side of bracket, points towards front of radiator area.
3) 30 or 45-degree bend points approximately towards the horns?

exactly!
the 45-degree bend is not really needed, but that way it takes the air from a bit higher so in the case of deep water its a bit safer.

[growley]

I just bought a 3" (what is supposed to be a 3 inch but ended up being more like 3.5") 90 deg bend but it was too large for the aforementioned reason. I measured the hole that goes through the headlight support and it was about 3 inches. Removing the headlight helps alot, but it is still hard to fit it in there with the frame and the wiring harnesses. I'm going back to the hardware store to get a smaller diameter bend.

[JW240]

I just bought a 3" (what is supposed to be a 3 inch but ended up being more like 3.5") 90 deg bend but it was too large for the aforementioned reason. I measured the hole that goes through the headlight support and it was about 3 inches. Removing the headlight helps alot, but it is still hard to fit it in there with the frame and the wiring harnesses. I'm going back to the hardware store to get a smaller diameter bend.
3" is usually inside diameter I guess...
Over here in europe, the things are measured in mm and the outside diameter. 75mm fits very good, so 3" OD or maybe 2.5" ID (IIRC, that means 76 mm OD) is the best I guess..

[brucepick]

... I'm going back to the hardware store to get a smaller diameter bend.

Standard # of trips to hardware store per repair project: 5
# of trips for plumbing repair projects: 15
# of trips per automotive modification project: 51 :badboy:

[growley]

3" is usually inside diameter I guess...
Over here in europe, the things are measured in mm and the outside diameter. 75mm fits very good, so 3" OD or maybe 2.5" ID (IIRC, that means 76 mm OD) is the best I guess..

heh forgot about that. I went back to the hardware store and got a 2" diameter bend. That's all I have in there right now.

[JW240]

heh forgot about that. I went back to the hardware store and got a 2" diameter bend. That's all I have in there right now.
I drove around without anything on there for some time, thats also possible... (duh ;-) )

[BiG_BrIcK_240]

how about i just rip out the warm air tube thingy?

[JW240]

how about i just rip out the warm air tube thingy?
can be done, but then the air is sucked into the airbox from inside the engine compartment, and from a lower point. Better to rip out the t-stat, put a cap on the preheat hose connection and rip out the sorkel thingie and replace that with a bit of 2.5" tubing (with or without bend)

[klr142]

can be done, but then the air is sucked into the airbox from inside the engine compartment, and from a lower point. Better to rip out the t-stat, put a cap on the preheat hose connection and rip out the sorkel thingie and replace that with a bit of 2.5" tubing (with or without bend)
Better to remove the T-stat, and re-route the preheat hose to the lower spoiler to inhale cold air.

[JW240]

Better to remove the T-stat, and re-route the preheat hose to the lower spoiler to inhale cold air.
yeah thats a good one! forgot about that.. but look out for water..

[Tick]

I'll get pics up of this eventually but the way I did it on my 740 was left my original fender cai which picks up behind turn signal in front of wheel, high enough I don't worry about water. (in fact I cross creeks with it) then capped off the preheater almost exactly like you've got it there, red cap off a can of berryman's, then just inside on preheat side I took a drywall saw and blew a hole out through the bottom of the box to three and a half inches - used more plastic rattle can lids cut into segments to fishbowl the air off both sides directly up with a ****load of silicone (I'm'a go put zipties in for affect) and bought the appropriate radiator hose (probably off some damned ford) but it was about the same three and a half inches with something slightly softer than a ninety and shot straight out through the front to sit behind air dam. This way even with the cai capped the engine runs like it was meant to stock and unless they're both submerged they're not going to drink.
Maybe it defeats the forced ness of the thing but it makes a mean chuckle with the amm descreened and a k&n sitting at idle and a rabid honda at wot (minus the beer can chipper noise and the mini me 'wheeeeeeeee') well, it's hard to really tell what they sound like at wot when they're that far behind.
-Tick

[klr142]

Lol, nice.

And about water... You know my method of cutting open the front of the airbox? Let's call that a SUMMER airbox only. If you have a K&N in there, it might be ok, but, with the stock paper air filter in there, it gets wet when it rains. In light rain it's ok, but when it starts pouring, and when there's lots of spray from the cars in front of you, the air filter gets soaked! And, the car feels groggy, because it can't breathe through the waterlogged filter. So that's an update on my setup... I'm going to switch to just tossing on a K&N cone filter though, hopefully I can get some sort of hose/piping to place it behind the left headlight, near where the car's stock intake goes. Then make up some sort of heatshield to only allow it to pull air from around there. Should be less restrictive than the stock airbox, I think.

[chunky]

i finally got around to doing this but i gutted mine then wrapped it in some insolution stuff from home depot, and pulled off the warm air hose. worked really good, the needle sits just a tad lower on the gadge. i now need to find a cap of cover the warm air hose hole in the airbox

[Crazychopstick]

Did this mod this weekend too, I haven't plugged up that preheat hole yet but I did flip the snorkel upside down so it's open towards the lower bumper(lame ram air of sorts).

[chunky]

i just pulled the snorkel and the 90* bent it hooks to off since there so restrictive. now i'm just pulling aur from behind the headlight

[olov]

NA mods = waste of time

but still fun :D

my first mod on my NA 244 was to ditch the box for a cheapo cone, no real improvement but i can hear the vacuum

but my kjet airbox got 3in ductwork and no passenger high beam :twisted:

[Crazychopstick]

NA mods = waste of time

but still fun :D

my first mod on my NA 244 was to ditch the box for a cheapo cone, no real improvement but i can hear the vacuum

but my kjet airbox got 3in ductwork and no passenger high beam :twisted:

Well, the airbox mod shouldn't bee looked at as a performance mod, i like to think of it as "fixing" the thermostat be ripping it out.:)

And doesn't Kjet not like cone filters? I remember reading that somewhere, I dunno.:???:

[olov]

yeah, i kept the kjet box, just cut a bigger inlet for it and ran pvc to it

[chunky]

i finally got around to doing this but i gutted mine then wrapped it in some insolution stuff from home depot, and pulled off the warm air hose. worked really good, the needle sits just a tad lower on the gadge. i now need to find a cap of cover the warm air hose hole in the airbox


pics:
http://img.photobucket.com/albums/v519/chunky420/volvo/c7f85de6.jpg
http://img.photobucket.com/albums/v519/chunky420/volvo/2111bcbe.jpg
http://img.photobucket.com/albums/v519/chunky420/volvo/ad8f7d70.jpg
this was after driving around for 25-30 min. after i let it warm up for about 5 min. that's about where it stays all the time, might gat a little from time to time but for the most part it stays about there.
http://img.photobucket.com/albums/v519/chunky420/volvo/2006_0209v0004.jpg

[Crazychopstick]

What did everyone do about the heat hole comming off the exhaust manifold?

I want to bold a U shaped pipe on it to direct most of the heat downwards.

[klr142]

Nothing. You guys are being more anal than I was, suprising... And all for naught. Oh well, continue...

[740Weapon]

if your going to insulate the box, you should go for gold and insulate the intake manifold.

[JE Jr]

Coluldn't you guys just put some duct tape (that is the silverthingie, right??) over the preheathole and just take out the thermostat, flapper and the other winter-crap??

I have two airboxes for my 740, one summer with just cold air and one for the winter with th preheat, slightly modfied for better flow.

[Addicted242Boost]

Drilling holes in the airbox make the car sound cooler upon revving and WOT too ;)

[klr142]

Drilling holes in the airbox make the car sound cooler upon revving and WOT too ;)
Cutting out the front of it works even better... ;-) But, definitely be prepared for worse wet weather power, and frequent replacement of the filter element. Ask me how I know... I think I'd rather spend the $40-50 on a big cone than do this again.

[DAW]

The warm air can be a blessing for cold weather operation and I didn't want to disable it altogether so I used a larger, s.a.e.-type or thrust washer (relatively large id, for a given od type washer) and installed it between the thermostat body (which contains a wax pellet and actuates a rod which protrudes out of it), and where the thermostat seats in the flap mechanism. By doing this, the thermostat still functions but it recalibrates the effective opening temperature that the flap begins to let cold air in. I tested it in our oven (wife not present) and in the refrigerator and selected washer thicknesses until I had it opening at 50 degrees F. instead of the 105 degrees or whatever it is stock.

I lowered the temp of the intake charge significantly by doing this but I can still start up and drive away when it's January. If you have the whole box apart and are doing this mod, I'd recommend setting it up with a new ($20) thermostat to calibrate. DAW

[Tick]

^^^ Now that's mad scientist. I like it.

Got pics?

[DAW]

I'll see if I can get a camera in there and click some pics. It's good to have access an old-school hardware store with the drawers of various nuts/bolts washers of both metric and s.a.e. standard choices to select the washers from. The giant stores with things in prepackaged bags of 5 are useless for this type of work. DAW

[DAW]

Look back at photo #3 that JW240 provided. He took some excellent photos and did a great job of writing up his mod, BTW. He stacked stainless steel washers between the body of the thermostat and the plastic post/rod of the flapper door. What's in the center opening of the washers id the metal actuator rod of the thermostat (it's about 2mm dia and will extend further out of the thermostat as temp increases). When the thermostat fails it no longer causes the hot-air door to close in response to warmer temps in the box.

Look at that photo and visualize it with the stack of washers removed and a good thermostat in there and then some large id washers inserted between the retaining shoulder/lip of the thermostat body and where that lip seats against the housing.

What this accomplishes is to preload the spring of the actuator post/rod so that it "wants" to close the hot-air door earlier. If you drew a graph of door-closing vs box temp, what I'm describing just shifts it to the left some. It's a lot like lengthenning the actuator rod on a turbo (internal wastegate), it preloads the actuator spring so the boost limit/wastegate opening occurs at a higher pressure (because it has to fight the added pressure from the spring you adjusted in). DAW

[tjts1]

Forget the stack of washers. Just rip out the air flap mechanism (it pops right out of the airbox if you pull hard enough) and stuff a couple of crumpled up balls of aluminum foil into the hot air hose. It works great and the airbox stays at ambient air temp even in stop and go traffic.

[Homer]

God you noobies. Re-Route the preheat hose to behind the PS headlight and discard the flapper.

[Tick]

God you noobies. Re-Route the preheat hose to behind the PS headlight and discard the flapper.

Hey, I gutted my box good and proper back when I thought I was the only person stupid enough to modify a volvo.

I think we understand the idea of cold air. What he's describing is a way to retain the stock warmup function in a way that makes sense. As well as a way to test function of it. In cold climates this is useful.

Besides the fact that some people are convinced they'll fail smog if they lose the preheater hose or redirect it as you're describing. Which is not true, at least here in cali for my 740 they looked it up last time I smogged and I was off the hook after much debate.

[charlotte001]

why not just go for an induction kit with a cone filter ? would be easier than gutting the standard restrictive box I'd have thought.


The pre heat hose: If I'm correct that's the annoying bit of metal junk pipe going from the manifold to the air box ? If not then correct me. That does absolutly nothing other than supply a small amount of hot air to make the engine start a little better on cold morning ! I've removed every single one from all the cars I've owned in 16 years and none of them have failed any test infact new cars don't even fit it anymore. As one VW service manager said when I took a Passat in "I know where it goes I have no idea what it does"

So don't let anyone tell you "oh it has an effect on anything it doesn't plus it doesn't supply enough warm air to do any good anyhow (check it on a computer meter)


Charlotte

[Homer]

why not just go for an induction kit with a cone filter ? would be easier than gutting the standard restrictive box I'd have thought.


The pre heat hose: If I'm correct that's the annoying bit of metal junk pipe going from the manifold to the air box ? If not then correct me. That does absolutly nothing other than supply a small amount of hot air to make the engine start a little better on cold morning ! I've removed every single one from all the cars I've owned in 16 years and none of them have failed any test infact new cars don't even fit it anymore. As one VW service manager said when I took a Passat in "I know where it goes I have no idea what it does"

So don't let anyone tell you "oh it has an effect on anything it doesn't plus it doesn't supply enough warm air to do any good anyhow (check it on a computer meter)


Charlotte
Well you're wrong it does. Helps with cold starts.:roll:

[bag3lbit3s]

I'd have to admit, I did notice having it on vs. not having it. When it's really cold it made a noticeable difference in warming the engine up. But I just don't think it's really that necessary, I don't even have it on anymore. It's just in the garage and when smog comes up I put it back on. And the pre-heat part on the airbox is just duct taped over.

[dezquest]

I did the air box mod this weekend. I deleted the pre-heat hose and heat shield. It was a noticeable difference. I actually Ghetto-rigged the Warm air inlet of the air box. I completely removed the thermostat in the box. Then I took a RedBull Can cut it in half and siliconed it over the air inlet for the warm air (LOL). It definitely sounded better and pulled harder when I punched the accelerator. I like a lot, but I still might do the air induct with a cone filter in the near future. This mod was very sinple and easy to do. Took me like 15mins.

[JW240]

re the warmup of the engine with or without the preheat hose:
i drive the same stretch of road every morning, same speed (small rural road), and i definately see a slightly longer warmup time than before i deleted the pre-heat... The temp gauge takes maybe one minute longer to reach the 9:00 position where it is always.
I doubt this will cause excessive engine wear, as i drove around with a broken coolant t-stat (engine wouldn't warm up, gauge always showing 7:00) for maybe 500-1000 miles, and the engine is still in very good condition....

BTW, i like the redbull can idea! true tbricks!

[klr142]

For what it's worth, I took my stock airbox off for the drags on friday night, and replaced it with a cone on a little extension pipe that centered the filter just a little right of where the airbox was, and I was slower. I don't think it was just the slightly higher ambient air temperature. I blame it on the fact that my cut open front airbox operated better by sucking in cool air. It cost me hp that I could feel, and 3 tenths of a second, and one mph at the line. If I was able to route the cone ahead of the radiator support and directly behind the grill, I think the results might've been different. But sticking a cone inside the engine compartment without a very decent heatshield and cold air supply seems to have hurt my performance.

I can't say if it was worse or better than the airbox mod you guys try in this thread though, which isn't nearly as good as when you cut the front of the airbox off. Cutting the front of the airbox, removing the T-Stat and routing the hot air pipe to the front spoiler for additional cold air, along with a K&N or a new paper air filter in the airbox would be the optimal setup if you ask me. Apart from doing some radiator support bending to get a cone filter ahead of the radiator/condensor.

[DAW]

If you don't mind taking a few minutes to do the swap, the optimum is probably to have two airbox assemblies: a winter, modified to regulate intake air temp at 60 degrees F. or so; and a three-season box gutted of the temp-door mechanism altogether. Both could use the same rectangular K&N filter (or stock). That little funnel that directs outside air to the thermostat bulb for the temp-door could be cut back/opened-up on the summer-use box and there is a plastic air deflector/shield mounted by two screws to the radiator support that could be taken off for summer.

Don't sell the design engineers short with respect to the configuration of the intake snorkel/plumbing. Frequently, removal of these components will hurt power. There may be some trial and error to find the best summer setup but using the warm air tubing to source cool air sounds better than just plugging it. DAW

[klr142]

Cutting open the front of the airbox works much better than any sort of adaptation to the stock snorkel design. It only comes in not handy when you use the AC(if so equipped), and in the rain if you have a paper filter. And the filter gets dirty much faster, but that's what you get for increased performance and noise.

[Dinoboy]

Hey guys,
I have an '87 240 and am trying to locate the thermostat/flapper. Are they the same thing? I took apart my airbox a while ago but didn't really see any flapper thing or whatever. Is the thermostat the same thing as the Air Mass Meter? Thanks.

[BrickBaller]

AMM is not the same thing. The flap is inside the big airbox just in front (as the air travels) of the filter. As noted it tends to fail and draw in hot air all the time. Rip it out, rip out the preheat hose (unless you are in Canadia, eh?) and have both holes draw in cold air, easy as pie.

[charlotte001]

wierd I removed mine and I don't notice any difference at all. I'm in the east coast of the uk (everyone knows british weather) and the car doesn't run any different with or without preheat pipe

Charlotte

[grizlyadams]

wierd I removed mine and I don't notice any difference at all. I'm in the east coast of the uk (everyone knows british weather) and the car doesn't run any different with or without preheat pipe

Charlotte

When its -25c outside it will help starting your car!! in milder climates, it doesnt make any differance.
Griz

[ebender]

I have had no problems in Boston winter (gets below zero fahrenheit) with no tube no thermo/flapper.

[klr142]

It's not going to make ANY difference with starting the car... Only the length of the warm up time and possibly the performance at operating temperature.

[brucepick]

Well you're wrong it does. Helps with cold starts.:roll:

Nope. No help with cold starts.
Exhaust manifold is stone-cold when cold starting.

What it does help, is that once the manifold gets heated up a bit and the motor is still pretty cold, it provides warmed air to the intake. Maybe helps combustion just a bit when outside air is like freezing and the thermostatically-regulated air is at whatever the ideal intake temperature is. Assuming the f***in' t'stat is working right, which isn't likely.

Even assuming all is working as designed, the benefits to warmup and even to the envoronment are so miniscule that even tree-huggers like myself don't give a flyin' floopie.

[A-Rode]

.....:lol:

[N/Avolvo]

what if you just put in a new theromstat so it worked properly. The thermo isn't that expensive

[klr142]

What if? What if what? Then you'd have a stock Volvo intake, that's all.

[klr142]

http://www.ovtuners.org/gallery/albums/MY244/IMG_0182.sized.jpg

[Michael Garvin]

Does anyone have any links to get parts for a tube style cold air pipe for a non turbo 240? Similar to an intercooler styl pipe/hose setup.

[Krisverde]

So it's safe to remove the pre-heat hose but cap the hole off? nothing will happen? Also will it cause the car to fail emissions at all?

[DaButcher]

This is how I did it:
http://volvo-power.net/gallery/albums/ny2/normal_DSC_2113.JPG
http://volvo-power.net/gallery/albums/ny2/normal_DSC_2112.JPG

ps. also removed internals of airbox ;)

No need to remove battery when dis-assembling the airbox.
Oh, yes.. I also removed that upper part of the plastic intake on the airhose, which was so restrictive.. So now I have a much larger radius intake.

I think I feel some more power back, from the defective thermostat which was closed on preheating :S

[Krisverde]

^^ How is that working out for you?

[DaButcher]

Hi, it's better than it was.
My preheat hose was torn off, also the thermostat was stuck in the always prehet modus :P

So, yes.. Before, I got warm air, at all times.
Warm air => less effective engine

I doubt we are talking about like many hp here, but I guess this fresh air mod will help with emissions, I also think it will give you a higher mpg-count.

ps. this is better than fitting a conical filter, as the conical filter will also suck warm air!
We also did some dyno on a golf, air filter in oem box (new) vs conical filter (green filter).

The difference in power was so low, that it was in the margin for the dyno, lol..
However, I dont think this fresh-air mod is useless, as fresh air is better than the warm, under bonnet air.

[Krisverde]

How does that hose work out when it rains? does your filter get wet at all? I may just route the pre-heat hose down there, or behind the PS headlight.

[DaButcher]

How does that hose work out when it rains? does your filter get wet at all? I may just route the pre-heat hose down there, or behind the PS headlight.
It hasent rained for many weeks now, so I dont know.
Doubt it will get wet though, as the hose is not, how do you say, it's not smooth? it's got elevations, which would catch the drops of water? my theory though.

There is also a 180deg angle there :-)

[Krisverde]

I may have to look into finding a hose like that, It never rains much here in Arizona anyways, but when it does come time I want something that will hold up. I would also think that hose should hold up.

[klr142]

I live in Oregon. That should be enough said.

[DaButcher]

I bought the hose from www.dealextreme.com , its really a pc hose called fan duct.
ps. they have free shipping intl., also you pay them through paypal.

However, you could also get a similar to OEM ALU hose from any kitchen/bathroom dealer, or some sort of store which sells stuff for renovating houses, as many ventilation systems use theese very thin ALU hoses.

edit: this blue hose is an 80mm fan hose thingie, so I used a clamp-ring and clamped it onto the airfilter.

url for fanduct: http://www.dealextreme.com/details.dx/sku.9994

[Krisverde]

So I did the mod today my t-stat was stuck in the pre-heat position, and I think I felt a little more power after removing it.
This was my t-stat
http://i78.photobucket.com/albums/j103/Krisverde/Volvo/HPIM0383.jpg
I ran the pre heat hose to here...but i'd like to add the splash pan back on so I may have to cap that hole off..any suggestions though? I tried by the passenger light but it seemed to pinch the lower radiator hose...
http://i78.photobucket.com/albums/j103/Krisverde/Volvo/HPIM0384.jpg
Then I found this when I pulled the airbox out... what is it?
http://i78.photobucket.com/albums/j103/Krisverde/Volvo/HPIM0387.jpg

[DaButcher]

So I did the mod today my t-stat was stuck in the pre-heat position, and I think I felt a little more power after removing it.
This was my t-stat

I ran the pre heat hose to here...but i'd like to add the splash pan back on so I may have to cap that hole off..any suggestions though? I tried by the passenger light but it seemed to pinch the lower radiator hose...

Then I found this when I pulled the airbox out... what is it?
http://i78.photobucket.com/albums/j103/Krisverde/Volvo/HPIM0387.jpg
This is to clamp your battery in place.

[Homer]

This is to clamp your battery in place.

Which I need and forgot to buy at the dealer yesterday. Damn

[BRUNOP39]

i know this is an old thread,,but thinking of finally doing this,,,i have read here of removing the airbox,,,,,,but by doing this you are also removing the air filter correct?wont this contaminate the amm wire..please let me know ,,that would mean more cfc spray cleanups to the amm,,,let me know friends.

[DaButcher]

i know this is an old thread,,but thinking of finally doing this,,,i have read here of removing the airbox,,,,,,but by doing this you are also removing the air filter correct?wont this contaminate the amm wire..please let me know ,,that would mean more cfc spray cleanups to the amm,,,let me know friends.
no, you keep your filter there.

[PSYKOSTEVO]

I did this mod. And it makes the car easier to start. Before it was stuck on preheat and you had to hit the gas to get the car to start, now it's way better. No noticable power gain, but you know it's got to be better than exhaust fumes.

[BRUNOP39]

ok
i will remove the damn pre heater window,,so that is all i need to do then

[BRUNOP39]

mine is stuck in the closed position always

[Fake-R]

I did this mod. And it makes the car easier to start. Before it was stuck on preheat and you had to hit the gas to get the car to start, now it's way better. No noticable power gain, but you know it's got to be better than exhaust fumes.

...You don't get exhaust fumes. The preheat hose is just connected to the manifold, which gets hot faster than anything else on the damn thing.

DEI FTW?


Also, rather than putting something in place of the elbow infront of the grille, I just left the hose open. Not too worried about water, because it is behind the headlight and all, and I still have the K&N, which gets covered in oil anyway.

[Krisverde]

I ran the hose here.
http://i78.photobucket.com/albums/j103/Krisverde/Volvo/HPIM0389.jpg

[klr142]

I did this mod. And it makes the car easier to start. Before it was stuck on preheat and you had to hit the gas to get the car to start, now it's way better. No noticable power gain, but you know it's got to be better than exhaust fumes.Except, there's no heat coming from the exhaust until after the car has run for at least a few seconds, so I'm not sure exactly how that works...?

[PSYKOSTEVO]

Except, there's no heat coming from the exhaust until after the car has run for at least a few seconds, so I'm not sure exactly how that works...?

good to know.