Do you want more air flowing through your intake?

Post by **MadeInJapan** » 17 Nov 2007, 21:23

"R" Kelly who does the write-ups on Volvo Speed just posted this and its' very helpful.
Good thing is it costs $0.00 and takes 5 minutes:

I just did my "surgery." I'll see how much difference it makes.

Post by **Maxbaby** » 17 Nov 2007, 22:53

Interesting idea MIJ, I'm interested in your results. I was doing some reading on "spacers" for between the throttle body and intake manifold for my Nissan Frontier on another forum and that's supposed to add some horsepower... Dunno if that's been done for Volvos, but if anyone has such information, I'd be interested in learning more. It's apparently something that the onboard computer adapts to and doesn't require any special reprogramming...

sixdown · Post by **sixdown** » 18 Nov 2007, 11:23

I removed the deflector four months ago, and there hasn't been a noticeable difference. There may be some change in performance, but nothing I can pick up. As for rain, I haven't had any problems with water getting in...I believe the deflector was meant to deflect rain and debris.

Post by **MadeInJapan** » 18 Nov 2007, 16:12

I took mine off yesterday and drove 300 miles today...I notice no difference.

chuckcintron · Post by **chuckcintron** » 18 Nov 2007, 16:54

Is this the same on an 850? I'll have to look at mine when I get a chance, but if this allows any chance for chipmunks to get in there, I think I'll leave it on. I had a bad experience once with a chipmunk in the air intake of my pickup truck.

Post by **tjts1** » 18 Nov 2007, 20:41

Our 96 NA 850 doesn't have this extra piece bolted on. Just the small lip part of the fiberglass cross member. Any intake modification on an NA 850 is completely useless without first fixing or completely eliminating the hot air intake thermostat in the lower airbox. This only applies to NA cars.

The lower airbox is attached to a Y shaped dual intake. One side is connected to the cold air intake at the grill, the other side is connected to a silver hose coming from near the exhaust. Inside Y shaped intake, there is a thermostat, spring and trap door. The thermostat tries to maintain a constant minimum temp of 70f by adjusting the ammount of cold and hot air coming in. When the thermstat fails (and it always does after 10years), it does so in the HOT air position. This is how I found mine.

Cold air on the left is completely blocked off so the engine has to breath in super heated air from the exhaust through the much smaller tube on the right.

Remove the door, thermostat and spring.

Use some large pliars to break off the plastic bits holding in the thermostat.

Then reinstall the trap door backwards with the hinges facing the hot air side. Use a large wad of aluminum foil to stuff the hot air side full and keep the door in place. Now the engine will only breath cold outside air.

The intake goes from looking like this.

To this.

Once you have this done, reassemble every back together as it came out including both the hot and cold air hoses so it looks exactly the same from the outside.

If you haven't done this modification yet on the NA 850, you have no idea how much power and fuel economy you are missing. The hot air intake is probably costing you at least 20 peak hp and 2-3mpg. Its a night and day difference. All of the older NA RWD volvos are have this device hiding inside the airbox but i think it makes the biggest difference on the 850. I have done the same modification on an 89 240, 90 740 and 94 960. All had positive results and passed smog with flying colors for years after.

waynej · Post by **waynej** » 18 Nov 2007, 21:44

Your profile is empty but I'm guessing you live in a warm climate. Your modification causes real problems in northern winters. Very slow warm up,poor mileage and sometimes poor acceleration.

Post by **tjts1** » 18 Nov 2007, 23:55

waynej wrote:Your profile is empty but I'm guessing you live in a warm climate. Your modification causes real problems in northern winters. Very slow warm up,poor mileage and sometimes poor acceleration.

I've never had that problem when it was 5F at 6000ft elevation in Truckee California with any of the other volvos but maybe the 850 is different. I guess I'll find out in 2 weeks go up there again.

DON'T DO THIS MODIFICATION IF YOUR VOLVO IS AFRAID OF THE COLD!

Post by **hausmeister** » 19 Nov 2007, 12:56

I'll also have to post my findings.

I removed the pastic in front of the intake as soon as I saw it... can't really say that there was much difference, maybe at high speeds. I also have a k&n - if nothing else the sound is better with it

After I read about the airbox thermostat I checked out what mine looked like and decided to take it out and block the hot air side, like tjts1 did.
Not really noticable.
But what I did notice is that as soon as it got colder the car didn't seem to pull very good, same when it was raining heavy.

So I decided that the Volvo engineers knew what they did and so I put it in again. I did notice a positive difference.
I don't think you want to remove it if it gets cold where you live.

My thermostat also seems to be a bit different (vacuum operated?), so I'll post some pix I made:
http://666kb.com/i/atnz8czidwlk95z5x.jpg
http://666kb.com/i/atnz8qmgx96mdv3ut.jpg

Post by **tjts1** » 19 Nov 2007, 15:40

hausmeister wrote: My thermostat also seems to be a bit different (vacuum operated?), so I'll post some pix I made:
http://666kb.com/i/atnz8czidwlk95z5x.jpg
http://666kb.com/i/atnz8qmgx96mdv3ut.jpg

Yes, the S70 has a totally different setup from the 850. I wouldn't mess with that one. The information I posted only relates to the NA 850.