Alfa Romeo Owners Club of Australia Forum

Technical => 939 Series (159, Brera and Brera Spider) => Topic started by: nickq on June 18, 2021, 06:58:56 PM

Title: 159 3.2 cold air intake?
Post by: nickq on June 18, 2021, 06:58:56 PM
Hi everyone,
I've recently and very happily acquired a 159 3.2 manual. Im loving everything about it however I'm finding that the V6 is quite muted compared to previous Alfa V6's I've had. The stock exhaust has a good amount of bass low down but higher up in the rev range the car just doesn't have that characteristic song in the cabin. I've seen some videos on YouTube about new exhaust systems but I don't want the car to get too much of a drone on the freeway and have seen the magic cold air intakes can do on other vehicles in the past. My main question here is has anyone fitted a cold air intake to their 159/Brera 3.2 before and does it help give the engine a bit more voice in the cabin or is the only way to enhance it getting a louder exhaust system?
Any advice anyone has is much appreciated!
Title: Re: 159 3.2 cold air intake?
Post by: Alfatango on June 20, 2021, 09:51:13 PM
I fitted a K&N filter and am very happy with it. It probably adds a tiny bit of induction noise and doesnt do the "turbo" induction noise but that's not I was after.
Title: Re: 159 3.2 cold air intake?
Post by: Colin Edwards on June 21, 2021, 11:15:42 AM
Hi nickq,

The 159 comes from the factory with a cold air intake.  Any feed to the filter cannister external to the engine bay or upstream of the radiator is a cold air intake. 
Colder air = denser air = less viscous air = potential for more power.  Last place you want intake air from is the engine bay.
Title: Re: 159 3.2 cold air intake?
Post by: nickq on June 22, 2021, 05:52:01 PM
Thanks so much Alfatango and Colin. Is there any other recommendations you'd have to give the 3.2 a bit more song?
Title: Re: 159 3.2 cold air intake?
Post by: Colin Edwards on June 23, 2021, 12:31:14 PM
Hi nickq,

For a bit more engine noise as opposed to exhaust noise, give the following a try.
1.  New clean air filter - similar to genuine AR part - don't use a cloth / cleanable filter
2.  New spark plugs as per the manufacturers specification - lash out and get the best you can afford - NGK Iridium or similar.. I was amazed how my V6 still managed to run ok with buggered spark plugs.
3.  Have an Alfa Romeo EXPERT workshop clean the inlet tract / ports / valves with the magic solvent.  Best left to someone who has done it before.  Its a fair job on the V6.  Given its direct injection, the V6 inlet track is not cleaned with fuel mixture.
4.  Replace ALL the front upper and lower control arm bushes with polyurethane.  Another big job but worth the effort.  In addition to help direct engine bay noise and vibration to the chassis, the stiffer bushes will improve front end steering response a fair bit.  Make sure the new poly bushes support caster and camber adjustment via upper control arm eccentrics.
5.  Last resort.  Remove the sound isolation from the passenger compartment side of the fire wall.

The car will be in a better state of tune, handle better and probably be a bit lighter - win, win ,win!
Title: Re: 159 3.2 cold air intake?
Post by: Alfatango on June 24, 2021, 06:56:24 AM
https://www.google.com/amp/s/www.nulon.com.au/amp/products/pro-strength-additives/extreme-performance-engine-treatment

I added this and the engine sounds angry in a good way. Like it wants to rev. Could be a placebo but will be adding it again. Just ensure it doesn't overfill your engine oil.
Title: Re: 159 3.2 cold air intake?
Post by: Alfatango on June 24, 2021, 07:01:10 AM
https://www.google.com/amp/s/www.nulon.com.au/amp/products/pro-strength-additives/petrol-fuel-system-extreme-clean

Also this worked exceptionally well for me as I added 2 of these over the space over 2 full tanks and it fixed my cold start issues.
Title: Re: 159 3.2 cold air intake?
Post by: Stu159 on July 02, 2021, 09:22:19 PM
Hi Nick,

When I needed to replace one of my centre cats, I went for a high flow system from there back. It made a noticeable difference to throttle response and sound, but had a small amount of droning. Not enough to be annoying though. When I had to replace brake discs & pads soon after, I ordered them from Squadra Sportiva in Germany, as they had the best deal on offer. Much cheaper than I could get locally. They also sell a BMC sports air filter that I bought at the same time. It removed the drone sound completely and added a nice note to the exhaust. All arrived in x 6 days and they were more than helpful.
https://shop.alfisti.net/Tuning-Styling/Alfa-159/Motor-Sports-Airfilters/BMC-Sports-Air-Filter::6540.html

Stu
Title: Re: 159 3.2 cold air intake?
Post by: Ascari32 on August 03, 2021, 06:55:44 AM
Hi nickq,

The 159 comes from the factory with a cold air intake.  Any feed to the filter cannister external to the engine bay or upstream of the radiator is a cold air intake. 
Colder air = denser air = less viscous air = potential for more power.  Last place you want intake air from is the engine bay.

Very succinct, and very true!