Alfa Romeo Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
42 Posts
Discussion Starter #1
Hello, I have a 1986 GTV6 car and am looking for a OEM great condition used or NOS air intake box and the hoses. If your interested in some trades I have some GTV6 parts I'd be willing to trade with to keep the costs down. OR, should you have any ideas of a better intake system let me know. I have been told that the factory intake box is really good as is, or just open it up a little bit. I'm not aposed to a cold air intake system, but the radiator is right there where the intake would be, is there a kit or solution on the best way to seperate them?

Thanks in advance,

Best regards

:D
 

·
Registered
Joined
·
1,330 Posts
I have an air filter box from a GTV6 that was reserved for a guy in the UK. I wire-brushed it, primed, and gave it a fresh satin black paint job (both clam shells and the gold clips) so it looks like new. It's been sitting on a shelf waiting to hear back from him for over a year. No response lately... so it's back in the shop window. I can send pix if you like.

Let me know which hoses you need, and I may have those covered too. The fat 90 degree ribbed one?

Best to connect directly:
[email protected]

Cheers,
Peter
 

·
Registered
Joined
·
4,075 Posts
I have both aftermarket and stock systems in stock. However 1986 was a year with a lot of changes, and I don't know if the GTV6 had the silver, or the black air box that year. In any case, I have plenty of both. I also have some used big rubber intake tubes. The aftermarket system is a lot better, at least from a performance perspective.

Greg
 

·
Premium Member
Joined
·
14,664 Posts
I have two stock '88 Verdes. The gray one has the stock intake box and Euro downpipes and the red one has an aftermarket K&N intake and standard exhaust system. The gray car has about 25k extra miles on the motor. The gray car is faster than the red car. In fact, the gray car had an aftermarket intake on it when I bought. I replaced it with the standard air box. I noticed a loss of noise but no loss of performance.
 

·
Registered
Joined
·
1,330 Posts
Good to know alfaparticle!

I wonder how different the Milano air box is to the GTV6? Volume, flow, turbulence, and all those other specs that are Greek to me.

When building my 24v 3.0 GTV6, I would like to keep the original air box, just to keep the engine bay tidy looking and more 'factory'. All the conversions I've seen have been refitted with those K&N cone filters, tho. A 164 LS or 'Q' motor may require less restriction than the stock GTV6 air box can provide. Wish I had an answer to that issue.

I know... go out an buy myself a Dynamometer, and try it out both ways!
 

·
Registered
Joined
·
4,075 Posts
The GTV6 and Milano box are the same as far as volume and flow. They are different colors. I am fairly sure the mounting holes are the same, but I would have to double check that.

All aftermarket intakes are not the same. I guarantee my intake gives more power than the stock airbox. The stock airbox causes a large drop in pressure across the filter. The decrease in pressure drop has been verified by at least one independent source (Stever Rosser, who is the guy who wrote the megasquirt conversion instructions for the GTV6). The increase in power was also noted by Steve, as well as in a test in the "Overheard Cams" magazine.

Greg,
Silicone Hose Kits
 

·
Premium Member
Joined
·
2,176 Posts
All aftermarket intakes are not the same. I guarantee my intake gives more power than the stock airbox. The stock airbox causes a large drop in pressure across the filter. The decrease in pressure drop has been verified by at least one independent source (Stever Rosser, who is the guy who wrote the megasquirt conversion instructions for the GTV6). The increase in power was also noted by Steve, as well as in a test in the "Overheard Cams" magazine.
Hi Greg,

Dumb question, but doesn't a drop in pressure across the filter indicate that the filter is 'filtering'? In other words, it's not a deficiency of the airbox, but an indication that the filter is doing it's job, right?

To achieve less drop in pressure across the filter, I'd imagine you'd either have to replace the filter with something that filters less, or increase the surface area of the filter.

???

bs
 

·
Premium Member
Joined
·
14,664 Posts
I know that hot air from under the hood makes less power than cooler air from outside the car. I think that Al Mitchell told me that he gained about 10HP when he switched from an under the hood cone filter to a cold air box on his GTV6 race car. Also, years ago someone on the Alfa digest recorded air temperatures in SPICA throttle bodies on a car with the standard Alfa box and the Shankle "Quadraflow". The Alfa box gave lower temperatures and more power. The standard air box on the Milano and GTV6 gets most of it's air from outside the hood. The under the hood cone filters look like they get a greater proportion of their air from under the hood.
 

·
Registered
Joined
·
4,075 Posts
Hi Greg,

Dumb question, but doesn't a drop in pressure across the filter indicate that the filter is 'filtering'? In other words, it's not a deficiency of the airbox, but an indication that the filter is doing it's job, right?

To achieve less drop in pressure across the filter, I'd imagine you'd either have to replace the filter with something that filters less, or increase the surface area of the filter.

???

bs
It's not a dumb question, but the answer is no. Just because there is a drop in pressure does not mean that filtration is taking place. It's actually quite possible to have large drops in pressure with no filter at all, just restrictive pipe sizing, bends etc. Conversely a well designed filter can have a lower pressure drop with the same filtration capability as a poorly designed part.

I know that hot air from under the hood makes less power than cooler air from outside the car. I think that Al Mitchell told me that he gained about 10HP when he switched from an under the hood cone filter to a cold air box on his GTV6 race car. Also, years ago someone on the Alfa digest recorded air temperatures in SPICA throttle bodies on a car with the standard Alfa box and the Shankle "Quadraflow". The Alfa box gave lower temperatures and more power. The standard air box on the Milano and GTV6 gets most of it's air from outside the hood. The under the hood cone filters look like they get a greater proportion of their air from under the hood.
Yes, that's true, all thing being equal colder air is more dense and makes more power. However air pressure in the manifold is the bigger issue. For example, we all know a turbo car has air temperatures far higher than a normally aspirated car, but it's the extra air pressure in the manifold that results in the increase air density and power. The problem with the GTV6/Milano air box is this loss of pressure. It's sort of like reverse boost. That said, temperature is a factor and should be kept as low as possible. A lot of testing with the Nordskog gauge (its shows plenum air temperature) has shown that if the filter is located all the way at the front of the engine bay by the fresh air duct, a cone filter will have intake temps within 5F of the factory air box as long as the car is moving. Most of the cone setups I see locate the filter too far back, essentially above the exhaust manifold.

Greg
 
1 - 9 of 9 Posts
Top