3.5" MAF in a 3" Pipe - Any Issues?

[Speed_Dreamin']

Would there be any issues with running a 3.5" MAF in a 3" cold air intake system? I'm wondering if there would be any noise or air turbulence issues from the step up in system diameter before the MAF. My car currently has a 3" air intake system and I need a new MAF. I'd like to leave room to grow to a 3.5" system in the future, by buying a 3.5" MAF now instead of a 3", unless there are any known issues with this setup.
Thanks.

 

[TurboBob]

I have run my car with a 3" MAF pipe, 3.5" sensor, and a 4" filter. No issues at all.

I would not expect any issues with your setup.

Bob

 

[earlbrown]

You won't see any issues and actually you'd be much better off.

If you take apart a LT1 MAF and measure the actual flow area you'll notice it's only 60something% of a 3;' pipe.

If you do the same with a 3.5" LS1 MAF it's high 90% of a 3"pipe.

Based on cross section what you're thinking is NOT overkill by any means. The other upside is that you're pre-MAF filter/piping will be larger and have less pressure drop.

A couple years ago i did a test with my powerlogger. I stepped my 3" pipe up to a 3.5" MAF and then BACK DOWN to a 3" filter. (that way there was only one change) The spool was notable faster both with the data logging on the powerlogger and the seat of the pants.




Note: faster spool doesn't always mean a faster car if you're blowing the tires off.

If you can't find a coupler to attach your new MAF to your smaller pipe shoot me a PM. I think I still have my tapered silicone coupler in the play room.


...but I do love me a good burnout

 

[Speed_Dreamin']

Thanks guys! Will a 4" ID filter seal directly to a 3.5” MAF, or do I need a reducer for that joint? I don't see how a silicone reducer would work there.

 

[TurboBob]

yes, it works fine.

Bob

 

[earlbrown]

If you're putting a filter directly on a LS1 MAF you need a 3.5 inlet. I like the AEM's better than the K&Ns for flow as the neck is shaped like a velocity stack instead of a sharp edge.

To go from 4 to 3.5 you'd need a reducer and a short piece of 4" solid to clamp down on.

And another pair of clamps of course.

 

[TurboBob]

If you're putting a filter directly on a LS1 MAF you need a 3.5 inlet. I like the AEM's better than the K&Ns for flow as the neck is shaped like a velocity stack instead of a sharp edge.

To go from 4 to 3.5 you'd need a reducer and a short piece of 4" solid to clamp down on.

And another pair of clamps of course.

actually, it works just fine. the rubber conforms really well and it makes its own little velocity stack.

B

 

[earlbrown]

Holy crap, Bob! I've never thought to try and squish out 1 1/2" of circumference! A T-bolt clamp doesn't have that much travel so I guess you have to use a worm type....


....have you had success using multiply silicone hoses or were they rubber toilet connecters from the Depot?

 

[earlbrown]

Now I want to grab some couplers and MAFs and play around. lol

 

[TurboBob]

im talking about a 4" filter on the 3.5" MAF. works fine. worm gear clamp in my case.

Bob

 

[1986 Buick GX1]

If you're putting a filter directly on a LS1 MAF you need a 3.5 inlet. I like the AEM's better than the K&Ns for flow as the neck is shaped like a velocity stack instead of a sharp edge.

To go from 4 to 3.5 you'd need a reducer and a short piece of 4" solid to clamp down on.

And another pair of clamps of course.

What's the P/N of the AEM filter you're running? Dry flow? 3.5 or 4.0?
Thanks

 

[earlbrown]

What's the P/N of the AEM filter you're running? Dry flow? 3.5 or 4.0?
Thanks

The one I have might now work with your setup. I made this a while back and just got my engine back in my car last week. It's a 4" outlet filter that necks down to 3.5" for the MAF then necks down to 3" for my turbo.

I couldn't find a cold air kit I liked with minimal flow restriction so I built my own. I've put enough miles on my engine now to justify going through the trouble to install this setup so I hope I can free up a couple ponies from lowering flow restriction.

After putting hands on it I do like the AEM better than the K&Ns. Not only do they have a smoother output that will increase flow I don't have to worry about screwing up my MAF readings if filter oil sticks on the sensor pickups.

 

[Speed_Dreamin']

^ I like it! BTW, I ordered a 3.5" outlet K&N to attach to the 3.5" MAF. Not doubting Bob that the 4" fits , I just hate trying to make parts do something they are not really meant to do. Usually ends up being a pain.

 

[1986 Buick GX1]

The one I have might now work with your setup. I made this a while back and just got my engine back in my car last week. It's a 4" outlet filter that necks down to 3.5" for the MAF then necks down to 3" for my turbo.

I couldn't find a cold air kit I liked with minimal flow restriction so I built my own. I've put enough miles on my engine now to justify going through the trouble to install this setup so I hope I can free up a couple ponies from lowering flow restriction.

After putting hands on it I do like the AEM better than the K&Ns. Not only do they have a smoother output that will increase flow I don't have to worry about screwing up my MAF readings if filter oil sticks on the sensor pickups.

I found a 3.5 AEM dryflow filter to fit the KB ram air but wanted 4" options as well. Thank you

 

[deezdad]

On tin mans website he sells velocity stack k&n filters in various sizes, like Earl I thought k&n didn't offer a velocity stack type filter, I know years ago tinman use to say the filters he was using (not k&n) far out flowed k&n, so something might have changed cuz now he's selling them..

 

[deezdad]

I found a 3.5 AEM dryflow filter to fit the KB ram air but wanted 4" options as well. Thank you

Do you have a part # by any chance of that 3.5" filter? I just picked up a KB ram air as well, by looking at it its plain to see its at least somewhat of a restriction, my plan is to cut the round end off the canister and install a 12" filter so 3" stick out the end into free air and the rest of the filter can draw air freely as well, as you accelerate colder air would replace the engine air, seems like it might work..

 

[1986 Buick GX1]

Do you have a part # by any chance of that 3.5" filter? I just picked up a KB ram air as well, by looking at it its plain to see its at least somewhat of a restriction, my plan is to cut the round end off the canister and install a 12" filter so 3" stick out the end into free air and the rest of the filter can draw air freely as well, as you accelerate colder air would replace the engine air, seems like it might work..

This is the 3.5 filter approx. 9" long.

They make 5", 7" & 9" long filters in both 3.5 & 4.0 but nothing 12" long in the dryflow.
You could call them @ 800.992.3000 to see if they make the size you seek. It seems that Summit Racing said AEM is owned by K&N now, all the same.