Air Filter Size

[73RR4SPD]

Hi All,

With my combo (73 RR - 512" stroker - 650HP, 4 spd - street driven 95%) can I get away with a 14" x 2" air filter? Or will I see significant power losses moving away from my current 14" x 3" filter?

I'm wanting to put my factory bulge hood back on and space will be an issue, thinking to go to an Xtreme air filter top to help with air flow between top air filter housing and hood. I visited this site Second Strike Air Cleaner Calculator and found the losses to be quite minimal, however, real world might tell us different, hence this post.

Thanks in advance.

 

[Runner 68]

B or RB Block?

 

[73RR4SPD]

RB. I am currently running this Edelbrock setup. I believe it’s a 1” drop base, so I could look at a different drop base.

Edelbrock 4207

 

[WileE]

I'll bet you'll never know the difference.

 

[493 Mike]

You may be able to go to a 16" diameter filter to gain more surface area.
Mike

 

[Runner 68]

RB. I am currently running this Edelbrock setup. I believe it’s a 1” drop base, so I could look at a different drop base.

Edelbrock 4207

I will be dealing with a height issue on my build as well. Stock 68 Road Runner hood. Thankfully the low deck B gives me a little more breathing room. No pun intended.
Good luck.

 

[73RR4SPD]

Thanks for the input, I guess I’ll know when I get it back from the body shop.

 

[Geoff 2]

I would make sure that you do not cause a restriction between the air cleaner base & lid. That will lose a lot more HP than the filter element......
I think a 2" filter would be restrictive. Have you used K & Ns calculator to check the reqd area?
Seems silly to me to build a 650 hp engine & then restrict it's output....

 

[sam dupont]

You will lose that much or more HP by having a 100lb person riding with you.

 

[sam dupont]

I would make sure that you do not cause a restriction between the air cleaner base & lid. That will lose a lot more HP than the filter element......
I think a 2" filter would be restrictive. Have you used K & Ns calculator to check the reqd area?
Seems silly to me to build a 650 hp engine & then restrict it's output....

Link please. I looked, but must not have used the correct words

 

[73RR4SPD]

You may be able to go to a 16" diameter filter to gain more surface area.
Mike

Good point Mike, I'll look into that.

 

[73RR4SPD]

I would make sure that you do not cause a restriction between the air cleaner base & lid. That will lose a lot more HP than the filter element......
I think a 2" filter would be restrictive. Have you used K & Ns calculator to check the reqd area?
Seems silly to me to build a 650 hp engine & then restrict it's output....

Hi Geoff, Silly's not what I'm after. I didn't find K & N's calculator but I did find this which is similar to the link I posted earlier....Air Filter Calculator - Calculate air filter size for BHP/Power - StrikeEngine you can type in engine specs and it'll give you an idea of surface area of filtration you'd need (rough guess I think). From there I went to K & N and found dimensions of different filters to come up with what I might need. It appears my engine is looking for 271 sq inches of filtration. 14 x 3 yields 249, according to this website, 14 x 3.5 gets me there. So I might try looking at other sizes (larger diameter and lower height). As many have mentioned, lots of other factors involved. Thanks Geoff, yes I'll have to watch the restriction a lower drop base creates.

 

[Geoff 2]

73RR,
I assumed that K&N would have a formula on their website.
I have a catalog [ remember them! ] which has the formula: CID times rpm divided by, 20, 839.
I don't know what your peak rpm is, but I used 6500. That equates to 160 sq inches, or a 14 by 3.5" filter, buuuuuuuuuuuuut K & N say to subtract 0.75" to allow for the top & bottom rubber seals. So that would be a 4.25" tall element.