3" Heimholtz Box Mod

[lowetgt]

A few guys gave me an idea to increase the H box diameter to work better with my 3" intake setup. I didn't want to lose it in the first place, but seemed like a restriction/bottle-neck. I picked up an extra one at the JY and started experimenting. I think the end result will work more than adequate.

This is what the H box looks like sliced in half.


I got a piece of 3" OD exhaust pipe and cut it down to 5" long. Cut off the original tube ends and opened them up to accept the 3" pipe.


Pre-assembled to take measurements.


Measured out for placement of slot to coincide with the original one.


Positioned and a real good fit.


Mod vs stock.


Pic before I urethaned(windo-weld) the box back together.

[Mazda_Powered]

nice! that's a great idea!

[bomdoutscort]

Not sure but 3 inches on the intake is too big for a na engine and even most forced induction engines.

[lowetgt]

I have a 3" intake on it now with a K code hybrid. It performs well and sounds amazing! Many say that the box has a function an affects the torque. With the light flywheel, I am looking for all I can get, plus I was bored...I get that easy LOL!

[FE3-323]

good call on modifying that. + a bunch o creativity points. im honestly surprised no one thought of that years back.

good mod!

[lowetgt]

I appreciate it! I need to thank agrowagon for giving me the idea. Here it is after a coat of paint. Hope to install it later while the kids are napping and get some more pics and an opinion after a few test runs.

[Mazda_Powered]

looks great man! have you tested it for leaks?

[lowetgt]

A crude test, but yes. It seems to do fine, I used black urethane (windo-weld) so it is resealed well. I have a small propane torch and I plan to disable the igniter to use it to see if it has a vacuum leak once installed. I fear carb cleaner might ruin the paint or affect the urethane negatively.

[lowetgt]

Installed pics!





It seems to help, but it is not an amazing difference; what would you expect from 3 more ftlbs. I like that I don't have a rigged IAC hose anymore. Still sounds great and performs well.

[FE3-323]

[D323]

points for creativity; but like said, 3inch is probably too large for your application.

I am looking for all I can get

ditch the hard 90 degree bend if you are.



I'd like to see a dyno to see the ft lbs difference... I am really curious... I know from some of Mike's posts that it does make a difference with smaller diameter pipe.

[lowetgt]

Yeah I agree, that 90* bend is hideous, but I did mod the inside to have a smoother transition. Better, but not ideal. Tight 3" 90s are hard to find without paying twice what I did for the whole tube kit.



I also "port-matched" the adapter.

[lowetgt]

Made a vid, the camera doesn't get the subtleties like the intake hissing/sucking sound, but it's OK. This is an original '91 exhaust with an intentional leak.

http://www.youtube.com/watch?v=JSVIYoQVHc4

[wgnths]

man i cant appreciate enough but guys like you who have the creativity and to act on it is just a purrfect match!! gotta love wat you do keep up the inovative-ness hehe

[Hadoken]

Wait, isn't there a term for choosing looks/sound over performance?