Airbox for EFI kit

[jhelgesen]

Hey guys, I'm working on an airbox for my mega squirt EFI setup. Haven't decided between aluminum or stainless yet. Would anyone else be interested in one?



The more interest, the cheaper they can get.

[turbo6bar]

What size runners, though?

[ohecht]

I would be interested if and when I choose the Megasquirt EFI route. My main reason would be to make the conversion reversible by preserving the original CIS airbox.

Olivier

[MotoSook]

John's design looks like something that one could simply remove the throttle body off the CIS airbox and install it onto the plenum. CIS airbox remains intack and in storage.


John, think about positioning the TB in a spot and at such an angle that will allow a cone filter just under the deck screen for cool air...as well as ease of plumbing for a turbo or super charger. Some NPT bungs for taps...or extra injectors for enrichment.

[FenderGuy]

aluminum or stainless ? which ever makes the engine look like it has a polished look to it...how much are the costs?

[MotoSook]

Aluminum will be lighter....if you want bling..polish it.

Too clean and purposeful.....needs more of a hippo look.

[jhelgesen]

Aluminum vs stainless will be which ever is easier for my buddy to machine and weld. Leaning toward aluminum right now.

Runners will be available in whatever size we need, just have to change the side blanks and tubes. I need some good measurements, but I think they are 33 and 38 mm id's.

Still have to work out positions for the extra openings, brake servo, injectors, sensors, etc. Tell me what you want.

Have to figure out what to do with the big flat spot on the top, good spot for a decal, mount a bobble head doll or something.

If anyone had a busted airbox I can use to measure, I would appreciate it.

[MotoSook]

John, I have both size runners and airbox. Can't do it rigth now, but e-mail me and I'll get to it this weekend...flat spot...clear plex for the bling crowd..like the speaker boxes in the RIcers.

[A Quiet Boom]

Originally posted by Souk
John, I have both size runners and airbox. Can't do it rigth now, but e-mail me and I'll get to it this weekend...flat spot...clear plex for the bling crowd..like the speaker boxes in the RIcers.

]


I've seen plexi used like that as a safety blow-off on nitrous drag cars, heck of a lot better than launching the plenum through the hood from a violent nitrous backfire.

[banjomike]

any answer on the size of the runners? I understand that the euro cis had bigger runners. anyone know that size?

[jhelgesen]

Originally posted by banjomike
any answer on the size of the runners? I understand that the euro cis had bigger runners. anyone know that size?

Mike,

I'm working on getting sample airboxes to know all the needed sizes right now. I'm trying to get all the sizes needed for 2.7, 3.0, and 3.2's. Shouldn't be hard to have all 3 available.

[911pcars]

Thought I'd add more to discuss/consider.

Aluminum:
- Easy to fabricate/weld
- Easily accepts various finishes (polish, anodize, paint, etc.)
- Relatively lightweight
- Good for one-off unit
- Can stamp complex shapes for mass production
- Can cast inexpensively for mass production
but......
- Excellent heat conductor (or heat sink)
- Heavier than some alternate materials

Plastic, CF, FG:
- Lightweight (lighter than Al)
- Easy to fabricate
- Complex curves/shapes possible
- Fairly good heat insulator
- Easy to mass produce
but...
- If mass producing; setup, masters and molds may be expensive
- Fabrication skills necessary
- Lot of work for a one-off unit

Titanium:
- Good heat insulator
- Light weight, but very strong (able to withstand backfires w/o damage)
- Can stamp complex shapes for mass production
but ....
- Special welding requirements
- Expensive; may or may not be cost-prohibitive

(Note: "easy" and "easier" are relative terms)

Sherwood
http://members.rennlist.org/911pcars

[A Quiet Boom]

My last reply was short because I was busy but here is what I've been planning to make for myself. Basically I want to build the complete intake from aluminum, I have the welding and machining skils to do this, unfortunately it would be a one off due to the time taken for construction. So my question is this, I'm pretty experienced with engine airflow and I think I have a very good double plenum design but as I said it will be a lot of work so I have to ask myself if this solution which is obviously simpler than mine could produce similar HP and torque. Does anyone know if the CIS runners are considered a "bottleneck" in the system? If not then this airbox idea is great and leads me to a couple of other questions, how for example will you install EFI injectors in place of the CIS injectors, can the existing holes be modified or will new injector bungs be required? Second what is the reason for the offset throttle body, I'm assuming it's for decklid clearance? Also have you considered using a Ford 5.0L throttlebody bolt pattern? The reason I ask that is that they are readily available in sizes from stock 60mm all the way up to around 100mm making future modifications cheap and simple with off the shelf throttle bodies. Just a few thoughts, I look forward to comments.

[A Quiet Boom]

One last note about stainless, if you don't "back gas" the weld you'll get nasty slag buildup especially in corners where it's difficult to grind down, something important to take into consideration.

[ohecht]

I know there is a separate thread detailing the development of a kit to fit electronic injectors, etc.

CIS to EFI kit

I like the idea of using Ford TBs with TPS and more easily obtained parts in the future.

Olivier

[jhelgesen]

Originally posted by A Quiet Boom
Second what is the reason for the offset throttle body, I'm assuming it's for decklid clearance? Also have you considered using a Ford 5.0L throttlebody bolt pattern? The reason I ask that is that they are readily available in sizes from stock 60mm all the way up to around 100mm making future modifications cheap and simple with off the shelf throttle bodies. Just a few thoughts, I look forward to comments.

The offset TB position is to keep it in a stock location, no linkage issues.

The bolt pattern shown is just a generic one to start the drawing, could be made with what ever pattern you wanted, I plan on using a Ford TB myself, got one from a 2002 or 3 mustang with a TPS.

[A Quiet Boom]

Thanks, I found the articles after searching. I'm very interested in this setup since it would be much simpler than building a complete intake. As for my suggestion on Ford throttle bodies, the ones to look for are for the 5.0, same with injectors because there is a huge aftermarket for those cars. I went to tbitz website and read about all the things he's done and found it to be very interesting as well. My situation is that I have a '66 912 that came with a 2.0E and Zenith carbs, I upgraded to a 3.0 and installed larger venturis to use the Zeniths for simplicities sake but now I've acquired a '78 targa widebody project and would like to turbocharge the 3.0 and install it into that project, returning the 2.0 to the '66 and selling it. I've already got the turbo manifolds, pipes and intercooler so all I really need is the turbo and a decent EFI system to finish the project.

Has anyone boosted a MegaSquirt yet? I'd be interested to here the results.

One last thought, have you considered air horns inside your air box for each runner? I've seen this design on some plenums for 4cyl cars and heard good things about it. Either way I really think smoothing the transition to the runners from the box would be a big improvement.

[JK-81SC]

How about carbon steel? Low cost, and easier to weld than aluminum. With a nice powder coat finish, it would last forever.

You can offer a higher cost, low weight version for the racers. What is the weight difference anyway, a pound or two?

Look's like you're using SolidWorks for the design. Change the material properties and check the weight difference.

[A Quiet Boom]

Originally posted by JK-81SC
How about carbon steel? Low cost, and easier to weld than aluminum. With a nice powder coat finish, it would last forever.

You can offer a higher cost, low weight version for the racers. What is the weight difference anyway, a pound or two?

Look's like you're using SolidWorks for the design. Change the material properties and check the weight difference.

Excellent suggestion, I made a TB adapter elbow for my brother-in-law's TVR 2500M to Ford 2.3L turbo conversion project and you're right it was very easy to form and weld as well as machine the flanges. The weight savings vs. cost of aluminum plus the extra constuction time to weld aluminum properly probably don't justify it over steel. Great idea, why didn't I think of it LOL