Building my own intake manifold

[mrturrari]

It's been over 6 months since I started working on this but it is finally to a point where I am thinking it actually might work. I was a little worried the material was going to be too thin (0.060") to get good welds but my friend who did all the welding had very little trouble with it. He has a very nice tig setup and lots of experience with aluminum.

The runners are 11.25" long (14.25" to the valve) and 2" OD mandrel bent tubing cut and bent to taper down to the port. The runners go from 2" at the velocity stacks down to a little under 1-3/4" at the flange and it works out to be about a 2 degree taper. The plenum is about 3 liters and will have a gen3 3sgte TB attached to it once I figure out what angle it should be in the car. So I still have do final test fitting to place that and add some thicker plates for tapping in vacuum lines and throttle linkage but it is 90% done.

I can't find any of my pics from earlier in the building of it but here are some from when I finally had all the peices assembled with masking tape:




Getting the runners to fit through the holes after welding them together:


Velocity stacks needed a little help getting to the same height before tacking them in place:



Here it is all done except for the TB flange, vacuum ports and throttle linkage:



And lastly side by side with a stock manifold:

[Raptor13x]

Looks pretty!

[mr2magic]

Hot!

[presure2]

awesome work mr.t!

[PearlJammzz]

Looks good, glad you finally have her done . This is going on my old MR2 right? ;p haha

[Drew]

looks good man. I have considered taking a stock intake manifold, cutting the top section of the plenum off, smoothing out the runners and welding it back.


More pics if you can find them. Im impressed. anxious to see the change in the powerband

[TURBRO]

If you don't mind me asking, how much did it cost you in materials? Where did you purchase them?

[Everett]

Originally Posted by TURBRO

If you don't mind me asking, how much did it cost you in materials? Where did you purchase them?

Or in other words.......How much to make me one?


Awesome work!

[mrturrari]

Material for the flanges and velocity stacks I found on ebay, the mandrel bends were from Wolf Aircraft and the rest was just sheet aluminum I have picked up over the years. I think the grand total for everything was about $200 and then I gave the guy who welded it $120 for the hours/material it took to weld it up (he is a friend so wasn't going to charge me).

The price for me to make one of these for someone else would be more then anyone would be willing to pay.

[mrturrari]

I finished the rest of the welding tonight and port matched it to the TB. I also drilled and tapped most of the vacuum ports and the place where the throttle cable attaches. All that is left on the manifold itself is for me to get a couple of 1/8" vacuum ports and drill and tap for them. Here are more pics:







I'm hoping I can finish this project up this weekend but we'll see.

[mrturrari]

Finally got all the vacuum leaks sealed and took it for a spin. Definitely makes a difference. It pulls all the way up past 7000rpms without a noticable fall off in torque. I may need to try to overclock some more to get the redline a bit higher now. It's now just smooth power from 4000-7000 and even up to the rev limit it doesn't sound like it is struggling anymore. I haven't tuned it yet but AFRs are about 13-13.6:1 up top. It was tuned with the previous manifold to be 12.5-13:1 so there is definitely more air getting in.

There are still a few things to finish up. Currently the throttle cable adjustment is keeping my idle speed up so it won't stall as I am missing a idle adjustment screw, the A/C idle up valve is pulling unfiltered air from atmosphere, the intake is just hanging there and I need to rerun all the PCV lines so they don't look like spaghetti.

Overall I am very pleased but man it was a lot of work. If I had to do it again I would change a couple of things and planned it out a little more thoroughly.

Here's some pics installed:

[MRH]

sick brother, I would love one of those! after all my crap is fixed!

-H

[mrturrari]

Videos with sound...

http://warp.scl.utah.edu/mr2/Videos/Freeway.mpeg
http://warp.scl.utah.edu/mr2/Videos/1stgear.mpeg
http://warp.scl.utah.edu/mr2/Videos/Sounds.mpeg

[YELLOW_MR2]

That looks nice, but I couldn't hear your manifold.

[PHOENIX]

Nice job jeff.

[mrturrari]

Thanks Dave and everyone.

As for the sound... here is a video with the stock manifold, 763 cams and stock turbo exhaust:

YouTube - NA Mr2 5sfe to 7000rpms

And here is one with the new manifold, 101 cams and a 2.5" KO Racing exhaust:

YouTube - NA Mr2 5sfe to 7000rpms

Now I realize the 101 cams make a huge difference but even when I had them installed with the new exhast on the stock manifold, I was still noticing a big drop-off in power above 6500rpms because of the TB and manifold. You can hear on the second video that it no longer sounds like it is struggling up there. Time to see if I can raise the rev limit again.

[Drew]

wow. night and day difference in the sound. How was the difference on the butt dyno? This is exciting to see for sure!

[mrturrari]

Butt dyno tells me I am making more power from 4500-7300rpms. The manifold runners are supposed to be tuned to 6000rpms so hopefully that is a sign that all the theores and math I used are good.

[Redstar]

Awesome project!

[nitrofreak06]

that's awesome. sounds great too!