Boring out turbo manifold for n.a. throttle body

Post by **Sveedy** » 04 Oct 2020, 15:04

So I decided to jump in and try this. Basically I used a router to cut away the metal instead of a stone or grinder. I did use a small sanding drum to feather things out in the very end. The actual cutting time was only about 15 min. but the set-up took a couple of hours, it being the first time.
Then there was the feathering and general smoothing out. So maybe 3 hours total.

This is the beginning of the template. A 2 5/8" Dia. hole would be about right. I would have used a piece of MDF if I had some about, but this is Melamine.

Then I made a jig to hold the manifold upright. 3/4" ply. 14" base. 17 1/2" vertical. And a gusset.

Stuffed a towel into the manifold to reduce chips from getting in.

Template mounted on manifold. You can see how much needs to be removed.

Pattern cutting bit with top mounted bearing.

Set up and ready to go.

Part way through.

Through and ready for feathering.

Feathered out.

Cookeh · Post by **Cookeh** » 04 Oct 2020, 15:39

Top stuff. Easier, in my opinion, than drilling and tapping an N/A manifold. You're also guaranteed to have better airflow as its obviously going to be matched! Whilst you've got the gear out, do the runners too - theyare far from a perfect transition.

Post by **Sveedy** » 05 Oct 2020, 09:01

Thanks ! I will work the runners a bit. Doesn't look like I can do much to them, other than getting them to better match the gasket. Not sure how I could get them ported to match the head. But based on the gasket alone it looks like a bit off the bottom of each runner could be removed.

Cookeh · Post by **Cookeh** » 05 Oct 2020, 09:08

Thats exactly it, use the gasket as yptur pattern. As you've noted, there is quite a bit of material that can be removed.

Post by **Sveedy** » 17 Oct 2020, 08:09

Thought I'd update, even though there doesn't appear to be much interest ( maybe should have been posted elsewhere ).
Throttle response is greatly improved, particularly from a dead stop. One of the only complaints I've had with this car is its sluggishness off the line, but not anymore. And as a bonus I'm getting apx 2 mpg better millage based on a two+ hour interstate road trip; 75 - 85 mph avg.
Not seeing any downside so I'd have to give it a two thumbs up for a modification.
Cost wise it was pretty reasonable, considering the Snabb kit runs $ 475+ shipping etc. I'm into this for less than $ 150.

Post by **Sveedy** » 17 Oct 2020, 08:22

And from that drive - Wind turbine blades headed west. Well over 100ft long !