Tried to upgrade my throttle body (again), killed the #Focus (again)

20 Oct 2017

I’m still trying to figure out someway to upgrade the electronic throttle body on my 2009 Ford Focus 2.0. I’ve messed with the gears inside of it, and it killed the Focus a while back. That post is here. I had to wind up replacing the throttle body.

This time, I’ve been trying to make a Mazda3 throttle body fit. Has the same Duratec engine, but with a 2.3 displacement. The throttle bodies physically match up on the outside quite well, with the Mazda 3 having a larger butterfly valve. This means more air would be able to flow into the engine, with air = power.

Of course, nothing can be that easy when dealing with electronically controlled engine components. Tried with the Mazda and Ford throttle position sensor, and neither let it work. Also tried rearranging the wires in the plug. After making it half a block down the road and realizing that throttle response was severely limited, I turned back to take it all apart again.

Luckily I didn’t mess around with my previous throttle body this time, so I eventually got it working again. I also polished my throttle body, although I did not do port and polish yet. In the coming weeks I’m going to get another Focus throttle body and see just how large I can port it, and then I’ll polish it and install it if all goes well. For now, it has eased the motion of air coming into the engine.

I’m pretty sure that there’s a bump in power, but it could just be due to the butt dyno effect. It did increase the volume of my K&N intake some. If anyone has suggestions on a plug and play throttle body that will work for the Focus, let me know. Would be appreciated.

Comments

ThatElementGuy(ElementSquad)(#HashtagPolice)

JoshuaK

Very saddening indeed.

StevenCollins

Would it work if you got a newer focus st throttle body?

ChesterFrancis

If it’s an electric throttle I would bet there’s some computer wizardry that is keeping it from running happily with a bigger throttle body. If the MAP/MAF sees more air than it allots for a given % of throttle applied, I wouldn’t bet against the computer stepping in and cutting throttle.

That’s not the problem, it’s that the Mazda TB couldn’t accommodate the Ford TPS. The TPS is at fault, not the TB itself. The MAFS already gets a lot more air due to the intake, and it copes well.

Third attempt’s the charm, maybe?

I’m hoping so. For now at least it’s polished.

Michael, the type of guy who messes with the performance of his 500k+ mile #Focus while waiting for his 350R to get delivered!

Everything can go faster. LoL

what’s this about a 350R?!

Sad.
Even sadder that I have no experience in electrical throttle body. My car has the old school wire, so it’s quite simple to do stuff.

Yeah, it’s a unique thing for me to work with. It’s the first vehicle I’ve tried modifying with one. They do have their plus sides in daily use, but modifications prove harder.

I don’t think you’re going to find a plug and play solution sadly though I could be wrong. That’s the problem with most newer cars using a drive by wire assembly. Though if you’re feeling like it’s something you really want, you could probably get a machinist to bore out the original throttle body.