12 replies to this topic

[Alberto]

Anyone have any pics of how they installed their AIM TPS sensor?  I need to install mine and trying to figure out how to go about attaching a cable or something between the arm on the TPS sensor and the throttle body...

 

Thanks.

[BlueJay73]

I'd like to see some as well. Both arm-type and string pot type.

[TrailBrake]

AiM has some good examples in this video. This should start right at the point you need 

[Alberto]

Thanks Matt.  I think you posted that on facebook and it was helpful.

 

BlueJay - seems like the better option for me in my 1.6 is the string pot.  Mostly because the range of motion of the rotating arm thing is shorter than the range of motion of the throttle body.  With the string pot, the range of motion is greater than the throttle body and you can configure the specific range at closed and wot.  

 

I'm going to be switching to a string pot soon.

[BlueJay73]

The AIM video shows a string pot thread going to the bell crank of the throttle. (And, I am playing around with this on my own car right now, so I can confirm what follows is what happens.) But the bell crank rotates; it does not pull the string linearly. As it starts rotating, it pulls the string kind of straight out from the sensor body. But as it keeps on rotating, it pulls the string down, so that the string is not being pulled out at the same rate as it was when it was coming out straight and level. So, as the throttle pedal is being pushed down to the floor, the string is not being pulled out at the same length as if it was being pulled out straight and level. Seems like it would cause errors in the results.

[Alberto]

Yeah, I expected that would happen...

At what throttle % do you think it starts occuring? 75% 90%?

Can you post a video?  Would be interesting to see it in action before I jump into this.

[BlueJay73]

I actually did figure out a way to avoid this problem. I tried to post with pictures, but the pictures were sized either too small to see much or too large so that they won't send. As soon as I can send some reasonably sized pictures, I will. Anyone want to school me on how to send a picture on this site?

The pictures will also show how I mounted the Aim string pot sensor. I have a '99, so your throttle body may look different.

BTW, my research showed that most people just tapped into the stock TPS wire. Apparently it works fine.

[Steve Scheifler]

IF the string stays on the outer circumference of the bell crank it should be linear, just like the throttle itself. So I guess you are simply connecting to the “top” at the closed position and not winding the string up on the crank. Is there not a way to position and connect it to work like the throttle?

[BlueJay73]

On mine, there is no way that I can think of to have the string positioned and attached so that it will wrap around the bell crank like the throttle cable does. And if it could, I would think the string would get worn out pretty quick.

In lieu of pictures, which I haven't had the time to send, here is what I did, and it makes the string travel linear:

There is a square "post" that sticks out from the side of the throttle body housing.

I attached a small pulley to that post (pully is on a 2 inch screw; screw is attached to the post with a worm-gear clamp).

This pully is directly in line with the string pot sensor.

The string rests on top of the pully, so that when the bell crank rotates and pulls the string down, the pully keeps the string up and level, and the string gets pulled straight out.

Looks a little "Rube Goldberg-ish", but it works like a charm.

Gotta send some pictures...

[BlueJay73]

Pictures are small.  IMG_1779.jpg   118.43KB   3 downloads  IMG_1782.jpg   115.33KB   3 downloads

[Alberto]

Looks kinda like an idler pulley

[BlueJay73]

I needed one tiny pulley, and I'll never need one of those again.

They come in packs of 10.

Now, to figure out how to mount the MXm to my dash...

[Steve Scheifler]

I’m not convinced that setup gives a linear pull but may not accurately visualize movement through the range.