Need Help Identifying this TPS, or Finding a Full Resolution Alternative
 

I have a S4 FC and I've been trying to find something that will work as a full resolution TPS. I'm going to be running an AEM EMS-4 standalone and would rather have this type of throttle position sensor as opposed to the crappy plunger we're normally stuck with.

https://www.rx7club.com/attachment.p...1&d=1380102346

Any help or advice would be appreciated, hopefully this'll also be of great help for others with a standalone in the future.

You can use a TPS like this Here. This is in a Miata application but it should work.. There are a couple of other options from Bosch But are more expensive.

EB Turbo

Damn, would've snatched that up if I didn't already buy an FD TPS pig tail. Looks super easy to fit on a S4/S5. Oh well, maybe if my FD one ever fails I'll have this option.

The problem with the two examples above is that most everything available is made to fit an 8mm D-shaped shaft, like the Miata in Cody's like. The FC has a 10mm double-flat throttle shaft. To get any of the Bosch, GM, Ford, etc. sensors to work on it, you need to do some grinding on the shaft to make it fit and build a mounting bracket. I've done a couple of these and have seen plenty of attempts. I've never seen one I'm happy with, including my own. And some are downright POS.

The easiest, most foolproof solution is to swap the entire S5 throttle body and TPS assembly in place of your S4 combo. It bolts up and it work correctly. If that's not an option, do a search for modified cam lobes that several people have made for the S4 TPS that replace the lever arm that actuates the sensor and creates a full-range signal. I've made a few of these and they're no more involved than trying to fit an alternate sensor and the results are far better. I know there were some posts in the Haltech section showing this modification.

I'm new to RX7's so this may be a nob observation. But my experience helping friends is an S5 TPS is a double sensor with one narrow band and the other wide band. The S4 TPS is just a single narrow band. The issue is, at least for a HalTech, the only sensor used on the S5 TPS is the wide band one. The narrow band just becomes decoration.

The narrow and wide band sensor units look physically identical. So why couldn't you just swap the wide band sensor off a S5 TPS bracket to an S4 bracket and call it a day?

It wont get resolution throughout the full sweep, once you go 1/3 throttle on the S4, the TPS plunger is maxed out and reading 100%, the S5 one is basically the same deal.

So the plate that controls the plungers on an S5 is different orientation to the wide and narrow band sensors as far as the sweep of the plate is concerned?

Or are you just saying the stock wide band TPS sensor is simply crude in operation compared to say an FD's?

What he's saying is, the S4 throttle body doesn't have the full range cam that the S5 throttle body does. If you look at both setups beside each other it becomes obvious. The S5 TPS won't simply swap to the S4 throttle body and be of any use. The idiot proof swap is to do everything as an assembly and then use only the full range sensor of the pair on the S5 throttle body.

S4 TPS Cam Plate
 

I had success doing this. It's been running without issues for two years now.

I used the S4 TPS in a full sweep mode. I measured the TPS plunger travel and plotted the cam radius to match.

Print the attachment and cut it out. Trace onto a .08-.100 thick piece of aluminum and cutout. Smooth the contact surface and applied a little silicone grease.

Make sure the PDF is to scale by checking the dimensions. I've been burned by this before.

I mounted it using one nut. It hasn't moved. You could probably slot or drill a new hole to match another mounting hole in the TB.

This is pretty forgiving. I use a Haltech PS1000 so I could set the TPS voltage at 0 & 100%. I get a full 0 - 100% sweep without any wear on the plunger face.

Plus this enabled me to keep the oil control pump rod.

I've done these myself. Great solution!

Thanks to Beefhole.

https://www.rx7club.com/haltech-foru...stions-933210/

And thanks to you!

Ruddyrid, did you ever do the tps plunger mod?

Nah I didnt actually, for the time being I think I'll just leave it as is. I need to stop perfecting everything and just get to the track!