I am having a hard time with the narrow range s4 tps and accel enrichment settings. I don't know how close the ms and what the enrichment % should be. Could someone give me their settings for me to try?

 

Are you just using the basic accel enrichment, the tps_dot or MAP_dot vs injector PW look-up table?

If so, before I moved to using the EAE/wall wetting model enrichment, the following worked pretty well for a stock S4 linkage, T2, TPS only:

TPS PW added
20% 0.1
150% 0.6
500% 1.4
1000% 2.0

TPSdot Threshold was 100% (so 20% above didn't do anything, but provided the slope for the area between 100% and 150%
Cold Accel enrichment was 0.1, and Cold Accel Multiplier was 120%, although I never really had it working very well when cold.

 

if you have a narrow range tps you need to use map for accel. enrich instead of tps

 

eh, you don't really need to. Sure, the TPS may only read up to 30-40% of total throttle travel, but its that first 30-40% where you really need the acceleration enrichment most anyway. Plus, the TPS measurement responds more quickly than the MAP to a throttle event, so you get slightly better response (you don't need to wait for the manifold pressure to actually change, and for that change to make it through any vacuum lines to the MAP sensor to begin the enrichment). Even with the narrow-range sensor, I was always able to get much better response using the TPS sensor.

With that being said, moving to an S5-style full-range setup works better than the narrow-range S4, and moving away from a plunger-type TPS to a twisting potentiometer type over the full range is better still (it doesn't jitter & bounce around nearly as much, especially at high revs/loads, and reliably returns to the same value at WOT & closed throttle)

 

I tried finding an easy replacement for the S4 TPS and wasnt able to find much. I do have a S5 NA TPS in my box, it just didnt look like it was a drop-in affair. Do you have any links/guides?

The car is very jerky and annoying with slight throttle movements so I may move to the MAP based until I can figure out a better solution.

 

Basically, I used the cam wheel for the full-range S5 sensor on an S4 throttle body, with the S4 plunger. I did need to tweak the position of the S4 plunger slightly, but it all fit together pretty easily, even using existing threaded bosses on the throttle body.

With accel enrich turned off, is the car still very jerky at very low throttle openings? What size primary injectors do you have? With 870 primaries & 4 squirts/cycle, at lower loads I'm pretty close to the opening pulsewidth for the injectors, where the amount of fuel they deliver starts becoming inconsistent. In this case no amount of accel tuning will help. Smaller injectors, the ability to run lower fuel pressure here, or synchronized injections timed to each rotor with 4 channels (one for each injector - MS3 style) and 2 squirts/cycle would all help.

If its small throttle movements, but at higher loads, a datalog would help a lot. Do you have a wideband O2 sensor?

 

As I recall, the last time I set up an S4 TPS for accel enrichment I had to spend some time tuning the v/s threshold of activation. You'll also spend much of your adjustment on the higher change rates as the S4 TPS has such little resolution.

Blending mapdot and tpsdot will likely offer some options.

There are many TPSs which have been retrofitted to S4 throttle bodies. The popular Haltech Ford TPS is an easy one. All you need to do is shave down the throttle shaft nut so it fits within the TPS, and then make an angle bracket to hold it in place.

 

Has anyone successfully installed a full-sweep potentiometer TPS on an S4 throttle body while still retaining the mechanical OMP linkage?

I have the GM TPS on there, but there's no way it will work with the actuator rod for the OMP on there too. I'd really like to have my OMP back. Pre-mix is less than ideal to me.

The alternative is to figure out some sort of fancy bicycle cable actuation, but so far I haven't come up with something feasible.

 

I could sware there is a wright up somewhere on here about this but can't find it, and they kept the OMP linkage.

 

Here is something that would work. https://www.rx7club.com/engine-manag...ative-1047258/

 

Pretty cool write up. Think I might try this instead of hunting for a s5 tb