I fairly recently purchased a used 05 S2000 with a Novi1200 supercharger on it running a 3" pulley installed by LHT.
Haven't driven the car much as there have been several issues I've had to sort out.

Anyways here is the fuel system setup:
Fuel Pump - Unknown (I know it is not factory as it was given to me in a container when I bought the car. The invoice from LHT shows a pump but not the model)
Fuel Rail - OEM
Fuel Injectors - ID1050Xs
Fuel Pressure Regulator - Aeromotive 13115 FPR (Direct bolt on style set to ~50PSI when referenced to atmosphere)
Fuel Damper - OEM
Fuel Return - OEM Return System
Fuel Pressure Sensor - AEM-30-2130-100 Installed into the FPR using the SOS Remote mounting kit

I have been working on tuning the fuel map and noticed in the datalogs that above 50% Duty the Fuel Pressure starts to oscillate.
From the logs that I have collected it seems to fluctuate around my target pressure +/-7PSI.
(I have only started getting into the 6,000~7,500 RPM section of the tune and only have 2 or 3 pulls where the fuel demand gets that high)
The AFR seems to fluctuate a little as well when this happens. (only around +/- 0.5 of the 11.5:1 target) (I know that toward the end of my pull it was closer to 11:1, already updated the tune but haven't tested it yet)
The fluctuation of the AFR doesn't seem bad, but the AFR sensor doesn't react immediately and is more like an average and could have a couple of lean strokes in there (Honestly not sure how big of an issue that is)

My question is this typical for my setup or is there an issue that I need to troubleshoot?
Also, if this is typical how big of an issue is it?

Here are some screen shots of the datalog.
(Fuel pressure is in purple on the top graph, keep in mind that the SOS kit includes a restrictor to dampen the oscillation the sensor is seeing)



I need to find out what pump is installed in there and if it is running the factory wiring.
Out of curiosity I was thinking of probing the fuel pump voltage at the pump and running it to the Kpro so I could datalog it and have it be in sync with everything else.

If this is typical and is something that should be addressed what is the best course of action?

 

Normally LHT installs the Walbro 255lph. They talk about it in almost every supercharged s2000 install video.

 

Not sure what is normal or typical but here is something to compare with.


AEM 340 pump, Radium rail, fpr and pulse damper, Bosch 1500cc injectors.
Pressure sensor remote mounted from rail similar to SOS kit but with no restrictor.
No smoothing enabled on the analog input, the big pressure jump right before first WOT is around 23psi which seems kind of nuts.
AFR doesn't seem to be affected all that much though so not sure how accurate the readings really are.
I have the same type of sensor for oil pressure and it is way more stable.

 

Thanks!
I assumed it was that pump but wasn’t certain.

 

Thanks for the info!
yeah I don’t have have any smoothing enabled on the Fuel Pressure but had to put max smoothing on the Oil Pressure. I am using the SOS kit for that as well which didn’t come with a restrictor, but instead of removing the factory Oil Pressure switch I instead teed off of the feed for the supercharger. I plan on inserting an analog Low Pass Filter tuned to ~45Hz as the ADC samples at 100Hz and the digital filter is worthless for filtering out aliased signals (99, 101, 199, 201Hz, etc… all appear as a 1Hz signal to the processor so it is impossible to filter them out without wrecking the transient response)

I’m not done designing it yet but I am working on making a companion board for the KproV4 that would break out all of the Analog inputs to a connector on the side of the ECU with a dedicated Ground pin, Clean 5V, and antialiasing filter for each input. Additionally I was thinking of adding an IMU so that I could record the Gs as well.

 

Just a quick bump to see if anyone else has any data/suggestions to add.

 

Walbro 255lph is most likely what's installed in your car at the moment since that's what LHT always installs. It's unlikely that they upgraded the wiring with a SOS rewire kit so I recommend you do that soon. If that pump is not getting enough voltage I can see how your FP will oscillate. If it's not that then your FP sensor could be the culprit.

 

Use the seamless auto kit or DIY, I would not use the SOS kit.

 

Any specific reason why not?

 

The SOS wiring kit still utilizes the stock connector going through the fuel hanger, which is way too small and will get hot and melt, and potentially cause a fire. Also, the relay setup they have is known to come loose and cause it to also get very hot, enough to melt or potentially cause a fire. Join the boosted s2000 facebook group and you'll see plenty of examples. I included one of many below (not mine, just one from the group). It is better to do it yourself with at minimum 10 AWG OFC wire or larger, with studs or similar to go straight to the pump instead of the original connector. The seamless kit is completely overkill and uses like 6 AWG OFC super flexible wire and comes with good sheathing already, so it's more than you'll ever need. The SOS wiring kit is also like 14 and 16 AWG wires, which is not much bigger than stock.