Can you figure this out?

[fe9_fe9]

Hi,

Car is a 402 LS2 with an e40 and a set of PT7675B turbos and meth. PRC 237cc heads, FAST 102mm intake and a 102mm Nick Williams TB.

I went to the dyno and spent around 4 hours without figuring this out. Car noses over at the top end and we lose RPM signal on the dyno everytime. We tried different locations to pickup signal but we keep losing it in every run. In the logs I notice a huge spike in IDC and dynamic cylair. Boost is steady and no boost spikes. The more I up the boost the more we lose power and the car acts up. Also note how the RPM behaves during the run. It's like the car won't rev further.

[fe9_fe9]

Here are two other runs. The first one is at ~15 psi



And this run is at ~14 psi



I'm planning to start checking plugs, wires and coil packs for issues. Also might be pulling out valve covers to see if there is anything irregular. All of those logs here we lost RPM signal at around 4K RPM and we were unable to get a proper dyno graph out of those pulls.

Appreciate any hints or suggestions.

Thanks,
Faisal

[ingsteve]

You are commanding 11afr and reading around 9.
Have you tuned your maf first? You are too rich.

[SAM_69]

Usually when i had any RPM signal problem i change the rpm pickup sensor on the Dyno and if i'm not mistaken you can use a primary and secondary one. also DynoJet use three different kind of it. Depends which one you're using.

As for the IDC and Dyn CylAir spike to diagnose that problem i'll start with a comparison test and checking the coils and the injectors

Good luck figuring this out buddy.

[edcmat-l1]

First, you're way, way too rich.

Second, you have no timing in it.

Third, post the tune so we can see if there's a reason for the spike at the end of the one pull.

Dial it in and see what it does.