Fast Classic on SBF with nitrous

[RSNovi]

Hello All,

I am setting a FAST Classic on a 358 SBF with nitrous. In the past I have always tuned a blower setup so this is a little different. So far I really like the FAST software, but I have a few questions.

With blowers I have always used speed density, but this car only pulls 5 in of vacuum at idle. I am starting to wonder if alpha-n would do a better job. I am able to get the car to idle fine, but it stalls when placed into gear. Any advice on this?

Second, it seems like the O2 sensor is almost always 9.1 AFR and it doesn't seem like the car smells that rich when idling. I am wondering if the sensor is bad because it really never fluctuates.

Thanks for the help.

Chris

[TurboNova]

This is the delima about speed density and the classic Fast. With the new XFI you can scale the map KPA and RPM columns for what you want them to be for RPMs and engine vac. With the classic FAST you cannot.

So either you live with the left column having little numbers to be able to change or go to Alpha N. This is a choice you should make before getting too far.

For the O2 sensor, you can check the volatges with the O2 unplugged. Look in the help menu FAQs for the voltages you should see in your dashboard.

I have never seen an O2 sensor go bad and show a rich value, usually they show really lean and are stuck.

[RSNovi]

Thanks for the reply. Since we haven't got very far without going to the track, I think I might switch over to Alpha N and see if that works a little better.

I also just realized that the Classic uses the NGK sensor which is quite expensive so it might be worth doing some troubleshooting before running out and buying another sensor.

The unfortunate part is the system was purchased used and then it was custom wired so I have been finding a few weird things. The MAP wasn't working at first, the best we could get the TPS was 38% at idle, and when they first fired the car up it was pouring fuel out of the exhaust because they had the wrong injector value, etc... I am hoping to help him get his car running half way decent and I am having fun learning a new system.

Chris