I'm taking my car to get tuned on Sunday. I have two questions.

- I have a tuned PFC with 550 primaries and 1300 secondaries. I've purchased 850 primaries and 1600 secondaries to install. Can I just install them and change the injector size on the PFC or will it keep the existing percentage duty for the injector maps? I plan to install them and then drive to the shop to get tuned. Do you think I'll have a problem getting it to the shop running that rich if it doesn't adapt?

- I run a cat and a Racing Beat Dual pipe exhaust on the street and would like be able to swap out to a mid pipe and a Apex'i GT exhaust. Do you think it's a good idea to run the mid pipe and Apex'i GT exhaust for the tune and swap back to the other setup for the street on the same tune? Any draw backs besides less power and running rich?

Thanks

 

You'll probably have to adjust the lag settings for them as well. I believe the injector maps are changed for you when you enter in different injector values. Not 100% positive, but I remember reading that. Good luck with it and the tune. Post your results!

 

1. You will have to adjust lag settings and injector sizing. You cannot enter bigger than 1500cc injectors with the Commander though (you need the Datalogit). The injector overlap will have to be adjusted, but the tuner should handle that.

2. Yes, get the car tuned with the straight exhaust. Be sure to have some restrictor plates installed BEFORE tuning to deal with boost creep. You do not want your tuning cut short because you can't control boost on the dyno. After the tune, you will just run richer with the cat.

 

OK, so can anyone recommend some safe temporary lag timing adjustments for my setup. 850 in the primary spot and 1600's in the secondaries both from Gotham Racing.

 

Hey how do you do the restrictor plates?

 

It is like a gasket that goes between the MP and cat back but instead of having a 3" opening, it has a 2.5" opening. It can be cut out of thin SS sheet.

 

About .30 lag for the 1600s. You will have to adjust the 850 lag as the car idles in order to lean them out. Maybe about -.10 as a start.

Search on 850s on this forum.