CIS enrichment under boost
 

I plan to put an aftermarket 0.8 spring in the waste gate of wife's 924t. Stock is 0.4 to 0.5 bar boost. I'm pretty sure I'll need some more gas to take advantage of the air at bigger boost. Has anybody done the same & have any ideas?

Warm up regulator - any mods here

frequency valve - go bigger here?

stock injectors - they have enough flow for more boost?


drew1

You'll have to adjust the mixture somehow...best way to tell is by putting the car on a dyno to get an air/fuel reading. If you're just a bit lean then you can try having software burnt to adjust the pulse width of the injectors [keeping them open longer/increasing the duty cycle]. If you're moderately lean then you can get an adjustable FPR and try increasing fuel pressure but be modest...apparently increased fuel pressure puts strain on other components in the fuel system and can affect drivability. If you're WAY lean you'll have to get bigger injectors AND an adjustable FPR, then ideally have the car tuned perfectly across the range. Hope this helps, and have fun with more power!

The really ugly way to get more fuel is to connect the cold start injector to a adjustable pressure switch of that type you can find in old saab turbos. This will give you extra fuel above a certain pressure, but you can't adjust the amount of fuel since it is an on/off switch.

//Magnus

Thanks for reply G96 & Magnus.

Still in the thought process, but I see this as a potential problem. I guess first I'll have to get a gage that reads O2 sensor & duty cycle.

Still waiting on rod bolts to get machine work done & the motor together.


drew1