swan

'ello all,

From what I've read, a 10-15Kw gain is promised by fitting these alone. I've also seen reports that this leads to the engine running lean.

Can anyone that's actually got one fitted confirm the actual performance improvement, if any, and whether it impacted at all on the AFR?

TIA.

submannz

It will significantly increase the flow of air in and out, so will run the car more lean, we just tweak the fuel pressure regulator a little.

swan

Thanks, is the standard WRX fuel pump up to it? What about real world performance improvements?

swan

Another question, I'm sure using the lamda sensor, surely that will "keep up" and ensure the car doesn't run lean?

David_Wallis

I thought fuelling was controlled by the maf.

David

dowser

To get the best out of this mod, you'll need a remap. Fuelling, timing and boost control will all be unsuitable. Whether it's dangerous, or just crap to drive while spooling, will depend on your car and it's mods.

Note: if you're using the OE JECS then lambda is only used during closed-loop operation at low revs and load. At other times it reads fuelling from the maps.

Richard

john banks

MAF and TPS so if VE is improved then a different load point may be hit with the same airflow. In practice the effect will be small. However, worth noting that most equal length headers seem to lose you low down torque. If using a large turbo that could be an issue - was for me (despite mapping a lot of the losses out) and I returned to OEM headers - response off boost is better and turbo spools 250 RPM earlier. Some types of headers seem to have better results than others. I think you need to remap to take advantage of equal length headers and minimise the torque loss low down personally.