Just before winter set in, I installed a Helix O2 housing and a high pressure actuator. I just got around to retuning for these parts with my UTEC and I'm surprised to see that with the winter temps (about 40 here) I'm hitting 95-97% duty cycle at 21 psi in the 7000-7500 rpm range with 660cc injectors and low 11 AFRs (alky turned off). Obviously, the alky will provide me some cushion when I turn it on, but I was just very surprised to be getting close to the limit of these upsized injectors. I guess if I were doing it again I'd go up a size.

BTW, I seem to have developed a boost glitch either in my Forge 1G BOV or my boost controller wastegate. About 1 in 10 times, when the boost should be building it's getting bled off audibly but then all of a sudden in the upper RPMs whatever is holding open suddenly snaps shut and the boost spikes to 23+

Does this sound like a solenoid problem (I've got a Blitz EBC), a BOV problem (I was just playing around with the springs, but it does this with either spring) or perhaps a wastegate problem (I recently install a high pressure actuator and I think there's a chance that it's binding on the lower heatshield a little, but I can't think of how that would cause this problem).

Anyhow, it was good to really test out the O2 housing. Definitely a gain there!

 

THat's weird. I'll have to see what my duty cycle is with the 680's.

 

What you are seeing is normal. The 660's are marginal if the car is making good power with the 20G and probably about the same for the WR.

David Buschur
www.buschurracing.com