Maybe I missed it, but I did not notice anyone using CO2 for boost control while I was at WCF. Does anyone still use this? And if not, how is everyone running such low boost and ramping so high without the aid of CO2?

 

Use (2) 3port solenoids or (1) 4 port.. And you will make all the boost. I run a 15lb spring and a 4port and can make over 55psi no Co2..

 

I did happen to notice several cars running a single 3 port and a few running dual 3 ports. I didn't see anyone running a 4 port. I run 12 psi springs and I am limited to 38 psi on a 3 port. I have read mixed reviews of the 4 port solenoid in terms of resolution. A lot of the domestic guys run co2 and love it. I remember years ago most of the SFWD guys ran co2. I wonder if guys are running larger springs and just regarding the timing down low to allow a higher boost ceiling?

 

Why deal with C02 when the 4 port solenoids work?

 

That's exactly what I am saying, I didn't notice anyone using a 4 port that I could see. So apparently, for some, they aren't working or they would use them. So, back to the original question, how do these guys run such low power out of the hole and some much boost up top using only a 3 port.

 

super large turbos don't spool worth a crap at low loads like first and second gear. a lot of guys running 3port solenoids use a 15-20psi spring, but only see ~8-10psi in first gear and 10-13psi in second gear. Simply because the turbo can't even spool enough to open the wg at 0% duty cycle.

as a semi-similar example, my t3 can hit 15psi at 5600 in under half a second in neutral with very minor launch control settings, yet guys with 1200hp turbos can barely get 8-10psi at 8k with extremely aggressive launch control settings and holding it there for several seconds

 

You can use a 3 port the same way as a 4 port if you drill a small hole in the top of the wastegate. that have been done a long time here in europe before the the 4 ports was around..