Car is due to get its smog check in a few months? only upgrades are a Custom built rear turbo, intercooler, 42 lbs injectors and hpTuners. I think I'm gonna do a pre-Test, and see if it will pass with the custom tune. If not Ill change the tune to stock, except for the 42lbs injectors. Anyone here have problems passing the smog, either visual or sniffer?
Side note once I "pass" smog what cam's should I look at for the STS?

 

LPE GT-7 Cam is my baby...

 

Good question. Anyone get harrassed at the smog shops even with the CARB exemption and no custom parts?
Lewis

[QUOTE=2002ws-6]Car is due to get its smog check in a few months? only upgrades are a Custom built rear turbo, intercooler, 42 lbs injectors and hpTuners. I think I'm gonna do a pre-Test, and see if it will pass with the custom tune. If not Ill change the tune to stock, except for the 42lbs injectors. Anyone here have problems passing the smog, either visual or sniffer?

 

Does Cali still sniff? I believe you will pass the visual.

 

Straight from the horses mouth:

Cam choice in turbo applications is critical. In many cases, a stock cam will work better than a typical "race cam" that would work well with an aspirated engine. What you want to avoid is the "intake and exhaust valve overlap". This is the time that the exhaust and intake valves are open at the same time. In aspirated engines, this theory facilitates the scavenging of all burnt exhaust gasses from the cylinder after the power stroke so that an "uncontaminated" and 100% burnable charge fills the cylinder on the next cycle which produces maximum power. Some of this condition can be tolerated with supercharged applications as it merely blows some of the boost out with the exhaust. However, on turbocharged applications (many people believe that the boost also is just blown out with the exhaust) however, the opposite is truer to the case. With exhaust pressures sometimes exceeding boost pressures, the exhaust can flow into the cylinder and into the intake manifold during this overlap time which contaminates the intake charge, decreases HP, and can cause pre-ignition as well. Also, most cam applications begin flow at .050" of valve lift. On forced induction systems, there can be substantial flow below this amount of lift because of the higher pressures behind the valves.
So, if in doubt go smaller on your cam rather than larger. Go wider on lobe separation angles (114 degrees is usually safe) Smaller on durations (stick around 220) and check with the cam manufacturer to make sure that it is a good "turbo" cam and not just a generic supercharger/turbo cam. A good option is to install a set of higher ratio roller rockers on your stock cam. Better pushrods and stiffer valve springs will help as well because boost and cylinder pressures will be way higher than stock. Stiffer springs will help close the valves against the pressure of incoming air and stronger pushrods will help open the exhaust valve against the increased cylinder pressures.

 

I just passed smog on mine last week. The tech who did it just looked at the smog legal plate on my STS tube and the plate on my shorty headers, then he looked and saw the cat's and then hooked up the ODB2 connector and checked for codes and everything was good to go. As for the smog check itself it passed with flying colors. I have 42lb injectors and a walbro pump and my custom dyno tune and everything went fine. I was a little nevous though.

 

Congrats on passing the smog. which shop is this? Just for future references. pm me if you prefer. Thanks.

Lewis

 

Sounds good! Can you give us some more details about your setup? how much power,how it runs on 91 oct. ect? I would like to do either a stroker or a turbo in the future and stay emmisions compliant.

Thanks, Chris

 

I'm running an STS setup with the T67 upgrade turbo, Pacesetter shorty headers, stock exhaust, 42 lb injectors, walbro 255 lph pump. The tune was done by Nelson performance out of TX. I also have a predator that I can tweek the tune if needed. Car puts out 431 rwhp and 462 rwtq on 91 octane at 6 psi. I'm hooking up the methanol injection kit and electronic boost controller this weekend. I'm going to run 10 psi and then see how the dyno goes. Hoping for 520 rwhp and 560 rwtq. Still haven't got any 1/4 mile runs in yet. I'm putting in a 9" rearend and centerforce 12" dual friction clutch at the middle to end of this month. Once I get both broken in I'll look to start getting some good 1/4 mile times.