Contour Enthusiasts Group Archives Forums Modifications Zetec Performance Stupid Question to ask about an I4

Originally posted by Seawulf:

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Oh For Gods Sake! I don't check the forums in a day and it all goes to heck. First of all boost is boost and both SCs and turbo's are difficult to tune right.

Both will negatively affect fuel economy depending on circumstances. A light foot on the throttle can do wonders for your mpg. A turbo is arguably better for fuel economy since it operates off waste gasses from the engine and not a belt that needs engine power to turn, they say the cruise exhaust velocities would spin the turbo a bit and make the engine breathe a little easier.

Yes a SC is easier on the engine, but that's because it's weaker. At least on the Zetec they are. Pound per pound of boost, all SC for the Zetec are weaker than even the smallest turbo's. My first base setup for my car using a turbo more suited for a 1.6L engine put out 145whp and 156wtq. That's only 5hp less than the base Jackson Racing unit but I only revved to 5800rpms and the JR setup was revved to 7000rpms. That was done on stock fuel and ECU on a lean AF.

Like I said the HP was slightly lower than JRs list figures, I killed the SC on TQ. A stock JR will barely do 130wtq and at similar boost levels will always e 20-30wtq behind a turbo.

The reason this is is because a SC has more lag than a turbo. Yes, lag. Because the SC is tied to the crank and rpms so it doesn't reach full boost until near the redline. My turbo hits full boost by 2700rpms. A properly sized turbo will hit full boost by 2500-3000rpms. I believe a standard t3 super 60 will do full boost around 3500rpms, and that's way faster than the JRSC or even a vortech.

My initial setup also cost around $800 and lasted for over 20k mi before I decided to upgrade and push more boost, so if you are pretty mechanically handy a turbo is cheaper to do. If not and you want the closest thing to a bolt on for our cars, then the JR is it.

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I got video of my boost from a stop. Right off the bat it is at 5psi and quickly moves to 7 psi (full boost) at 3000 rpms. How is that lag?

How much boost were you at when you hit 145 whp? I was making 150 whp at 5800 rpms at 7 psi. For me I never cared about torque because that would have been the end of my trans. But I was at 140 at about 5000 rpms at 7psi.

BTW me pushing my car I still get 300-350 to a tank. That is called good tune. I didn't even throw my car on a dyno....that is how easy the S/C is to tune.