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cali smog


robert.davis

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so i pretty much have my mind set on buying some pacesetter headers for my 720 just wondering if i wanted to smog my truck and put all my stock exhaust back on (minus the manifold i would be swapping with the headers) would it still pass? anyone try this or knows someone whos had this experience 

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40 minutes ago, bottomwatcher said:

Pacesetters are junk! Leak, loud no improvement in power and will fail visual. Does it even have a port for the PVC? Headers do nothing for naps z.

So agree not worth all the headache to smog for a header. Sell the 720 and buy a 521. No smog. 

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First a header won't have provision for EGR AIS or the ATC. Fail on the spot.

 

Second, the Z24 exhaust manifold is not in any way restrictive on an engine that barely makes any power above 4,500 RPMs so no real improvement. They are expensive, they never fit properly, PITA to install, noisy, leak, always come lose, over heat the engine compartment and cabin floor, always rust out. Only advantage is they are lighter.

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1 hour ago, bottomwatcher said:

Pacesetters are junk! Leak, loud no improvement in power

 

I hear this a lot from people who really don't understand how engines work.

Here is what happens.

You take a restrictive stock exhaust system off, and replace it with a free flowing one.

The engine breaths better due to less back pressure, and less exhaust mixing with the new incoming charge.

This makes the new incoming charge to be lean, due to less exhaust gas, but more oxygen per charge in the mix for what the engine was tuned for.

 

As far as leaks, I normally put that down to poor installation, as I have never had problems with PaceSetter, or any other tube header.

And as far as cali smog inspections, well, you choose to live there....

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First of all the stock manifold must be restrictive in order for there to be any chance of an improvement. The Z series is not a high revver but a low speed torque monster due to it's poor breathing head design. 

 

I think the 720 uses a 2" exhaust pipe but you could replace it with 2" if not, or 2 1/4" if it does..... and a turbo muffler.

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I can confirm that my Doug Thorley header makes a difference in both tone and overall volume (DB) of sound coming out. It also slightly increases under hood temps, mostly noticeable in the winter because the snow melts off the exhaust side of the hood faster as opposed to intake side melting faster with a stock exhaust mani, also they look good under the hood.

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I agree with Duax on the installation argument. Proper installation and possibly a few mods to the hardware used can make any cheap pile of crap header work. One of the main fail points on those garbage headers is the 3-bolt flange at the outlet. People tend to overtighten the bolts and squish the gasket or the gaskets get hard over time and blow out. I cut them off and weld on V-band clamps, but you could also use a slip fit with a strap style clamp.

 

I do remember seeing a chrome smog legal header for those. Probably been 20 years though.

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