bassani true duals?
It sucks living in california, It doesn't seem possible to come up with a header that doesn't move the stock cats, is 50 state legal and actually makes power. California just makes it too hard with all their restrictions. I wonder if california will ever change? I'm sure everyone would agree that if your car runs clean and passes smog, it shouldn't matter what parts you choose to put on your car.
This is so STUPID, I wish there was something that could be done. Doesn't anyone else care?
Yea that's the graph with the midrange gains. When I was in CA there were few options for smog legal setups, in fact initially installing shorties partially because of smog and somewhat for other characterisitcs to factor in afterwards. Honestly I was suprised as the gains of the combination far from initial estimates and now I'm making as much tq as a pair of longtubes and catback. The scaling might be unusual there's a solid gain of 18 lb ft though.
When designing a smog system separate factors adjust for running performance, not just peak numbers. For instance...some states just require an ODBCII scan, which means no converters and LTs are now legal, allows you to smog with several different exhaust configurations. CA is still the most strick area, and it's hard to overlook the placement of cats since you can see them if you look under the car. My setup dynoed the numbers below with a good tune and supporting components that I assembled beforehand so I wouldn't have to change or buy anythink additional afterwards.
Redneck Z are you planning on the comp 216/220 soon? That's an interesting formula because of the increased exhaust duration in comparison to the cams that are out already with symetric patterns. With a few degrees more duration on the exhaust (without going to far split pattern) it sounds like a great combination for short tube headers with gains at all rpm plot points...the short tubes may absorb four degrees additional exhaust duration, effectly functioning like a 216 single pattern, which should be great tq and depending on the advanced technology or may peak at or around 6200.
The Best V8 Stories One Small Block at Time
This theory for midrange gains could be attribited to many factors, not just peak numbers or raw gains of the flow of the exhaust. It's possible to predict the dyno numbers although this won't be as great as track time or area under the curve. Instead, the additional pull of a straight through system with no restrictions contributes to the almost 20 lb ft additional tq in the midrange (!). And the pull is a noticeable improvement over old y no doubt. Now, adding a cam that holds the exhaust duration open for just that extra length, in theory and on paper looks like a perfect tq combination for stock rpm ranges. I was lucky to have another dyno in another area to confirm some of the numbers. I don't remember the exact numbers, although in theory short tubes headers with a calculated length do not have a different top end restriction as LT headers. Amazing that I'm making about as much tq as LT headers.
Ok, here's some food for thought. When you modify the timing the cam, you're now talking about changing the powerband up or down, aren't you? If you have supporting components to conteract the increase in tq or increase in revs that might develop, then you're on the right track. Cam companies don't just throw things together they design the timing for the application to pick up the air velocity in a target rpm area. That's why the same cam part or same duration has different effects in different applications for different tasks.
Ok, here's some food for thought. When you modify the timing the cam, you're now talking about changing the powerband up or down, aren't you? If you have supporting components to conteract the increase in tq or increase in revs that might develop, then you're on the right track. Cam companies don't just throw things together they design the timing for the application to pick up the air velocity in a target rpm area. That's why the same cam part or same duration has different effects in different applications for different tasks.


