Motorsports Village

The answer to zip ties

http://www.dragzine.com/tech-stories/co ... echnology/

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Steve

6.7772 @ 101.51 1/8th 10.747 @ 122.24 1/4

Not sure I even agree with their theory. I would want the long runners to have a shorter duration to be closer in tune with the runner rpm. They have it opposite. I doubt it is much difference as they claim. Cam's don't gain much when close. Just another way to get the "buzz" going about another cam they can sell that costs more ... like the 4-7 swap. Charge $100 extra for something that doesn't cost any more to make.

Rick

here here rick

That is why it is better to do it with Rocker ratio, if you are. Did you notice the test?
where were the short duration lobes and where wre the longer. I bet it would have picked up even moving them to the other 4.. :~)

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www.adgersperf.com

I don't think the bang for the buck would be there. I know Ken uses zip ties on the carb to kind of do the same thing. Will there be be that much difference overall or just make the AFRs look better?

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Steve

6.7772 @ 101.51 1/8th 10.747 @ 122.24 1/4

We both did the zip tie thing with gas and alky and honestly it did not make a difference on the track..

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running E85
Best ET 8.07
Best MPH 170.71
Barry

When I was doing the zip tie thingie I was trying to balance EGTs and did get them to within about 60* or so but like Barry, I never did see any ET or MPH from doing that. I finally did figure out that "sometimes" high EGTs aren't necessarily because a cylinder is lean. High temps can be caused by poor atomization of the fuel which results in some of it being burnt down the exhaust.

IMHO a properly ported intake "should" eliminate most of this and frankly I'm surprised to see NASCAR doing the cam thingie with all the money they spend in intake and head work.

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Big Boyz Toyz!



Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves.

William Pitt, British Prime-Minister (1759-1806)

The different lobe cam is to even airflow between cylinders, not mixture distribution.

No matter what you do the end runners will have longer runners if you have a single four carb, there is no other way around it. That makes those cylinders tuned to a lower rpm range. I'd want the lower rpm runners matched with lower rpm cam lobes. Their info showed it the other way around.

Rick

Seems like it took 25 years to trickle down from Nascar.

Yep it's old news now for Nascar!!

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running E85
Best ET 8.07
Best MPH 170.71
Barry

If using 2 different intake lobes equalized the flow (and therefore "theoretically" VE) why would there be a need for different ex lobes?

If the different intake lobes fixed the un balanced flow wouldn't all the cylinders produce the same amount of ex?

AND "IF?" all the cylinders were at the same ve level and producing the same power, wouldn't different ex lobe requirments be based on the ex ports/ex systems ability to ex the cylinders, and not the difference in intake duration?

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Slow racing is better than no racing!

Randy

They also make the assumption that the air flow differences is whats causing the AFR differences. Rubbish. Fix the manifolds not the cams.