Quote:
Originally Posted by abadsvt
"Peaky" Can you explain? I always thought equal length was an ideal setup.
Josh
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4 into 1 vs. stepped try-y's... has always been healthy debate. Both have their 'applications'... but one is much better suited than the other,
for a given application.
"Equal length" became a buzz word from the application. That buzz word was in reference to, obviously, making the primary tubes equal length... vice that of a tube header
without equal length primaries. Now remember... we're referencing 1950's era buzz and technology. But... simply stated, yes... 4 into 1 'equal length' headers were much better than what the OEM and most aftermarket had available. But... how are they better... and most importantly, what application(s) are they better for?
In an application where the operational power band is relatively narrow (which really limits it's ability in most cases)... an equal length 4 into 1 header is choice. An application that suits that specifically is drag racing... where you pretty much operate in a limited range, in the latter quarter of the RPM band. Another application... would be on the engine dyno... where you are trying to make "peak" numbers... if only for a cock swinging contest. The 4 into 1 equal length design is well established for these applications... and is used in many forms of racing where the length of the track, or the lack of turns is present... like that in super speedways or longer oval tracks... where you are at a sustained throttle position, in the latter part of the RPM band.
The Try-y... also a 1950's design/creation... changed the approach and opened up many doors into the understanding of fluid dynamics. The basic design theory is 'pairing' of cylinders in the firing order. When the next (paired) cylinder's exhaust valve opens, the vacuum in the system pulls the exhaust out of the cylinder. This design improves the scavenging of individual cylinders and the tube length effects the time of the phasing, of the individual pulse.
Try-y's have always been though of as making better low and mid range power, but give up some at the top end. Meaning: they don't make the peak numbers that a 4 into 1 design would make.
That is far from true in this day and age. With the advent of the "X Design" program and late model engineering practice... the newer Try-y designs make, not only more power under the curve...
but peak power as well.
Now... for the practical application. If you were to only drive your car at full throttle, in the latter quarter of the power curve... the 4 into 1 would be something to consider. So... if your drag racing... that is pretty much your best bet... in most cases. If your driving on a long oval where you rarely fluctuate more than about 2k RPM... the 4 into 1 would be something to consider.
But... we drive our cars on the street and some of us at the track as well, which both are very similar. Normally, where you utilize more that 75% of the RPM band width...
just as it would be on the street like it would also be on a road course... the Try-y makes more sense. More usable power under the curve... and in the majority of cases, more peak power.
Todays professional race teams know this... the C6R Corvettes, Trophy Trucks... and even the left hand turn club (NASCAR) utilize the Try-y specifically for road course efforts... they all use the Try-y design. Katech Engine Development, who builds engines for Pratt&Miller and the Corvette C6R, a few Trophy Truck's and some NASCAR efforts (not to mention they were the proverbial **** back in the Trans-Am days)... dropped a set of ATS Try-y headers on a standard engine package that is the mainstay of their aftermarket business... and they made more power everywhere... under the curve and even peak... over their custom dyno headers that were made for that particular engine package.
Considering 'our' application in duality... the streets and even some road course work... I very much believe the Try-y design is better suited for 'our' use. If they were not... we wouldn't have even considered the design in the first place when ATS developed it's Try-y header with Burns Stainless for the First Gen F-body and specific use with the LS7 or higher performance LSx applications.
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