Most drag cars are inlines... those that arnt are old school kids that dont know anybetter... twin turb grand national... i seen a dyno for one the other day.. 836 horsepower to the wheels. Even on prostock v8`s (302 -351 displacements atleast) are still running singles.. But its completely on unstreetable application i seen a diagram by nasa a couple of months back stating that if you had primaries long enough (50 inches) you can run alot of overlap without reversion becoming a problem. Plus they use such high tech insulations that having the turbo`s that close to the head doesnt help. There isnt any heat loss anyways. Not to mention heat wraps and what not that they pile ontop of their coatings all this cuts down on reliability of teh manifolds. You wouldnt want a setup like that anyways unless you had a 2000 rpm idle with overlap that huge. (100 degrees or more) and a turbo that big.
I keep thinking that seperating the exhaust pulses has a good benifit though because they even do it on turbo housings Making 2 diffrent inlets from 1 bank. apparently by splitting the pulses up they arnt diluted as much. besides at that power level you would have to buy 2 massive turbo`s instead of 1 one god massive turbo. 2 turbo`s each capable of a 1000 horsepower would cost you some major dollars. where as you can pick up a gt 60 for like 4000 thousand. Instead of 2 gt 42(i think they are) for like 3500. I know there is obviously an advantage, everywhere iv read and everywhere iv seen a twin turb application is more durable and has the potention to make more power then a single because your splitting up the heat that each turbo has to endure and the heat the flange has to endure. The turbine housing its self and your increasing exhaust flow. I dunno I plan on having my build up rolling around in spring. And we`ll have to pit the dyno numbers against the dyno numbers of the biggest single when i roll it out put some miles on it and pin it to a dyno.
Ex-cat cams dealer. Today we do motor mounts.. Tommorow. Intake manifolds
