Intake runner length

[black2kstang]

I have an 08 gt500 motor with a 76mm turbo with a modified ford gt intake and i have a few questions that some of you more knowledgeable guys may be able to answer for me. How does intake runner length affect power and spool time of a turbo? I have been told by a few people that the basically non existent intake runners on my intake are killing me right now. I want to know why the science works like that. Also, what other intake options do I have?

 

[blackvette101]

When i was building turbo cars i seem to remember that the longer the runner the more low end torque and better spool. And the shorter runners were good for higher hp. It was all because of velocity and the no length runners in the manifold pretty much have little velocity. I remember reading an article in muscle mustangs & fast fords and they did a test on a 700+ rwhp procharged cobra that used the stock lower manifold and then they switched to the mach 1 manifold and picked up like 80+ rwhp. They said the reasoning was that the compressed air would stack up against the intake valve for the length of the runner and then when it would open it would create a ram effect as opposed to just trying to pull air out of an open plenum with no runner. On the spool side the longer the runner will make better torque down low well your spooling up and should make it spool faster. As far as manifold options you'll probaably have to go sheetmetal. I know MMR makes one. I believe that in a turbo or centri blower set up that you need to have some sort of runner, short or long.