Intake runner length

[tpepmeie]

I just wrote a bit on my blog about the LT5 intake runner length. In short, the factory manifold length is well optimized for torque at 4800 and 6000 rpm. With enough cam, there is potential to hit another tuning peak at 7500 rpm.

Getting a 1-d simulation to match actual performance was not easy. I've got it correlated well now, and can match within +/- 1% over the powerband. You have to account for the pipe end correction to get it to model the peaks correctly. The actual wave reflection occurs up to an inch above the actual runner entrance.

Anyway, I believe it's hard to beat the stock runner length for almost any build. Would be even better if we could get the same length but without all the bends in the intake path. But then the runners would have to cross over each other (LS-style), or stick out of the hood!