Thread: common problems with log manifolds

Choking the turbo? Turbo is the choke point. Just about all OEM turbo cars have low overlap cams. Turbos are a flow restriction, thus they cause back pressure that leads to reversion. This is why our NA SR20's still had low overlap cams, they are turbo motors at heart. Same applies to NA motors that shipped with OEM log manifolds (trucks usually).

Having a lot of overlap is only beneficial to NA (helps with scavenging) and with very big high flow turbo setups.

ok yeah now i understand, i had the whole choking part backwards, so thats y longer runners on manifolds work better along with better engineering techniques, am i following this right?

Yep, pretty much all covered, if your gonna run a log mani on a ve, best to find some vet cams. Simple as that. Or use a very large turbine housing t3 turbo. But even that wont solve reversion issues. Logs just make it more difficult to make good power and reliably with no issues.

As for tubular manifolds. Someone that knows what they are doing and use the proper thick wall SS material and you wont have issues. The ebay mani's use thin wall crap material. T304 Schedule 10 material on a couple manifolds ive used and never had a problem.

BTW ive seen plenty of cast iron log manifolds crack.

womp womp. so that means i gotta get that ve mani flange to start my new manifold. going with something similar to a sidewinder/ top mount set up