Hot Rod Magazine in the US has done it again.
They tested 20 inlet manifolds to suit the popular LS1 style engines. While this might seem like a clear cut exercise, the results are fascinating.
There are some things to bear in mind however. The test engine is far from stock (a cammed iron block 6.0L LSX), and that peak power is less important to those of us that need lots of torque and a good spread of power to get around a tight circuit, compared to the drag racing fraternity.
Another point to remember is American horses seem to be much smaller than Australian ones, and therefore more fit into a smaller area than they do here. The US seems to consistently yield higher dyno readings than our local ones.
They tested some of the original equipment fitted manifolds from various models as well as a bunch of aftermarket gear.
The Fast LSXR manifold range appears to be by far the pick of the bunch, but as the most expensive option, those of us on tight budgets would do well to look at some of the other options including the stock LS6 manifold or the US only TrailBlazer SS (TBSS) manifold.
The (rather ugly) TBSS manifold appears to win the “bang for buck” category, giving an excellent low to mid range torque and power (in fact, it provides more torque at 4000 rpm than any other manifold tested).
It’s a shame they didn’t test a set of Individual Throttle Bodies! We may have to do that for them.
LS6 manifolds use the three bolt throttle body flange whereas the TBSS uses the larger 4 bolt style which also allows for more aftermarket throttle body options. The LS6 manifolds also seem a bit thin on the ground these days, but there’s no shortage of TBSS’s on US ebay and should cost about $250AUD landed.
Personally, I ordered one for the tow car and one for the race car, which will do until I can get my hands on a set of EFI Hardware Individual Throttle Bodies for it!
See the article HERE (Click me)