Project Light Speed Part 2 - LS1 Engine Header Test

The Turbo Shop (TTS) supplied the headers for our test. They don't make a production set of 1 5/8-inch headers for a late-model Camaro, but they whipped up a custom set for us. Our testing revealed why TTS chose not to build these smaller headers!

Evaluation

So what did we learn from this exhaustive flog-fest? First, the Vette manifolds for a stock LS1 even at the 400hp level, are extremely efficient. We learned that larger primary pipe tubes tend to work well on a stock LS1, which leads us to think they will work even better on a modified engine with a better cam and heads. There is data to support the notion that longer primary pipe lengths approaching 40 inches plus a longer collector length may be worth more torque. Generally, we'll see torque improvements with a longer collector, but these TTS headers were designed to fit in a late-model F-car as opposed to perhaps a first-gen Chevelle or Camaro where there would be more room for a longer collector and primary pipe lengths.

The TTS headers feature extremely thick 1/2-inch flanges to prevent warping, so all we had to do was bolt them on using ARP's metric header bolts.

The bottom line is that a stockLS1 can obviously make as much as 400 hp using stock Vette iron exhaust manifolds, so don't toss those Vette pieces in the trash! It is also clear that the right size headers can still improve power on one of these engines with the right combination of parts.

Stick with us as we look into the best ways to make more power with our GM Performance Parts LS1. The idea here is to make power without resorting to spending a ton of money. We want to make this LS1 sing for a song.

The TTS headers also incorporate an oxygen-sensor bung in the header to supply the feedback information the computer needs.
The next two TTS headers we tested were very similar except for their primary pipe size measuring 1 3/4 (left) and 1 7/8 inches in diameter (right).