Daily Archives: June 19, 2020

Thinking about what I need to make an autocross-specific engine

I have been watching Richard Holdener videos on YouTube, for data on making the “best” engine for my Sprint-T. The TPI intake from the late 1980s had extremely long intake runners that made huge torque at low RPM, way more than what a “normal” engine of this size could produce.

TPI MEGA TEST-WHAT WORKS BEST? As you can see, Richard ran a “too big” cam for the stock TPI, and basically lost nothing at low RPM while the big cam prevented the engine from falling on its face as the RPM went past peak torque.

TURBO TPI-BOOSTED TUNE PORT Boost just made things more awesome

TPI TECH PLUS BOOST-FASTER THAN FORD? More boost makes more better.

Taking the results and projecting to the LS, what I need is a super long runner manifold with as large intake ports as will bolt up to the heads, and as much displacement as I can get controlled by a 300° duration cam with big lift, about 0.600″. Basically what I’m looking for would be something like this intake with spacers to extend the runners or maybe 3d printed plenums with extended runners built in, plus a super rowdy cam and let the intake runners “fix” the low RPM problems caused by the too-large cam while the cam “fixes” the lack of power at high RPM problems caused by the intake manifold to make an engine that makes power everywhere on the RPM range. That is what I would do if I had an unlimited budget.

But because my budget is very much limited, I’m going to have to take what I can get and like it…