secondarries

[Hib Halverson]

It is true that the port throttles are open anytime the engine is is at WOT, however, anything below 90% TPS (ie: "almost WOT") that's not the case. Below 90% TPS, SPT opening strategy varies according to TPS and RPM.

Stock or near stock 350s need port throttles to have good driveability and good torque at high part throttle in the lower RPM ranges.

Highly modified 350s may not need them and drag race-only 350s don't need them. Also, any engine modified by someone who doesn't give a s@@t about performance/drivability other than at WOT/high-rpm doesn't need them.

368s which are otherwise stock or near stock may not need them.

Bigger than 368s...rip 'em out.

If you're takin' 'em out, and you're actuators are good, send them to me.

[Paul Workman]

Originally Posted by Hib Halverson

(snip) ...any engine modified by someone who doesn't give a s@@t about performance/drivability other than at WOT/high-rpm doesn't need them.

Hib... with all due respect... you're dead wrong about this. You're basing your statement on what "someone" has said or written, methinks, but certainly NOT on actual experience or testing! Theory goes just so far, and then truth is where you find it.

It's all in the tuning. May I suggest you put whatever tech references you're referring to aside and acutally drive one, so modified. I think you'd have some about what "some" have said or predicted about performance/drivability up to that point.

Incidently, the second generation LT5 under development did NOT have dual runners. Instead the runners resemble the siamesed Lingenfelter runners; i.e., one BIG oval port. Evolving from dual runners to a single runners, while maintaining the 4-valve head suggests (to me and others) some performance gain could be had without giving up performance and drivability. This is something perhaps suggested by the Lingenfelter mod success, but for certain has been demonstrated over and over again by those that have removed the secondaries (essentially reverting to a single port) in favor of drivability and performance. If they had it to do over, would Lotus have gone with the dual set of runners, etc? I wonder...