Does anyone think that there would be a benefit from installing an open or dual pipe type throttle body spacer? Just like a carb spacer. We all know the LT1 intake lacks sufficient plenum volume for larger engines. Would this help? I've got a C4 and there is tons of room to put one. I'm talking 6". Opinions?
Scott

 

It can't hurt. I run a 2" spacer on my Hogan sheet metal manifold and I would run more if there was more room under the hood. It can make the length of the throttle cable problematic but a stock cable worked for me.

 

Was the intake designed for your particular combo by filling out one of Hogans spec sheets?? Did you by chance measure the length of the intake runners on that Hogan?? What gasket is it matched to? How much cam do you have?? What rpm do you turn??

Curious minds want to know as we are thinking of building a couple different sheetmetal intakes to play with so I'm looking for ideas. Plus interested in how it compares to the sheetmetal intake I currently have. Mine has six inch runners and is gasket matched to the raised port LT4 off gasket. Lowered the overall powerband and we didn't expect it would.

If you had Hogan do one specifically for you, I wouldn't think you would need more volume as some I've seen taper in the back for clearance.

 

Spacers and pleanum volume are a goofy area. The motor can make more power on the dyno AND go slower at the track. I know of a guy testing his 1000+ HP 398 cube SBF (NA no less) that found a big gain in power with more plenum (33hp) but the car went down the track slower. He was switching to more converter (8600 vs 8200) to see if it could get the ET back that it lost because it did pick up some MPH. This was only with a glide tranny, and if that was a TH350 it would have gone even slower. The more gears you have the less plenum area you need. The only way to tell is test on the dyno AND the track.

Bret

 

Thanks for the input! Someday I'll try it. I'll let you know!

Scott