I guess you could say in and out

and what provides more power on the dyno isn't always the fastest way down the track

Well going from a 2.5 pinch to a 4'open collector I seen a 12 horsepower increase on the dyno.. which was a significant find more than any other single change that we made including from small carburetor to Big carburetor.. but the smaller collector accelerates the car so much faster it actually provides a better time slip. Now keep in mind this is on a fairly heavy two speed small block.. mph is definitely down with the smaller collector

Now Brett will work his magic.. with this process we enlarge the plenum and shorten the runner..

Almost All mods Lengthen the runner on the plenum floor for best results on a single plane like that. Yours will want that too. Huge plenum short runners equals slow port velocity. Bad for fuel atomization and cylinder fill.

This is a legal intake for my class rules. .

Now Brett will work his magic.. with this process we enlarge the plenum and shorten the runner..

OK ,from the pics you didn't shorten the runners at all. You just added plenum. I thought that when you ssaid you would be shortening the runners, that you were going to remove/shorten those four walls dividing the runners. You Didn't and that's good. you left the runners as is. If you would of cut those out and shortend them, That's where the mistake would of been. But you Didn't, alls well.

The things we do to try to go quicker

Anxious to see what happens on the dyno but more importantly how the car accelerates at the track...

We have tried alot of carb set ups on the Vette. We started with a 4150!!! Unfortunately only one way to find out what works. Also you can stack spacer to the roof of the dyno and maybe make more power but velocity and efficiency especially down low may kill the cars ET. We have used 2.30, 2.40, 2.45, 2.50. Our issues with the larger carbs has been the deck height of the engine. Possibly with a shorter deck we could take more advantage of the bigger carbs. So far the 2.40 has been the fast one. But we have had probably 8 different booster packages and 4 different metering blocks in it as well. We will likely be trying the 2.45 again this year with the shorter deck and are expecting it to be faster. We will find out soon as the block is about done to shorten the deck height to closer to the other small block we run against. Those seem to be where the really big carbs shine.


I believe Shiloh and the Vette run the same cube engine 417?!?
Ultimately the dyno is a tool and you need to be able to interpret what the tool is telling you. Interpreting that data and applying it to the racecar on track are always the hard part.

We have tried alot of carb set ups on the Vette. We started with a 4150!!! Unfortunately only one way to find out what works. Also you can stack spacer to the roof of the dyno and maybe make more power but velocity and efficiency especially down low may kill the cars ET. We have used 2.30, 2.40, 2.45, 2.50. Our issues with the larger carbs has been the deck height of the engine. Possibly with a shorter deck we could take more advantage of the bigger carbs. So far the 2.40 has been the fast one. But we have had probably 8 different booster packages and 4 different metering blocks in it as well. We will likely be trying the 2.45 again this year with the shorter deck and are expecting it to be faster. We will find out soon as the block is about done to shorten the deck height to closer to the other small block we run against. Those seem to be where the really big carbs shine.


I believe Shiloh and the Vette run the same cube engine 417?!?
Ultimately the dyno is a tool and you need to be able to interpret what the tool is telling you. Interpreting that data and applying it to the racecar on track are always the hard part.

Anxious to see what happens on the dyno but more importantly how the car accelerates at the track...