[RickSBC400]

And its important to understand no one on this forum understands what it like to race in Denvers 10,000 plus DA. A 650 HP/660 TQ engine makes 470 HP @ Denver with 475 TQ, and the averages are way down. In my way of thinking, a 12.30 car shows the math like this:

107 MPH @ 3800 pounds is 359 crankshaft HP
1320/107=12.33

Just like walking up the stairs on the west side from trackside to the top of stands, boy that takes the wind out of you! The rise and run on those stairs is not up to code! haha.

 

[RickSBC400]

Hey Mark!

I originally thought the OP just had a mellow street cruiser when I read that he didn't much go over 3,000 RPM on the street.
He pointed out that's not the case at all....and he's got a nice, healthy SBC.
I was bummed the last time at the track in mid-November when it was unseasonably warm, with a DA of 1400+ at 1100 feet elevation. I'm spoiled over here compared to you guys.

I'd love to race at the DA/altitude you are at sometime.

 

[RickSBC400]

I'm probably going to chassis dyno the combo with both intakes over the next year for fun. This is all the fun part of the hobby to me, I wont sweat how down on power I am or where I am. This is relatively cheap fun and I'll post my story about the dyno numbers on the board too for fun. I really like this board for performance conversations.

 

[blue_69_malibu]

Just like walking up the stairs on the west side from trackside to the top of stands, boy that takes the wind out of you! The rise and run on those stairs is not up to code! haha.

A group of us used to get together for a ski trip out in Breckenridge, CO every year. Base elevation of 9,300 feet or so. I'd always caution everybody not to have more than two drinks on the first night as the Altitude is hard to deal with until you get acclimated to it.
Eventually, we'd stay in Denver the first night after landing.....and then head out to Breck the following day.....just to ease into the Altitude.

 

[VORTECPRO]

I'd love to race at the DA/altitude you are at sometime.

Let me guess.............the carb shop chassis dyno?

 

[RickSBC400]

A group of us used to get together for a ski trip out in Breckenridge, CO every year. Base elevation of 9,300 feet or so. I'd always caution everybody not to have more than two drinks on the first night as the Altitude is hard to deal with until you get acclimated to it.
Eventually, we'd stay in Denver the first night after landing.....and then head out to Breck the following day.....just to ease into the Altitude.

sounds like wise decisions and help you enjoy the slopes more when up there. Even I have to limit my drinking to soda pops if I'm wanting to snowboard the next day and not have a headache.

 

[RickSBC400]

Let me guess.............the carb shop chassis dyno?

There is a place in loveland called Automotive Performance Center and he has a chassis dyno I am hoping to get time on. His rate is a little lower than the Denver shops and I live about halfway between loveland and denver so it's a coin flip.

 

[blue_69_malibu]

Always got the biggest kick out of going through Loveland Pass and the Eisenhower tunnel.
To the East, sunshine and blue skies.
To the West, snow every where. And lots of it.
It was almost like the gateway to a different world.
On one bad trip back to Lakewood, CO.....we got stuck in traffic on 70 and I had to spend four hours in the back of a Ranger.....when they had no room back there and the seat flipped down from the side.

 

[1968 hot rod]

I have a friend that was a LEO in Colorado Springs I think.
Does a lot of hiking and off road biking out there.
The pictures he posts are awesome.

 

[RickSBC400]

Always got the biggest kick out of going through Loveland Pass and the Eisenhower tunnel.
To the East, sunshine and blue skies.
To the West, snow every where. And lots of it.
It was almost like the gateway to a different world.
On one bad trip back to Lakewood, CO.....we got stuck in traffic on 70 and I had to spend four hours in the back of a Ranger.....when they had no room back there and the seat flipped down from the side.

you described it perfectly when you come out the west side of the tunnel its a flashing 'dange icy road' sign and usually a blizzard and a snowpacked icy road. not for the faint of heart! And going Loveland pass is even worse most the time. I'm getting to old for that so I don't chase powder days anymore but I still do enjoy snowboarding up in our front range mountains.

 

[71350SS]

I thought I read that you have a EFI unit to use. Asking the more experienced here, wouldn't that make a difference in what manifold you use ? I think a throttle body EFI would work better with a single plain but I'm asking the board would that make a big difference in what manifold to use ?
What say you

 

[RickSBC400]

I thought I read that you have a EFI unit to use. Asking the more experienced here, wouldn't that make a difference in what manifold you use ? I think a throttle body EFI would work better with a single plain but I'm asking the board would that make a big difference in what manifold to use ?
What say you

I also have overthought this with my ignorant brain on the topic, and add to it, will the vacuum that is decently high relative to a tighter LSA cam also help with the signal and pulling in the mixture to each cylinder?

 

[dougo1]

gears

I am running the Air Gap intake and a Holley 750 CFM ultra double pumper on a 396 CID 350 HP! It ran 425 HP/ 400 PFT.

 

[RickSBC400]

I installed the single plane. If all goes to plan and weather cooperates will see if I can get it installed in the car this weekend too..

 

[68Chevele]

I installed the single plane. If all goes to plan and weather cooperates will see if I can get it installed in the car this weekend too..

You'll make plenty with those heads and that intake, I wouldn't worry too much about not making enough power there.

 

[RickSBC400]

You'll make plenty with those heads and that intake, I wouldn't worry too much about not making enough power there.

Thanks, and to add to the testing, I bought this to dream that I'm improving the signal a bit, ha!

High Velocity Heads SS4150-1DPAL 1" Aluminum Super Sucker Carb Spacer | eBay

1" Aluminum Super Sucker Carb Spacer For 4150 Carbs. 1" over all height Aluminum Super Sucker Carb Spacer for 4150 Carbs with 1/2" of Spacer in Manifold. Raises carburetor 1/2" from intake manifold.

www.ebay.com

 

[68Chevele]

Thanks, and to add to the testing, I bought this to dream that I'm improving the signal a bit, ha!

High Velocity Heads SS4150-1DPAL 1" Aluminum Super Sucker Carb Spacer | eBay

1" Aluminum Super Sucker Carb Spacer For 4150 Carbs. 1" over all height Aluminum Super Sucker Carb Spacer for 4150 Carbs with 1/2" of Spacer in Manifold. Raises carburetor 1/2" from intake manifold.

www.ebay.com

I am not sure what that short spacer results, but I do know that my 2" 4 holed tapered spacer added 2 tenths and 1 mph on my peanut port engine in testing with my Holley Strip Dominator single plane intake one day, one week later when I swapped to a dual plane intake that car lost 2 tenths with the 4 hole spacer, but I picked that back up with a 1" open spacer. Just have to test them.

 

[RickSBC400]

I am not sure what that short spacer results, but I do know that my 2" 4 holed tapered spacer added 2 tenths and 1 mph on my peanut port engine in testing with my Holley Strip Dominator single plane intake one day, one week later when I swapped to a dual plane intake that car lost 2 tenths with the 4 hole spacer, but I picked that back up with a 1" open spacer. Just have to test them.

yeah it is kind of an interesting design where half the spacer sits down in the intake. i also own a 1" regular hvh 4 hole spacer, so when I go on the dyno maybe i'll try both those out for kicks after getting optimum timing figured out.

 

[2/75NastyNewbs]

Does signal matter with EFI like with a carb though?

 

[RickSBC400]

Does signal matter with EFI like with a carb though?

I look forward to dyno testing this setup in the next month or so depending on weather and dyno dude i'm going to use. I'll post the results. If the torque number is weaker than I'd like, or the curve looks too soggy on the 'low end' then i'll put the dual plane on later this summer and dyno test it with that. I'll port match to the intake gasket on that too so it has the same massaging the strip dominator got.