383 sbc first dyno experience

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Re: 383 sbc first dyno experience

Post by steve cowan »

Erland Cox wrote: Wed Sep 14, 2022 5:40 pm Hi Steve!
Did you dyno with that air filter?
I did a test on a 350 in one of my road racing Camaros with filters.
Frome bare carb to a Summit aluminum fitler base with 14" filter and a nice radius from filter to carb was +25hp.
Best hp was 445 with 4779 Holley.
Your filter base does not look like it has a good radius.

Erland
Thanks for looking Erland,the airfilter base is a decent radius bell mouth with that filter and base was down 3hp on dyno as compared to no airfilter.
20220831_152105.jpg
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Re: 383 sbc first dyno experience

Post by steve cowan »

20220521_091039.jpg
20220521_091206.jpg
Bellmouth radius is from QFT ( quick fuel technology)
K and N filter,I have tried other air filter bases and this seems to be the better option.
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Re: 383 sbc first dyno experience

Post by Erland Cox »

This is what I used with the filter and top on the dyno. + 25hp versus bare carb.

Image

A 4779 carb that I have ported the top of so it looks like a HP carb.

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Re: 383 sbc first dyno experience

Post by ChopperScott »

Erland Cox wrote: Fri Sep 16, 2022 9:35 am This is what I used with the filter and top on the dyno. + 25hp versus bare carb...
Interesting. I recently acquired the same assembly to run under the cowl hood.
Drop Base 1.JPG
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Re: 383 sbc first dyno experience

Post by skinny z »

Erland Cox wrote: Fri Sep 16, 2022 9:35 am This is what I used with the filter and top on the dyno. + 25hp versus bare carb.

Image

A 4779 carb that I have ported the top of so it looks like a HP carb.

Erland
ChopperScott wrote: Fri Sep 16, 2022 10:41 am
Erland Cox wrote: Fri Sep 16, 2022 9:35 am This is what I used with the filter and top on the dyno. + 25hp versus bare carb...
Interesting. I recently acquired the same assembly to run under the cowl hood.

Drop Base 1.JPG
How tall a filter element would you run with those? And how far would that put the lid from the top of the carb?
I've a choke horn on my original BG 750 VS but I'm assuming there's no choke horn in either case above.
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Re: 383 sbc first dyno experience

Post by steve cowan »

Erland Cox wrote: Fri Sep 16, 2022 9:35 am This is what I used with the filter and top on the dyno. + 25hp versus bare carb.

Image

A 4779 carb that I have ported the top of so it looks like a HP carb.

Erland
I am going to dyno another 383 I am building by the end of the year and would like to test the 2 set ups.
Erland,
On the road race vehicle is the drop base above the hood or below?
Next year I want go to a fibreglass/ carbon fibre hood and reverse cowl scoop for my car,one is for weight and the other is to get airfilter into a area not influenced by outside air due to vehicle speed travelling down the track.
I prefer that there is no under hood heat interference as well.
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Re: 383 sbc first dyno experience

Post by steve cowan »

ChopperScott wrote: Fri Sep 16, 2022 10:41 am
Erland Cox wrote: Fri Sep 16, 2022 9:35 am This is what I used with the filter and top on the dyno. + 25hp versus bare carb...
Interesting. I recently acquired the same assembly to run under the cowl hood.

Drop Base 1.JPG
Scott,
What are your thoughts on the drop base setup for your vehicle.
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Re: 383 sbc first dyno experience

Post by skinny z »

steve cowan wrote: Fri Sep 16, 2022 5:29 pm
Next year I want go to a fibreglass/ carbon fibre hood and reverse cowl scoop for my car,one is for weight and the other is to get airfilter into a area not influenced by outside air due to vehicle speed travelling down the track.
I prefer that there is no under hood heat interference as well.
That would be your classic cowl induction hood wouldn't it?
Made a tray out of cake pan with a rubber seal to the underside of the hole in the hood. And as tall a filter element that the cowl allows.
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Re: 383 sbc first dyno experience

Post by steve cowan »

skinny z wrote: Fri Sep 16, 2022 5:42 pm
steve cowan wrote: Fri Sep 16, 2022 5:29 pm
Next year I want go to a fibreglass/ carbon fibre hood and reverse cowl scoop for my car,one is for weight and the other is to get airfilter into a area not influenced by outside air due to vehicle speed travelling down the track.
I prefer that there is no under hood heat interference as well.
That would be your classic cowl induction hood wouldn't it?
Made a tray out of cake pan with a rubber seal to the underside of the hole in the hood. And as tall a filter element that the cowl allows.
Your probably correct Kevin,
In all my years I have spent little time with hood scoops/ cold air boxes etc but I am sure they do work.
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Re: 383 sbc first dyno experience

Post by skinny z »

steve cowan wrote: Fri Sep 16, 2022 5:47 pm
skinny z wrote: Fri Sep 16, 2022 5:42 pm
steve cowan wrote: Fri Sep 16, 2022 5:29 pm
Next year I want go to a fibreglass/ carbon fibre hood and reverse cowl scoop for my car,one is for weight and the other is to get airfilter into a area not influenced by outside air due to vehicle speed travelling down the track.
I prefer that there is no under hood heat interference as well.
That would be your classic cowl induction hood wouldn't it?
Made a tray out of cake pan with a rubber seal to the underside of the hole in the hood. And as tall a filter element that the cowl allows.
Your probably correct Kevin,
In all my years I have spent little time with hood scoops/ cold air boxes etc but I am sure they do work.
As an example Steve:

1.jpg

My GlassTek 2" cowl hood.

2.jpg

Glassed in the cowl opening...

3.jpg

Made an appropriately placed hole for the filter elemnt to poke through.

4.jpg

A 16"-18" cake pan and weatherstripping make a sealed tray.

I've a sealed top and a 4" element. No super dropped base like the pics above this post (Erland and Scott).

5.JPG
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Last edited by skinny z on Fri Sep 16, 2022 7:38 pm, edited 1 time in total.
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Re: 383 sbc first dyno experience

Post by ChopperScott »

skinny z wrote: Fri Sep 16, 2022 12:05 pm How tall a filter element would you run with those? And how far would that put the lid from the top of the carb?
I've a choke horn on my original BG 750 VS but I'm assuming there's no choke horn in either case above.
I'm using a 3" tall filter. There are different spacers available to raise the base higher...
Allstar Drop Base with Spacer.pdf

steve cowan wrote: Fri Sep 16, 2022 5:31 pm Scott,
What are your thoughts on the drop base setup for your vehicle.
I won't have any comparable data until I get the suspension dialed in and it's running consistently.
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'73 Camaro Z/28 NETO/N
434 SBC 11:1, 1.294, 6.178 @ 108.87, 9.81 @ 134.93 (3060#, Naturally Aspirated, Sunoco Ultra 94)
Chopper Air Port 917-589-1278
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Re: 383 sbc first dyno experience

Post by steve cowan »

It will be interesting to see results.
I would like an extra 25 hp on my current combination :D
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Re: 383 sbc first dyno experience

Post by steve cowan »

I received my drop base today.
Of course it won't let me close the hood and I will have to space it up away from carb linkage.
I am going to dyno another 383 soon that will be close to same power so I can test between the two.
20221005_173920.jpg
20221005_173911.jpg
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Re: 383 sbc first dyno experience

Post by steve cowan »

Wondering if aircleaner is a help or a hindrance??
20221005_175728.jpg
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Re: 383 sbc first dyno experience

Post by rgalajda »

GM air cleaner. No spacing required for linkage. Better contour for air filter. This is what I am using
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