Is my holley 9379 too small?

[70caminoman]

Ok I agree, maybe i could use a little bit more cam. I think that the cam is more around 240 @050 with 1.5 ratio increase in the rockers. Also I see this argument come up all the time with single plane vs. dual plane. I have to disagree, especially on a limited cubic inch motor like mine and a head that is probably not more than 195-200 cc after all of the porting I have done. I agree with you at the drag strip maybe a Victor E or a well ported vitor jr would come out on top.... IF I had more CI or a bigger intake runner. But on a 355 like mine I have a really hard time believing that a single plane is going to beat a well ported air gap at the track, espesially after I figure out what spacers it likes.

Has anyone done a good test at the track, not dyno numbers to proove me wrong or right??? I would love to see.

[hondo383]

somebody who posts here did a manifold track test like that a while back(years LOL)...77cruiser or something I think he had a little bigger engine.

[70caminoman]

I haven't read that one, but I have read quite a few and it seems there is never a winner lol, the arguing goes on to eternity with both sides making good points. I guess the only way for me to know is to try 2 intakes at the track and see which one is the winner.

[hondo383]

no doubt..
always comes down to combination...just throwing a single plane on and swapping a couple jets doesn't give you any good info because it will prob show slower to start but(usually) be way faster with more rpm,gear,converter,cam etc.....its all how it fits into to what you need and how much you want to change.
I have made 596hp on a 505 with that carb..

[70caminoman]

Damn really? That's a pretty decent number. guess my carb should be Ok after all, especially when I finish getting the fuel curves right. I kinda wonder what mine is making, and I really wonder how much I'm going to be able to shave off my ET next year. I mean I've only been to the track twice with it so i could hardly call that optimized. But, for my weight and given that it's a pump gas 355 with not very exotic parts or really racy stuff it doesn't seem like it should be able to go as fast as it is.

[77cruiser]

somebody who posts here did a manifold track test like that a while back(years LOL)...77cruiser or something I think he had a little bigger engine.

Not me.

[nitrokid60]

Your thought to use a Go-Pro will help you, as you will see your a/f as you make your pass down the track. Yes, it's rich on the top end (h/s bleed adjustment to lean it a little), but you want to see what it's doing on the bottom end (launch, 60 ft.), 330 ft. and so forth. An o2 sensor is a good tuning aid, but remember it is not infallible. Tune the combo you have now before spending money...the other racers are correct to try different spacers. The car will tell you what it likes. Remember one change at a time, and log your information.

[hondo383]

I am not saying the 9379 was the right/best carb for the 505 I built(customer had it) but it worked well.
also not saying its right/best for you, just speaking to your original question, I don't believe its restrictive airflow wise on your engine.

[70caminoman]

What about 1:1 throttle linkage. I know this constitutes a total recalibration. But, is the throttle response better, does it help heavy cars? Thoughts?

[FastBuick]

I have run 9.85 in the quarter mile with a 355 in a 3150# car. I only had 210cc intake runner GM Fast Burn heads with a Edelbrock Super Victor intake and a Holley 750 DP carb. The cam duration was around 268 -272 on the intake and 272 -276 on the exhaust @ .050". I would have to look it up to see the exact number but it was in that range. You are talking like 240 is big. That is still a really small cam for the application.

[70caminoman]

For a track car with a tight converter yea I guess it is small. I just like my combos to be on the high compression side for the cam. Mine is 11.3:1 and with intake closing 62 ATDC that gives me a 9.2 DCR. I like comression and I like to keep my DCR around 9:1. I did see a different isky cam that I liked 274 Advertised, and 246 @050 on a 108LSA with 4 deg adv. With the 1.65 Rocker it would be 590 lift after the lash. Also would increase the 050 duration to about 249-250. Would this be big enough? I don't want to drop the comression ratio too much if I am going to keep the car a street car.

[FastBuick]

What RPM do you plan on turning? I know you said it lays over at 67-6900. Do you plan on turning it to at least 7000 RPM? Your car has manual brakes correct? How much street driving do you plan on doing? Does this car spend more time at the track or on the street?

[randy331]

Has anyone done a good test at the track, not dyno numbers to proove me wrong or right??? I would love to see.

I've done such a test, ( or similar ) but I don't believe it will prove anyone right or wrong, only what it did on my car.

The engine combo is similar to yours, same cubes, but 062 vortecs I ported, and 10/1 comp and less cam than you have. Stock bottom end.
The car is 2900Lb with 5.38 gear and powerglide with 2 different converters tested, one 4600 stall and a 5400 stall.
During the course of one summer, we tried a performer rpm, and a GMPP vortec bowtie intake, both with port work by me. Both intakes were on the car 2 times that summer and both converters were tried with each intake. Shift rpm, jetting, etc was tried with both intakes to hunt best ET.

The single plane would out MPH the dual by 1-2 MPH, but would never 60' as good. We tried a open spacer on the dual plane trying to get it to MPH like the single plane, and we tried a 4 hole spacer on the single plane trying to get it to 60' as good as the dual plane. The dual plane would 60' in the high 1.47-1.50 range depending on the air and traction. The single plane ran a best of 1.502 60', but generally low 1.50s.

At the end of the summer the best 1/8 mile ET for the dual plane was a 6.902 and the single plane was a 6.896. Close enough to call it a wash to me. But clearly the dual plane ran better in the early part of the rpm range, but not as good when rung out past peak HP up top.

On a dyno session I was in on, ( 421 cubes ) we did a single vs dual swap. ( Performer rpm vs 300-25 ) and the cross over point where the single plane started making more power was about 4600 rpm on that engine.

Personally, with your low stall and heavy car, and based on what I've seen in the past, I'd bet on the dual plane intake, BUT,.. this could depend on the port work you have done.

Randy

[70caminoman]

This is a street car definitely. I drive it mostly on the street. I don't mind agressive as it already is fairly right now. I would like it to be able to turn around 7000 RPM. Car has manual brakes and manual steering right now (lol every hp counts). I also don't mind going up in stall I plan to when I put the 4l80e in. Thats what I'm building for it now. I wanted to wait on mine to up the stall because for one I don't want to invest anymore into this trans but with a larger stall I would like to have the lockup available to make it more street freindly. I plan on 3500-4000 stall in that trans

[quickd100]

I'm not the sharpest tack in the wall but IMO you have PLENTY of carb. I dyno'd a Mopar 512 a couple years ago that made real nice power and torque and when I put the airflow meter on it, it was only using 785cfm. Most people use more carb than they need. Dave