As was discussed in the other thread, you severely limit yourself with a Q junk.

Can we please not go there again, I shipped my Quadrajet to Lars today, so thats a done deal and I feel good about it.

The straight performer is probably what you are looking for. You won't have clearance issues with the performer. Smooth off idle to 5500. Nice driver

I tend to agree, but feel like I am choking my AFR heads and I keep reading that the RPM manifold loses no signficant torque on the bottom, and has better average torque over my operating range

If you can get the Performer RPM in spreadbore it better matches your cam.

Yes, they make a Performer RPM Quadrajet, and it matches the cam at least on the bottom end

 

I have got some advice to consider the Chevrolet ZZ4 intake 10185063, which is claimed to be a manifold right in between a Performer and Performer RPM. Slightly taller than the Performer and the intake port dimensions are very close to the AFR 180s.

This may be exactly what I am looking for if it is true. Does anyone have any comments on this, and does anyone know where its made....if its not USA, I am not buying it no matter how good it is.

 

I'm running that intake.

Performance tests show the regular performer is slightly better power wise. Close to being within the error of the dyno.

I find the build quality of the ZZ4 intake to be a bit higher. Fitment of the various doo-dads.

http://www.hotrod.com/how-to/engine/...d-comparisons/

ZZ4 peak hp 451, peak tq 500
2101 peak hp 456, peak tq 494
RPM peak hp 465, peak tq 501
I guess that says the edelbrock has a hair more top and a hair less mid. At peak, the RPM Q-Jet makes 1lbft more than the ZZ4 and 9 hp more than the 2101.

Great article to read. Note that there's a typo in the first table (it says peak hp 471 rather than 451 for the ZZ4 manifold).

 

I'd not worry about any adverse comments about the Quadrajet. I had one on my '78 vette with a Performer RPM Q-Jet (not an Air Gap) on a 406 that I built. Not only did it run mid 11s with 3.08 gears and a TH-350 trans, it also got 17 mpg on the highway.

 

Couple of additional items to consider:

Iwas - check out the Edelbrock 2601 for an air gap, spreadbore design.

Cold air box in general - They are a great idea but you have to be certain to grab air from an area of the bodywork that creates ambient or higher air pressure. Small increases or decreases in pressure at the carburetor make a big difference.

 

The 2601 is a Performer Air Gap. From what I can tell, it performs only slightly better than a straight Performer, and has the cold start and warmup issue.

 

To be honest, the article confirms what I have known for a long time that changing intakes on a built motor, in great tune, is worth on average 0-5 HP over stock intakes (like the aluminum L-82), and intakes like the performer rpm is worth maybe 5-8 HP, maybe... Would I use an after market intake on a new build? Yes...would I change just an intake on an existing motor? No. Torque numbers may move some but overall no change.

 

In this article if you look at the less than 5.0" pad intakes and take out the highest and lowest peak torque results you end up with a 10 lb/ft difference in the remaining intakes and a 5 lb/ft difference in average torque.
Looking at the 5.0 to 5.3" pad height intakes minus highest and lowest results there is only a 6 lb/ft difference in torques difference in average is 7 lb/ft.
These results are on a 500 lb/ft engine. So were talking about 1% to 1.4% difference in torque production.
Not a whole lot of difference.

Now look at this chart from David Vizard.







On this chart you can see that a mere 10* to 15* difference in intake temperature amounts to that 1% to 1.4% of torque that is being chased by intake manifold choice.

If it's 100* outside and 160* under your hood and you are using under hood air to supply the engine, you are loosing somewhere around 6.5% of torque.

That's could be a loss of 31.25 lb/ft of torque for that same 500 lb/ft engine.
Efforts to lower intake air temp can be significant torque increases.

Other considerations for the intake may be of greater importance when comparing nearly identical intake designs, like pad height and general behavior in street driving.

 

I'm inclined to agree with you. I'd love to see a dyno overlay between the 3 intakes I mentioned in the above post.

What's interesting is outside of articles there's plenty of people claiming 15-20whp by switching to the tall dual plane, some with dynos backing them up. Usually I see the before and after dyno having some significant tuning on the after, though.

When I have more time and money, I'm hoping to do a single day chassis dyno session to see the difference between a 7104 and the ZZ4 intake on my setup.

 

Sorry BK, didn't mean to suggest that you didn't know what you're doing. I believe that perhaps your 77 may not be seeing it's full potential with the current configuration.
Your comment about as the air passes through the radiator it's temperature (underhood?) decreases got me to thinking.
I wonder just how hot the air is after it passes through the radiator. I'm looking at more of a street driving experience vs drag racing, but it may still be useful.
So I collected some data today.
Outside air temp was 55*F



At only 55* F and idling, so no driving had taken place to really soak the engine with heat yet, I recorded a temp just aft of my electric fans while they were running of 157*F. This may not normally be possible without risk to limb with a stock fan set up. Also not possible while driving without a remote temp sensor mounted just behind the radiator to record the temps, which I do not have.



Water temp is shown here. This cap is accurate as checked with a non contact thermometer and the gauge inside the car.




190*F on the water temp and you get 157* after the radiator at an outside temp of 55*. Imagine if it was 90* outside.

Then I decided to measure the temp just outside the airbox on top of the stock intake air duct.




I am a bit surprised that even on a 55* day the air around the airbox still achieves the same temp as the air coming through the radiator. I thought it would take a hotter day to get to that kind of temp and after driving a bit.
Now I need to see what it is on a 90* day after extended driving. Could be even higher.

 

I agree, except in my case I went with the rpm airgap with the current 3.08 gears, I'm changing to 3.70s and think that I might be better of with a single plain at this point to take a little from the bottom end with the 3.70s and the 3.06 first gear and give a little more toward the top. I also think that the performer would make a world of difference over the cast iron intake that came on the l48.

DO MA NEU!

 

[QUOTE=Shark Racer;1589039470]I'm inclined to agree with you. I'd love to see a dyno overlay between the 3 intakes I mentioned in the above post.

What's interesting is outside of articles there's plenty of people claiming 15-20whp by switching to the tall dual plane, some with dynos backing them up. Usually I see the before and after dyno having some significant tuning on the after, though.

When I have more time and money, I'm hoping to do a single day chassis dyno session to see the difference between a 7104 and the ZZ4 intake on my setup.[/QUOTE)

Yes, this is part of the difficulty, knowing what is true. Based on this Hotrod story, intake manifold design means very little in reality and doesn't really make any significant difference. Maybe that is true, or maybe there is something missing from this report. I really don't know. I have people tell me an RPM intake will add 25-30 HP to my motor. This hot rod report does not support that. What is real?

 

One question that comes out of the Hot Rod report is this -

How is it possible that a straight Performer Air Gap can produce almost the same torque as a Performer RPM? If all the theories are true about longer runners and taller plenums then how would this be possible? The Performer Air Gap has the same intake port dimensions as the Performer...exactly the same. The height is only .25 higher.

 

ReelAV8R - I dig what you're doing there.

I'm sure we could get some real interesting data if we installed an IAT in an open and closed element air cleaner and datalogged it going down the track, or even a few gears. It's probably been done and documented before as well.

 

The internet is a wonderful thing. If you check this article from Hot Rod all your answers can be found in the charts.

http://www.hotrod.com/how-to/engine/...d-comparisons/

 

I think that is a good idea. I could put a remote sensor inside the air cleaner and record temps with CA hooked up. Then disconnect the CA connections and just let the intake draw in under hood air. Could be interesting data to come out of that kind of test.
Pretty much every body who bothers to jet their carb does so with the hood open and the air cleaner off. Have to right?
So if it's jetted to the air temp with hood open, which would be considerably cooler than with hood closed, it would mean that the engine would be running much richer once the hood is closed and the under hood temps peak unless we are able to control and roughly duplicate the hood up air temps.
Just another loss of torque and power due to high intake temps.

 

I jetted mine with the air cleaner on. I plugged all the thermac connections since they're wide open in the conditions I care about anyways. Of course, I wanted to test it the way the car would be driven. I did the gross "is this driveable or not" testing with the air cleaner off to save time. Once I got to "which jet is best for pulling hills at half throttle", I did it fully equipped.

Looking forward to hearing your results.

 

Exactly...I was referencing that exact story, and I am quite familiar wiht the Edelbrock site (I sure wish others would read it, since so many people get these manifolds confused....when you talk about a Performer and forget to add the RPM, you are talking totally different manifolds. Just like the Air Gap, they make both a Performer Air Gap and a Performer RPM Airgap...totally different...then add the Quadrajets, makes for a lot of different manifolds and people toss around words without regard to accuracy and just confuse it all).

ANYWAY, when I stated that all these manifolds are the same, I am basing it on this hot rod article, showing the differences are very minor and possibly undetectable by seat of pants driving, which is all I intend to do. No racing, no drag strips,etc. As I have said before, all I want is a relatively strong engine, without going to extremes, and without a bunch of sacrifices i.e. cold air intakes, big carbs, even to the point of different fuel lines, different throttle cables (hate those Lokar units), and even drop base air cleaners.
'
Its all relative.

 

REELEV8R - Nice work collecting some data there. What I would like to see is air temp at the back of the radiator, when the car is moving, 40, 60, 80 mph. See how close to ambient outside temperature it would read. Actually I like your idea of reading temps inside the air cleaner. Try it with and without the outside air connection, at various car speeds, if possible.

 

I ordered a couple of remote sensor thermometers off of ebay, super cheap, that will go up to 230*F. Once they arrive and the weather clears again I'll do some testing. The guages are so cheap that they may not be completely accurate so I'll check them for that before I use them.
I also am curious about the air temps off the back of the radiator at various speeds. And the engine compartment temp as well.
I'm Guessing that those temps will be significantly affected by outside air temp and the speed of the car. To be relevant it may take an 80* or hotter day, but I'll give it a go at 50* or better to see what the results are.
I'll do all the test in various conditions. Cruising, idling, accelerating normally and accelerating WOT. Video it all, then sort out the data.