Ok some might remember my post about going carb to efi well ive givin up and want to do something a little more exotic to my engine then the boaring FI thing, i found soemthng mentioning having dual carbs, i thought it sounded cool so i want input, if its possible how much , how hard and what are some of teh advantages/ disadvantages of doing this

Assuming its possible mind you

thanx for the help in advance

 

Well they look badass....but thats really the only advantage of dual carbs. They are more of a pita and never perform as well as a single 4bbl.

A tunnel ram can is an exception...they can perform very well, but they're not really street friendly for several reasons.

 

Another option: http://www.camaros.org/crossram.shtml

 

would that work on a 84 v-8 305 trans-am?

 

"Work"? It'll probably be able to get to your show spot under its own power. It'll get spanked nicely at the track by your typical single 4bbl. On the street, a nice nightmare to tune so you'll really enjoy the sight of the hood up in your garage while you choose to walk to the grocery store.

A single 4bbl with today's intake technology is so simple and works quite well. If it's flash you're looking for, a polished TPI is a pretty sight when the hood's up.

 

In regards to the tunnel ram---

they only work in the highest of RPMS, and I'm assuming you have an LG4, or some other relatively stock low performer motor that would never support the 4000-10,000 rpm range of a tunnel ram. A tunnel ram intake needs a hell of a motor to back it up, with an outrageous cam, high compresion like 12.5, and Zoomie exhaust to make power. its really riducilous (damn I want one!!)

But HOTROD tested Edelbrocks 2x4 system against several other intake styles and noted no real improvements, but it didn't fall behind. it scored about average. to make it work with your motor you'll need to toss a cam in it, and put some headers on it if you want to make out of your driveway.

I agree with 5.7kid- from the sounds of your technicall know-how, you'll never get it tuned right. and its not worth doing on bassically stock street car.

 

Okay, after 430T/A's comments I had to pull out that Jan 2002 HOT ROD and look at it again.

In the test of the Edelbrock Street Tunnel Ram they say:

"This combo made the most power of all the manifolds tested, and was the only one to crest 500 HP. Barry Grant has told us for years that a tall runnel ram with small runners can be a streetable, high-torque setup, and this proved it. It seemed to have no driveablility issues except for, like the other tunnel rams, an occasional lean backfire when cold starting. Compared to a four-barrel, the peak numbers improved by 12 hp and 16 lb-ft."

The test motor was a 9.5:1 350 with a roller cam (242/248 @ .050") and AFR 195 cc heads, making 503 HP @ 6100 Rpm and 452 lb-ft @ 5600 Rpm.

Granted it doesn't belong on a stock longblock 305, but it isn't that outrageous.

 

A tunnel ram may run well enough to be streetable, in the righ t car, but I bet it has some ****ty road manners. it will probably fall flat on its face when its paired to a 2.73ed, stock converter/tranny 305 car with stock heads. and stock exhaust. I do. who knows

 

The hot rod test did'nt tell the real truth about tunnel rams. It was only an engine dyno... The ? is how will it do on the track and streets.

Not too good like others already said. I will be useing one with a pair of holley 600 cfm double pumpers on my 78 trans am drag car with a 550 hp N/A engine, 700 hp on N20...

For a tunnel ram to work 1st you have to know every little thing about carbs. Have many years in tunning/setting up carbs.. I'm only 21 but been building engines working on cars since I was 12. I have never shyed away from the good old time proven 4 bbl carb, Never even messed with efi and have no care too. That many years messing with carbs I have them down patt no prob.

After the tunning part comes the real work matching parts together. A tunnel ram will fall on its face under 2500 rpm even with race gearing and stall speed. Unless its a vert light car with very high torque number like a big block would lay down

To really make an engine/car run good times with one you need to have an engine that is built to make power in the 4500-8000 or higher range. Use low gears such as 4.56, 4.88, etc, and a stall speed in the range of 4,000-5,000 rpm..

Now if you have a light weight car like 2500 lbs you can get away with high gears such as 4.10, 4.56's and alittle lower stall, since a lighter weight car don't need as much torque to get it to moving

 

[QUOTE]Originally posted by Night rider327
A tunnel ram will fall on its face under 2500 rpm even with race gearing and stall speed

What do you think the same engine with a Victor Junior & 800 CFM mech secondary is going to do when you jump on it at 2500? Shear the driveshaft with brute low-end torque?

All the modifications you noted about gearing, torque converter stall speed, vehicle weight etc would apply to any single 4 BBL intake manifold like the Victor Junior, Strip Dominator, (operating range of 4500 - 8500 for the 4-spd version) and dozens that I am not current on. Any induction system with low velocity at low engine speeds will behave similarly.

To generalize and say "To really make an engine/car run good times with one you need to have an engine that is built to make power in the 4500-8000 or higher range" is wrong. Of course it isn't going to have the street manners of a dual plane intake, but with correctly chosen (390-500 cfm) carbs, a big-inch engine and mild camshaft pulling on them the Edelbrock Street Tunnel Ram would be fairly streetable. It is designed with long, narrow runners just for this. It gives the racy look of two fours with better road manners.

I stand by HOT ROD's line: "Barry Grant has told us for years that a tall runnel ram with small runners can be a streetable, high-torque setup, and this proved it." I think Barry Grant has more experience on carbureted induction systems than all the users of this post combined. Is he just making this stuff up?

 

I really wouldn't bother on an engine that small, just stick with a 4 barrel. The only engines that used more than 1 carb were huge engines that were meant for drag strip performance anyway (ie. 426 Hemi 2x4, 427 BBC 3x2).