Technical Should I Even Consider A Tunnel Ram? Let's Get Scientific

Now before anyone gives me crap, I know this has been a topic that has already been blasted all over the internet. But, from the many hours I have spent scouring the web I still havent came across all the information I am after.

In a street/strip application, lets say that's 80% street and 20% strip, is a tunnel ram an adequate intake? Does it perform well mannered enough on the street vs the advantage at the track?

From the information I have gathered, this is not a question of the intake itself but rather is purely dependent on the correct setup underneath. The world wide web seems to be split 50/50 on deciding what that correct setup is. Some say extremely high compression and wildly large cams, while others claim 10:1 compression and cam with at least 230° @ .050 is sufficient. I choose to believe the people that can provide a more straight foward and scientific approach on what the ideal setup really is rather than just saying they're race only. Of course not only is cam and compression a factor, but so is engine displacement, rear end gear, vehicle weight, and transmission. The idea there is quite self explanatory.

I myself am simply trying to understand what a correct setup is, and if my current engine has the means to warrant the use of a tunnel ram. Or if it will leave something to be desired.

My current setup is this:
454 .030 Chevrolet
840 Rectangle Port Closed Chamber Heads
Comp Cams XE274H with 230° in/ 236° ex @ .050 and .552 in/ .555 ex on a 110° LSA
Compression is 10.2:1 with -13.7cc dome pistons
Transmission is a Munice M20 4 speed with 3.55 rear end gear, have another center section with 4.11s.

I simply cannot be convinced to go out and purchase a tunnel ram on looks alone, although I will agree that they look awesome. I'd just rather go fast than look fast I suppose.

 

Many a 2x4 tunnel ram equipped car has been "spanked" by a single four barrel setup.
A tunnel ram alone NEVER made anyone a hero.
80% street/20% strip, which situation do you want to be the least miserable in?

 

how fast is it now? how fast do you want it to go? how much money do you have? what kind of street driving do you do? (errands in town, cruise nights only, commuting, highway driving...????) would you consider other ways to go fast, if it makes it faster and more streetable than a tunnel ram, but costs more?

 

The Edelbrock TR2X with 500 cfm Thunder series Edelbrock carbs ran very responsively on the street on my stroker big block. Shameless plug, it's for sale. Only pulled it because the blower replaced it. This was on an 8.5 to 1 490ci rectangular port engine with a similar flat tappet cam, prior to the full roller setup. More compression would probably be quite snappy.

 

My 28 sedan is going to have one with 2 600 Holleys that have been set up for a TR. BBC.

 

If it were mine -
A good single plane intake (Dart, Edelbrock, etc.).
An 800cfm Holley (or Holley clone),(I prefer the double pumper).
Trade the 3.55's for 3.70's.
28" tire (rear).
MSD Digital ignition box, (infinitely adjustable timing).
Pocket ported heads (are they ?).

That's a good start.
No tunnel ram for a mostly street car.

Mike

 

Science has proven that tunnel rams look cool

 

All TRs are not the same , I run an edelbrock "street" tunnel ram with 2x450 Holley's on 388" sbc, IMO partly because I have a 4-speed this setup is very street able , those big runner " breadbox " TR's are for 7K rpm and up, probably a bit much for the street ...

 

Be aware that you may have to modify your firewall at the top (around where the windshield wiper motor is) for clearance; I would't do that to that car! Maybe a cross ram would be a better choice for the street? Old school technology, but I think they actually look better than a tunnel ram. I have a small block cross ram setup with new linkage and factory re-manned 600 CFM carbs I'll probably never get around to using. I am Butch/56sedandelivery.

 

Is that the offy intake or the Edelbrock????...

 

No idea really on how fast it is now, I honestly haven't got to drive it much yet or beat on it very hard because of the stock rear. I'm basically wanting to do everything you described except I wont do much highway driving. The end all goal for this car is to run 11.90s driven to the track and home. So yes, I'd like to make it faster but I dont have a very big budget, so aluminum heads and hilborn efi are out of the question. At least for now.

 

Right now it has an Edelbrock Torker II-R with an Edelbrock 750 CFM Mechanical Secondary. It runs good with this setup. And I have got 26" tires on the rear so it helps the 3.55. I'm running around 55-60 at 2500rpm in 4th.

 

The tunnel ram I'm looking at buying is a Weiand 5985 with holley 450s.

 

I got an old bread box for an sbc if any you guys are looking for one

 

Nine out of ten people say the TR-1 does not work.

 

Never ran it. Wouldn’t without filling the inside
Stuff like this is just supposed to look cool

 

Just thinking out loud, the proper single 4 will leave this in the dust.

 

So when all is done correct on the same Long Block will the TR actually make the car run Faster or just Quicker than without the TR?
The Wizzard

 

Op its all up to YOU if you will get the Performances you are loking for , its all about maching Parts & your tunning skills & hours on hours of experimenting & notes even more with out a Dyno . ( I use a datta loger & paper) When it comes to TUNNING Carbs , its not just jets & squirter's , power Valves , (More then that in tunning the carbs ) & also tunning the car itself . I run a tunnel ram on street. Edelbrock 7070
Drive regularly for over 2 1/2 yrs
I have posted about Tunnel Ram on street hear in the pass , In my Area ,for some reason , Guys think that a Ragged out all steel 30 model A can not be fast , I guess it's because they only see Two 2 barrel Holley Carb on tunnel Ram sidesaddle ( 1,100 cfm's ) @ over 103 mph in 1/8 on 6 inch wide Bridgestones , I have now switch over to twin EFI Laptop tunning, power pretty much the same ,I picked up 3 mph though ,
I feel good of My Tunning skill on Carbs hours spent,
But not cost of the EFI , More experimenting to come.

 

I guess you can be the scientific one, and see what happens. First, do something about the rear end. Then get the car to the strip and see how quick it is. Work on getting it to go as quick as you can with the 4bbl. Then put on the tunnel ram, and see how much quicker it is. And how driveable it is. Let us know.

If the next logical step in your mind is to get new heads and EFI, you might instead consider a blower and carbs....figure it'll drop about a second off the 1/4 mile time, and driveability should be acceptable, and cost might be less?

but yeah, we'd like to see how much quicker it goes with a tunnel ram, compared to the single 4bbl.

 

I doubt you'll gain much , if anything , ran mine recently with dynosim 6(latest version) there was very little difference between the 2x4 TR and a 750(3310) on a Wieand stealth .,

 

My brother ran this [2350 LBs with him in it] car with a 406 sbc, powerglide with a 3500 stall and 3.91 gears. He used to to drag race, ran it at Bonneville once with 2.76 gears and cruised it to cruise nights and to hotrod functions. It ran a best of 10.32. I rode in several times and it was streetable. Cam wasn't ridiculous and he seldom buzzed engine over 6500 RPMs. Oh yeah, he ran a pair of 600 holleys but I don't remember which tunnel ram.
Sorry if that wasn't very scientific.

 

My wife’s cousin had the old “bread box” TR-1 on a 350 in his ‘31 Tudor. Crower hydraulic cam, two 1850 Holleys, M-20 4 spd, and highway gears. I don’t know what grind the cam was but it pulled strong from 2500 rpm.
He drove to OKC for the Nats in 1990 (I think it was?) and I saw the top of the manifold off a week after that trip. There was about a 1/2” of gas sitting in that thing, a bomb waiting to detonate.
I always thought the large plenum area with it’s flat floor and steady cruising at highway speeds was causing gas to fall out of suspension and puddle up in that thing. The old Chevy Cross-Fire injection was prone to do the same thing.
I think you can make a TR-1 work but as others have mentioned fill the floor in it. Edelbrock even introduced a cast aluminum filler for it that served two purposes. It reduced plenum volume and more importantly the top of the ports were now flush with the plenum floor leaving no where for gas to puddle.

 

Put a rear in your car that can handle the power you have now. Take it to the track and beat on it a bit to get a baseline. Then start working on tuning the car as far as tuning the engine you have for best performance. Then tuning the suspension to work on the track. You have a lot of things you can do on most cars before you get to where you need the extra top end that a tunnel ram will give you. You will then need another season to tune the engine again after that change.

 

I like it. Use a single 4-barrel as a stepping stone to the TR, see how far that takes you before taking that quantum leap into the unknown. My brother and his buddy were running a worked 454 in a '57 Chevy years ago, it was sick HP for around 1977 and the weak link was the '57 Chevy rear even built-up. The cure was a Ford 9". The rear IIRC was a 4.56 and he was rowing a M22.

 

The real answer to street use for a tunnel ram is manifold vacuum. If you run a stock cam and have high vacuum, the carb will work well. With low manifold vacuum, the carb get's little signal and nothing good happens. Obviously port velocity has something to do with that but the only thing a carb knows is the vacuum that pulls fuel from the venturis. That's why when you open a carb instantly and the accelerator pump doesn't work properly, you have instant bog until air flow picks up enough fuel to correct the a/f mixture.

 

If you wanna look fast go ahead and put it on.
If you wanna BE fast test, tune and repeat.

There is a good chance you will actually make it slower but you will never know unless you test and tune the current setup.

 

The pair of 450 Holleys will kill it on a big engine. Will be better on the street but lacking on the strip. While TR looks cool, a good 4bbl setup will beat it for time and consistency. Most guys can't properly tune a single 4bbl, what are your skills on carb tuning?
SPark

 

For what it's worth.... here's my actual experience and takeaways:

I have a crusty ole Model A coupe that I have beat on for over 15 years. 60 over 396, 10.5 to 1 compression, mildly worked oval port heads (port matched and polished), Comp XE274H cam. The car has an M-21 and 3.50 gear nine inch with 31 1/2" tall rear tires.

I ran a 2x4 offy hirise with Eddy 500 cards and progressive linkage for years.
This year I found a swap meet, oval port weiand street tunnel. I had read why so many said it wouldn't work. Well, at the HAMB drags this year it picked up 6 mph in the qtr.

No, I don't have the ideal street/strip setup but I have fun. The car's street manners are better and I think the intake looks bitchin. The plugs after the 300 mile trip looked cleaner and more even from hole to hole. I'm sure the light (2900#) car and 4 speed helps it's streetablity.

I wouldn't run a streeter dick single 4 on this car anymore than I would add a/c or cruise control. It's a grity ole hot rod that I have a blast with.

Summary......do what you want and work on it til it works. Most that say "you can't" never have tried.


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