True. Individual runner intakes cannot be compared to open plenum or "shared plenum" intakes as far as CFM goes. An individual runner intake will not make the peak HP levels that a common plenum intake can at the same cfm carb wise. Individual runner intakes have a lot of advantages, but ultimate all out horsepower isn't one of them....
Not sure that your Dyno tests comparing a single four barrel on a Dual Plane, versus two four barrels and a tunnel ram are really anywhere near an apples to apples comparison.
You have my attention. Would like to see more data. I have a Weiand tunnel ram. Are you going to sell the tops separately in a kit? What's the plan?
There are full kits available in my store. You can also buy just the tops and carburetors together, if you already have a base. What kind of data are you looking for?
I just came across the website for RSR early this morning and was wondering if anyone ever bought one of these setups, and if it actually worked as advertised?
I'd like to try one for my 352 Windsor "roller" motor with Trick-Flow canted valve heads... First, I'd have to buy the intake adaptor from Moon racing equipment... I'm sure those tops will bolt on the 289/302 Weiand TR intake...
build one for a windsor,,,,, its one of the stock small blocks that love velocity,,,,,,,,keep up the good work,,,,down under(australia ) we backfill intake ports with small tongues to increas velocity on the sbf engines it works real well ,,,,so much better than 4v boss style heads which australia has lots of
Hi, I have run my Model A pickup for many years and thousands of miles with a tunnel ram, they work great if you have the right gear ratio for what you ask them to do, I have a quick change and 4 speed, I run 4.11s around town, and 3.08s when we drive to Bonneville, when I get to Bonneville I put 4.88s in it to drive around the pits, I dont think there is a ,fits all, gearing for any car with a tunnel ram.I had a Edelbrock box tunnel ram on it for many years untill it exploded, now I put a tr2x on it and it runs smoother, THANKS Chris
SlowMoe, I sold one to a guy in Mobile - not sure if that is close to you. If you are interested in talking to him, let me know and I will see if I can set it up. He loves it. - Wayne
Yeh but every time the subject of 2x4 or 3x2 carbs comes up there are people saying a single 4 barrel will make more power. If you look at the runners on the new engines they are long and as straight as you can get. Injection is the big difference. You have the right idea keeping the volocity up with the dual plane and a little smaller runners. I can see where running throttle bodys and individual electronic injectors for each cylinder would work very well in the tunnel ram manifolds.
Sorry to bring up an old post but I have been doing some research on TM's and thought this was funny becuase Offenhauser did this 30 years ago. Notice the note says "should only be used for all out competition racing. Not designed for street use.
Not the same thing. The Offy has two plenums with four cylinders each, and no provision for evening out the fuel distribution. My design has four separate plenums, and each plenum is shaped to force even fuel distribution. The Offy pieces are real crap - I have a set and tested them. Those Offy pieces only have decent fuel distribution when all venturis are fully open - thus the "only all-out racing" note.
OK, well If I stumbled onto it others will also. Maybe you should show them side by side and address the differences so others don't think you just dug something up that was done 30 years ago and put a different marketing spin on it. Can and has been proven. Standing up, laid down, or curling in a circle, intake runner length is the same in theory. Here is a good link about ram induction from the Chrysler 300 club. http://www.chrysler300club.com/uniq/allaboutrams/ramtheory.htm Here is one from a tunner site that is one of the best articals I have found about runner tunning. Good read but long. http://www.team-integra.net/forum/b...e-manifold-tech-runner-size-calculations.html
Maybe it because of the hole through the middle between the carb base looks like a tunnel or a bridge. You know if he only sells them with the highly mod carbs is that not the same thing you would do with a tunnel ram to make it work for what ever you were going to do with it anyway being street or race.
The carburetor mods are completely different than what you would do to tune a normal tunnel ram. They are related to having four completely separated plenums. The giant single plenum hurts the bottom end on a regular tunnel ram, no matter what you do to the carburetors. You can make a normal tunnel liveable with enough gearing, but my setup works great with normal gearing, stock stall, low-RPM cams, whatever you want. It does not have the top end performance above 420HP or so. It really is radically different - it just uses the tunnel base, which is not source of the cantankerous behavior of a normal tunnel at low RPM.
I would disagree completely that they cant be ran on the street, I ran one in my prostreet truck on a big block and it ran like a dream, very responsive, driver friendly, tons of power, and it never loaded up on me, etc....etc. Just my .02 cents worth
Been watching this thread and just seeing what the responses were for a long time. I've run a couple different tunnel rams, and have one on my present car. I'm also getting ready to put another on my current build, as I've had good luck on the street and strip with the current tunnel ram. My 327 has a Holley Pro Dominator tunnel ram, with twin 450 Holleys. It's a short tunnel ram, when compared to most the others, but with a TH350 and 2500 stall, and 3.73 rear gears it not only runs well around town, but gets 16mpg on the freeway. Took some tuning to get there, but it sounds like the tunnel ram discussed here does also, or it could be sold as an independent bolt on, not with carbs. As you can see in this picture, the Pro Dominator has a very small plenum and short runners compared to other tunnel rams, and that actually makes it a bit tougher to tune, as the larger plenums allow the fuel/air to mix better before hitting the cylinders. On my 454 I will be running a Weiand with twin 600 Holleys, and vacuum secondaries. My experience with them has shown me the longer runners and larger plenum don't take me as much time to tune, and carbs take very little work to make them run well at low end. It will be backed by a super T10 4 speed, and 3.73 gears also. This generation Weiand has a little less plenum than newer Edelbrocks, but works well on the street with little tuning issues.
So are you saying you only sell carb and these adapters as a match set AND they willl be correct for all builds? Iwould think you would sell more of these if you gave some general guidlines for carb selection and set up andallowed people to buy the adapters and run the carbs they want.
these guys know how to build one When they're done the ports will taper and get larger at the plenum end. We'll also thin down the outside so that it'll be lighter and better looking. We'll make a separate valley cover. It's a little hard to believe by looking at it but the hood should shut on this tunnel ram setup with about 3" clearance between the top of the carbs and the underside of the hoodscoop. That should be enough clearance as long as we don't run an air cleaner. They do make a similar looking scoop that's bigger so we can go that route if we want to. </ARTICLE> </ARTICLE>
The carbs have been correct for many different mild builds. On a couple of 383s with large-to-huge roller cams, I had to reduce the size of the low-speed air bleeds to richen up the low-speed cruise mixture, but that's it. I've used the same setup on bonestock Goodwrench 350s, 355s with roller cams and decent heads, 383s with non-humongous cams, and 327s with old school cams. One 438-inch Windsor race build never was happy with this setup. I warned the customer he was coloring outside the lines, but he was not worried about top end loss so we tried it. Never was right and I took the unit back for refund. I desperately wanted to be able to run normal carbs with some tuning guidelines. No reason then for me to have money tied up in expen$ive carburetor inventory. However - when we did the first setup with Holley 600s we had to drill the air bleeds differently for each of the four plenums to get the fuel curve right, in addition to cross-jetting. We used 8 wideband O2 sensors to see what was going on. I have considered publishing a recipe for the 600VS Holleys, but don't have a lot of faith in people being able to get this correct. Maybe could have them convert to screw-in bleeds - but again this is pretty advanced stuff for most guys. Many people have an allergy to doing anything to a carb beyond changing jets - some an allergy to doing anything besides turning a mixture screw or idle speed screw. And then I worry about guys having a couple of old swap meet carbs that really don't work right anyway, modifying them, and then saying my product does not work. Selling new carbs with the tops means nearly everyone bolts it on, sets the idle, and enjoys the ride with no further fuss. I don't claim any real magic to the carb setup - if garden variety Holleys had screw-in air bleeds I would just sell folks a package of jets and bleeds rather than new carburetors. It's funny that the bleeds are the biggest issue, since when you have screw-ins they are the easiest possible thing to change on a Holley - way easier than jets. If anybody has some ideas about how to do this I would love to hear. I also thought about having folks send their carbs for me to modify. Then I could run them on my engine and make sure they are right. But the downside there again is someone sending me carburetor-shaped scrap metal. Long post - thanks for reading to the end. Honestly I would much rather have a lower-cost, higher-volume product if I could figure out a way.
With gear, stall, and smaller carbs they are OK. You also had a lot of cubic inches. My deal is for the guy who doesn't want to put in more gear, or stall, or anything else, but wants to have the tunnel ram look. If you have 3.23 gears, stock stall, and a near-stock cam, the regular tunnel will be painful. Mine will instead be a lot of fun for that guy. I know it's a niche.
A friend of mine has been building these tops for Edelbrock intakes and it has the super sucker tapers on the bottom.
What if you offered a couple different services? One with brand new carbs and adapter, one with adapter and air bleeds (for those that already have carbs w/ screw in air bleeds), and one with adapter and service to convert customer's carbs for screw in air bleeds? Then everybody's reasonably happy? I think you've got a good product, but you're marketing to a select crowd. If you gave the customer some options, you could sell more of your stuff w/out a huge inventory in QFT's. I know you can buy air bleeds in packs of like 10, so it seems like that would work out pretty good. Just a thought. I know you want to sell your product in the condition you know it will work, and the different packages I suggested would still let you do that at a reduced cost for the customer and a reduced inventory for you. Whatever happens, good luck!
Tim (fortfun) - I'd guess you are very close in your comment about people being able to tune with the gas and air bleeds. You'd be on the phone 24 hours a day trying to diagnose problems for people. I've done a few things in the same vein as what you are doing. I made my Offenhauser crossram (like the Chevy Z-28 version) work very well on the street with both a single or the twin Holleys. Took a bit of filling and daming but it worked. I also tuned a few of the old Man-a-Fre's for people that had no idea what to do. I had one of those on the same car/engine as the crossram noted above for many years...till the throttle shafts started to wear badly. This wasn't a weekend car..it was my "only" car. Learning how to tune full mechanical carburetors on roadrace motorcycles was fun too. Anyway, if I were you, sell as a kit......to those you don't know/the masses, but sell just the top to those you might know, and know...that they understand tuning...more thAn just jet changing.. I may be doing something similar in the future with my high dollar "Studebaker" engine. Roller cam, highly adjustable gear drive, knife edged crankshaft, really..expensive porting, (and I did the porting...still expensive!). I have a Mopar tunnel ram base I may try after I get the custom single plane manifold worked out. Just as a kit...! Mike P.s. - Turbo - Done a coupla 409's in my time too...that one above looks like real fun. Nice work on the intake.
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