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Summit tunnelram in the streets?

7763 Views 5 Replies 4 Participants Last post by  1937Austin
Anyone running the summit setup? I'm looking into buying a new setup for my sbc, which is a decent standard 350. I'm guessing the cam is more or less stock as it idles smoothly. It has full lenght headers. What does the tunnelram needs when speaking of cams? I want a driveable car but a little punch for saturday nite fun wont hurt. Gimme your thoughts. Oh, and f()(% mileage.
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I'm not running one currently, but I have had them on my own cars and installed them on customer cars. They're usable on the street, but you do have to spend some time getting them dialed in and tuned properly....then keeping the carbs in tune once you get things working right.

As a general rule, tunnel rams are designed to operate at a higher rpm then a single carb, so cam selection should also be for higher (3500 to 7500) rpm range... Then, if you're running an automatic tranny, it's going to take a higher stall converter to allow the cam to work properly.... They will work ok at lower rpm's, but there are a ton of single four barrel carb and intake combinations that will work better then a tunnel ram at street rpm levels. All that said, the kewlness factor of a tunnel ram is always high, whether or not it's worth the extra expense and effort would have to be a personal decision.

Finally, tunnel ram and fuel mileage shouldn't even be used in the same sentence!!!!
If you decide to run tunnel ram, with a mild built 350 I wouldn`t run any higher CFM than 2/390 CFM rated carbs, and my own opinion would be Holleys, and you might still have to jet those down, that will give a better low speed throttle response, mount the carbs sideways for easier access to the bowls in the event you have to pull them off. Just buy the matching linkage for them. As Dave said it will take a bit of tunning.
Where do I start? I'm not running the Summit (Weiand) setup, but rather a Holley Pro Dominator with twin 450's on a somewhat built 327 bored .040", with 2.02 heads. First off, I had better lowend and streetable power with the old Edelbrock Performer RPM than with the tunnel ram. Not that it doesn't perform well now, but it's not as great off idle as it was.
I've had to tweak things a bit to get rid of a horrible off idle stumble. I ended up changing the accelerator pumps from stock 30cc to 50cc pumps, and that helped a lot. I also changed gears in the rear (which I always planned) from the high 3.08's that were in the axle I bought, to 4.11 gears. Again that helped by keeping the engine in it's best power band. I'm still tweaking the tune to get it as perfect as possible, just because I love the look. Something to be said for having a street legal car with a pair of Holleys and a Hilborn scoop sticking out the hood! :)
Of course I could have gone fake injectors like my buddy's Austin and had performance and looks!
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Damn, that's a sweet pair you have there. As mentioned you can't argue about the look of stacks above the hood. The current setup on my 350 is a EBperformer rpm with the shiny carb on top and I know it's a good combo. I just might throw a scoop on top of the hood just to keept driveable and cool looking. My now 11 year old daugther is aiming for this car as her 16 birthday gift and that leaves me with the potion to keep it on the "safe" side so to speak. She's wild at heart so she'll probably aim for the tunnel ram when she finds that solution
Yeah, I went the Hilborn scoop on mine, but with the 327 setback so far the rear of the scoop actually sits under the cowl, so I had to adjust the height to come up precisely under the cowl as high as possible, which allows about half of the scoop opening to prtrude through the hood in front. Would have liked to have just had the whole thing sticking way up through the hood, but this way the hood is stronger for the tilt frontend, and I didn't have to cut and box the cowl.
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