bob

Thinking of going to tunnel rams and I don't have a clue as to what intake seems to be the best bet. Anyone have any dyno experience with them or know of any that will make decent power around 6000?

vette131

contact richie zul or jc perf, there the only people i've seen running tunnel rams.

Mbam

Did lot's of testing back in the 80's, so the info is stale, but if I remember right it was the Edelbrock Victor & Dart. On a 540 Cu in 750/850 carbs were way up over Dominators. Wound up using the Victor because I already owned them.

Picked up 20 HP or so by having the manifold ported. I sure you will get some more current opinions.

jdnca1

I used a Dart on my old 632". Worked great, no hesitation or stumble anywhere. I don't know what combo you are putting it on but the key is to stay small with carburation. Mine made 900HP on pump gas with 2X775 race demons. 2 dominators would probably have made more power on top with lots of drivability problems elsewhere. You can spend 4 X's as much on a custom sheet metal intake, but usually us boaters don't turn 7500+ rpm to really see the difference. If you have a tunnel ram properly matched for your application you will make more power AND more torque over a single plane. I'd guess its worth from 20-40HP over a single plane becoming more noticable on top.

bob

Thanks much for the info! I do have a pair of 850's now for each that flow close to 900 each. Thought is to build 588 motors at 9.5 cr and set them up so I can use blowers or tunnel ram. I have 8-v's so the higher cr will help as I do not have inner coolers. Just in case gas gets completely out of control!

cstraub

CFE is a good place to start. Talk to Scott. Carl's induction systems are some of the best.

MESABALANCING

If I'm not mistaken Dart no longer offers the tunnel ram the one from CFE and Profiller are the only ones I use they work well and Marc from BAM is right the small carbs are the way to go marine.

Mbam

Actualy CFE is the one who did mine.

jdnca1

I'm not sure about Dart no longer offeing a TR. I will say that my last Summit racing catelog still had them listed, I did notice the price went up $100.00 sometime in the past yr or so though. I guess its only a phone call to know for sure.