Im a fan of my t-ram. But it depends on setup and why you are running it. I have a lot of reversion because of my cam and was having terrible distribution problems with my single carb. I got a T ram for cheap and slapped it on, a little tuning and Im good to go. I under carbed it a bit though and am running dual 450's. It runs great.
~Brian
im with you cp if a person will take the time and tune properly t-rams work good,but most have them for show.im glad atleast someone has agreed with me for oncemy ole man has a victor jr with a 1050 on his 496 works great.hope this article has helped you some
I went with an RPM Air Gap on my 468, but it's not finished yet, so I cant say how great it is. Seems like the best bet for my needs however...
I'm sorry after all of this , your question didn't get answered. Trq is important, very important , but here is the deal, if your jet can pull 5600 when you are cruising at 4000 it is almost freewheeling, it is not against the wall yet. When you hit it and it runs up against the impeller that is when your trq need is high. So most dual planes that will help you make trq at 3500 how much are they going to help at 5600. In that case a good single plane or rpm air gap will do great. I hope that helps.
Sleeper CP
this isn't exactly what i have been told...from what i know in a jet you are alway under a significant amount of load at any rpm. This is how i understand it and easiest to explain. in a car at cruise say 65mph you are maybe turning 3000 rpm but your load is only 15-20%, in a jet boat that is not the case. as rpm go up and speed go up your load continues to increase. it does not drop off because you are cruising. from what i have heard at a cruise say 45mph at 3500 or so your load could be up around 60%. this makes sense to me if you just think about what happens when you let off the gas in your boat at 45 mph...the thing immediatly slows down and comes off plane. what happens in a car? you coast. this just show the drag that boats have to overcome not to mention the fact that we do not have gears to releive load. Touque is everything in a jet..that is the key reason why most jets perform the best with big cubes...they make a lot of torque right now. hope this helps.
I'm no expert so i may not have all my info correct if this is the case i would love for someone to explain it better.
ap
Torque is everything, cause that is what is turning the impellar. It is where you want this torque that is important. As I see it (doesn't meen it is right) for most jet boats (especialy high performance lake / race ) you want to mash everything into the 4/4500-6/6500 rpm range (the pump is like having a fairly high rpm converter). You don't want it to be totaly junk below this, but it doesn't take much to spin most impellars 4000. That is where a properly tuned tunnel ram will start to shine. With the right combo, you can really get the power/torque curve to bulge in this area with a good cam / tunnel ram / carb selection. Also, they look cool!!!
With a performance jet boat, I will give up 75 lb/ft @ 3500 to gain it @ 5500 any day!!! (unless you are already struggling down there as it is!).
My cent and a halves worth anyway!?!
Warp Speed
Torque not hp is what gets you moving. Lots of good opinions here. I agree with most. If your turning hard enough to take advantage of a tunnel ram
(6000+) then it might be worth your while. The harder your turn them the harder it is on the motor. My combo is simple 514BBF, single plane offy portosonic w/850 and I turn an A/B cut impeller 5400 rpm. gets me to 80 on
gps and i still have yet to put the bottle on. Intake, cam, head combo can't be stressed enough.
Hot rod boats are hot rod boats. Race boats are race boats.
My wife calls the Miller our "show off" boat. If that's what it is, then show it off.
Yes, TR's are definitly in the show off catagory in MOST boats. That is mostly why I have one, BUT it does also work! Most boaters are not racers. MOST jet boats will not run close to the OPTIMUM RPM potential of any TR. I will give up that little bit of optimum performance for the look factor. It still hauls *as, and looks cool as hell. It may be somewhat of a waste, but thats OK. I know it is not the "right" manifold, but it works for Me. Again, if your gonna show off your ride, then show it off right!
Tommy
PS- My fastest boat has a torker and single 750, V-Drive. My jet has TR and 660's. How backwards is that?
The jet is way cleaner and pretty, gotta show it off.
all interesting enough but if you look at some dyno sheets and compare them to the RPM's the impeller turns, if you shoot for the lower max TQ rpm number with your impeller you will come up way short! This has been gone over tons and tons and will never be resolved, it is good to talk about tho. Pumps WILL turn above the max tq rpm not just to it. If we keep the disscussion to typical jet boat engines (ie not small blocks even tho they are used and rotary's) then the trend will show if proper planing of components are present the engine will spin the pump up closer to the hp#. If the max tq rpm was the ideal goal then most boats would be better suited with a AA or a AAA impeller,this is certainly not true. Since tq is what is used to calculate hp it is and important#, but in selecting an impeller and chosing a rpm for the engine to run max at I'd look at the hp# and work off that. Thats the way I see things after looking into this a ton!
Squirt,
I'll agree with that; if he is wants to turn an A impeller 6,000 rpm's he is going to need at least 700 hp to do it at 6000. That's what he needs to build the engine for and not worry about the mid range trq. Everything in the middle I look at it as "flash" in a high speed trq converter.
Sleeper CP
Well I am gonna go between a dual plane and a tunnell ram and go for a tall single plane manifold. It will give me more top end and be a good mix I am gonna order the Profiler Sniper Jr. and have it port matched to what ever heads I end up with. This thing should pull hard and I bet I will be the only one locally with this on a jet boat....
http://www.profilerperformance.com/b...ntake-206.html
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