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Tunnel Ram Performance?

30K views 148 replies 37 participants last post by  sunkisst 
#1 ·
Didn't want to thread jack the other thread! I have been asking a few guys about the difference in performance between a single plane hi-rise 1 carb. verses a tunnel ram with 2 carbs on a jet boat?
I run a Brodix 2000 intake with a 4500 carb.base with a spacer for a 4150 and a worked over 850 Holley DP! Would I see and feel performance gains with a T/R and 2 Holleys? And what would the gains be? WT:)devil
 
#2 ·
If I remember right back on hot boat there was a thread that had guys arguing back and forth for days on this topic. I'm sure the answers will only get MORE intelegent than mine. But I recall in the end the tr had more "potential" if you're willing to find it. And I would dare say more potential for sucking the fuel.
 
#6 ·
I have seen this stack it on as high as they can! :D:D COOLEFECT!

why not just a nice dominator coby? carbs on a tram are fun to tune:)sphss
Tom I have one and it is a 3 circut to hard to tune!:|err I was thinking that a tram had more performance since most everyone runs one!
 
#5 ·
Tell you what... Ive always had high rise single plane manifolds on the motors ive built... The motor i recently built has a tunnel ram and 2 750's on it.. The performance is great but tuning the 2 carbs is a pain in the ass. NOT to mention sucks the fuel like no other.. I sucked almost 20 gallons in 2 hrs.. :D There is a strong change in the mid to high rpm area.. Much more responsive feeling to me. Down low in the rpm on the launch isnt as strong, but i still have some tuning to do on the carbs. There are guys on here that run em and have strong power throughout the rpm range. im sure some will chime in.
 
#7 · (Edited)
I love this whole gas usage complaint. If the A/R is the same, and you are using more fuel, then common sense tells me it's making more power. There is no reason a TR can't get the same fuel comsumption rate at the same RPM in cruize. But you have to work at it. If you don't know your way around a carb that well, a RIGHT single on the RIGHT manifold can be easier. Bottom line is, the more motor you have, the more it whats a TR. Fueling a 632 at 7000 with a single is a joke. A wimpy 396 @ 5500, isn't so TR friendly.



 
#23 ·
This is pretty much my opinion as well. We used a TR with a pair of 1050's on our 598 NA motor. It worked pretty well before the blower bug bit... :)devil

Well mines not on a jetboat but I switched from a flowed 850 (990cfm) on a Weiand Team G to and Edelbrock 2R tunnel ram with a custom top and 2 Holley 750DPs (4779-9s). Now I gained 400rpm on the flash and between 100-150rpm up top. It's a solid 2/10ths quicker in a 1000' as far as gas consumption I see no difference. I drug my kids tubing with it 2 weekends ago and burned 16 gallons in about 5-1/2hrs and that was basically non stop running with 5 teenagers ranging from 14-20 in age. So it's no worse than my single 4bbl was. Now it took longer to tune and you buy another jet kit or start trading with a buddy because it's literally double on everything you do on a single. Now that it's tuned I really don't see any issue or down side with it other than initial price and I do run primary powervalves.
Oh and you'll spend more than you realize plumbing a tunnel ram to or I just forgot about that. :)sphss
Loren, pulling tubers with a flat.... that's just plain wrong :D

Lets face it, a tunnel ram is a must on a jet or v-drive if you can't afford a blower. Multiple carbs sets you apart from the average joe blow. A 468 will run just as good with a single 850 no doubt in my mind, as far as fuel consumption, stay away fron the 660's those things absolutely DRINK fuel. I always ran 750's and put 650 bowls on them with the transfer tubes so I could run them inline without a lot of hardware. 50 cc accelerater pumps, a light spring in the secondary vacuum diaphram get them jetted right with a vacuum tube connecting both secondary diaphrams (you drill the tops and connect them together) and you are good to go trouble free, no hesitation and great mid range and high end. You can hear when the secondary's are coming in when cruising, and stay on the primarys for the ride home when you are on your last 2 gallons...................... Tunnel ram vs Single carb............. no brainer in the cool look at me dept. !!!!!! I run the same set up on my blower motor and it gets good fuel economy and runs great, I adust it every spring and don't have to touch it, I go through my lifters once a month, ck my timing and adjust them just for kicks, but they are usually right on !!!!
We agree on the cool factor, but if a 468 is much more than stock, a properly tuned TR will always make more power than an 850. Been years, but we had pretty good luck with 660's on a mild 427 lake motor in a flat. Good idea on the smaller bowls to put the carbs in line. Like Loren said above, plumbing sideways mounted carbs gets really expensive....
 
#8 ·
coby talk to scott on this subject;)he has back to back dyno charts where a t-ram made more power every where,me im a single carb guy no matter what.

we argue alot:pbut in the end i really dont now???to be honest best thing to do is dyno back to back and see what happens.

tuning 2 carbs is not voodo,need some one experinced,scott is your guy.

friend and good engine guru. i build and tune my own shit,but he is always there for the advice i need.
'
good luck my friend.travis:)devil
 
#9 · (Edited)
Well mines not on a jetboat but I switched from a flowed 850 (990cfm) on a Weiand Team G to and Edelbrock 2R tunnel ram with a custom top and 2 Holley 750DPs (4779-9s). Now I gained 400rpm on the flash and between 100-150rpm up top. It's a solid 2/10ths quicker in a 1000' as far as gas consumption I see no difference. I drug my kids tubing with it 2 weekends ago and burned 16 gallons in about 5-1/2hrs and that was basically non stop running with 5 teenagers ranging from 14-20 in age. So it's no worse than my single 4bbl was. Now it took longer to tune and you buy another jet kit or start trading with a buddy because it's literally double on everything you do on a single. Now that it's tuned I really don't see any issue or down side with it other than initial price and I do run primary powervalves.

Oh and you'll spend more than you realize plumbing a tunnel ram to or I just forgot about that. :)sphss
 
#10 ·
Lets face it, a tunnel ram is a must on a jet or v-drive if you can't afford a blower. Multiple carbs sets you apart from the average joe blow. A 468 will run just as good with a single 850 no doubt in my mind, as far as fuel consumption, stay away fron the 660's those things absolutely DRINK fuel. I always ran 750's and put 650 bowls on them with the transfer tubes so I could run them inline without a lot of hardware. 50 cc accelerater pumps, a light spring in the secondary vacuum diaphram get them jetted right with a vacuum tube connecting both secondary diaphrams (you drill the tops and connect them together) and you are good to go trouble free, no hesitation and great mid range and high end. You can hear when the secondary's are coming in when cruising, and stay on the primarys for the ride home when you are on your last 2 gallons...................... Tunnel ram vs Single carb............. no brainer in the cool look at me dept. !!!!!! I run the same set up on my blower motor and it gets good fuel economy and runs great, I adust it every spring and don't have to touch it, I go through my lifters once a month, ck my timing and adjust them just for kicks, but they are usually right on !!!!
 
#18 ·
just pull the intermediate air bleeds out and that 3rd circuit will flatten out for ya coby. wish i was closer, i'd help ya tune it cause there's nfw i'd chose a tram over a single dominator for the way we race here.
 
#25 ·
i'll be the 1st to admit, tuning a tram intake itself is beyond my experience:)sphss only time i've ever gotten a tram to work good for myself is by runnin small carbs on it, i was runnin 450's i think, its been awhile , but it was on my taylor sj. i put it on a 11 to 1 460bbf , jetted it right, had to change pump cams and shooters to get the stumbled outta it from a deadstop take off, but i still got killed leaving the hole:)st i pulled the tram off and changed to a single plane and carb that flowed 950cfm and it worked so much better leaving the hole, but yes i could tell up top i had given up some hp above 5k, but i was winning so i left it alone:D
 
#32 ·
This is all great info. and thanks for the responces! I was just kicking this around because I had asked a friend about Trams and he said that they made more power. I can see it on the big end but low end would seem to suffer because of overloading. But, I know that can be overcome with proper tuning and skill with the setup!
Does anyone have any numbers to show the difference between the two? Besides seat of the pants!

Tom, I will try a domonator when I settle this motor in the TX this winter that a friend has that is an older 2 circuit! Here we go again!!:D Thanks WT:)devil
 
#41 ·
Does anyone have any numbers to show the difference between the two? Besides seat of the pants!

Tom, I will try a domonator when I settle this motor in the TX this winter that a friend has that is an older 2 circuit! Here we go again!!:D Thanks WT:)devil
My friend Danny Crower built a Hyd roller cam 502" Chevy approx 10:1 compression for a friend of his, single 850 on a Dart (type) single High rise. Two years later after a valve job and put back on the dyno with a T/R and two 1050's it made 75 more lbs ft of trq at peak and 80 hp at 6,500. I was damn surpised but Crower wasn't.

Sleeper CP :D
 
#34 ·
Heres a little something very few people are aware of about the Weiand Pro Ram. When Bill Jenkins sat down to design that thing he did something very very genius, mostly for himself, and R&D. The plenum to base bolt pattern is the same as a Dominator. This allows for endless tuning aids, very easily. I.E. Remove the plenum and install two 4 hole spacers in its place and waa laa, an IR manifold. Now you will never come up with a carb big enough for a big inch hi RPM BBC, but talk about throttle response and low end torque. It has to be witness to be believed. Want longer runners? Leave the 4hole spacers and reinstall the plenum. Want 2 mini plenums with no balance between them? Install two 2" open spacers in place of the plenum. It goes on and on. Absolutly the easiest TR to mess with and learn on that I have ever seen.



 
#35 ·
i dont get it, what kind of tunning problems are you guys having with TR's? Both my TR's have been fine, as soon as i mash the gas the motor climbs like a mother. The only time i had issues was with some 660's i had sitting on my old manifold but the linkage on them had been messed with. After talking with many the problem sounds like my shooters were empty by the time i needed them when mashing at half throttle... either way i had a quick hickup and it went to max rpm and screamed.
 
#36 ·
I agree. My motor is over carbed two 750 demons on a weiand TR with a 462BBC. But tuned correctly they couldnt run any cleaner. from idle for long periods of time through the middle and wot they work like a dream. Once a season I have JP work his magic and im happy. Plus the look is great. I wouldnt switch to a single carb setup.
 
#37 ·
heres what i have found,tunnel rams on dynos will win everytime.they will make more power everywhere;)put them in a boat and you can have some minor tuning issues.run very well.

i have always enjoyed beating the guy that thinks his t-ram is cool and he makes more power,blahhhh blahhhhh blahhhhh.he doesnt look so cool when his ass got kicked by a single carb.:Dbut thats just what happens some times:)hand
 
#43 ·
Didn't want to thread jack the other thread! I have been asking a few guys about the difference in performance between a single plane hi-rise 1 carb. verses a tunnel ram with 2 carbs on a jet boat?
I run a Brodix 2000 intake with a 4500 carb.base with a spacer for a 4150 and a worked over 850 Holley DP! Would I see and feel performance gains with a T/R and 2 Holleys? And what would the gains be? WT:)devil

Last fall I purchased a pump gas 565 from www.sunsetracecraft.com Their basic combination of a pump gas race 565 with a single 4500 on a hi riser makes 750HP and 730 TQ, I switched to an Edelbrock TR and two 600 DP Holleys, mine made 807 and 770 respectively, and I know I left power on the table by going with the small 600's. I was building a lake boat and looking for good all around performance and reliability, rather than the last ounce of power.

Mine starts right up, idles clean, and has great throttle response, plus I got the retro look and bling factor I was looking for.
 
#49 · (Edited)
nothing atomizes fuel like (properly tuned) multiple carbs...not even fuel injection. :D
RealityI can only assume that you have never read the specs on some of the new DFI in chamber Bosch injection systems like the one in the new twin turbo V6 Ford SHO Taurus. 10 to 1 compression and 13 lbs of boost? Now that's engine management. Ever seen what gasoline looks like when it is shot through an injector at 2400 psi directed at a specific spot in the chamber, and the spot in the chamber changes as determined by rpm, load, throttle position, etc. Carbs, even mutli carbs, even multi Webers, and Dellortos are nothing more than a brick with a hole drilled in it. Model T's had carbs, and mag ignitions:))eek:))we have moved passed that.



 
#57 ·
Thanks for the pic havasubyou.

The boat is a regular layup Cole TR-2, 17'10" in length, and I have no idea what the total weight is, thanks for the kudos.
 
#61 ·
I bet you need to restrict the IFRs. Try running it with all 8 idle screws 3/4 turn out. If that helps try inserting some .017" wire in your IFR holes in the metering blocks and try it again. I bet that will lean it out and clean up the idle and part throttle. I think factory jetting on those was 71 primary 80 secondary so you're close.
 
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