Full P Power Tunnels

[D. Newland]

Mic-You've obviously spent a ton of time on this topic and you've got some great ideas and direction. IMO and as you pointed out earlier, the P-Ltd tunnels are using every bit of available mAh's out of a 5000 mAh pack. To go to a full P 4S setup, you're going to need 7000-8000 mAh packs on board so you don't run into trouble when you drain 6000 mAh's out of them during a heat race. BTW, my P-Ltd Tunnel is my most amp thursty P-Ltd boat in my fleet. I'm sure that will be the same if one goes bigger. Might as well use that battery space to up the voltage rather than up the mAh capacity.

I know Lohring has done some work with Q setups, and that seems like a more logical approach to a more powerful FE tunnel. It gives you 40" to play with and it tackles the watts needed by up'ing the voltage rather than up'ing the amps.

 

[RonShaw]

Moonlighter is helping me build a P and Q as well so I will be watching this thread to see what you guys are up to. My P will be a LeeCraft ( ) and my Q will be an older HTB that closely resembles a LeeCraft. Im sure thats not a surprise to many..... Thanks for starting this thread.

 

[rumrunner]

How many P powerd tunnels are out there? What are your set ups? Really think 34" - 36" would be needed?

Doug

Doug... Nice looking boat. I love the WoodStuff hulls...

I have a Warhead II up on the shelf waiting for me to get time to build it up. I have the Lawless 7.5 lower, modified for FE use. I needto have Kris Flynn make up some flex-cables here shortly, once I finish making the motor adapter.

Will be awhile before I get to finishing this. It would be fun to see two FE OPC classes going... The P-Ltd class is pretty strong, but I suspect, at some point, people here in the states will start feeling the need for MORE POWER... and step up to P...

Darin,

You really need to finish your Warhead as in testing ours with a .45 nitro it appears to be an upgrade over the Shaman which is a great boat till you put a mod .45 on it. Then it becomes a rocket ship that needs an experienced pilot and may not finish. We have run the Shaman on 4S and 5S with a 1515 2200kv. On 4S single lap times are into high 13's and 5S sub 13 unofficially. Cannot wait to

get to a time trial with calm conditions. The Warhead should be a better FE P or Q boat. At Huntsville on a 1/4 mile in not the best

conditions our .45 Nelson ran a mid 24 2 lap not close enough to Tommy's 22.293 second record but close enough to see the Warheads potential. Here are a couple pics of a nitro Warhead and a full P Shaman. The boat in the backround is my own HTV with a Q 1520 1600kv Castle. For those interested the Shaman is 31" and the Warhead is 33". My boat is 32" with a wider mid section which seems to make it better in rough water. For FE I made my own cowling that fits the Warhead and Shaman which allows for a 3/4 taller radio/battery/esc box.

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Mic how high is the prop on your warhead with the Nelson and how high on the electric ?

 

[lohring]

Brian Buaas and i did some testing with the Leecraft XT-460 hull. It's a little small for todays nitro powerheads, but I've had a lot of experience running it. I was beaten in both 7.5 cc and 11 cc classes in the 2005 NAMBA Nationals by the HTB 360. The Hornet, though no longer in production, is better still for 7.5 modified tunnels. The Shaman isn't any too big as a stock 7.5 tunnel.

As a Q tunnel we were pulling somewhere between 2500 and 3000 watts. It was running at lap speeds that were faster than the best 7.5 mod Leecraft tunnels. A P tunnel would need to pull around 200 amps for this power. These days there are motors and speed controlls that can handle twice this current. However we are pretty much at the power limit for a 34" hull. I think spec classes that hold the currents to 100 - 150 amps are the way to go to fit both popular hulls and shallow pockets.

Lohring Miller

 

[RonShaw]

Brian Buaas and i did some testing with the Leecraft XT-460 hull. It's a little small for todays nitro powerheads, but I've had a lot of experience running it. I was beaten in both 7.5 cc and 11 cc classes in the 2005 NAMBA Nationals by the HTB 360. The Hornet, though no longer in production, is better still for 7.5 modified tunnels. The Shaman isn't any too big as a stock 7.5 tunnel.

As a Q tunnel we were pulling somewhere between 2500 and 3000 watts. It was running at lap speeds that were faster than the best 7.5 mod Leecraft tunnels. A P tunnel would need to pull around 200 amps for this power. These days there are motors and speed controlls that can handle twice this current. However we are pretty much at the power limit for a 34" hull. I think spec classes that hold the currents to 100 - 150 amps are the way to go to fit both popular hulls and shallow pockets.

Lohring Miller

Lohring,

I'm very new to FE, so you can probably take my comments with a grain of salt. With my motor and ESC selections, I'm hoping for Full P speeds better than my 40 mod that is still very competitive. That was the reason I selected the 460 for P heat racing. I think the Q speeds may very well be in the 70's so I selected a 36" boat for this task. Hopefully I will be able to test soon......

 

[Kris Flynn]

You can defiately get the 5mm to 3/16 square from Hyper. I can do cablrs, just sorting some for myself and a buddy now

 

[HTV Boats]

I know the old time FE thoughts on power are big watts and expensive ESC's to run full P & Q boats. I do think tunnels are a different animal and will not neccessarily benefit just throwning big HP on them. The .21 class runs 40-60 mph and the .45's run 45-65mph and the upper end in mph does not get you in the winners circle. That and you just can't add weight to compensate extra power. You wind up either blowing over and spinning or barrel rolling in a turn. You may look good on a downwind pass but as in all racing the course is broken down into 4 critical area's. 1 entry speed and transition through the first half of the turn. 2 transition and acceleration out of the turn. 3 acceleration from turn exit to mid point. 4 top end at the end of the starightaway: which if too great may mess with #1 and really cost you lap times. These 4 segments occur 12 times during a 6 lap heat and I have them listed in what I feel is the order of importance. 1 & 2 being 60-70% of the race in my opinion. So I feel raw HP is about 30% of a winning boat.

What I see in FE power is to a nitro tunnel racer that has struggled to break the 60mph barrier the FEgods just handed us 70+. Try and keep any tunnel from blowing over above 70., good luck. Take spec power at about 700-900watts more than enough power for 30" hulls that get critical in the upper 50 mph range. Bill Britton with his 29" Lynx added a 200amp Swordfish ($100) and a $45 40X74Keda 2300kv motor and put down 2 of the best 21 tunnels in the country in a local mixed heat race. With a Shaman that power combo could compete in .45 tunnel today. Take a step further and our 1515 1y is not the motor you would race in a P mono or hydro but it takes a .45 size tunnel to some real speeds. Thats 1250 watts and 2500w peak. On the boats out there today 3000-4000 peak watts and 6S are beyond what we need. The better guys will figure out them eventually but remember that big straightaway speed is less than 25% of the equasion.

As was mentioned total milleamp consumption will factor in and the few of us that are testing now to race heats are in that crap shoot. Do you add weight with bigger battery. Remember 5000ma 4S is much lighter than 5000ma 6S. You can save ma's with lighter props. Each boat and driving style will dictate how far you push props and weight and that is what is going to be fun figuring out as we start heat racing. My first heat with a 5S Q tunnel 5300ma 1P 1600kv 1520motor and a M447 I was in the lead and hit the LVC at 5 3/4 laps. Next heat was an M445 and back to 1st place. Actually I think is was faster around the course due to acceleration. This is all virgin territory for all of us. The answers will come from trial and error and heat racing. We are going to make mistakes and learn. If you think your gonna pack 8000-10000 ma bateries and 4000watts of power in any tunnel your going to be in for a rude awakening after 1 lap. Bring em! It worked in your cats on a SAW but tunnel heat racing with big power is driver and setup class. Going to be fun trying different combos. With $100 to $250 speed controls and $200-$250 motors your not going to scare off tunnel guys who spend $600+ on .21 and .45 grenades and find the FE is faster. One reason FE has struggled is the concept of $500+ escs and that again for motors. Limited or Spec is flourishing on low entry cost and tunnels may make a mid cost entry point that might not have a chance nationally in a hydro or mono. Just my opinion so bring a high dollar tunnel to Charleson and prove me wrong.

Mic

 

[lohring]

Brian Buaas is getting close to 80 mph with his SAW P tunnel. I've watched a lot of nitro tunnel SAW passes and that P speed is comparable to 7.5 mod nitro SAW speeds. I think for a real P tunnel you need a boat that's similar to a 7.5 mod nitro tunnel since that would indicate the powers are similar. If you want to finish races, you need a bigger boat for heat racing than SAW. When I stopped racing nitro tunnels, the existing hulls were all getting a little small for the best 7.5 mod engines.

It's always less expensive to run higher voltage and lower current to get power from an electric motor. Unfortunately, our rules mostly encourage the opposite approach. By specifying motors and/or speed controls you are limiting current as well. This forces an emphasis on hull design, setup, and especially props. I think you will see more and more spec racers as a result.

Lohring Miller

 

[HTV Boats]

What it looks like to me is a challenge and a lot of different ways to accomplish similar results. If you look at all the 2 lap outboard records in both NAMBA and IMPBA the differences from .21s up to .90s are fairly close and .45 and above not neccesarily much faster. This over a 20+ year period with many changes in hull design. Now these record holders are the cream of the crop but some of our everyday heat boats can get within a couple seconds of the records. Maybe why in open tunnel classes a .45 size is not a handicap. FE P &Q power seem to replace ,45-.90 motors well. On certain courses in rough water the larger boats have an advantage but I have seen smaller lighter boats prevail with driving skills. Maybe why tunnelheads are so passionate about their boats as they can take a slingshot and defeat larger power. Again from spec on up it will be good racing. Charleston SC in a couple months will have some answers and probably more questions. If your an FE racer in the Southeast come watch for an afternoon and I guarantee you'll build a tunnel for next year.

Mic

 

[RonShaw]

...........Maybe why tunnelheads are so passionate about their boats as they can take a slingshot and defeat larger power. Again from spec on up it will be good racing. Charleston SC in a couple months will have some answers and probably more questions. If your an FE racer in the Southeast come watch for an afternoon and I guarantee you'll build a tunnel for next year.

Mic

Mic,

You are absolutely right!!!! It's a great time to be in tunnels as it is the fastest growing class due mainly to the interest in FE. There is going to be a lot of extremes at these first few 2012 races as we all push-the-limits to find that sweet spot between speed and handling, that will give us the best heat racing lap times. If I were Shawn Junker, Mike Luszcz, Ron Drake, Alfred Lanza, or Dan Hutchison, I would load up on inventory and show up at the WTC with a load of boats to sell. I would be very surprised if they have any left after that weekend.........