fast9

I just got my new Aeromarine t-boat on the water. Just starting to get things dialed in. Lots of tweaking left to do. As of right now it is running about 50-51 on the radar gun with the engine pretty rich. What should I be shooting for as far as competitive race speeds? Right now I am running the X572 they sent me. No mods, just sharpened and balanced. This is my first gasser, and I do not have a collection of props yet. Looking for suggestions on what to try next.

rcboateric

You might try a mod 7016 prop from Chris, if you're running a mod engine and 257, the best needles setting are 1 on H and 2 on L, the top speed is depends on your setup.

martno1fan

You will no doubt be running a stock motor if your racing? if so speeds you should probably be aiming for are mid to high 50s,from what ive seen on the boards these are the speeds guys are running competetiveley in race trim although 60+ mph has been reached with stock motors.
Mart
try over on jims boat dock theres more guys on there who run these cool boats

rcboateric

I'd like to see how a 21 lb. Thunderboat runs over 60 mph with a stock engine, if it does, the stock engine needs to turn 18000 rpm with a 7016 prop in the water, Can a stocker turn that high? if so, it must a full mod engine.

martno1fan

Theres a few stock thunderboats that have hit 60+,i too was sceptical but thats the speeds that they have recorded with your favourite toy the gps,if you did your homework you would allready know that.The rokett i have has recorded speeds in the mid 50s with stock motors in race trim regularly so id think 60 would be possible if setup for all out speed.The blazer thunderboat has hit 59 mph in the video i linked in early testing and apparently has now hit low to mid 60s with a bone stock motor.Dont be fooled by the size of these boats they are fast dam fast .They also tested it with a full mod and it hit mid 70s apparently,i also know the rockett hit 64 mph with just a mild modded zenoah Joe told me so himself so im certain mid 70s is more than possible.He also sent me a mod(ride pads) for the boat that gives an instant gain in speed of 4-5 mph he reckons.
ps speed isnt allways about rpm its about making the best of whats available,match the right prop to the motor etc.
Mart
[link]http://www.blazermarine.com/videos/Lauterbach42708.mpg[/link]

Jim Geigers Rockett somewhere in region of 54 mph i believe stock motor again.
[link]http://uk.youtube.com/watch?v=HxalhItqJvw[/link]

rcboateric

The Thuderboat speed record is 56.948 mph at the NAMBA, if you think your similar boat can kick this record out, please go ahead.


http://www.namba.com/content/records.asp?EventType=10

martno1fan

I dont get your point yet again you are missing the point not everyones interested in speed records but i supose all these people are lying or maybe there gps is wrong but hang on gps are never wrong right?.It seems to me your once again trying to start yet another argument,and im not playing.The facts are out there go find them or dont i couldnt care less.
Mart

rcboateric

My point is simple, I was just trying to find out the true speed for the Thunderboat, if you're not agree with that, borrow a GPS and put it in yours and run it.

martno1fan

True speed? well theres many thunderboats arround just do some research and im sure you will find all that i have?,most are in the low to mid 50s in race trim as ive said and ive talked to many who race them ive no reason to not believe them .My boat has a full mod so id say its over those speeds .The guy who started this thread has recorded speeds of 51 mph with the motor not fully tuned in yet so what does that tell you?.Tell you what why dont you buy a thunderboat yourself and stick that hornet motor in you like so much and ill gurantee you will be surprised how fast it will go and it wont blow over like a cat either .
Mart

rcboateric

I really would like to see a Thunderboat that can run in 70's or 80's just like our cats and riggers, I'm not hating everyone who has a similar boat that could run over 60mph or more but why don't you respect that NAMBA, the boat speed record is 56.948mph or unless they forgot to update it.

martno1fan

Hey mate im not disrespecting namba at all im just telling you the speeds that these boats can and have done is all,namba is fine for those that attend but lets face it people have gone faster than some of those records as you well know.Its just what speed they manage on that one day that gets recorded and called a record and the conditions play a big part in any speed attempt too.Look at Wallys cat he broke the record but he has gone faster as we all know so i bet hes allready planning the next attempt,i too would like to see a thunderboat doing 70 mph hopefully mine just kidding it honestly doesnt bother me i just run for fun.My boats plenty fast for me as it is,as you know i havent even messed with it from day one because i like how it handles as it is,im sure it would or could go faster but i just havent had the time to play with it much this year.
Mart

rcboateric

I'm looking forward to see those Thunderboat owners that can going there to replace that speed record just like Wally did, otherwise, its speed limit is 56.9mph to me so far.


Class: Classic Thunderboat
Name: Jim Johnson
Date: 09-08
Sec: 3.951
MPH: 56.948
Egine: Zenoah
Hull: Insane
Prop: Propworks 6717

juicr

The Blazer Marine Lauterbach will indeed do 60 mph with a stock Zen and a M&D pipe. We run a PropWorks 6518-3-415. The boat is modeled after the "Deepwater Special"

rcboateric

I believe that what you said, a current Thunderboat speed record holder won't hold that for a long time.

Ron Olson

My Feedback: (1)

At last, somebody posting an answer to the question instead of joining in on the pissing contest!
The NAMBA record trials are in a couple of weeks at Legg Lake so just maybe a new one will be set for the T-boats.

Scott Schneider

Just because ONE Owners of a Thunder Boat at a SAW event did 56.9, does not mean that there are not others with thunder boats going faster ?

A SAW contest is a pissing match of the moment, maybe your fast that day, maybe not ? .... But in a class as new as the Thunder boats, he was the fastest that day in a class that had no pre-established record on the books.

Weight has a LOT LESS effect on how fast a boat go's when talking "Air Trap" hydros that when trimmed right ride on a pocket of air actually flying to some degree.
Weight does however make cornering sloppier and acceleration slower []

Ron Olson

My Feedback: (1)

Scott just brought up a good point. When a new class is started and it is one where speed records can be set in SAW and oval, there is someone who lays down a speed as a baseline and that person gets credit for holding a record.
Someone that I know has set many IMPBA records and he ran a boat at a record trial event in Flint, MI a few years ago where the boat was a slug but since it was a newly established class, he had another record to add to his already large list of SAW records.
SAW doesn't mean a thing in real-world racing as those boats are set up to do one thing, go fast. Most don't turn for crap in SAW trim. Give me a boat that will do 6 laps, make it back to shore under its own power and I'm happy.

Now, back to square one. What's a good prop for a stock Zen (with tuned pipe I'm presuming) for a Thunderboat?

martno1fan

Good posting,i have to agree especially on your last point about the weight not been such an issue in these types of boats,some of these boats are enormous yet still run very fast,in fact to a degree id say the weight is a good thing as it helps keep the boat running level because as you say these things are actually flying when flat out and they are really something to see.
Ron as regards the best prop for a stock motor in a thunderboat id like to know that one too as my new one will have a stock motor,ive heard lots of recomendations from 6717/3 to prather 275 and quite a few in between.Another thing to take into account is which thunderboat your running because the zipps are smaller than most of the others.The lauterbach is 52" long compaired to the zippkits rockett at just47" and weighing arround 14-16 lbs so its also probably one of the lightest so possibly could be one of the fastest too.

rcboateric

The weigh did effect my cat, added 18 oz of the epoxy to its front for keep it nose down a bit, that helped a lot, as the results, the cat runs more stable now and won't flip over at all even on the choppy water at low to mid 70's, I thing I can bring it to race with other boats, but the issue is I last at least 2 mph of the top speed for this adjustment and never made it back no matter how I re adjust the prop height, my best prop is 2176 hight rake prop, before that I tried a few props on this cat like 6718, 6717, 6518 and all these only could run low 60's.
Scott, I have a question for you, if I send my mod engine back to the its builder to raise its intake and exhust timing, will this change would increase the top speed for a few miles? I known it would lose some low band torque but I wouldn't care about it.

martno1fan

Eric rather than add weight why not move the motor forward more if you have room? that way the boat is lighter yet hopefully more stable in chop etc?.I did that on a mono and it helped a lot and speed was better so you might keep your speed but have a more stable boat,sorry for going off topic guys.
Mart

rcboateric

I just hate to drill 5 more extra holes on her, re install the radio box, a new brass tube and a new shaft, she runs pretty stable now after that changed.

Scott Schneider

As you readjust the power band of an engine, your loss's in torque and need in allowing engine to spool up harder will require using a prop of less blade area or diameter.
In most cases those who choose to go the "High Rev" route with engines are required to educate them selfs on the art of prop cupping. You need to find a prop the hull and engine equally like, then modify it for the increases in efficiency required to get the speed up to a higher place.

martno1fan

Hey Scott which route do you choose .
Mart

rcboateric

Hi Scott, What do you think of Wally's cat that just reset the IMPBA record, all he uses is the Sprint cat that is light weight designed, SS engine, high CG for the engine, low drag hardward system and the prop may be one of the 2716 series, I'm very interested in that engine, Would you think if the speed is from that engine? if so, I have an internet calculation for that but not sure if it's accurate or not, let say Wally's prop is a cupped 2716 4.8" prop, a cat prop slip % is 20, the speed is 78 MPH, if entering all these info to it, his engine RPM should be 21450, if everything is correct, Why that SS engine spinning a prop like that high RPM and others can't?

http://www.props4u.com/prop_chart.htm

tmt32mj

FYI eric,
Wally set the XLS27 cat record, using a QD in a dragcat for it. His SS engines didn't break the record. His sprint cat didn't break it neither.
To answer the origonal question. Ken Dutlinger won the Cincy race with my 6518/3. So it's 2 votes for the 6518. Try it and see.