Youngblood Jetboat Basic Boat Specs
THIS DATA IS FOR GENERAL INFORMATION ONLY – THE DATA IN NO WAY REPRESENTED AS ACCURATE, OR AS AN ABSOLUTE, OR AN EXPRESSION OF, OR A CLAIM OF SAFETY – INFORMATIONAL ONLY – USE AT YOUR OWN RISK! FOR VARIED OPINIONS, PLEASE ENTER THEM IN OUR GUESTBOOK OR JET TECH FORUM.

Most popular overall lake/performance boat 1. TX-19 2. TX-20 3. TX-18	Smoothest Ride 1. TX-20 2. TX-19 3. TX-18
Quickest 800 foot. 1. TX-19 2. TX-18 3. TX-20	Quickest ¼ mile 1. TX-18 2. TX-20 3. TX-19
Easiest to set hardware 1. TX-19 2. TX-20 3. TX-18	Least Change to Hardware/Water Conditions 1. TX-19 2. TX-20 3. TX-18
Safest on lake 1. TX-20 2. TX-19 3. TX-18	Fairly safe top speed for boat – good water – closed course TX-18 115 -120 mph TX-20 110 -115 mph TX-19 105 - 110 mph
Fastest speed for hull TX-18 142 mph TX-20 120 mph range TX-19 115 mph

Approximate General Specs:
BARE Hull

TX-18 Bottom = Tunnel Length = 18' 4" Beam = 81" Ultra light = 325 lbs - Race Only Midweight = 360 lbs Lake weight = 400 - 450 lbs	TX-19 Bottom = Gullwing Length = 19' 4" Beam = 88" Transom height = 23" Freeboard = 13" Ultra light = 330 lbs – Race Only Midweight = 380 lbs Lake weight = 450 to 500 lbs
TX-20 Bottom = Tunnel Length = 20' 4" Beam = 84" Ultra light = 350 lbs – Race Only Midweight = 375 I 425 lbs Lake weight = 425 – 500 lbs

Performance –
This is VERY basic information with many variables in engine design power curve and setup as well as hull design and final rigging setup. This final setup is critical not only in proper setup of the hardware, but the total weight and balance of the boat as well as safety. You cannot expect to take a lake weight boat and add a stereo, false floors, an all iron blower motor, carpet, seats, and engine covers and expect the boat to run as quick as a race boat with lightweight components. I only know of one exception!

Approximate Speeds with TRUE net HP.
An impeller chart does not lie. Once a jetpump reaches final impellar speed it is like a dyno with the brake fully aplied. The impeller chart will indicate your true NET HP on a boat setup with the pump fully loaded and not cavitating. Speeds in excess of 100 MPH require a total combination of proper engine power and power curve matched to the proper impeller and a properly setup hull and hardware. In a properly setup boat an old rule of thumb was 600 net hp would produce approximately 6000 RPM on a B impeller and 100 MPH. Various brands of impellers also have different efficiencies. I have a program that can assist in impeller sizing and boat performance for the various impeller manufactutuers if you desire assistance.

Let's talk about horsepower......
This is probably the single largest exaggerated component in the performance business!  If your engine has not been on a dyno, then the best test for your power rating is to see how well you can spin an impeller and then compare it to an impeller chart to indicate your net hp. Now this is with a fully loaded pump that is not in cavitation. If you have been on a dyno, was it an engine builder dyno or an independent testing service? The calibrations between various dynos and their geographical locations can be as much as 5 to 10% from one to the other, possibly more. Know your dyno service and the efficiency of the dyno! Secondly, use the UNCORRECTED Data to correlate with the impeller chart. Yes, it is true that the corrected and uncorrected can be both the same when the weather is good, but if you know what your UNCORRECTED raw power numbers are in summer air conditions, then you will be much closer to charting your engine power correctly. On a given day, the uncorrected is all you really have! The corrected numbers are for comparative analysis comparing with days of varying weather conditions and of course bragging rights! In the summer air, especially in the Southern US, the uncorrected power can be 5% or more less than the corrected. Take this factor with the fact that some dynos are calibrated HOT, and you may see an actual impeller chart power of 5 to 15% lower than your engine power expectation. DON'T BE DISCOURAGED AND GET LOST IN THE NUMBERS! Work with your combination to obtain the best performance that you can get in your boat! If at ths time you do not have the results you feel that you need, then maybe it is time for a better engine and/or hull combination. Seek the assistance of persons knowlegable in the field.

Now that all of that has been said find general MPH figures below:
Very general – no absolutes!
Stock 300 to 350 hp = 60 to 70 mph
350 to 450 hp = 65 to 75 mph
450 to 500 = 70 to 80 mph
500 to 550 = 75 to 85
550 to 600 = 85 to 95
600 to 650 = 95 to 100
650 to 700 = 100 to 105
700 to 800 = 105 to 110
800 to 900 = 110 to 115
900 to 1000 = 115 to 120


An idea to consider in the impeller department.
Most jet pumps begin to loose efficiencies in the 7000 RPM range. So, if your ride is setup correct and your engine is indeed spinning the impeller in excess of 7000 RPM, then you may need a higher ratio impeller. The most important part is to match the power curve of the engine with the impeller. For maximum performance applications, build your engine to make peak power in the 6000 to 7200 RPM range and impeller to peak HP. In some racing applications, there has been some racers that are utilizing Pro-Stock type engines that produce peak power in the 8500 to 9000 RPM ranges. These racers have experienced some success using gear reduction units between the flywheel and jetpump. One case was using an A impeller or larger and turning the pump shaft at 7000 while the engine was spinning at 8500. There is some efficiency lost in the gear unit, but there is also some torque multiplication that takes place during acceleration. I don't know anyone using this successfully in a daily jet boat.... but it gives you something to think about.