I must say....

[Tim_Duggan]

Depends on the hull!

Kaboom 7.5 lower handles best on a HTB290 & 3/16" cable is a plus. Propshafts suck though!

OS is my favourite though. Pin angle adjustment independent of propshaft angle is useful, and the best propshafts.

 

[LarryConrad]

I've run K&B, Lawless and OS on .21s and have OS lowers on most of my B tunnels now.I like the mount and the propshaft. I've run K&B and Lawless on 7.5's . Had problems keeping the header on my Rossi when I had a Lawless on my Leecraft and went back to a K&B. I shouldn't have that issue with the bolt on header on my Nelson when I start testing my Warhead with the Lawless.

 

[RonShaw]

OS is best 21 lower and prop shaft assy combo by far. Lawless and K&B for everything else but get your prop shaft assy from Hyperperformance. Some 40/60 tunnels like the prop shaft closer (K&B ), others like the extended thrust distance (Lawless).

 

[moparbarn]

somewhere, back a good while ago, someone (rod geraghty, i think) did a frictional loss dyno study on all available ob lowers. k&b had the least friction/drag, therefore the least h/p loss of any. he tested k&b, os, rek/irwin, tt & lawless. from what i remember, all were tested with oem flex's & prop shafts. i use k&b because of this test. not the best lower for adjustment, compared to os. setback can be adjusted with the mount. but again, not the best, because you're also moving the engine & lower back, changing cog.......os & lawless give you setback with the engine farther foward. all just options to suit different setups, hulls & driving style. i have so much k&b crap, i'll just keep using it with otto's or hyperformance prop shafts, brass or ss liners & kris flynn flexs.

 

[Rene Danner]

Here is a race from yesterday,and it looks like I need one of those Nova powerheads B)

 

[RonShaw]

You were lucky to finish that race Rene. Someone in the yellow tunnel almost took you out at bouy 6!!!!

 

[Rene Danner]

Yeah I know, I had to change motors after the 2nd round and went back to my back up motor and was able to finish this heat.It was a tough day with the tunnel for me we will try something else for the last race of the year in 2 weeks..

 

[Slideblues]

How bout " Top Tunnel Prop "

Whats yer fav........

Gene

Best all round, GR 40x53 bag stock

Second choice, PSRP 1440 fast but touchy setup

 

[rumrunner]

Sport 20 Jimmy johnson 40x53 handle all round for heat racing (lynx )

Mod 20. Props 4 u 40x53 same as above. Lynx cut 642 andy brown fast but loose .(shaman and sniper2 )

Supersport 40 abc 47 x60. Heat racing (warhead)

Mod 40 Abc. 47x60 (warhead)

Mod 40. Mitch junior special (hornet ) this is a beast!!!!!!

EF and open. Props 4 u. 665

Fe p limited Props 4 u. M445. (lynx)

Modvp 40x53 (vision)

This is what I run no secrets.

 

[RodneyPierce]

A prop I have been working with the on Sport .21 tunnel is a Sholund x442 reduced and lynx cut. Its got me in the low 50's per a Stalker radar gun right now but need a little more time to get the hull ironed out and a bit more stable on the water.

 

[wayne middlemiss]

could somebody put up a pic of what the lynx cut looks like, im not sure I have seen it before just to clarify it for me please.

 

[ozbryan]

40x53 is a great prop and always a good starting point.

I have run 40/53, chopper (can't remember the number) 3 blade and now a x442 lynx cut on my HTB/Nova. All have worked well with set up changes. The X442 is probably the pick of the bunch.

On my sport boat 40x53 and a X442 lynx cut are the two I have found that work best.

 

[LarryConrad]

A pair of X 442 Lynx cut, 3.10 TE cup,40.64 mm diameter, 3.33" TE cup, 40.40 mm diameter, and a X 640 Lynx cut 3.21" TE cup, 38.94 mm diameter. My original base line setup on my Vision as suggested by the boats designer was neutral angle on the prop shaft, with the bottom of the bullet 1/8" above the bottom of the sponsons. With the X 442's it was fast through the turns with great throttle response and acceleration from an off plane crawl. Boat was very flighty and easy to blow off, so I started lowering the engine till I obtained the stability I wanted. Current setup has the bottom of the prop shaft 1/8" above bottom of sponsons, neutral angle, static balance at 7 3/4", The lower engine setup favors the smaller diameter X 640 prop, corners like it's on rails and is very stable in the wind and in race water. Finished the day Sat in 2nd out of 5 boats racing with no dnf's. Just need to pick up the top end I lost with my original setup. Props were done by Mark Sholund.

 

[Kris Flynn]

Hi Larry,

are they the ones you are selling me?

 

[LarryConrad]

Hi Larry,

are they the ones you are selling me?

LOL! they will be hibernating for the winter in my prop box in about a month and a half when the water around here starts getting hard.

 

[ozbryan]

Send them down under Larry the water is never hard in the LAND of Oz! Hahaha

 

[LarryConrad]

I have a couple of sweet tunnel props here that came from down under... a X 637 and a 40X53 that Aaron did for me a couple years back. The 637 really lets the RB on my Vision sing, but the bow comes up really hard and fast exiting the turn,and the boat gives little or no warning before blowing over if the wind is just wrong. The 40x53 is my baseline prop on my OS sport engine. Two weeks till the last race of the season here in Minneapolis. If the weather stays decent through this weekend I may get a chance to test these Lynx cut props... on my Lynx.

 

[Slideblues]

That Lynx cut is interesting........

Page 7 turned out to be a purdy good read

Thanks for the pic Larry,

Gene

 

[LarryConrad]

No problem Gene. Wayne asked for a photo, and the camera and a few of the props were right handy. TCMBC's last race of the season is September 28th. Sport and B tunnel are two of the most popular classes up here. Strap a couple tunnels to the tail cone on your Buel, point her North and head her into the wind, and come join the fun.

Larry

 

[wayne middlemiss]

thanks Larry I appreciate it, now im aware of them & yes I have seen them but not taken much notice of them as to what they were .lol