JackLS1R1

I have done a lot of searching, and I am curious if installing a drive nose cone on my setup will be worth it or not:

1996 Checkmate Convincor 253 - Notched transom and no pad

Has a built/forged 502 EFI and M1 Procharger with 5 PSI

Drive is a swept back Bravo 1 X. Has hydraulic steering. 30P 4 blade prop

Boat runs low to mid 80s GPS speed.

Will installing a nose cone benefit me? I am looking at this IMCO: http://www.imcomarine.com/cal_store/...r-pick-up.html

Thanks for the help!!

Slippery

I don't know. However, I remember years ago talking to Ron Baker and Harold Naus (sp?) about nose cones. This was late 80s early 90s so Im sure technology and hydrodynamics have changed a lot, but they told me unless you're experiencing blowout or a high prop slip number it not only won't make you any faster, it might slow you down if it causes handling issues.

As with everything else, I think it's the entire setup combination that makes a difference. In other words, adding more cam without changing heads, exhaust, etc isn't going to let you take full advantage of the performance potential and is only liable to benefit the guy who sold you the cam..

Not what you want to hear, I know, but that hull is good enough and common enough that there should plenty of examples of good running combos out there.

I'd get in touch with the guys that own them and see what they're running instead of trying to reinvent the wheel. Take advantage of the dial in time someone else has already done.

Just my 02

Cheers

s

Slippery

Bummer. I was hoping there would be more responses to this. There's a ton of knowledge on this site & I was really interested in hearing some thoughts on this topic.

I forgot to include the following in my above response:

Our boat has a 2010 Merc XR drive. NOT a Sport or Sport master.

Our transom isn't notched, but we do have an Imco extension box, drive mounted fairly high, V-bottom (no pad) .

I have not run the boat as fast as the previous owner because 1) I'm running less HP and 2) I'm not as good a driver

I have run the boat deep into the 90's with no blowout.

This was Lee Spindler's (Schiada) personal boat. If it would have needed a nosecone, or a crescent shaped drive, it would have been wearing one already. The drive itself is the weak link in my boat, not the shape of the drive.

I think there was a time when adding a nose cone was "the thing to do". I believe a lot of lower units got nose cones that didn't need them.

Again, just my .02 and your mileage may vary. Hopefully some of the experts will chime in.

s

bulletbob

Post over in the Checkmate owners forum.You might have better luck. Best of luck.It's sounds like you have a nice setup.

JUPITER PULSARE

JackLS1R1, 1st of all, your Convincor 253 should have a "V" pad bottom. In other words, you have a 24 degree deadrise but at the very stern of the boat your raised "V" keel is much shallower (flatter) than the angle of deadrise to the lifting strakes. This allows the boat to fly a bit higher out of the water than a true deep V with a 24 degree deadrise. If you are running a very high X dimension and can surface the prop a nose cone may help your top end speeds. From what I've read and experienced in the past, 85 mph plus seems to be the magic number for adding a nose cone and you seem to be knocking at the back door of that number. You really never know until you try. It would be great if you could borrow a nose coned or Sportmaster style lower unit without spending the $$$ first. I currently run a Torque Master on a 21'2" Checkmate Starflite/Mercury Pro XB 250 that will run into the low 80's. I'm going to borrow a Sportmaster to see what happens! I have a 28' Checkmate 2800SX Outboard (so I'm very familiar with their bottom) but with 400hp and only 72mph I'm not pushing the speed envelope even though I'm running Bobs nose cones on both motors..more for the low water pickups than anything else....

Griff

At your speeds, a nose cone may give you some gains. I do not think it will hurt anything unless it is not installed right. The only way to know for sure is to try it.
There was a 32 AT that hit a wall in the upper 80's -low 90's and if I remember correctly, after adding nose cones, it went into the mid 90's.

JackLS1R1

I still have not pulled the trigger on this. Contemplating adding this EMI nose cone that is 2' longer than most

http://eddiemarine.com/drive-accesso...emi-nose-cones

Any other thoughts or suggestions on this... I don't want to loose MPH like I have read some guys on here have....

82predictor

Contact the guys at kunkel's marine in ohio. They have had several 100+ mph 253/270 / 283/ 300 boats and know what works and what doesn't. talk to jason or his dad they should be able to point you in the right direction.