Speeds of 42 Sonics
 

Can someone provide me gps speeds for a 42 Sonic and what power/drive setup they have. Looking for ~80mph and would like to know how much power it will take.

Also, any tricks on this hull to improve speed and how much was gained with the change, i.e. weight shift, extension boxes, bottom work, etc.

Thanks,
Rick

Re: Speeds of 42 Sonics
 

RV,
I had a 2001 358 with 500efi's it ran 79mph GPS. If you have a 2002 or newer you will have the infusion layup which will save approx. 10% in weight. You will need at least 800hp per engine to get in the 80's if my figures are correct. Our new 386sts with 800hp per engine will be in the 90's but hoping to be just in the triple figure. Hope this helps.

Re: Speeds of 42 Sonics
 

RV
My 01, 386 with 575 SCi's, XR drives with Imco boxes runs 83 GPS. The 575's are rated at 550 HP. I think three HP 500's would get you close or above 80 in the 42.

Re: Speeds of 42 Sonics
 

Thanks for the response, anyone else...

Re: Speeds of 42 Sonics
 

My 2000 42 with 500 efi's bravos 24p bravo 1 props all stock, empty with just 2 guy's 1/4 tank of gas in salt water went 75.3 gps. Installed generator all the crap you need in freash water the best I got was 72.6.

Re: Speeds of 42 Sonics
 

I'm got 72.2 with 26 pitch P5Xs but we are still at 19% prop slip. Julie from Throttle Up is working with me. Can't say anything but great things about them. Waiting on Sonic to send me a drive spacer to get the props in the water better.

2005 Sonic 42SS
525 EFIs
Bravo XR ITS Drives

Re: Speeds of 42 Sonics
 

captwk how much of a spacer you going to? my firend with 358 500 efi with its had to go 2 full inches to get dialed in correctly!

Re: Speeds of 42 Sonics
 

I have a 1998 42 that had the mer 800SC #6 drives, we are now going with injected 1100's. I hope it hit in the mid 90's, it was runniing in the mid 80's

Re: Speeds of 42 Sonics
 

Rick I went through my motors 2 years ago there are 509's 585hp each. I am turning a stock 24p bravo one at 5100rpms I am at 73 gps. 1997 42 Sonic with generator.

David

Re: Speeds of 42 Sonics
 

2000 42 sonic, 750s, xrs, 80mph

Re: Speeds of 42 Sonics
 

Does anybody have any owners manuals on operation of the boat anything that came from the factory for a 42'. I bought the boat but all the paper work that came with the boat was missing.

Re: Speeds of 42 Sonics
 

26 Sonic I'm looking at 2" also. The boat now has a 1" spacer. The problem I have now is major blow out trying to get up on plane. I have to power up to 2500 rpm' to get the boat moving then hold the rpm' around 3500 while having major blow outs on both drives, then when you think ther props start to take a bite hold the rpm' at 4000 while still blowing out then it takes off. If you don't feather the throttles carefully around the 3500 rpm' you loose everything and have to start over. Throttle Up says I need the 2" spacer to fix the prop slip that they calculate is around 19-20%. Does anybody else have any insight on this? Also can you guys give me some measurments off your boats on prop shaft centerlines from the keel of your boats? Mine are 3 3/4" from the keel measuring up from the keel. My cavitation plates are 11 7/8" up from the keel bottom.


42 Sonic
525 EFI's
Bravo XR ITS Drives
15X26 Hydro P5X props

Re: Speeds of 42 Sonics
 

RV here is a dash picture

Re: Speeds of 42 Sonics
 

Captwk,
Thanks for the dash picture, very nice!

I will get you propshaft center line distance from bottom of hull for you tonight. This measurement will be from the hull at the point of the propshaft, not from the bottom of the V. This will give you a more accurate measurement than from the bottom of the V. IF you PM me your email address and I will send you a picture showing the measurement location so there is no confusion.

What is your dimension for this measurement?

Rick

Re: Speeds of 42 Sonics
 

captwk,
The propshaft center line is 6-1/2" below the hull.

Rick

Re: Speeds of 42 Sonics
 

I am only gooing in the mid 70s with my 94 with tripp 500. However Sonic told me that in 96 they raised the X on that boat by an inch and a half, and saw big speed increases. I saw a 2001 advertised for sale with 700s and Bmax drives that was indicated to go in the 80s.

Re: Speeds of 42 Sonics
 

I have all the paperwork with mine, but there isn't much there. Mostly just liturature from the various parts supliers.

Re: Speeds of 42 Sonics
 

The "owners" manual is just all the installations manuals, vendors information, and a generic Mercruiser engine manual. Nothing in there about how to operate anything on the boat. It is pretty much "figure it out for yourself"

If you have any questions, let me know I'll do my best to explain

Bill

Re: Speeds of 42 Sonics
 

I have those Merc. Manual's, I was just woundering like the operation of the head/ shower. Fuel selectors and the main breaker switches under the seat.

Re: Speeds of 42 Sonics
 

Call me or give me your number to call you

Bill

Re: Speeds of 42 Sonics
 

What I did to measure my prop centerlines was take a laser level and placed it on the bottom of the cavitation plate. Took the spot on the transom were it hit and measured down to the bottom of the keel, 11 7/8". Then I measured from the cavitation plate to the prop centerline, 8 1/4". took 11 7/8" minus 8 1/4" and got 3 3/4" up from keel for prop centerline.

Re: Speeds of 42 Sonics
 

captwk,
I understand how you made your measurement. The only reason I suggested the method I did was your method assumes everyone has the drives the same distance from the center of the boat. If the drives on the boat I measure is a little further then the prop will be a little deeper in the water eventhough it is the same distance from the bottom of the keel. I dought that there is much difference from one Sonic to another but this way tells you how far in the water the prop is.

Seems like your method, using the laser is very accurate. I would suggest doing the same process only shoot it straight forward (right in front of the drive) on the transom and measure down to the bottom of the boat at that location, not the bottom of the keel.

Rick

Re: Speeds of 42 Sonics
 

Here's a shot of Captwk's transom...

Re: Speeds of 42 Sonics
 

The 42 Sonic is an evoloution of my old 38 foot Banana...which then became a Coyote and finally Sonic. You can see photos of this boat running in the photo section.

The boat was all fiberglass. We laid it up very light and came up with a 3800 pound 38 foot boat, hull and deck ready for rigging. The engines I ran were 496 cu in with two four barrel 1050 carbs on each engine. The drives were #3's. Fuel was Av gas.

The fastest we ever saw on the Nordskog speedo was 96mph. In a 205 mile race in the Bahamas we averaged over 83 mph. Remember this was in 1979 and the boat was an all out race boat.

I am sure the quality of the build of a modern day Sonic is very good and much improvement has been done in the area of weight savings. I understand that production boats carry a lot more weight, but I just wanted to let you know what speed the boat was capable of and it was stable at that speed.

Sonic has done a beautiful job in the evolution of this boat and it turns heads everywhere it pulls in. Good luck in your pursuit of more speed.

Charlie McCarthy