|
11-09-2011, 03:12 PM
|
#1
|
leds
Country: channel islands
Location: guernsey
Occupation: panelbeater
Interests: boats,motorsport,socialising
Boat name: Family Affair, RG Racing
Boat make: Fairline Sunfury, Phantom 21
Engines: 2 x 4.3 v6 Volvo, merc 200 XS GEN II
Cruising area: channel islands/french coast
Join Date: Oct 2009
Location: guernsey
Posts: 93
|
Merc 2.4 efi over rev
Has anyone fitted a rev limiter to a 1990 merc 2.4 efi before? during rough races we are having a problem with the motor over reving and then cutting out,i thought by fitting a limiter it would solve this problem but im not sure if its possible to do
__________________
|
|
|
11-09-2011, 04:17 PM
|
#2
|
Registered User
Country: UK
Location: Weston Super Mare
Occupation: Electrical Engineer
Join Date: Mar 2004
Location: Weston Super Mare
Posts: 6,351
|
i cant see any rev limiter being quick enough to limit what is in effect free revving the engine with no load. I'd be more concerned as to why the engine cuts out as the limiter built into those ecu's simply go full rich at a certain revs and shouldnt make the motor cut out
__________________
|
|
|
12-09-2011, 11:24 AM
|
#3
|
Registered User
Country: Ireland
Location: Dublin
Occupation: Boatbuilder
Boat make: Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
Engines: 300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
Cruising area: Malahide, Dublin
Join Date: May 2004
Location: Dublin
Posts: 1,803
|
I've had that happen before, switched from an A4 7500 limit to an A48 (drag ecu 11500 limit) and it hasnt happened since.
That wasnt the reason we switched the ECU, but noticed now that you mention it that it hadnt happened since.
|
|
|
12-09-2011, 09:20 PM
|
#4
|
leds
Country: channel islands
Location: guernsey
Occupation: panelbeater
Interests: boats,motorsport,socialising
Boat name: Family Affair, RG Racing
Boat make: Fairline Sunfury, Phantom 21
Engines: 2 x 4.3 v6 Volvo, merc 200 XS GEN II
Cruising area: channel islands/french coast
Join Date: Oct 2009
Location: guernsey
Posts: 93
|
hi alan,sounds like this could solve the problem where did you get the drag ecu from?and what sort of price are they?cheers
Quote:
Originally Posted by Hydrostream
I've had that happen before, switched from an A4 7500 limit to an A48 (drag ecu 11500 limit) and it hasnt happened since.
That wasnt the reason we switched the ECU, but noticed now that you mention it that it hadnt happened since.
|
|
|
|
12-09-2011, 09:57 PM
|
#5
|
Registered User
Country: Guernsey
Occupation: Engineering
Boat make: None, boo!
Engines: Turbines mainly!
Cruising area: The inside of my workshop!
Join Date: Mar 2008
Posts: 2,646
|
Trouble is it will also allow your motor to rev to 11500, even if only for a moment, which can be incredibly damaging on a motor that isn't as balanced as a drag spec one.
Am I also right in thinking that the A48 ecu leans out on the way to high revs to heat the block in preperation for the big revs? This wouldn't be good news for a motor usually run at 6-7k
|
|
|
13-09-2011, 01:58 AM
|
#6
|
Registered User
Country: Ireland
Location: Dublin
Occupation: Boatbuilder
Boat make: Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
Engines: 300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
Cruising area: Malahide, Dublin
Join Date: May 2004
Location: Dublin
Posts: 1,803
|
Quote:
Originally Posted by larby
Trouble is it will also allow your motor to rev to 11500, even if only for a moment, which can be incredibly damaging on a motor that isn't as balanced as a drag spec one.
Am I also right in thinking that the A48 ecu leans out on the way to high revs to heat the block in preperation for the big revs? This wouldn't be good news for a motor usually run at 6-7k
|
Thats food for thought, although I doubt it would ever see 11500 even if you kept the pedal down. Do a lot of the ROS motors not have the limiters removed?
I've never heard of the lean out on the drag, I ran that ECU for about a year on my SportCat until the bridgeport did what bridgports do best! And always ran that motor between 6 and 7, ran it to 9 occasionally, funny it died on one of those occasions
Daren, the ECU came on a motor I bought in the states. Im not using it at the moment if you want to try it, see if it cures your problem. Would probably pick one up on S&F. Or look for a Bructto ACU/PCU thats what I want to play with next!
Might actually be worth an Email to Tony Brucatto about your problem.
|
|
|
13-09-2011, 09:20 AM
|
#7
|
Senior Member
Country: UK
Location: Devon
Occupation: Garage Proprietor
Interests: PowerBoat Racing
Boat name: If Only
Boat make: Bernico F3 OCR, Bernico Prototype Inboard, and some Ribs
Engines: Yamaha Pro V 115
Cruising area: UK, France
Join Date: Jan 2005
Location: Devon
Posts: 3,095
|
You could always try using the throttle pedal !! They do a really good job of limiting revs !!
__________________
If Only
National Outboard Immersed Propeller Mono Record 103mph
|
|
|
13-09-2011, 09:44 AM
|
#8
|
Registered User
Country: Guernsey Channel Isles
Location: West Coast
Occupation: Hotelier
Interests: Powerboat racing
Boat name: Vodkatini,Cap Camarat,Easy RiderSuper Rider & Hirrondelle
Boat make: Phantom 21,Jeaneau 925 Avenger19.Lorne Campbell Slipstream Tremlett 21.Tigershark 21
Engines: Volvo 5 litre,Merc 115 Tower,Twin 250 Suzukis and 145 Mercruiser LX
Cruising area: Channel Islands and French coast
Join Date: Jan 2009
Location: West Coast
Posts: 612
|
I thought your prop looked a little small when I overtook you a few times
Then you returned the compliment !-Good racing Leds cant wait for the
Prestigious Herm Race
__________________
Guernsey - The home of offshore powerboat racing
|
|
|
14-09-2011, 03:49 PM
|
#9
|
Registered User
Country: UK
Location: Weston Super Mare
Occupation: Electrical Engineer
Join Date: Mar 2004
Location: Weston Super Mare
Posts: 6,351
|
drag ecu's lean out at around 5000rpm to build heat ready for the big push to stupid revs.
|
|
|
15-09-2011, 09:38 PM
|
#10
|
leds
Country: channel islands
Location: guernsey
Occupation: panelbeater
Interests: boats,motorsport,socialising
Boat name: Family Affair, RG Racing
Boat make: Fairline Sunfury, Phantom 21
Engines: 2 x 4.3 v6 Volvo, merc 200 XS GEN II
Cruising area: channel islands/french coast
Join Date: Oct 2009
Location: guernsey
Posts: 93
|
Quote:
Originally Posted by OCRDA
You could always try using the throttle pedal !! They do a really good job of limiting revs !!
|
thats the plan bob but when your racing in force5/6 winds and a big swell like last weekend you arent going to get it right all race!!!
|
|
|
15-09-2011, 09:45 PM
|
#11
|
leds
Country: channel islands
Location: guernsey
Occupation: panelbeater
Interests: boats,motorsport,socialising
Boat name: Family Affair, RG Racing
Boat make: Fairline Sunfury, Phantom 21
Engines: 2 x 4.3 v6 Volvo, merc 200 XS GEN II
Cruising area: channel islands/french coast
Join Date: Oct 2009
Location: guernsey
Posts: 93
|
Quote:
Originally Posted by Big Dutch
I thought your prop looked a little small when I overtook you a few times
Then you returned the compliment !-Good racing Leds cant wait for the
Prestigious Herm Race
|
i dont remember you overtaking us you were well and truly tangoed!! bring on the herm race lets hope the weather is with us this year!!!!
|
|
|
15-09-2011, 11:26 PM
|
#12
|
Registered User
Country: Ireland
Location: Dublin
Occupation: Boatbuilder
Boat make: Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
Engines: 300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
Cruising area: Malahide, Dublin
Join Date: May 2004
Location: Dublin
Posts: 1,803
|
Quote:
Originally Posted by Burty
drag ecu's lean out at around 5000rpm to build heat ready for the big push to stupid revs.
|
Well you learn something new every day!
It did run fine on the cat for a long time, although probably explains the lack of balls that engine had in the mid range!
__________________
|
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Threads |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|