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Thread: Fuel For My New Mojo
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10-14-2013, 01:33 PM #11
assuming the computer used to run these engines is similar to a car. the computer will detect the knocking/pinging and retard the timing to compensate for it. as long as it continues to detect, it'll run in a retard state and you will have some sacrifice in power. I don't think anyone will ever notice a boat running full tune and one running with the timing advance in a retard state, but as mla suggested, this will have some longterm effects on the overall wear of the rings/pistons/valves and seals. most engines today have quite a bit of "safe" room in the tune tho..
went to 2 tuners over the years to get the old mitsu evo's tuned. it was fun to watch the pc hooked up to it real-time detect and retard the ignition when picking up on knocking/pinging. one was on the interstates out by the salt lake city airport and done while driving. tuned the last one to the brink at a shop in portland on a dyno. original baseline dyno was 330hp/310tq. when I left, it was at 363hp/362tq with no other parts swaps, just an ecu tune. shows how conservative the engine tunes can be. sure mike has even bigger gains from diesels and tuners.'06 Supra Launch 20SSV-gone but never forgotten
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10-14-2013, 02:11 PM #12Junior Member
- Join Date
- Sep 2013
- Location
- cape cod
- Posts
- 18
Thank you for your help
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10-14-2013, 10:09 PM #13
I put 400 hours on my 08 XLV and ONLY ran 87 and it never gave so much as a hic up.
Levi
Former owner of a 08 Mobuis XLV, Cat340, 2650 Lbs.
I miss that boat!
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10-14-2013, 11:46 PM #14
Fuel For My New Mojo
As mike mentioned elevation plays a big factor as well. The higher up you are the thinner the air the less compression pressure the lower the octane needed. I know in Lubbock which is about 3400 ft above sea level you can't even buy 87, their low grade is 86 because the air is thinner. They say for every 1000 ft climb in elevation your engine loses 3% of its power. I don't think 87 to 89 is a big enough difference to cause any major damage. If it requires like 110 race gas and someone was using 87 then yeah, that would be a big deal. If you use 87 and don't want to pay for 89 then fill you tank half with 87 and half with 89 and now you have 88. Compromise haha
Sent from my iPhoneDavid
2017 Moomba Mojo Max Surf Edition, 2 Pair Wetsounds Rev10s powered by an SD2, 6 pair Wetsounds XS650M and Wetsounds XS12 powered by SD6 all controlled by a WS420. 2 Lumitec SeaBlaze X2 Spectrum underwater lights
SOLD***2008 Mobius LSV, Gravity III , Wake Plate, Z5, Exile SX65c's, Exile XM9s, Exile XI12D, Exile Javelin, Exile 30.2***SOLD
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10-15-2013, 09:39 AM #15
A lot of higher elevation areas (like CO) start at 85 octane for regular...I always wondered why that was and never realized that may be because of the elevation lol.
Boats previously owned - 2000 Supra Launch, 2003 Outback, 2006 Mobius LSV
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10-15-2013, 11:18 AM #16
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10-15-2013, 12:21 PM #17
i have been told dont waste money on over 89 either as it is calibrated for 89.. if you blend higher with 87 that is worthy, but dont expect any improvements by running 93.
Long running debate on here and wakeworld about 87 v 89. Many of us have done 87 plenty with no noticeable issues.
I ran a couple of Acura TL's that demanded 91 or higher.. was a pain but its all about the compression, computer, etc.
I try to stick to 89 most of the time though.Brad
2011 Launch 21V Sold... boatless replaced with a Jeep JKUR
2006 Moomba Mobius LSV sold
2004 Outback sold
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10-16-2013, 08:32 AM #18
Funny but on my '08 I'm pretty sure my boat manual says run 89 but my Indmar manual says run 87.
My Mom said I'm not allowed to get wet!
2008 LSV (sold)
2000 Outback LS (sold)
LLTR!!!!!!!!