FUEL Octane with TD Tune?

jonlafon1

jonlafon1

Lifetime Member
Joined
Aug 18, 2014
Messages
4,303
Reaction score
3,349
Points
1,603
Location
Mount Morris, WI. Chaney Lake, Upper MI eh!
Country
USA
Snowmobile
2022 Sidewinder LTX_SE

2024 Catalyst RXC

2017 Sidewinder LTX-SE. 11750 miles (SOLD)
Saw this on TD website and thought I would post. Could be old I don't know. I guess what caught my eye was the Fuel recommended for the 17 psi tunes.. thought it was interesting.. :cool:
TD FUEL.jpg
 
I have never seen anything but 91 (labeled that anyway) where I ride! Sure glad I always splash some octane boost on every fill up. Cheap insurance
 
Thats older info, I think it was in the early development of the tunes. On my tune bundle it only lists 93 for max spool 20 and 93 octane with c16 for maxspool 19 which is the same flash as max20 in terms of boost but a leaner tune that requires the big fuel pump. Maxspool 17 , max17 and powertrailand all say 91 on my flasher and eco says 87.the bundle was purchased this fall.
 
justinator said:
Thats older info, I think it was in the early development of the tunes. On my tune bundle it only lists 93 for max spool 20 and 93 octane with c16 for maxspool 19 which is the same flash as max20 in terms of boost but a leaner tune that requires the big fuel pump. Maxspool 17 , max17 and powertrailand all say 91 on my flasher and eco says 87.the bundle was purchased this fall.
Click to expand...
93 for max 20? Do you have the fuel pump and regulator?
 
justinator said:
Thats older info, I think it was in the early development of the tunes. On my tune bundle it only lists 93 for max spool 20 and 93 octane with c16 for maxspool 19 which is the same flash as max20 in terms of boost but a leaner tune that requires the big fuel pump. Maxspool 17 , max17 and powertrailand all say 91 on my flasher and eco says 87.the bundle was purchased this fall.
Click to expand...
Funny I just downloaded my new tunes for the fuel pump and it shows 98 octane for max 20.
 
DMCTurbo said:
Funny I just downloaded my new tunes for the fuel pump and it shows 98 octane for max 20.
Click to expand...
No Kidding, lol .......mine definitely says "93 octane min". It doesnt need octane that high imo,unless your giving it the pickle for real long distances over and over again, imo. On that tune with pump 91 with a little boostane to raise it to an estimated 93-94 octane I showed a max of .2 degrees of timing retard on about 2500-3000ft pulls at 20.5 psi.
 
Every time it pulls timing it is deto, wouldn’t that deto cause damage overtime?? Better to not have this?
 
Crossfire12 said:
Every time it pulls timing it is deto, wouldn’t that deto cause damage overtime?? Better to not have this?
Click to expand...
Thats almost nothing, it takes either 2 or 2.5 degrees of timing retard to activate knock light on dash. If it was a concern then I think the tuners would of activated the knock protection much earlier. Most modern 2-strokes operate the same way, they are constantly adjusting timing to keep knock at bay and when the timing retard reaches a predetermined set point it sets the octane warning on dash. Once again the manufacturers have a threshold on whats ok and what is not to determine when its time to activate protection system. Only way to see whats going on is with datalogging. I would only be concerned if sled seems to pull timing frequently and repeatedly indicating other issues with sled or fuel problems. The knock sensors job is to pick up imperceptible levels of knock and retard timing to prevent it from occuring again or reaching the point of audible knock which we all know is very bad. I would venture to say that any tuned sled, including smaller 240-250hp tunes have some degree of timing retard going on in certain/specific conditions or loads throughout the course of a ride.
 
justinator said:
Thats almost nothing, it takes either 2 or 2.5 degrees of timing retard to activate knock light on dash. If it was a concern then I think the tuners would of activated the knock protection much earlier. Most modern 2-strokes operate the same way, they are constantly adjusting timing to keep knock at bay and when the timing retard reaches a predetermined set point it sets the octane warning on dash. Once again the manufacturers have a threshold on whats ok and what is not to determine when its time to activate protection system. Only way to see whats going on is with datalogging. I would only be concerned if sled seems to pull timing frequently and repeatedly indicating other issues with sled or fuel problems. The knock sensors job is to pick up imperceptible levels of knock and retard timing to prevent it from occuring again or reaching the point of audible knock which we all know is very bad. I would venture to say that any tuned sled, including smaller 240-250hp tunes have some degree of timing retard going on in certain/specific conditions or loads throughout the course of a ride.
Click to expand...
Do knock sensors "wear out" or can they lose sensitivity over time? (Should they be replaced at some point?).
 
Turboflash said:
Do knock sensors "wear out" or can they lose sensitivity over time? (Should they be replaced at some point?).
Click to expand...

Like any sensor I think they can fail. On my Subaru 2.5 RS the knock sensor became over sensitive and was constantly retarding the timing and hurting mileage and performance. It took me quite a while to track down the cause but once I changed the knock sensor the performance went back to normal.
 
jonlafon1 said:
Saw this on TD website and thought I would post. Could be old I don't know. I guess what caught my eye was the Fuel recommended for the 17 psi tunes.. thought it was interesting.. :cool:
View attachment 161101
Click to expand...

I actually like the octane guidance in the TD chart. Its always better to be conservative with the varying boost levels we are all running our 998s at.
I run the Hurricane SM and PM tune bundles and even though some of the selections are said to be safe on 87 octane I would only use 87 if there was no higher octane fuel available and then I would ride accordingly.
Typically I always use 91 fuel with Torco octane booster added no matter what tune I am using.
 
You must log in or register to reply here.


Back
Top