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Hi all , just bought a 2020 PRO XP4 , says to run 91 octane gas , where i ride they dont sell 91 (89 no ethanol is the best) has anyone used a octane booster with good results ? if so , which one ? thanks ! Dennis
 

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VP Madditive Unleaded or Torco Unleaded work well. About 1/3 can a tank will get you a little over 91 from 89.
 

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RWB713 ... beat me to it .... I buy the Madditive Octanium unleaded from this guy he has the best prices by the case
 

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That's good to know. Half the vehicles I own require 91 octane. I'm just curious, where is it hard to find 91 at the pump?
 

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Depends on what kind of riding you do.. 89 will be fine if your not WOT all the time...mine will start to pull timing when above 74-7500 rpm..but I use a splash of Torco accelerator when I know I will be running hard
 

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OP:
You can go review the post I did on cooling if you want explanation, but if you added a surfactent, and ideally reduce the glycol concentration in your radiator, I believe you can run 89 without concern.

btw, if you're running at altitude, as I suspect, your octane requirment, even on a turbo, drops a bit. (I believe the wastegate references atmospheric pressure)

Huhner:
Interesting information! Thanks for the details. You'd normally expect we'd take more advance as RPM went up, yet you're sharing your seeing them pull some on 89. Either our ECU's are still advancing timing at that high an RPM, the CHT's (or charge temps) went up, or it's not dialing in full boost until that higher RPM. Or some combination of course.

Sounds like you've been data logging. Any of that consistent with what you've been seeing?
 

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Not data logging.. just watching knock retard on my PV3... Saying it's pulling timing at high rpms isn't totally correct.. I also have to be in the boost hard... Pulls timing at full boost and higher rpms.. this is on my stage 3 tune... And terrible 91 pump gas... But a couple ounces of Torco and no more knock..

My point is as long as your not absolutely foot to the floor, you can get by on lower quality gas and have no performance loss, and the computer will pull timing until it's safe, just at a cost of less HP
 

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Heck, here:
658453


Wanta reduce octane required by 2? Drop CHT by a 20f (or so). I'll get at least 10 of those from my winter coolant project, and as for surfactant results to CHT:


Easy stuff, and for adding a $10 bottle of stuff to his radiator an awful easy solution to try.
 

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Thanks Huhner5. Stage 3 et? yea, that explains things too. Timing tables probably changed, fueling, even boost levels. Yep, I get it.

Whose tune are you using?

I just picked up another set of PV tunes from Bikeman. I was talking to Joey about how the AA tunes suck fuel and he convinced me to try their's. My take is their tuning style is less likely to see such crazy fuel burns...
 

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I've seen as much as 6* of timing being pulled out of mine... junk 91 octane on a stage 3 tune (aftermarket assassin's)... Still safe according to Mike @ aftermarket assassin's but leaving considerable HP on the table
 

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Like said above, higher elevation requires less octane equivalent. Whats your elevation? I'm at 1000' and we have 93 and can find some 95 at a station or two close to drag strips.
 

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Thanks Huhner5. Stage 3 et? yea, that explains things too. Timing tables probably changed, fueling, even boost levels. Yep, I get it.

Whose tune are you using?

I just picked up another set of PV tunes from Bikeman. I was talking to Joey about how the AA tunes suck fuel and he convinced me to try their's. My take is their tuning style is less likely to see such crazy fuel burns...
I have ran the BMP stage 3 tune for almost 2 years and it hog's the fuel as well .. You may see a very slight improvement in MPG with the BMP stage 3 vs AA stage 3 ... but it will be very little ...but the difference in performance is noticeable , the AA is definitely higher performance
 

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I've seen as much as 6* of timing being pulled out of mine... junk 91 octane on a stage 3 tune (aftermarket assassin's)... Still safe according to Mike @ aftermarket assassin's but leaving considerable HP on the table
Wow! That's a lot! Redline would call that maybe 4 octane numbers and maybe 2.5% power loss. Damn!

I guess we don't talk about fuel quality much to we? I've no idea how to even start that conversation. Hm..

Once I get my cooling mods done (winter project) it looks like I'll have to start data logging.

Thanks again for sharing.

Sooner:
When I'm in Denver or higher you about can't buy premium fuels. I'm sure they're around, but I never seemed to bump into them as a visitor.
 

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I have ran the BMP stage 3 tune for almost 2 years and it hog's the fuel as well .. You may see a very slight improvement in MPG with the BMP stage 3 vs AA stage 3 ... but it will be very little ...but the difference in performance is noticeable , the AA is definitely higher performance
Well crud...

There went $100. Oh well. I'll still try it since I own it now.

Max, can you give me a sense of what you noticed? Joey told me they bring boost in more slowly so fuel at part throttle isn't going into enrichment so soon. I'd expect part throttle, and I do 70% like that, to be easier on fuel. I'd also expect it to not be quite as strong on part throttle transition as a result, but similar on WOT. Which might make 75% effort/pace riding a bit weaker feeling.

But your take would be interesting (damn, I feel like we've taken over this post).

BTW, and if you own them, how would you contrast an AA stage 2 vs BM's stage 3?
 

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When I'm in Denver or higher you about can't buy premium fuels. I'm sure they're around, but I never seemed to bump into them as a visitor.
Elevation, population, and demographic certainly play a role ( If you don’t sell it, obviously nobody wants to waste money to stock it ).... but it’s still odd to me the places you can/can’t find it sometimes.

I would say 91+ is available in at least 95% of gas stations across the country, but rural mountain towns, or general middle of nowhere towns, without a high motorsports tourist concentration, are definitely the most likely places to not find it.

I live in a town at 5600’, with 5500 people, next to a “city” of 40,000 at the same elevation, with no other bigger cities for 200 miles, and there’s not a station in the area that I know of that doesn’t sell 91 octane (10% Ethanol variety), there’s also at least 3 stations with E-free 91 as well, and several race gas varieties available by the barrel from a few different places too. E-85 is the most scarce common fuel around here... actually just had the first station start selling it a couple months ago.
 

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Well crud...

There went $100. Oh well. I'll still try it since I own it now.

Max, can you give me a sense of what you noticed? Joey told me they bring boost in more slowly so fuel at part throttle isn't going into enrichment so soon. I'd expect part throttle, and I do 70% like that, to be easier on fuel. I'd also expect it to not be quite as strong on part throttle transition as a result, but similar on WOT. Which might make 75% effort/pace riding a bit weaker feeling.

But your take would be interesting (damn, I feel like we've taken over this post).

BTW, and if you own them, how would you contrast an AA stage 2 vs BM's stage 3?
@dafish I am not sure if you ever seen my.. Tune Test thread .... PWR Tune ..AA and BMP.... Tunes
But this will probably answer most of your questions .
Since I did this test I have been running the AA stage 3 tune with 91 octane non Ethanol and 1/3 of a can of VP Octanium unleaded octane boost.
During the Tune Test , data logs showed that with just the 91 Non E fuel and no octane boost the knock sensor was active. This is why I now run the 1/3 can of VP Octane boost with the AA stage 3 tune just to be safe.

The tunes I have loaded on my PV3 are
BMP tune 1,2,3 &4 ... I have only ran tunes 1 and 3 ...I have not tried BMP tunes 2 or 4
Power Tune ...tune 2 (equivalent to BMP and AA stage 3 tunes)
AA stage 3 tune ....this is the only AA tune I have tested

Two days ago I order the new AA water cooled Turbo and the AA WCT stage 3 tune to go with it.... 😁 it should be delivered by UPS in one hour or less ...not that I counting the seconds or anything ...:LOL:
So now I have all the other tunes that I cant use anymore ....oh well just more money down the RZR tube ...what the hell
 

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btw, if you're running at altitude, as I suspect, your octane requirment, even on a turbo, drops a bit. (I believe the wastegate references atmospheric pressure)
Like said above, higher elevation requires less octane equivalent.
This is far less true for a turbocharged engine. In stock form, the turbo will almost fully compensate for that altitude difference up until the efficiency of the turbo is maxed out. Boost tables are based off of manifold absolute pressure, not relative boost pressure. So if you are at sea level with 14.7 psi atmospheric pressure, and the boost target is set to 28 psi, your turbo is going to maintain that 28 psi by adding 13.3 pounds of boost. Now if you go up to 5000', you're down to 12.2 psi atmospheric pressure, and that exact same machine is going to maintain that 28 psi boost target by adding 15.8 lbs of boost...so the minimum octane rating remains the same as the cylinder pressure will remain relatively the same, albeit it possibly a bit hotter due to the turbo having to work harder and raising the Intake Air Temperature.

Now once you get to the point of maxing out the turbo capabilities and efficiency, whether it be by elevation or tune mind you, then the cylinder pressure will ultimately decrease with elevation, but will also have a hotter IAT since the turbo is running at max capabilities. The difference in required octane ultimately may be slightly lower, however, nothing like the extent that an NA engine in the same situation would experience. I wouldn't ever us this theory when pushing the minimum octane required in a forced induction application as a result.

Devil's advocate to my own point, and as has been mentioned, your right foot plays a very large role in what extent you are pushing the limits of octane rating, AND the engines do have a knock sensor, so you run less ( not zero, but less ) chance of damage to the engine with lower than required octane when you keep your right foot at bay and rely on the knock sensor correction of the ECU tune...but then again.... why push the boundaries in a such a critical area?

But also, for the knock sensor to result in corrected timing / fuel via the ECU, your engine does actually have to knock or ping..which is bad, regardless if the ECU is correcting it almost instantly or not, engine knock is NEVER a good thing, and the ECU correction is not something you should rely on on a regular basis, as repeated knocking will ultimately cause engine damage, or shorten engine life at the very least. This is something I know both myself and @Max H deal with almost every time we put our foot down with a stage 3 tune, which means there are many others that are in the same situation as well, because we both have pretty common setups and tunes ( well, Max will be less common with the mentioned WCT install, and also may end up reducing any engine knock as a result )....When you get into the higher level pump gas tunes, you are constantly pushing the boundary of minimum required octane, and what one tune company considers "acceptable" knock level, may not be the same as another tune company. BMP vs AA as an example, BMP considers theirs tunes "safer", but AA will tell you there's are perfectly safe...so you have to be your own expert on some level and make you're own decision.

Case in point, this is at 5600', with 10% ethanol - 91 Octane, Full throttle clutch tuning run.
658503
 

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That's a damn good explanation .....well said ..(y)
 
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