Just bought a super-charged Apex....now what??

[TomKat72]

I just picked-up a stage 1 (10 psi of boost) supercharged Apex and now I'd like to know if it is really necessary to run mixed fuel (% of race fuel to a % of 92 octane premium fuel)? I know what MPI states on their web-site (50/50 mix) but I know that many companies build pump gas turbos that boost around 10-12 psi. but run on 92 octane.
I usually ride between 6,000 to 10,000 feet. The engine head is NOT shimmed and is running stock head bolts as well. Thanks for any help with this.

 

[summit889]

I just picked-up a stage 1 (10 psi of boost) supercharged Apex and now I'd like to know if it is really necessary to run mixed fuel (% of race fuel to a % of 92 octane premium fuel)? I know what MPI states on their web-site (50/50 mix) but I know that many companies build pump gas turbos that boost around 10-12 psi. but run on 92 octane.
I usually ride between 6,000 to 10,000 feet. The engine head is NOT shimmed and is running stock head bolts as well. Thanks for any help with this.

all depends on the kit. there are 4-stroke turbo kits you can run to 17 lbs. on pump gas and there are kits that will detonate at 12 lbs. on pump gas. running 10 lbs. on a supercharged sled with no headshim i would think you MIGHT get away with it at high elevations. get a knock sensor and start at 50/50 and work your way down. otherwise do what MPI says.

 

[Lococoin]

Any of the pump gas kits up to 17 lbs will have the head shim. Not having a head shim will require you to use a higher octane fuel unfortunately.

 

[summit889]

Forgot to mention. call Darren at E&S in Ft. saskatchewan. he runs them and will know.

 

[Xtremist]

dude WHY would you buy a supercharged sled, a turbo will just waste a supercharger. and besides superchargers being engine driven have more parts that'll **** up

 

[Ridin High]

why start judging and asking why someone buys something. Its obviously what he wanted. you didn't pay for it, so dont let it concern you man.

 

[kbxsrx]

You only need to mix fuel if you plan on running more than 1 year.
Either get a head shim or buy race fuel.

 

[Adrenaline Vince]

As far as I know you should run 50/50 with ou the head shim. I think its anything over 6 or 8psi. I ran 12psi with head shim and just ran 92 but now I run 16psi and use 50/50.

 

[canuck5]

I have not seen any kits running pump gas at 17psi. MCXpress has a kit which starts at 12psi and moves up to 15psi when you reach elevation, and this is with a head shim. At 10 pounds stock motor you'll need some race fuel, totallyamaha.com site has a boost calculator that is pretty accurate, takes (stock compression ratio, elevation, different calcs for types of machine, ect) into account check it out.

 

[Modman]

dude WHY would you buy a supercharged sled, a turbo will just waste a supercharger. and besides superchargers being engine driven have more parts that'll **** up

have you looked under the hood of your sled? If you don't think that your turbo has just as many parts that could screw up, you're only fooling yourself.

The supercharger has a belt and pullies, so? The supercharger is always making boost, so long as the crank is spinning. Not baggin' on turbo's.....just sayin'..... LOL

Not everyone needs tons of boost, some guys have different riding styles, maybe the supercharger suits his style better.

 

[shawnmcgr]

You might find this boost calculator useful. I think you're going to need some race gas regardless of altitude with 10lbs. boost. @ 7lbs you might get away with 92 pump depending on the altitude of the staging area you ride.

I'm told MPI sells a boost controller now that dumps boost (it will not increase boost above your pully configuration). So you can dump boost in the parking lot then close it up and run full boost when you get to altitude.

l8r shawn.

I can't load the excel file for some reason but it's available on Totally Yamaha

TY 4 Stroke - Totallyamaha :: View topic - calculator for hp with altitude, octane, c/r, and boost

 

[kbxsrx]

dude WHY would you buy a supercharged sled, a turbo will just waste a supercharger. and besides superchargers being engine driven have more parts that'll **** up

Have you ever ridden one?

 

[TomKat72]

First...let me say thanks to everyone who posted!! This is for you- .
Second......Where I ride 20lbs of boost is just a waste! We have some good sized mountains and decent snow but we dont have the huge pulls that are in other areas. Sooooo, a super is much more user friendly for the conditions we ride (my opinion).
Third.....found out today that it's actually boostin' around 12-14lbs. The guy I bought it from has been mixing it at 20% 110 to 80% 91 and has had no issues. I can get 93 octane at the pump and was wondering what some other thoughts would be if I could go a little less of the 110? I plan on running the same 20/80 mix he has been running but I'm just curious as to your thoughts....
Has anyone tried the Torco Unleaded Octane Accelerator?
Again, Thanks!!

P.S. I have rode 220-240 H.P. rides in the past but I think this is going to be a whole new bag of tricks....can't wait!!!:d

 

[TomKat72]

You might find this boost calculator useful. I think you're going to need some race gas regardless of altitude with 10lbs. boost. @ 7lbs you might get away with 92 pump depending on the altitude of the staging area you ride.

I'm told MPI sells a boost controller now that dumps boost (it will not increase boost above your pully configuration). So you can dump boost in the parking lot then close it up and run full boost when you get to altitude.

l8r shawn.

I can't load the excel file for some reason but it's available on Totally Yamaha

TY 4 Stroke - Totallyamaha :: View topic - calculator for hp with altitude, octane, c/r, and boost

Thanks Shawn for the link!!!
Sooo.....if I'm doing this correctly (input 14lbs. boost at 6000' elevation it states I can run 90.3 ocatane. Is that right? See bold.....
base hp base dynamic comp ratio base octane altitude boost new comp ratio octane hp after comp drop hp after comp &alt hp after comp, alt& boost
150.0 8.8 86.0 6000.0 14.0 7.1 90.3 144.8 118.8 256.7
148.0 10.3 88.0 0.0 17.5 8.6 98.8 143.0 143.0 313.2
148.0 11.8 88.0 0.0 17.5 9.1 93.8 140.0 140.0 306.7
148.0 11.8 88.0 3500.0 11.0 10.5 92.1 144.2 129.0 236.9

This tells base hp if boost and total hp are known boost boosted hp
base hp calc 143.1460674 12 260

 

[shawnmcgr]

No problem, the dynamic compression ratio you've got in the sheet looks low @ 7.1. Stock, according to this spreadsheet, is 8.8. Using that you need 99 octane at 14psi and 6000ft.

150.0 8.8 86.0 1700.0 14.0 8.8 100.7 150.0 142.3 285.2
150.0 8.8 86.0 3000.0 14.0 8.8 100.1 150.0 136.5 279.4
150.0 8.8 86.0 6000.0 14.0 8.8 98.9 150.0 123.0 265.9
150.0 8.8 86.0 9000.0 14.0 8.8 97.6 150.0 109.5 252.4

The spreadsheet seems to work and make sense but I wouldn't cut it too close. You don't always get what you pay for at the pump.

14psi on stage I sounds high, like spike readings due to throttle chop or low alt trail boost levels. You might PM shiznitt100, I seem to remember him having some high boost numbers on his stage I (he's gone to Stage II now) as he headed up the trail.

l8r shawn.

 

[TomKat72]

Thanks Shawn! I do beleive you're correct about the 14psi spikes. I haven't been able to do much testing besides the few rips down the snow dusted fields (lots of spin, imagine that). Once I can get a few more runs with some more snow and hopefully some traction I may contact shiznitt100 to pick his brain a bit.
According to an octane calculator, the previous owner has been putting in a mix equaling 95 octane. He has been running that mix since he's owned it (3 yrs now) with no problem. I just want to error on the cautious side.... If I mess with the boost calculator to get the required octane down to what has been being used (95 octane) it looks like 10psi boost is where it is realistically running. What's you're thoughts?
Required octane is tha last number.
150.0 8.8 86.0 1700.0 10.0 8.8 96.3
150.0 8.8 86.0 3000.0 10.0 8.8 95.7
150.0 8.8 86.0 6000.0 10.0 8.8 94.5
150.0 8.8 86.0 9000.0 10.0 8.8 93.2

 

[kbxsrx]

First...let me say thanks to everyone who posted!! This is for you- .
Second......Where I ride 20lbs of boost is just a waste! We have some good sized mountains and decent snow but we dont have the huge pulls that are in other areas. Sooooo, a super is much more user friendly for the conditions we ride (my opinion).
Third.....found out today that it's actually boostin' around 12-14lbs. The guy I bought it from has been mixing it at 20% 110 to 80% 91 and has had no issues.


The problem with that statement is, there are no visable issues, but what has been going on inside the engine; pistons, valves, rods, bearings, etc, everything that you do not yet see may be already damaged.
Everything works until it quits, I just hope if there are any problems hiding they do not worsen by saving a buck on proper fuel.
Good luck with the sled, I am by far the biggest supercharger fan.
I brought Superchargers to Canada, when working for TCI. From 2004-2008, I put my hands on every supercharger that came across the border to the West.

 

[Junior Highmark]

The guy might have bought a super charger because it's always creating boost, As long as the crank is turning..
Turbo's dont, they need to spool up. Lots of climbers have turbo's / superchargers because of that.

So he might have bought it to boondock with? Because it's always creating that 10 pounds of boost.

Not flaming turbo's, I love em, Tons of fun to just watch, none the less ride. But just trying to explain.

Hey, mabye im completely wrong? Mabye he did buy it for climbing? Who knows!

Just sayin'..

 

[TomKat72]

First...let me say thanks to everyone who posted!! This is for you- .
Second......Where I ride 20lbs of boost is just a waste! We have some good sized mountains and decent snow but we dont have the huge pulls that are in other areas. Sooooo, a super is much more user friendly for the conditions we ride (my opinion).
Third.....found out today that it's actually boostin' around 12-14lbs. The guy I bought it from has been mixing it at 20% 111 to 80% 91 and has had no issues.


The problem with that statement is, there are no visable issues, but what has been going on inside the engine; pistons, valves, rods, bearings, etc, everything that you do not yet see may be already damaged.
Everything works until it quits, I just hope if there are any problems hiding they do not worsen by saving a buck on proper fuel.
Good luck with the sled, I am by far the biggest supercharger fan.
I brought Superchargers to Canada, when working for TCI. From 2004-2008, I put my hands on every supercharger that came across the border to the West.

I totally see where you're coming from. But......what makes me say "he must be right as to where it needs to be or more-so seeing as he has been running it this way for over three years". If it were othewise, it should've detonated by now. Me personaly, I've never seen a motor run very long if it was shy on the needed octane. I can agree that one doesn't know exactly what is going on inside without openiong it up although I don't think that there is.

 

[TomKat72]

The guy might have bought a super charger because it's always creating boost, As long as the crank is turning..
Turbo's dont, they need to spool up. Lots of climbers have turbo's / superchargers because of that.

So he might have bought it to boondock with? Because it's always creating that 10 pounds of boost.

Not flaming turbo's, I love em, Tons of fun to just watch, none the less ride. But just trying to explain.

Hey, mabye im completely wrong? Mabye he did buy it for climbing? Who knows!

Just sayin'..

All too true!! Kinda like a Mexican donkey show. Fun to watch but not something I want to ride.