MCX Nitro head shim 17-18#'s what fuel

[Sleds R Fun]

I know this has been beat to death. I've been running up to 18#'s on av gas for 3800miles with no problem @ 4500-5500 ft.
Been thinking about mixing av and premium 50/50.
My Question: is anyone running MCX Nitros with head shim @ 17# on just premium?

 

[M5-]

I know lots of guys running premium at 17 Lbs but at closer to 7000 feet. It wouldn't hurt it to splash a bit of race in there at 4500 I'm thinking. JMO

M5

 

[Smiley]

I run mine at 18#'s with 1/4 race to premium. No troubles. Lots of guys run just premium.

 

[dexter]

I run mine at 18#'s with 1/4 race to premium. No troubles. Lots of guys run just premium.

elevation??????

 

[boostedballz]

Theres more to the equation than boost and octane. If the machine is not mapped for the higher boost you will run lean and detonate regardless of octane. Some guys like to run in to the safety margin but I'm not comfortable risking a $5000+ engine repair bill. Ellevation is the second variable. At sea level our 240 hp kit makes 240 hp at 12 psi and does so on 91 octane fuel reliably for many miles. Take the same sled up to 6000 feet and the tcv valve will increase the boost to 15 psi. Same HP as sea level same octane requirements same reliability. The max you will see safely on pump fuel is what we run our 270 kit at. Approx 15 psi at sea level and about 18 psi at higher altitudes in certain conditions even 19. This is all based of barometric pressure which again is a nother variable factor that effects boost pressure. Long story short 180 hp kit : 5-8 psi depending on altitude, 240 hp 12-15 psi depending on altitude, 270 hp 15-19 psi depending on altitude. All three do so safely on 91 octane fuel. You can also re map to 310 hp which runs 19-22 psi and requires minimum straight 110 race fuel (av gas won't cut er). It is also recommended to use head studs when running 310 as well. Hope this adds some clarity .

LL

 

[SLY]

Landon, I ran that 310 setup on straight 100LL last season as well as a couple of others. Also ran a knock box but didn't have any issues. Guess I will never know for longevity as we lost both sleds in the fire. Planning on running 17-18 on premium this season as it will be a little easier to deal with until I get sorted. I think the bigger 19T turbo runs a little cooler at the higher boost levels than the 16T but not totally sure if that has anything to do with it. I have a used 310 19T setup in the works but plan on turning it down to the 270 mark for premium. Think I'll put a knock box on for peace of mind

 

[Sleds R Fun]

Boostedballz good read!!
I have found Av gas to be a wonderful fuel and better than C12. The lead in Avgas is a lubricant however does cause crud around valves and seats.

I have the older (first Generation) Nitro 270 kit. Do you know if there capable of the re-program for 310?

Thanks

 

[Mcx Nytro]

I know this has been beat to death. I've been running up to 18#'s on av gas for 3800miles with no problem @ 4500-5500 ft.
Been thinking about mixing av and premium 50/50.
My Question: is anyone running MCX Nitros with head shim @ 17# on just premium?

Is this just for $$$??? Our av gas is cheaper than our premium. Or are you looking for some other advantage???

 

[M5-]

Boostedballz good read!!
I have found Av gas to be a wonderful fuel and better than C12. The lead in Avgas is a lubricant however does cause crud around valves and seats.

I have the older (first Generation) Nitro 270 kit. Do you know if there capable of the re-program for 310?

Thanks

I've never heard of 310 programming for the Nytro and besides I don't think the Nytro stock rods would take it for very long. The 4 holer is a much stronger engine stock than the 3 banger and seems to be able to take the 310, I wouldn't push that thing past 270 without building the motor a bit. JMO


M5

 

[bigbird]

I've never heard of 310 programming for the Nytro and besides I don't think the Nytro stock rods would take it for very long. The 4 holer is a much stronger engine stock than the 3 banger and seems to be able to take the 310, I wouldn't push that thing past 270 without building the motor a bit. JMO


M5

Ran the 310 all last year at 19-20lbs boost at 6000ft. Around 1500 miles. No problems. 50/50 av and premium

 

[M5-]

Ran the 310 all last year at 19-20lbs boost at 6000ft. Around 1500 miles. No problems. 50/50 av and premium

On a Nytro?

M5

 

[Washy]

Yes there is a 310 kit offered for the Nytro a 19T and programming to go with it. It requires higher octane Fuel. Its considered the Race kit. Although I would concur running 20 psi on stock rods is definately pushing the limit not saying it cant be done but....

 

[ROBERTSONYAMAHA]

I run a 270 19T on straight 91 pump from shell @ 17-18lbs boost at 6000 feet, not a hitch at all. Might run a splash of AV gas in the tank for peace of mind as premium out here is 1.48/L and AV gas is 1.64/L - Cody

Building a 2011 Apex with Power Steering and going to the 290 kit and stretching to a 174, so the Nytro might sit a bit more this year.

 

[Duke]

I could be wrong but running 22#'s on straight race fuel seems counter productive to me. I'd be willing to bet 18#'s on 1/4 race 3/4 premium would make just as much seat of the pants power than full race 1t 22. It would have alot better throttle response for sure. I use to run straight C12 up to 22#'s on my Apex, it was really lazy, I found it was way more violent at 17-18#'s on 50/50.

 

[bigbird]

On a Nytro?

M5

yes

 

[M5-]

yes

There Ya go shows how much I know.LOL


M5

 

[Sleds R Fun]

Is this just for $$$??? Our av gas is cheaper than our premium. Or are you looking for some other advantage???

Our Av is $2.10 per liter and Supreme is $1.48. If I could run an Av/supreme mix it would save a little.

 

[boostedballz]

We can map the older 270 kits to 310 also. Duke is right about getting carried away with boost. The only time I ran 20+ psi was in drag racing scenarios. On the hill I always backed down to 17 ish. Found it easier to hold a line and work the sled a little more. Never felt 310 would have got me over something I didn't make at 270. Typically rider, line , and a little luck make the difference at that point

LL