Low Boost imput?

[JCLG]

I have allready extroverts and 146"/1,75" track. I bought this sled that idea in mind that someday it might have some boost.

 

[fast n furious]

They are fun to ride but they don't make the big power which is fine for lots of people. Don't expect it to run with all the big turbos cause it won't. After riding my Rx1 with about 300 Hp my MCX Nytro 240 feels slow and the 180 kit feels like an 800 Doo. They are quite a bit stronger than a 2 stroke 800 but not as strong as one of the big kits. Pretty much what you'd expect. If it were me I step up for the bigger kit right out of the chute cause in the end you will probably be wanting to bump up the power, its just a fact of Life. Once you've got the boost bug your hooked.

Rx1M5

I would have to agree,I ran a nytro at 6-8lbs last season and it was a blast as a trail sled,more than enough power to handle most everything on the trail BUT once you are hooked on boost, you want more !!! My sled has been at Hurricane for the last 2 months getting some tweaking and should be a real blast this year. Cant wait

 

[Rx1M5]

Imagine all that can happen.


And this happened a time or another to me right around the 300hp mark.

Broke pistons, eggshaped cylinder, cracked block, cracked head, spun crank bearing and the numerous blown head gaskets.

That is for engine issues.



I had bent chassis many times, right between the primary and secondary clutches, chassis bent right there causing CC to become too narrow and all problems associated with this.

Even worn out reduction gears...


But I like this so much that I continue...

There's no way you should have had all those issues with 300 hp if you had a 4 cylinder. 300 is nothing for the 4 banger, I mean MCX sell a 310 kit for the Apex and they don't blow up otherwise they'd be out of business. I personnaly had over 8000K on my sled and my buddies both have over 10,000. I'm not buying the reliability argument for the 4 cylinder. The danger zone for the 3 holer on the other hand is probably right around 300 hp, at that point a guy should consider rods and pistons.

Rx1M5

 

[mulot30th]

I can tell you I had ALL thos issues at between 280 and 350 hp on different sleds, turbo and supercharged.

I have boxes of broken engine parts to prove that.

THE one and ONLY part I never broke is the crankshaft itself... onl one time did I have to have one journal re-surfaced but was not due to crankshaft breakage... spun bearing... never had crankshaft issues.. I also ran a couple times around 300hp with stock rods and pistons no problems also, but not for long runs, never tried.

All the rest, name it I broke it one or more times.


Something that come back to mind also.

Broken wiseco piston's wrist pins... which scrapped carrilo rod end..... engine was running 290hp on dyno.

 

[Rx1M5]

Maybe its the elevation difference cause I know lots of guys running the 310 kit out here???

Rx1M5

 

[mulot30th]

that 310 is how much boost

 

[great white north]

310hp should be 17psi boost on the mcx 310 kit. That is the maximum you can go on pump gas (94 octane),with mcx, if you have upgraded fuel pump and corrected fuel mapping in the mcx eca box.

 

[mulot30th]

I cracked a fully built engine's block last winter that at right around 375hp, running 100% racing fuel (c12)...


I was told this was not enough octane (108) by engine some tuners and that I would have need pure c16 (117 octane).


So.... I just can't even imagine running 310 hp with pump gaz....


Then I would have been told that I was stupid doing that.




310hp almost stock engine at 94 octane that would be reliable?


375hp at 108 octane on the most fully built engine money can buy (trust me on that) and get the engine's block to crack and lift the head?



Is there something I really did not get somewhere?

 

[stone88]

I cracked a fully built engine's block last winter that at right around 375hp, running 100% racing fuel (c12)...


I was told this was not enough octane (108) by engine some tuners and that I would have need pure c16 (117 octane).


So.... I just can't even imagine running 310 hp with pump gaz....


Then I would have been told that I was stupid doing that.




310hp almost stock engine at 94 octane that would be reliable?


375hp at 108 octane on the most fully built engine money can buy (trust me on that) and get the engine's block to crack and lift the head?

I ran my MC Xpress 290 kit all summer on the tar 17-19# of boost on 50/50 C-12 and 91 pump and no problems. At 19 # should be well over 320 hp . You must be doing something wrong or running it to lean.

 

[FLYBYU]

They are fun to ride but they don't make the big power which is fine for lots of people. Don't expect it to run with all the big turbos cause it won't. After riding my Rx1 with about 300 Hp my MCX Nytro 240 feels slow and the 180 kit feels like an 800 Doo. They are quite a bit stronger than a 2 stroke 800 but not as strong as one of the big kits. Pretty much what you'd expect. If it were me I step up for the bigger kit right out of the chute cause in the end you will probably be wanting to bump up the power, its just a fact of Life. Once you've got the boost bug your hooked.

Rx1M5

300hp = not too reliable... BUT BIG FUN

180hp = Ultra reliable and still fun

Switchback1080 had the first mcx 290hp kit in the states a couple years ago and still has no problems with it. Over 2000 miles on it. That's with 91 octane as well. I do agree you go more than that and not using race fuel your asking for problems.

 

[doo_man]

The 180 kit is easily upgraded too........for approx 3k canadian installed dealers will upgrade you to the 240 kit. One of our guys is doing it already..............

 

[JCLG]

Thank you for assistance. I ordered the 180 kit today from MCX.

Few weeks delivery time and after that I have some boost