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Blown Viper Motor. Diesel fuel.

And to answer all the others with their panties in a bunch. Read what you want to into my post but I'll simplify it. If your going to turbo make sure you do it right the kit does not come with all you need. Do it wrong and tick tick tick! Capish!

Plus its a kit on the cheap (does not contain all you need) not a cheap kit! Sheesh I hate the typed word sometimes.
 

Charlie,I am sorry if I insulted you in any way. I very much respect your intelligence and careful thought you put into what you say. That was just a very closed end statement for a fellow that I have known to think things through very carefully. At this point I think I will make a bold statement myself. Yamaha sled engine are indeed built very durable but were not built with 30 or more horsepower mods in mind. Any time someone chooses to do such mods they must realize that there is a calculated risk involved, the margin for error becomes very small. You have pointed out some other in other statements about turbo's that do make good sense. I will stop here as I do not wish to get into pissing contests with anyone, especially those of you I consider friends. Once again, if I offended you in any way Charlie I am sorry, I respect you as a very smart guy.
 
[QUOTE="Sasquatch, post: 1220896, member: 1170"
To me IMHO (and be hanged if no one like my opinion) a turbo puts the motor on the ragged edge or closer to it like all the two strokes now and before. Pin it and hold it at your own risk. Great short haul drag racer but a lake racer its not. If that opinion pisses you and everyone else off then I'll live with it. I'll stick to NA Apex power and run em down on the lake! I'm to fat to drag race! I shudder when people call for a turbo Apex. Please no![/QUOTE]

Simply adding a turbo does NOT put a motor on the ragged edge!!

Its all about the setup!! Correct octane fuel, Correct compression, Correct Boost, Correct Timing, Correct Elevation, Correct size turbo. Take any one of these variables and take it to and unsafe area, and you have a recipe for disaster!! Done right, its just as reliable as stock, I've been doing it since '02 :)

IMO, the factory kit should have came with a boost gauge at minimum. Mine was only building 4psi at WOT instead of 6. I've rode half the season under boosting without knowing :( 20hp less is quite noticable...
 
Yamaha sleds have been around since 2006. It is quite interesting that we are here in 2015 now, and there is still not an OEM Yamaha turbo offering out there, or one that is endorsed by Yamaha that is idiotproof. I will go further and say that the carburated turbo systems were in some ways superior to what we have now.
 
[QUOTE="Sasquatch, post: 1220896, member: 1170"
To me IMHO (and be hanged if no one like my opinion) a turbo puts the motor on the ragged edge or closer to it like all the two strokes now and before. Pin it and hold it at your own risk. Great short haul drag racer but a lake racer its not. If that opinion pisses you and everyone else off then I'll live with it. I'll stick to NA Apex power and run em down on the lake! I'm to fat to drag race! I shudder when people call for a turbo Apex. Please no!

Simply adding a turbo does NOT put a motor on the ragged edge!!

Its all about the setup!! Correct octane fuel, Correct compression, Correct Boost, Correct Timing, Correct Elevation, Correct size turbo. Take any one of these variables and take it to and unsafe area, and you have a recipe for disaster!! Done right, its just as reliable as stock, I've been doing it since '02 :)

IMO, the factory kit should have came with a boost gauge at minimum. Mine was only building 4psi at WOT instead of 6. I've rode half the season under boosting without knowing :( 20hp less is quite noticable...[/QUOTE]

As per what I have been told sadly 6 pds will get the result of the picture above on a stock engine running premium fuel.
 
Charlie,I am sorry if I insulted you in any way. I very much respect your intelligence and careful thought you put into what you say. That was just a very closed end statement for a fellow that I have known to think things through very carefully. At this point I think I will make a bold statement myself. Yamaha sled engine are indeed built very durable but were not built with 30 or more horsepower mods in mind. Any time someone chooses to do such mods they must realize that there is a calculated risk involved, the margin for error becomes very small. You have pointed out some other in other statements about turbo's that do make good sense. I will stop here as I do not wish to get into pissing contests with anyone, especially those of you I consider friends. Once again, if I offended you in any way Charlie I am sorry, I respect you as a very smart guy.

Brian, you are a close and dear friend and I hope that always remains so. Friends are always forgiven and my post was rash because it involves family! My post should have had more detail, less emotion, so my bad its not your fault!

NA there is a large safety built into the engine, add a turbo or supercharger and you take a chunk of that safety zone away. The larger the chunk you take away the closer to the edge you get. As you approach that edge you need a strong net, that net is usually made up of gauges and electronic devices to catch the motor before it falls to its death. The MPI turbo kit will get you to the edge with ease but Yami kind of fell short on the safety net in many ways IMHO!

Old rule of thumb is 100 bucks a hp when it came to turbos as per these forums. So what is missing on a kit that is priced at 1500 bucks? Many things not put into the adds for the spring check at all! Joe blow has no clue what he is getting into! I'll bet he is becoming more informed now!

I'm getting tired of the whole issue, if I was to turbo I would do it right go big or go home thought process. Over build is usually how I do things.

From the car world of my youth a inter-cooler was worth hp without increasing boost. You could run less boost and make the same hp with an inter-cooler. Waste gates controlled the max boost. Lower compression and lighter stronger rods was the norm to run more boost. Those things are all there in the sled world but the price goes up, way up!

I would never run the MPI kit without a pressure gauge, air fuel, boost controller and intake temp gauge all with easy to read gauges. I want to select the boost I want. ie max boost and supper safe boost. I also think a shim kit ie two head gaskets with a shim in between to keep them from blowing out to reduce compression a couple points is a huge step in safety that I would look at. Please don't attack me on this people its just my opinion and I'm getting a little anal.

For off roading my buddy installed oil temp and trans temp gauges that saved him thousands of dollars. People thought he was nuts when he stopped in a mud hole, shifted into neutral and went to fast idle till the temps came back down. A minute more and his trans would have baked! Information rules
 
Simply adding a turbo does NOT put a motor on the ragged edge!!

Its all about the setup!! Correct octane fuel, Correct compression, Correct Boost, Correct Timing, Correct Elevation, Correct size turbo. Take any one of these variables and take it to and unsafe area, and you have a recipe for disaster!! Done right, its just as reliable as stock, I've been doing it since '02 :)

IMO, the factory kit should have came with a boost gauge at minimum. Mine was only building 4psi at WOT instead of 6. I've rode half the season under boosting without knowing :( 20hp less is quite noticable...

As per what I have been told sadly 6 pds will get the result of the picture above on a stock engine running premium fuel.

Correct, the MPI kit was not made or advised to run 6 pounds of boost at sea level or close to that. Not trying to make you angry but if you alter the manufactures recommendation on anything do you not take this into your own hands? And if I remember right, and please correct me if I am wrong this sleds was made to run 6 pounds of boost? That gives no leeway for bad fuel or that odd weather day. See the link below for the information on fuel pumps, I would never run close to the edge on fuel, turbo800 in Utah is running in the 6000-10000 altitude range so he can get by with 6 pounds of boost and stock. I for one would not alter the 4.5 boost stock on a low altitude setup without fuel upgrade but that's just me.

http://viper-mountainperformance-co...ll-MPI-Viper-Kits-most-other-brands_p_14.html
Viper Stage Fuel Pump & Regulator Upgrade (Includes):

  • High Volume OEM Walbro Fuel Pump
  • Returning Style 1:1 Boost Sensitive Regulator
  • All required Plumbing & Hardware
  • New pump & regulator typically required above these boost levels:
    • 0-2000ft: 6psi
    • 2000-6000ft: 7.5psi
    • 6000-10000ft: 9psi
 
NA there is a large safety built into the engine, add a turbo or supercharger and you take a chunk of that safety zone away. The larger the chunk you take away the closer to the edge you get. As you approach that edge you need a strong net, that net is usually made up of gauges and electronic devices to catch the motor before it falls to its death. The MPI turbo kit will get you to the edge with ease but Yami kind of fell short on the safety net in many ways IMHO!

I still think there is a "safety margain" involved. At our elevation (MPI is also from UT) they run 8psi on pump fuel with the same kit, instead of 6. This is NOT possible at all elevations!! The higher you go the better the safety net. If its true your at low elevation, you shouldn't be running 6 but 4.5 as spec'd out!!

Old rule of thumb is 100 bucks a hp when it came to turbos as per these forums. So what is missing on a kit that is priced at 1500 bucks? Many things not put into the adds for the spring check at all! Joe blow has no clue what he is getting into! I'll bet he is becoming more informed now!

I think your thinking of N/A motors of $100/hp, not turbocharged! I don't know about you, but my kit was $2000 NOT $1500.

I'm getting tired of the whole issue, if I was to turbo I would do it right go big or go home thought process. Over build is usually how I do things.

From the car world of my youth a inter-cooler was worth hp without increasing boost. You could run less boost and make the same hp with an inter-cooler. Waste gates controlled the max boost. Lower compression and lighter stronger rods was the norm to run more boost. Those things are all there in the sled world but the price goes up, way up!

On a pump gas setup and a properly sized turbo, an intercooler isn't always necessary. They built the kit as economical as possible! Turbo kit builder are making large margins on their kits. I made my own kit on my REV using the same high quality pieces they would (Garrett turbo included) for 1/3 of what they sell for! Lower comp pistons or a head shim to reduce compression increases lag and response time, again not what they were going for!

I would never run the MPI kit without a pressure gauge, air fuel, boost controller and intake temp gauge all with easy to read gauges. I want to select the boost I want. ie max boost and supper safe boost. I also think a shim kit ie two head gaskets with a shim in between to keep them from blowing out to reduce compression a couple points is a huge step in safety that I would look at. Please don't attack me on this people its just my opinion and I'm getting a little anal.

While I would never tell somebody to go without gauges, this kit does run well enough for me. For the average Joe, I think they'd be just fine. After installing my AFR gauge, they programmed the box to be plenty rich IMO. I do still think they should have included a $30 boost gauge though...

For off roading my buddy installed oil temp and trans temp gauges that saved him thousands of dollars. People thought he was nuts when he stopped in a mud hole, shifted into neutral and went to fast idle till the temps came back down. A minute more and his trans would have baked! Information rule

My responses in RED
 
this kit in question was at 4 lbs and adjusted to 6 without an afr gauge. user error. none of these kits should be messed with without proper working gauges.
 
this kit in question was at 4 lbs and adjusted to 6 without an afr gauge. user error. none of these kits should be messed with without proper working gauges.

And you know this how? Sounds like you have first hand information your sharing with us. I'd love to have that proof!
 
turned up between dec 28 and jan 9? you make the call.

December 28
84 mph on stock gearing 4psi boost. Went the opposite and geared it up as much as I could it seems like it gets there quicker. 65-70 mph it starts vibrating( track ballooning)

January 9
Ok well cut the track down to 1.75 and took it out today the lake was rough and in behind a island i was seeing 94 on the speedo on the trail i just made 4 passes and 95-97.
got to town and there was a short stretch of packed sled trails with minimal drifts spanked her from about 45 and she was at 95 fast and climbed to 98 then I ran out of bay.

January 14
GHolding up good. Not much snow here still but she will run at 100mph and quiet. But sleds getting the 500 mile tune up and it's snowing up here.

January 22
Just pulled the viper off the lake tore it down to find out why it was running on two cylinders. Compression leak down test right cylinder leaking Into case, middle cylinder leaking Into case. 500 miles. Yay.


January 25.
No idea. Have to get a afr gauge and looking into stutter boxes. I don't think I should have to. It shouldn't be this complicated. 5-6 psi boost, premium. Side of sled black with Unburnt fuel.
 
You missed one.

Rev-it said! Jan 26th

It's mpi. Dealer set it up he didn't have time to run it in. He said it should be at 6 psi. Dropped it off due to sled not wanting oil in it. He worked on it and changed the separator valve took it for the final run home 50-60 miles later. Kaboom
 
I want to add something to the thread. If you run the MPI flatland turbo kit keep it to 4pds. I would not recommend running it without minimum of a boost gauge and a A.F. gauge. I apologize for my rash statement about the kit being a ticking time bomb in the manner I did. I should have been more clear but was letting emotion rule my thought process.

Bad info led to the motor in question melting down. To late for him but not for others. To those I offended with my words I'm sorry but as an opinionated person I'm kind of prone to repeat myself. So I'll throw a future sorry in as well.
 


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