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Warning, -16 late build Viper turbo breakdowns, bad rods.

Mountaintech said:
Where are MPIs AFRs without the 4 injector?
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Maybe the owner of the sled will chime in, but as of 3 weeks ago there was a local viper that got dynoed, 2016 viper with mpi trail turbo, as suspected the boost controller had the bad program where it was over boosting, that got unplugged, wastegate set to 5 pounds and confirmed on the boost gauge, sled pulled 181.6hp at 5 pounds and I believe 10.8 afr. No adjustments made to the gems controller and the mpi quiet muffler was used. Sled had zero miles and only a few dyno pulls.
 

daves origional post states 12.5 afr at 6 lbs boost and 193 hp. and many on here have had high afr numbers with the mpi "trail" kit even taking motors when running 6 lbs. i believe studroes144 had trouble keeping afr low at 6 lbs. yamadog had trouble at 6 lbs, yamaha tim had trouble, rev-it's mtx blew when turned to 6. i know all of these are different cases but all seem to have something in common. 5 lbs seems safe across the board with the trail kit.
 
tator said:
daves origional post states 12.5 afr at 6 lbs boost and 193 hp. and many on here have had high afr numbers with the mpi "trail" kit even taking motors when running 6 lbs. i believe studroes144 had trouble keeping afr low at 6 lbs. yamadog had trouble at 6 lbs, yamaha tim had trouble, rev-it's mtx blew when turned to 6. i know all of these are different cases but all seem to have something in common. 5 lbs seems safe across the board with the trail kit.
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Mine could not run 6 pounds, 5 was good with fuel, as soon as I went over that it would start to lose fuel on longer pulls. I wanted to stay under 11.5 wide open and anything over 5 pounds just couldn't do it, fuel pump upgrade and original wastegate maxed at 7 pounds it would hold a steady 10.8 even on long pulls of 115+
 
MPI original fuel settings (for low elevation) last season were below 10 AFR which caused poor performance. They had a bulletin for new settings that is on their website which puts the AFR in the low 11s & will generally pick up 500-600 rpm with no other changes.
 
tator said:
not sure why you guys are second guessing dave. he has been nothing but helpful with every bit of info he has provided. as far as the exhaust not restricting the motor that much, haven't we all experienced or read about the problems some are having riding in deep snow when it blocks off the exhaust? almost complete power loss. if the turbo is producing 4.5 lbs of boost and the exhaust takes 2 lbs of force to move the volume air at 8800 rpm that is only 2.5 lbs of boost net into the chambers. there could also be setup factors that resulted in the power loss. but dave brought a 180 mpi kit with his programming and injectors to 183 on the same dyno on the same sled. while having an afr at 11 flat which mpi can't do without a 4 injector. but none mentioned that.
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Tator the situation sucks. Hurricane does do wonderful work but when numbers are posted by him showing a competitors Turbo to be as bad as that MPI sled people are going to freak especially if they own a MPI or are thinking about getting one. I have fallen in same trap on occasion. But the difference is in the details. One sled should not be conclusive. Something was out of the ordinary. Personally I like Hurricanes use of PCV and bigger injectors vs MPI system but Extremes aren't needed to prove which is better. I hope he understands we all believe him and hope he keeps contributing his knowledge if anything this all should show someone that he does indeed have pride in his work and is a competitor. That's so important to me. More so than the details.
 
cannondale27 said:
Tator the situation sucks. Hurricane does do wonderful work but when numbers are posted by him showing a competitors Turbo to be as bad as that MPI sled people are going to freak especially if they own a MPI or are thinking about getting one. I have fallen in same trap on occasion. But the difference is in the details. One sled should not be conclusive. Something was out of the ordinary. Personally I like Hurricanes use of PCV and bigger injectors vs MPI system but Extremes aren't needed to prove which is better. I hope he understands we all believe him and hope he keeps contributing his knowledge if anything this all should show someone that he does indeed have pride in his work and is a competitor. That's so important to me. More so than the details.
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Concur. I don't doubt Dave saw those numbers but have to question why he did see those numbers. I fell into "the trap" as I just purchased an MPI. I was very torn between MPI and Hurricane. I stuck with MPI for the Yamaha backing. Nevertheless, I want to ensure I didn't make a mistake. I also want to determine what the problem was on the machine Dave worked on to ensure mine is good. I also want to verify others are seeing proper HP. This is probably a one off and I appreciate Dave's contribution and hope he continues, but we all must be careful how he word posts as the original post that started this almost made it sound like the MPI kit as a whole had problems.

I would really like to get more scoop on this issue and believe it needs to be resolved and put to bed, but we have definitely wandered away from the intent of this thread.
 
Guy's,I'm not intending to bash MPI or anybody else.I do intend however to offer my opinion based on what I've seen.I had an MPI sled on the dyno because the owner felt that it didn't make advertised HP.It didn't.I found the problem was the muffler.Fixed it.Tuned it and now I've told you about it.Now we have a jig made in the shop fixing some MPI mufflers for some other guys that have felt the same lack of power.And they are sending us mufflers to fix.
 
Srxspec said:
MPI original fuel settings (for low elevation) last season were below 10 AFR which caused poor performance. They had a bulletin for new settings that is on their website which puts the AFR in the low 11s & will generally pick up 500-600 rpm with no other changes.
Click to expand...
Are you seeing the 2016 mpi trail turbos run 11 afr from the dealer?
 
HURRICANE said:
Guy's,I'm not intending to bash MPI or anybody else.I do intend however to offer my opinion based on what I've seen.I had an MPI sled on the dyno because the owner felt that it didn't make advertised HP.It didn't.I found the problem was the muffler.Fixed it.Tuned it and now I've told you about it.Now we have a jig made in the shop fixing some MPI mufflers for some other guys that have felt the same lack of power.And they are sending us mufflers to fix.
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It's great to get your info. I think people where just a bit shocked by the numbers man. Are these new 2016 quiet mufflers giving you the problem.
The 2016 have the 02 sensor in the muffler.
 
HURRICANE said:
Guy's,I'm not intending to bash MPI or anybody else.I do intend however to offer my opinion based on what I've seen.I had an MPI sled on the dyno because the owner felt that it didn't make advertised HP.It didn't.I found the problem was the muffler.Fixed it.Tuned it and now I've told you about it.Now we have a jig made in the shop fixing some MPI mufflers for some other guys that have felt the same lack of power.And they are sending us mufflers to fix.
Click to expand...
Absolutely concur with what Joe ltx-le said. you just told me my $2800 investment isn't producing expected results, by a lot! If it were within 5 HP of advertised, I wouldn't have flinched. Only +11HP is pathetic and we are going to want details. What muffler are you experiencing this with, the Trail muffler? What is wrong with it? Is it just off center causing restriction or is there a design issue inside? Is this common or is it just a couple here and there?
 
Srxspec said:
Yes, they should be.

There is a good "walk through" of the GEMS fuel control box on MPI's website that I typed up last season and they have now published on their website.
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Allen,

Have you seen any HP issues with the stock MPI kit, especially as it relates to the muffler? My dealer that is installing it works with you for their turbos. I can have them call you if you prefer.
 
I almost bought a 16' viper with that turbo kit. Good thing I had the little voice in my head telling me I didn't need it. O and the girlfriend wasn't very fond of the idea of me spending 15,000+ either. haha
 
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