Sudden loss of power

[Norse]

Viper MTX '16 Mcx270. 4500km.

Went out for a ride today, everything seemed fine. Pulled over to talk to someone. After a few minutes I fired it up again and noticed it only got 4psi boost full throttle. It didn't make as much noise. After a while it started improving, but haven't gotten more than 13,5 so far. Still not as much noise as it's supposed to have.

Couple of weeks ago I discovered my boost at sea level was too low (13,5 out of recommended 15psi). It never has been higher from the shop. I accidentally adjusted to 16,5. Would that cause issues this fast?

I've looked over the vacuum lines, they seem fine. Turbo spins nicely. No intake leak from what I've seen. Hard to tell, but I suspect there is an exhaust leak on the manifold below fuel tank.

Any ideas? Thanks

 

[cannondale27]

Take a good look at your flex joint. They can leak and with a turbo the pieces could very well end up going through it.

 

[cannondale27]

Here is mine. Pieces. Big ones were found in muffler.
Can’t imagine they would make it though a turbo without damage.

 

[Norse]

Here is mine. Pieces. Big ones were found in muffler.
Can’t imagine they would make it though a turbo without damage.
View attachment 153702 View attachment 153703 View attachment 153704

Serious stuff right there, what caused it?

 

[cannondale27]

Serious stuff right there, what caused it?

Miles and age. This is usually the first piece to go in a car exhaust too.

 

[Norse]

Could it be caused by the deceleration backfire I got after reflash? I'm awaiting a new mcx manifold to reduce turbo lag, so hoping it's my exhaust leaking, and not valves or anything. Heading out to pull the fuel tank now.
Thanks

 

[Norse]

Yep it's got a 5" long crack with a lot of opening. No wonder I had massive turbolag. Also looked like there was an opening on the 2,5" pipe where it meets the 3 pipes. The welding line was in there pretty good.

 

[cannondale27]

Yep it's got a 5" long crack with a lot of opening. No wonder I had massive turbolag. Also looked like there was an opening on the 2,5" pipe where it meets the 3 pipes. The welding line was in there pretty good.


View attachment 153710

What a relief eh!

 

[cannondale27]

Pipes in snow is a stupid idea.

 

[Norse]

Yeah what a relief! There has to be other people who's had this problem so soon.

 

[cannondale27]

Yeah what a relief! There has to be other people who's had this problem so soon.

There were many that early stock exhaust header cracked. Been pretty quiet about that issue lately so factory reinforcements must have worked. Hope so.

 

[Mike P]

My 14 rtx is in the shop right now for what I think is a cracked header. Almost 14k miles on my sled with original header. On the final day of a trip in Canada last week my exhaust got so loud on the last 150 mile stretch I could not ride without ear plugs. AFR gauge was reading extremely lean and boost was not what it should have been. I think it started at the end of last season on my last 300 mile day in April. I noticed a backfire at the end of a hard pull and one or two more backfires will under engine break. This season no issues, until I about 1500 miles into the season and the AFRs seemed to drift now and then. Had a backfire once or twice. I will know Monday exactly what it is.

 

[Yamadog]

There were many that early stock exhaust header cracked. Been pretty quiet about that issue lately so factory reinforcements must have worked. Hope so.

I can tell you that I broke 2 of the stock exhaust headers on the 14 running 13lbs of boost. since I went to Ulmer's headers on both of mine no issues.

 

[Yamadog]

both of them blew the welds just before the bend

 

[Norse]

both of them blew the welds just before the bend

View attachment 153803

I'd trust an aftermarket header more because they're whole pipes. I'm ordering one SPI, one MCX, returning the one that arrives last. Can't be any noticable difference between the two.