2015 LTX with turbo, blown head gasket??

[Srxspec]

That's not how the system works on the Yamaha approved kit, the 180 kit uses a map/pressure sensor just like a PCV PTI to read boost pressure and add fuel accordingly. It's only if you decide to go with MPI's fuel pump upgrade does it alter any fuel pressure.

 

[cannondale27]

TD others do do something they add fuel using a PCV based off Boost and Baro. If that requires bigger injectors and a fuel pump to keep steady fuel pressure then that is what they do. Its not like we are talking 1000hp here. Pressure is no way as accurate to vary as the Injector or Orifice. Doesnt matter to the OP. I am just trying to ensure him that he has a good "system" the problem is the motor just couldnt handle the pressure.(Head gasket)

 

[cannondale27]

That's not how the system works on the Yamaha approved kit, the 180 kit uses a map/pressure sensor just like a PCV PTI to read boost pressure and add fuel accordingly. It's only if you decide to go with MPI's fuel pump upgrade does it alter any fuel pressure.

Good to know. So basicly same thing as Push but without the PCV.

 

[MIDWAY]

I wonder if maybe I got some bad gas in Canada or if I just pushed it too much? We ride very hard, I know some guys say they ride hard but I am telling you I was pushing this thing pretty hard. Squeezing 110-112 mph out of it a few times.

 

[cannondale27]

Midway it sounds to me from all this Namely SRX,Studroes and Yamadog are just saying the motor cant take that level of power for long. I know why you had it cause it sure is CRAZY power but just got to overbuild the engine. Boosted Nytro is starting on that right now. Studs and Headshim.

 

[Studroes144]

Yupp if it's as simple as just a head gasket, put it back together with a thicker head gasket at the very least, if not the entire head shim setup, and without a doubt get a set of arp head studs.

 

[Yamadog]

Oh hell if you have to take it apart Carillo rods. Low comp. pistons, upgrade fuel pump 4th injector and quick spool waste gate!!! 250+ HP is crazy fun!!! AND NOONE can touch you. Even the higher HP XF 1100's do not have the torque and you will have a smile a mile long.

 

[STAIN]

I think that is why Dave limits his low boost kits to 6 psi---stock compression motor won't take much more.....

 

[Studroes144]

Stock compression will handle quite a lot more than what people think, the biggest thing is making sure there is a great fuel supply and that you use good fuel, on straight 110 race fuel and running extra safe afr's the stock engine is capable of 10+ pounds of boost, but that would be highly frowned upon for a trail sled

 

[stingray719]

Ummm.....the engine will take it but the stock fuel system is not enough. Many Nytros (mine included) were beat on pretty hard with 280 horsepower and held up fine.

Think of it this way, pumps and regulators do not all put out the same pressure (if you had a Phazer very long you probably replaced a fuel pressure regulator), now take a chance and build a boosted sled on the edge of what the pump SHOULD do and play Russian roulette with your engine. No way I would run any performance engine at anywhere near 75% of expected fuel output, running at 95 to 100 per cent of expected output is crazy in my opinion.

My MCXpress boosted Phazer blew the ECU so I ordered a new one from the MCX folks overseas. Told them where I was and such and when I received the ECU and put it on it had a lean spot mid to top range. WTF? And it was a non adjustable system! So I engineered on an automotive boost enabled adjustable fuel pressure regulator and put a fuel pressure gauge on the dash....problem solved. But had I hammered it the way it was??? brrrrr.

My point I am finally getting to is DO NOT run your system on the edge of the fuel system. Safe in my opinion having built countless race engines in cars, motorcycles, super mods, and sleds is do not run over 75% of capacity as things happen that can push the limits.

 

[Yamadog]

It has in a controlled dyno application, MPI has pushed a stock motor to 12#'s but they have also lost quite a few at 6 or less when fuel was less than adequate. There are way to many variables on these to let it to chance. 6 is max and even with AFR and boost gauge you never really know what you got unless your a chemist or add octane like I do.

 

[Yamadog]

Ummm.....the engine will take it but the stock fuel system is not enough. Many Nytros (mine included) were beat on pretty hard with 280 horsepower and held up fine.

Think of it this way, pumps and regulators do not all put out the same pressure, now take a chance and build a boosted sled on the edge of what the pump SHOULD do and play Russian roulette with your engine. No way I would run any performance engine at anywhere near 75% of expected fuel output, running at 95 to 100 per cent of expected output is crazy in my opinion.

My MCXpress boosted Phazer blew the ECU so I ordered a new one from the MCX folks overseas. Told them where I was and such and when I received the ECU and put it on it had a lean spot mid to top range. WTF? And it was a non adjustable system! So I engineered on an automotive boost enabled adjustable fuel pressure regulator and put a fuel pressure gauge on the dash....problem solved. But had I hammered it the way it was??? brrrrr.

My point I am finally getting to is DO NOT run your system on the edge of the fuel system. Safe in my opinion having built countless race engines in cars, motorcycles, super mods, and sleds is do not run over 75% of capacity as things happen that can push the limits.

I agree stock motor but not fuel system 6#'s is the max the Viper can handle with stock fuel pump and anything over 8#'s will require 4th injector.

 

[Studroes144]

I just the fuel pump upgrade kit on my viper, best I could run before was 4.5-5 pounds with stock fuel system, after that it would run out of fuel, now I'm running 6 pounds safely and was able to adjust down my gems controller and not have to run it maxed out just to run 4.5 pounds. I wanna see 10.5-10.8 on long wot runs, as soon as I see 11 on the gauge I'm off the throttle, yes plenty rich I know, but I won't burn down any engines running on the safe side

 

[MIDWAY]

Going to tear into it next week, crossing my fingers! Hoping just gasket. Has anyone did any higher gearing? It is pretty wound out at 105-110 mph, was thinking of gearing it up

 

[Studroes144]

I swapped out the stock 24/50 gearing for xtx (21/41) gearing, haven't had a chance to hold it all the way, only what the trails allow, but it's pulling hard still at 105. Mine with stock gearing was shifting out at 109 mph, stock clutches with no machining.