Improving Performance on the Viper??

[Heritage]

I'm just curious about something...thought maybe you engine guru's could answer this....I was told the nytro has more HP than the Viper or Vector....I thought I read on here that the nytro used bigger injectors? If the engines are the same...why couldn't a guy use the bigger nytro injectors, on those sleds, and use a nytro fuel map program?? (of course going to 91 plus octane fuel)....or is there an after market option for this already...??

Maybe I'm wrong...but I just think a guy could get a lot more out of that 3 cylinder 1050...without turboing it.
I know you can change the exhaust, and get a bit more HP...I have also seen the air box mod kits, and clutch kits (which look like they had some speed to the viper)

Would there be other engine mods that would work in conjuction with bigger injectors (different cam etc)??

I am a piss poor mechanic...lol...that's why I like Yamaha 4 strokes...but this stuff is interesting and has me curious. I believe when the Rx-1 first came out...somebody had made an engine kit (non turbo)...that produced big HP...I can't remember who (what company it was)...and I wondered if anybody was doing the same for the viper/nytro/vector? Not everybody wants a turbo/supercharger....I think it would be cool to have a sleeper/non turbo viper that would give an apex (or other 800s) fits...just trying to think outside the box here.

 

[grizztracks]

As far as I know the injectors are the same and the difference between the Nytro and other 3 cylinders (at least the Vector) is cam shafts and valve springs.

 

[Big_Phil]

The Nytro and viper motors are the same I believe. The reason the nytro should make a little bit of HP is because of the rear exiting exhaust on the nytro. Nytros also run on 87 octane just like vipers. The vipers and ac7000 do use a different ecu than the nytros, Im not sure why.

Naturally aspirated, you wont get any more than 150hp with all the supporting mods done. Intake, full exhaust and fuel programming. (there are big bore, ported head kits out there, but they cost almost the same as a turbo for less power)

 

[actionjack]

Looks like you can get a Viper to 160 with the full EVO package. 160HP in that sled has got to be fun to ride.
http://www.ty4stroke.com/threads/evolution-powersports-viper-reflash-update.130987/

 

[shagman]

The Nytro and viper motors are the same I believe. The reason the nytro should make a little bit of HP is because of the rear exiting exhaust on the nytro. Nytros also run on 87 octane just like vipers. The vipers and ac7000 do use a different ecu than the nytros, Im not sure why.

Naturally aspirated, you wont get any more than 150hp with all the supporting mods done. Intake, full exhaust and fuel programming. (there are big bore, ported head kits out there, but they cost almost the same as a turbo for less power)

There are lots of vipers that are n/a running 160+hp. EVO full exhaust, ecu program and air box mod is 160+. I was there when the flash was made and the dyno testing done. Vipers and nytro are different fuel system and ecu. Vipers use all cat fuel and ecu. Also The rear exhaust does not make more power ( never been proven on dyno). Not looking to argue just stating facts.


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[grizztracks]

I'm not sure what you are referring to as "fuel system" but the throttle body assembly is basically the same assembly that is used on all the Yamaha FI 3 cylinder engines so at least that is not from AC, although the ECU is.

I just checked the parts diagram and the Viper and Nytro both use the same cams and valves so as far as I can tell they are the same engine. I'd have to say that any difference in HP between the two would most likely be related to intake/exhaust design along with fuel mapping.

 

[shagman]

Compete different throttle bodies between the 2 sleds. The one used on the viper is from cat. Do some checking and you will see. I'm not saying that one or the other has more or less power. Just that the rear exhaust doesn't make more power. As far as the motor and internals they are the same in both. Ecu's and programming of ecu's, timing and fuel are different. I was just posting because it was said above that you can't get the hp without motor work, which is incorrect. With motor work I believe 200 hp N/A is possible with this motor.


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[grizztracks]

From the parts diagram I don't see much if any differences in throttle body "assembly" between the two. The brake down of parts are identical which includes the injectors although I can't verify from the diagram that the bodies are identical because they only come as an assembly. I find it hard to believe that Arctic Cat went through the processes of designing a part that is specific for a Yamaha engine but I could be wrong. I'll have to see if I can compare my Nytro and Viper.

Intake and exhaust setups along with re calibrating engine parameters and fuel mapping definitely can add HP but the gains to get to 160 HP can be costly especially when you add in the cost to properly clutch the sled. I don't think a lot of Viper owners go to such extremes due to the cost so there are very few running those hp numbers. I also believe these NA engines could push the 200 hp mark but It makes me wonder how that would effect the longevity of a durable and very reliable stock engine.

 

[Big_Phil]

My brother has a viper, I will compare the throttle bodies, I just assumed they were the same since its the same motor. Also the injectors are either the same, or the same size. Both stock fuel systems can support 190-200 hp. The pumps are likely different because its an AC tank.

While I'm sure you could get 200hp out of this motor, but not in a way that is practical for a sled. Hurricane has a 1200cc stroker crank and a ported head kit, and I think they only get 180 hp out of that. You will never see a 200hp N/A viper motor. An Apex with a ported head, cams, exhaust, you name it can only make 170-180 hp and thats a 4 cylinder 5 valve motor.

 

[NOS-PRO]

Thought I would chime in....

Hpr numbers between the Nytro and the Viper are close with the Nytro slightly more because of the AC programming in the Viper ECU.

With the EVO performance tune (Which Dave_RX1's 2014 sled was the one we did the dynoing on with 346 miles on it, Shagman and myself there with all of our sleds) the videos you see in this thread made 160.4 hpr at the crank. My Viper with stock engine close to 5,000 miles made 171.0 at the crank and before the flash made 156.7. The more miles the more the 4 strokes loosen up. All our dyno runs to perfect the EVO flash were done on Dave's sled and 1 sled only to get the results we needed

This dyno session used all the same bolt on parts from EVO (Header, Muffler, performance flash and airbox mod that was switched between the 2 vipers. These bolt on's cost far less than a turbo kit....and no matter if it's modded N/A or turbo, you will need a clutch kit.

http://www.ty4stroke.com/threads/evolution-powersports-viper-reflash-update.130987/

Engines were not touched and the clutch kit Shagman and myself tested for Thunder Products "Big Venom Kit" are being sold like crazy because of the power this puts down to the ground with the lowest engagement and so far...best fuel mileage out of any kit that we have tested.

So to say you can't make a N/A Viper engine produce over 200 hpr I think is hogwash. Cams, porting, a little more compression with EVO's bolt on mods would be easy to get over 200.

 

[Big_Phil]

Lol. I dont want to start a pissing match, but there is no way you are getting 170+ hp out of a stock 1049 triple. Thats a 40+ increase over stock. The physics just don't add up. Yamaha did not leave that much hp on the table.

5-6 psi MPI supercharger kits only put out 175 hp, there is absolutely no way you will get 200 hp out of a trail 1049 triple motor with stock displacement. Maybe if you stroke it to 1200+cc, stand alone ecu, ported head, big cams, race fuel and spinning it to 12000 rpm.

 

[cannondale27]

They did leave that much HP on the table. Problem is harnessing it. The higher this engine revs the more power it gives. No gear reduction means you are limited by the clutches. Such a shame actually.

 

[1nc 2000]

So can I get this same kit from evo for my nytro with the same increase in power that I read about for the viper?