Kristoffer Hætta
Newbie
- Joined
- Apr 22, 2019
- Messages
- 1
- Age
- 33
- Location
- Kautokeino
- Country
- Norway
- Snowmobile
- Yamha Nytro MCX 270
Hey guys. I've owned a 2014 Nytro X-ride 153 for 5 years now, and I finally bought and installed a MCX 270 kit on it and it works amazing.
I got some tips from a friend that since we dont have any elevation changes here where we live, I might aswell not install the TCV and not use it, because it can freeze up and cause overboosting. So I never isntalled the TCV.
Anyways, I blew a belt few days ago while doing a wheelie and it hit the RPM limiter(for probably 0.5 sec) and it caused 2 valve shims and 2 valve locks to go out of place. Had to get towed home and open the engine >.<
I e-mailed the MCX guys at Sweden and asked if its a good idea to not use TCV since there isnt any elevation changes here and I got this answer:
The TCV is very usful.
You can control the turbo pressure however you like.
It is difficult to make a turbo kit without the TCV and get the boost as you like.
Without TCV you get often most boost at mid range rpm where the torque is highest, and here is where you get detonation.
Then it is much better to rise the pressure at higher rpm to get higher top end power.
And just before you hit the rpm limiter, I often drop the pressure rapidly to avoid hitting the rpm limiter if you for instance spin on a icy road.
So I believe it is very old fashion to not use a TCV.
There is a reason why all gasoline turbo engines use TCV now.
Saab starting to use TCV 1984 I believe.
Best regards Erik Marklund
I thought that the TCV cant ever drop the turbo pressure, just increase it. How can the TCV drop the pressure rapidly before I hit the RPM limiter? And how can the TCV rise the pressure at higher RPM also?
Am I missing something?
I got some tips from a friend that since we dont have any elevation changes here where we live, I might aswell not install the TCV and not use it, because it can freeze up and cause overboosting. So I never isntalled the TCV.
Anyways, I blew a belt few days ago while doing a wheelie and it hit the RPM limiter(for probably 0.5 sec) and it caused 2 valve shims and 2 valve locks to go out of place. Had to get towed home and open the engine >.<
I e-mailed the MCX guys at Sweden and asked if its a good idea to not use TCV since there isnt any elevation changes here and I got this answer:
The TCV is very usful.
You can control the turbo pressure however you like.
It is difficult to make a turbo kit without the TCV and get the boost as you like.
Without TCV you get often most boost at mid range rpm where the torque is highest, and here is where you get detonation.
Then it is much better to rise the pressure at higher rpm to get higher top end power.
And just before you hit the rpm limiter, I often drop the pressure rapidly to avoid hitting the rpm limiter if you for instance spin on a icy road.
So I believe it is very old fashion to not use a TCV.
There is a reason why all gasoline turbo engines use TCV now.
Saab starting to use TCV 1984 I believe.
Best regards Erik Marklund
I thought that the TCV cant ever drop the turbo pressure, just increase it. How can the TCV drop the pressure rapidly before I hit the RPM limiter? And how can the TCV rise the pressure at higher RPM also?
Am I missing something?
