Super or Turbo

[mbarryracing]

... Boost is Boost no matter how you get it. It's all the fuel system that makes it run well or be touchy. Just my 2 cents worth

Actually that is not a correct statement, boost for boost it's proven that a turbo will make more power purely because of the difference in efficiencies. The SC is mechanically driven and consumes HP just to spin it. As well, a SC pushes boost 100% of the time based on RPM since it is crankshaft driven, not just load / exhaust heat like the turbo.

 

[kinger]

I went through this 4 years ago and settled on the super and couldnt be happier. Its been turn key but I had ulmer clutch it for me on the dyno. Its insanely fast for the trails. Mpg is about 10 now. I would do this or MCX whatever you get a better deal on. I will caution you I am a power junky and this sled is almost too much now that I long tracked it, it is a rush but on long trips it wears you out trying to hold on! You'll be addicted after the first pull though!!!!

 

[Agman 57]

Ok mbarry, you are right as far as getting down to the last HP, but for just trail riding, which is what he is asking about, it is very little difference. My Nytro is building 1# of boost at idle, so that would take a small amount of power. But on a average run on the trails with a group and not on the throttle hard alot of the time, I will be running 5-8 # Boost. My S/C Nytro will run only about 1-2 MPG less then my Apex or other stock Nytro's. My average will be 12-13 trail riding. My Apex will only be 14-15. Kinger, how does that compare to how your MPG end up?

 

[mbarryracing]

Sorry for the confusion, my point wasn't suppose to be all about the MPG... I was more specifically targeting your boost is boost comment.
A turbo will make more HP at 5 psi boost then your SC at 5 psi boost, it's physics... and therefore a Turbo can also run a higher boost level before detonation then an SC can.
SC's are nice, just no place for one in my garage.

 

[MOUNTY]

Can you explain how a turbo can run a higher boost than a supercharger, and not detonate the motor. If you are pushing 5pds of boost with either, would the ratios inside the motor not be the same?

 

[mbarryracing]

Can you explain how a turbo can run a higher boost than a supercharger, and not detonate the motor. If you are pushing 5pds of boost with either, would the ratios inside the motor not be the same?

I can... all boost is not the same. This goes for different turbo's, as well, having to do with efficiency. Boost pressure inside the motor might be the same, doesn't mean the air quality is...
You can build 5 psi boost and beat & heat the air up doing it, and you can also build 5 psi boost very efficiently and not beat & heat the charge air as much. Higher intake air temps will detonate at a lower boost level then cooler air.
So with all things being equal (compression ratio, air temp, coolant temp, AFR, and fuel quality) an engine might start to detonate at 6 psi with a SC where as it wont detonate until after 8 psi with a turbo.
Likewise, you can have one model turbo make more HP and be more deto resistant then a different model turbo, all at the exact same boost pressure.
Reason why they provide compressor maps for for choosing the appropriate turbo for your application.

It is also fact that a SC has to run higher boost (and therefore higher intake air temp) to produce the same HP that a turbo does at less boost, something like 10psi to produce 230HP that a turbo can make at 7 psi. And we haven't even mentioned the maintenance required on a SC versus a turbo, yet either. The SC belt adjustments and changing the expensive traction lube.
But I don't want you to take my word for it, because I am an obvious turbo advocate. Go research it and see for yourself.

 

[sleeper]

What about the exhaust noise from a rear mount turbo, or the underhood heat of a front mount and loss of fuel capacity because you have to install a smaller fuel tank? To me either one has tradeoffs. SC takes horse power to run, turbos are a plumbing nightmare from what I have heard to install. I guess it is what tradeoffs you want to make. One trade off I can't accept is the loud exhaust or the use of a external muffler behind the seat. Don't get me wrong I have had my share of loud sleds but those days a over for two reasons trying to preserve or sport and all that noise isn't cool to me any more.
Sleeper

 

[Agman 57]

That is one of the good points of a s/c. You never have to alter anything from the back of the motor to the exhaust. Only thing is that it is good to install is a Air/ Fuel gauge. which needs a O2 sensor in the exhaust. usually in the front on the muffler.

 

[Riceburner]

I have had them both and currently run the big MCX Turbo in one of my Apex's.

I will say for a 180 to 200 hp, 6 ish lbs of boost trail sled, I prefer the Supercharger to the Turbo.

It is more fun to drive at lower speeds than the Turbo. My 300 HP Turbo makes less HP under 35 mph than my Stock Apex [You can check Ulmers dyno sheets on the build of my sled on this site.]

That being said, above 7 lbs of boost it is Turbo all the way for me for all the reasons mbarry said above.

I'll tell you the fuel mileage of the MCX 290 Turbo is at least 20 % better than a MPI Supercharger at 10 lbs, better than a stock Apex and equal to a Stock RX-1 from my experience.

Believe it or not I got 10 % better mileage a few weeks ago than a stock 2013 Nytro RTX. [trails were fast and he was on the bar and I only needed 1/2 throttle or so to keep up is the explanation I guess] Weird but true.

Soooo. Pick your poison. It is all good. Your choice likely should be a Turbo unless you are a low boost trail rider, IMHO.