Gems settings for MPI SC

[YammieDave]

Hi all,

I have an 09 Nytro that I purchased last year with the MPI 180 already installed. I went through and put new pulleys and belt on it last year because it wasn't performing (and it's missing when revved high) and it really didn't make any difference.

The previous owner sat it up with 28-28 pulleys, presumably for more horsepower, to run it here in Michigan at 700-1200 feet of elevation. I stayed with the same pulleys because I assumed it had been properly set up to run with these. It doesn't.

I don't have an AFR gauge to dial it in properly, and was wondering if anyone had a set of parameters that I could plug in to make it run right with this setup.

 

[MrSled]

Hi all,

I have an 09 Nytro that I purchased last year with the MPI 180 already installed. I went through and put new pulleys and belt on it last year because it wasn't performing (and it's missing when revved high) and it really didn't make any difference.

The previous owner sat it up with 28-28 pulleys, presumably for more horsepower, to run it here in Michigan at 700-1200 feet of elevation. I stayed with the same pulleys because I assumed it had been properly set up to run with these. It doesn't.

I don't have an AFR gauge to dial it in properly, and was wondering if anyone had a set of parameters that I could plug in to make it run right with this setup.

you need gauges to see what’s it’s doing. AFR and Boost

 

[YammieDave]

The previous owner installed a boost gauge, but no AFR. I'm looking at $200-300 to install an AFR gauge and sensor, and that just isn't feasible at the moment.

I was hoping I could dial in Gems to be "closer" than it is. This thing doesn't perform like it has a supercharger installed. I don't think it's much faster than my stock Nytro, and that makes no sense to me. It's my first time with a supercharger, so I'm kind of in the dark.

I was thinking maybe I could find someone here in Northern Michigan that could dial it in for me, perhaps using a portable AFR unit?

 

[MrSled]

The previous owner installed a boost gauge, but no AFR. I'm looking at $200-300 to install an AFR gauge and sensor, and that just isn't feasible at the moment.

I was hoping I could dial in Gems to be "closer" than it is. This thing doesn't perform like it has a supercharger installed. I don't think it's much faster than my stock Nytro, and that makes no sense to me. It's my first time with a supercharger, so I'm kind of in the dark.

I was thinking maybe I could find someone here in Northern Michigan that could dial it in for me, perhaps using a portable AFR unit?

This is a low boost unit? 5 to 6 lbs? What are your Gems settings?

BTW, I had one and it was a monster even at low boost. One of my buddies still has it and its pretty fast.

 

[YammieDave]

You're exposing my ignorance here, but isn't the amount of boost determined by the pulleys? It's an MPI 180, and (working from memory here) I believe it's supposed to have 26 and 28 pulleys (can't remember now which was on top and which was on the bottom.) I think it's supposed to be running 7 lbs if set up correctly for my 600-1200 ft altitude.

I haven't delved into the Gems yet. I don't know how to see what the current settings are, I just figure they have to be wrong based on the fact that it misses when you rev it, and it doesn't seem to have any more power than the stock Nytro. I get beat by my buddy's eTec 600.

I'll read up on how to check the Gems settings and see what I can learn.

 

[MrSled]

You're exposing my ignorance here, but isn't the amount of boost determined by the pulleys? It's an MPI 180, and (working from memory here) I believe it's supposed to have 26 and 28 pulleys (can't remember now which was on top and which was on the bottom.) I think it's supposed to be running 7 lbs if set up correctly for my 600-1200 ft altitude.

I haven't delved into the Gems yet. I don't know how to see what the current settings are, I just figure they have to be wrong based on the fact that it misses when you rev it, and it doesn't seem to have any more power than the stock Nytro. I get beat by my buddy's eTec 600.

I'll read up on how to check the Gems settings and see what I can learn.

what boost numbers are you seeing on the gauge? 180 is about 6lbs. Stock motor wont live past 7lbs at Midwest elevation.

https://ty4stroke.com/threads/nytro-supercharger-build-2016.143776/
Check out my build, maybe it will help some.

 

[YammieDave]

Thanks MrSled! Reading now. It looks like you have a 26 on the bottom, 28 on the top. I can't see the numbers but I believe that's the standard setup it ships with.

Mine was built with 28-28. I replaced the pulleys and belt because they were worn and the belt was loose, and I went with the 28-28 assuming that the sled was dialed in for this and didn't want to deviate.

Just initial notes as I read your thread. Nicely detailed build, by the way!

 

[MrSled]

Thanks MrSled! Reading now. It looks like you have a 26 on the bottom, 28 on the top. I can't see the numbers but I believe that's the standard setup it ships with.

Mine was built with 28-28. I replaced the pulleys and belt because they were worn and the belt was loose, and I went with the 28-28 assuming that the sled was dialed in for this and didn't want to deviate.

Just initial notes as I read your thread. Nicely detailed build, by the way!

Thank you!! so that would be why your boost is up, it might even run 8 lbs at 1 to 1 on the pulleys.

 

[YammieDave]

so that would be why your boost is up, it might even run 8 lbs at 1 to 1 on the pulleys.

And that would be bad. I asked the guy if I needed to run special fuel and he said no, it's set up to run on pump gas. I was running standard octane early in the season last year (my first with the sled) and then went to 92-93 octane somewhere midway through the season. It ran a little better, but still not right.

I'm kind of frustrated with all of this. Based on what I'm seeing, I wish the damn thing wasn't boosted at all.

 

[MrSled]

And that would be bad. I asked the guy if I needed to run special fuel and he said no, it's set up to run on pump gas. I was running standard octane early in the season last year (my first with the sled) and then went to 92-93 octane somewhere midway through the season. It ran a little better, but still not right.

I'm kind of frustrated with all of this. Based on what I'm seeing, I wish the damn thing wasn't boosted at all.

Thats too much boost on standard gas, high octane always on a boosted sleds. Never worth the risk. Did it ever run good? Does it over heat, push oil out or any signs of a blown motor or head gasket?

Ours at low boost or I should say stock boost 5 to 6 lbs would run perfect, still get almost 17 mpg.. and very fun. Sorry about your aggravation and grief. If you lived closer I could help better.

 

[YammieDave]

Thats too much boost on standard gas, high octane always on a boosted sleds. Never worth the risk. Did it ever run good? Does it over heat, push oil out or any signs of a blown motor or head gasket?

Ours at low boost or I should say stock boost 5 to 6 lbs would run perfect, still get almost 17 mpg.. and very fun. Sorry about your aggravation and grief. If you lived closer I could help better.

I didn't have any problems with overheating or oil loss. No head gasket problem, so nothing indicates the motor is hurting.

Last season was my first run with it, and it missed when you'd hit WOT from the start. Other than that, it runs fine. In February, I installed new sprockets, belt, and prefilter. I didn't get any change in performance. It still misses when you hit WOT, and it never seemed to pull any harder than the stock Nytro.

I'm getting about 11 mpg on average. 10 on days I'm riding harder, near 13 on days that the ride is lighter.

 

[MrSled]

I didn't have any problems with overheating or oil loss. No head gasket problem, so nothing indicates the motor is hurting.

Last season was my first run with it, and it missed when you'd hit WOT from the start. Other than that, it runs fine. In February, I installed new sprockets, belt, and prefilter. I didn't get any change in performance. It still misses when you hit WOT, and it never seemed to pull any harder than the stock Nytro.

I'm getting about 11 mpg on average. 10 on days I'm riding harder, near 13 on days that the ride is lighter.

I would guess you are hitting the rev limiter, does it have a clutch kit? If not that's your problem. It needs more top weight or overall weight to get it to pull hard and stop it from hitting the rev limiter at WOT.

 

[YammieDave]

I remember asking the seller if it had clutching work done to accommodate the SC, based on what I had read about SCs on a Nytro. He said no, it didn't need it. He also mentioned that it was dialed in by a performance shop somewhere around Grand Rapids.

I should also note that the reason I replaced the sprockets and belt was because the belt was loose and the sprocket teeth looked bad. Once I took it apart, I found that the PTO sprocket was not tight on the shaft. You could turn it with your hand and it would spin on the shaft. I put it back together all nice and tight.

Maybe my next step is to do the clutching first, but I'm losing confidence that this thing is even set up right at all. From what I'm reading in your feedback, it shouldn't even be running these sprockets in the first place.

 

[MrSled]

I remember asking the seller if it had clutching work done to accommodate the SC, based on what I had read about SCs on a Nytro. He said no, it didn't need it. He also mentioned that it was dialed in by a performance shop somewhere around Grand Rapids.

I should also note that the reason I replaced the sprockets and belt was because the belt was loose and the sprocket teeth looked bad. Once I took it apart, I found that the PTO sprocket was not tight on the shaft. You could turn it with your hand and it would spin on the shaft. I put it back together all nice and tight.

Maybe my next step is to do the clutching first, but I'm losing confidence that this thing is even set up right at all. From what I'm reading in your feedback, it shouldn't even be running these sprockets in the first place.

The guy sounds like a real salesmen, new nothing and just wanted to make the sale. Trust me if that sled was truly running correctly even on 6 lbs of boost it will need a clutch kit to make it work and stay out of the rev limiter.