To be fair in one of Burandts podcast they talk about how the turbo is not always the weapon of choice. Depends on snow conditions. A lot of times they choose the N/A sleds.
Not Average Joe Boost review
- Thread starter Chadly
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Out of Jackson/Teton Valley area. Ping me if you are ever nearby.
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volcano buster
Well-known member
What is the story with the yellow sled?
It may have been at one time, i dont know. But now, cylinders are fully ported, you can get it case ported as well, slp head, bigger y pipe that is port matched, some other little things.
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If you had a turbo or a tune they move the limiter to 8900 stock they have a soft limit which strats at around 8300 and a hard limit at 8500. On a stock sled you would be way out of the powerband at 8700 to 8800.
Just remove the limiter strap and set rear spring to soft and it will be just fine!
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I'm still not sure I understand the "flutter", some make the sound, some do not. Sounds like over rev to me, but I have no idea, never been around one.
Ah just now see you say you hear it more at lower elevations... but I would question that because it was very noticeable in most of Burandts videos.
There are 2 sounds you hear.
One is out of the exhaust, so videos where the sled is wheelieing at the camera etc. These are a much lower pitch and you will hear them under constant throttle like shown in above videos climbing. This I will say is more of a weird pulsing WHOOSH sound.
Gopro videos you will hear compressor surge as rider is on and off the throttle. This is much higher pitch and you get the classic turbo "chirps" or flutters as you let off the gas.
As someone who is very versed in turbo vehicles you can hear both sounds occurring and they are each unique turbo system components doing there thing. Before we got to demo ride the sleds in the spring the Poo Engineer who rode with us also explained how the exhaust sound is very unique and can be confusing to people. Gopro videos make the compressor sounds much more obvious as the intake is pointed more at the camera and exhaust away. Off vehicle videos make the wastegate sounds more obvious. as the skis are up and the exhaust note is much more clear and overpowers the intake noise.
Its STILL NOT THE REV LIMITER.
So today we had a brand new 165 Matryx Slash Pro NA in the group. I take back what I said about a little lag. The turbo has a huge amount of lag. I have 8 hours on my sled now and the NA was on its first ride. I also might agree with what was said above about the 22 having the snap of a 900. The NA flies out of the snow. I might be trying to find someone to trade this turbo for a 2nd NA. It rips going up hills but it sucks in the trees and it really does take twice the effort to ride. So far nobody who has ridden my turbo likes it better than their NA sled haha
The on throttle noise is the sound I’m referring to.
Making sense now, I just remembered they are dumping pressure right out the side of the pipe, and I believe that remains completely separate to the outlet?
Pretty much exactly what you said in the first post, just taking some time to wrap my head around how it works and sounds differently from current aftermarket turbos.
Im curious to see what can be done for clutching on them to help change the power delivery.
Since its running an all new weight (not sure if its just the wider pin area) or a true new ramp profile. Also its running the same old stiff spring steep helix that carls/etc have run for ever on NA and turbo sleds. It works but kinda bummed to see thats all they came up with is was a secondary combo developed in the dragon era. The boosts felt much like every NA or other sled ive rode with that clutching. Sort of more locked in gear and slower rev vs a super snappy rev and then upshift.
8 hours above the break - in time of 5 hours above 5000 or 5500 rpm?
No my sled is not broken in yet. Hopefully it will come a little more snappy once it's broken in but like I said the NA isn't even out of the extra fuel stage and it slaughters the turbo out of the hole
D
doudea
Well-known member
Broke in a buddies 165 Boost on Friday. I have to say the bottom end was lazy compared to several Turbos I've ran on previous 850s.
I know it may be shocking to some, but Polaris's stock clutching leaves a fair amount to be desired. Slinging 78g weights isn't doing the bottom end any favors for reducing turbo lag.
I'm excited to try a tucked weight and much steeper helix angle with a stiffer secondary spring. Confident that will help the bottom end response and back shift a bunch.
I know it may be shocking to some, but Polaris's stock clutching leaves a fair amount to be desired. Slinging 78g weights isn't doing the bottom end any favors for reducing turbo lag.
I'm excited to try a tucked weight and much steeper helix angle with a stiffer secondary spring. Confident that will help the bottom end response and back shift a bunch.
Too bad some guys aren’t impressed with the boost. I rode the 155 khaos boost for a full day last season and was extremely impressed! In some scenarios you could feel the additional weight, but most of the time it didn’t matter. It felt snappy like a na and was the best feeling turbo I’ve ridden.
Hopefully the pre production sleds aren’t that different. I haven’t ridden a production turbo to know yet.
On a side note. I now fear that because I was so impressed with the booster I may not be half the rider I once hoped to be. I certainly have never been given a trophy from mr. burandt…
Hopefully the pre production sleds aren’t that different. I haven’t ridden a production turbo to know yet.
On a side note. I now fear that because I was so impressed with the booster I may not be half the rider I once hoped to be. I certainly have never been given a trophy from mr. burandt…
I believe the weight has a lot to do with the bottom end. Here are some pics comparing the new weight to a 10 series.
Getting tuck in the P22 is almost impossible. The bearing boss and structural gussets are the culprit.
You also have a large diameter bearing that pushes the belt further up in the primary. That mimics a loose belt deflection in the P85 setup.
I haven’t checked to see if Polaris moved the pin boss or roller height, these also affect bottom end.
I also have a concern with the splined spider that may cause a floating belt to sheave measurement.
Getting tuck in the P22 is almost impossible. The bearing boss and structural gussets are the culprit.
You also have a large diameter bearing that pushes the belt further up in the primary. That mimics a loose belt deflection in the P85 setup.
I haven’t checked to see if Polaris moved the pin boss or roller height, these also affect bottom end.
I also have a concern with the splined spider that may cause a floating belt to sheave measurement.
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You've got me really close to swapping my turbo for an NA sled. TRS might be on to something as far as bottom end goes, but the whole purpose of an OEM turbo (to me) is to do absolutely nothing and simply ride. What you are saying about a heavy feeling sled is 100% due to a laggy bottom. No weight transfer early forces the rider to muscle the sled a lot more.
I wonder if the preproduction sleds were running the stock heads on less boost or a race gas mixture? The OEM production boosts have a low compression head (check the parts catalog) that allows for such high boost on pump gas...
I wonder if the preproduction sleds were running the stock heads on less boost or a race gas mixture? The OEM production boosts have a low compression head (check the parts catalog) that allows for such high boost on pump gas...
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