Pump gas M8 & M1000 turbo comparo
- Thread starter boosted1
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Nubulin
Well-known member
I am sorting out all the info for a PG M8 project this summer versus a M1000 mod (not turbo).
Cutler claims around 190hp at 9000ft altitude with their PG M8 kit. Doesn't sound huge, but a "215hp" full mod M1000 would be around 157hp at 9000ft.
I don't know much about the PG M1000 setup. You don't hear much talk about PG M1000 setups on here.
Cutler claims around 190hp at 9000ft altitude with their PG M8 kit. Doesn't sound huge, but a "215hp" full mod M1000 would be around 157hp at 9000ft.
I don't know much about the PG M1000 setup. You don't hear much talk about PG M1000 setups on here.
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RKT
Well-known member
190Hp at 9000ft WOULD be HUGE.. but it is never going to happen on 91 octane
145HP M8 at 9,000ft will be between 103-110HP at 9,000ft... so at 8.5 PSI boost (max allowed on 91 octane with stock head @9K) you would have to get 80-90HP on 8.5psi of boost.. This would be a very tall order..
If this were the case.. I think everybody would be running the PGM8.. Unfortunately...for all us power lovers, 8.5PSI will not get you 80HP.
Now a PG M10.. to get to 190HP is a smaller order but still stretching it on 91 octane.. 168HP stock (on a good day) about 120-130HP at 9K ft.. so you have an extra 20HP already.. unfortunately the M10 can not run 8PSI on pump gas due to injector limitations.. 6-7 is the norm (or at least it use to be... maybe things have changed recently that allows more.. that would be good)
So, 160-170HP is realistic on 91 octane with the 1000. the 1000 responds better to the boost due to its larger pipe and larger crankcase volume.. Not to mention the better cylinder porting..
160+ HP at 9000ft is ALOT of power!! This would put a smile on anybody's face..
There is no question that the PGM10 will run stronger than the PGM8.
Kelsey
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Nubulin
Well-known member
Yeah, all this turbo marketing hype has to be taken with a grain of salt......
Every turbo seller I talk to pulls the line "turbos don't lose power at elevation like regular sleds" bs. I don't see the physics of air density caring about turbo versus non turbo. The 3% power loss per 1000ft is the number that sticks on my mind and I assume it would also apply to the 190-200 hp pump gas turbo all things staying the same (boost level, etc).
I am no expert, but you can run more boost the higher you go with the same octane fuel. Kind of like with high compression heads. Therefore a PG turbo may be stable at 5psi at sea level might be safe at 8.5 at elevation?
I think the reality is if you want big HP on an M8 turbo you will need to run some race fuel mixed in at a minimum. That would be my plan if I go that way.
Correct me if I am wrong RKT.
Edit: here is an interesting (if true) explanation I found online.
http://www.2-stroke-porting.com/altiden.htm
Every turbo seller I talk to pulls the line "turbos don't lose power at elevation like regular sleds" bs. I don't see the physics of air density caring about turbo versus non turbo. The 3% power loss per 1000ft is the number that sticks on my mind and I assume it would also apply to the 190-200 hp pump gas turbo all things staying the same (boost level, etc).
I am no expert, but you can run more boost the higher you go with the same octane fuel. Kind of like with high compression heads. Therefore a PG turbo may be stable at 5psi at sea level might be safe at 8.5 at elevation?
I think the reality is if you want big HP on an M8 turbo you will need to run some race fuel mixed in at a minimum. That would be my plan if I go that way.
Correct me if I am wrong RKT.
Edit: here is an interesting (if true) explanation I found online.
http://www.2-stroke-porting.com/altiden.htm
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All I know is that an m1000 at 13lbs of boost goes up the hill faster than anything ive ever seen.
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mtn_extreme
Well-known member
I think you still have to factor in the difference of natural flow intake systems compared to forced air induction systems of the turbo. The density of the air would play a minimal factor when it is being forced into the cylinder.
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product tester
Well-known member
at 4300 ft the m 1000 at 4.5 #s of boost picked up 85 hp over stock.
Ok 19 hp per pound of boost know i know.I've never heard any one say it was that much before.So what is 4.5 pounds going to be at 6000 that is the range i ride at. After all i have read i would assume you will not lose much?I assume that that 4.5 pounds is in the pump gas category? or not?
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product tester
Well-known member
yes I have run the pump gas 1000 up to 6#s at 5000 ft with no deto have not dynoed at 6#s yet we will this week and Ill let you know we are not correcting numbers we just add from what a stocker did there fells like another 20 hp at 6#s but we will see.
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BadAftertaste
Well-known member
You're 'friends' should read more...
http://www.amazon.com/Maximum-Boost-Turbocharger-Engineering-Performance/dp/0837601606
probably the best way you could compare IMO... who cares about corrected. stock vs turbo on x amount of boost at elevation, gives you a true idea of what they are loosing.
as for turbos loosing at elevation, yes they can just turn up boost to compensate, but the turbo becomes less effient as it is pumping harder to make the same HP, meaning you still loose a little bit of your power, but not nearly the same level as NA. but with a dash of race, you can MORE then make up for the effeieciency loss!!
Ok Product Tester, obviously gaining 85 horse power off of 4.5 pounds is an extremely large gain. Surely that cannot be figured on a normal scale and expect to gain 19 horse per pound all the way up the boost levels?? That would put an m1000 on ten pounds building somewhere around 350 horses??
So, with that being said it should be assumed that there are other factors at play to build 85 horse gain on only 4.5 pounds of boost. That particular boost level must take advantage of the pipe pressure waves, timing, and fuel curve improvements over the stock setup?? Not trying to knock what your saying or anything like that, just lookin for how the gain was made.
So, with that being said it should be assumed that there are other factors at play to build 85 horse gain on only 4.5 pounds of boost. That particular boost level must take advantage of the pipe pressure waves, timing, and fuel curve improvements over the stock setup?? Not trying to knock what your saying or anything like that, just lookin for how the gain was made.
I had talked to some one at bd awhile back about the m-1000 and was told 10 hp per pound ,when i talked to another they said no way more like 7 now i hear 19 but with stipulations So hows a guy to compare with out any kind of standard. No troubles here i'm just wondering why so many different numbers with like boost . i realize that different set ups do different things but is there some commonality between these thing that a guy can look at. i have finally seen some turbo 2 strokes that run on a daily bassis and am getting interested. i did not try to get this thread off track, just wondering.
lmao
Heres a quick and easy way to figure it. Its not always perfect so dont shoot me, but its usually pretty close if things are set up right.
Natural asperated hp divided by 15 times boost plus natural asperated
hp = total hp
Example: 170hp/15=11.3 hp per lb.x 6lbs=68hp gain + 170hp=238 total hp.
10 lbs would be 283 hp.
12 lbs would be 306 hp.
15 lbs would be 340 hp.
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product tester
Well-known member
there are better gains at diffrent boost levels I would say sweet spoots are 5,11,13.5,and 17 #S in between theese levels there are not that big of jumps in power, but with my system this is where the 1000 makes great power
all systems do not make the same power in the same spots!!!!!
all systems do not make the same power in the same spots!!!!!
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RKT
Well-known member
The amount of HP produced per pound of boost is NOT linear, not even close to linear. So, there is no X amount of HP per pound of boost
The gains are are directly related to several "things".
Please note: these are generalizations only:
1) Compressor map of the turbo
2) Size of the turbo
3) Air quality
4) Pipe resonance
5) Porting and case configuration volumes
6) Volumetric efficiency
7) Bore and stroke
These are a few.. So, just because a 1000cc twins makes x amount of power at 5psi boost does not mean that an 800cc will make that same amount at 5psi with the same turbo..
Also, there is virtually little to no power gains at 1-2PSI of boost.. This, again, is part of the non-linearity of turbo power..
On an 800cc twin the "sweet" spot where power seems to increase substantially seems to be around the 9-11 psi boost level
On a 1000cc twin, that sweet spot is lower due to the engine iteself, not the turbo system.
Get any of those enignes above 10PSI and the power is incredible.. Unfortunately neither can run 10PSI on 91 octane.
Kelsey
