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my first turbo, need wisdom :)

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Bacon

Well-known member
Nov 26, 2007
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Napoleon, ND
Lol yes it is in any turbo set up ... but I'm trying to build a turbo to run on pump gas .. is it impossible or something

Not impossible, just not very likely with the crappy fuel that is available. Save yourself a lot of heartache and run good fuel. Either av or half race.
 

vendetta

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Oct 12, 2008
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Langley B.C
Ok so here's my last 2 cents. Everyone on the internet that claims to run pump gas turbos is B Sing. 2 stroks are way different then 4 strokes. The motor stock is fine I would suggest 2 ring pistons though. My buddy had a turbo rev 8 pounds 50/50 race gas. I have another buddy turbo pro 8 pounds(lots of motor work cause they are weak stock but did not lower compression). At least start your tuning with a good gas and then dial it back from there.

I love boost just want it to work for you and not melt down. Thing can go sideways really quick.
 
N
Nov 11, 2015
31
3
8
Ottawa Canada
Ok so here's my last 2 cents. Everyone on the internet that claims to run pump gas turbos is B Sing. 2 stroks are way different then 4 strokes. The motor stock is fine I would suggest 2 ring pistons though. My buddy had a turbo rev 8 pounds 50/50 race gas. I have another buddy turbo pro 8 pounds(lots of motor work cause they are weak stock but did not lower compression). At least start your tuning with a good gas and then dial it back from there.

I love boost just want it to work for you and not melt down. Thing can go sideways really quick.

Thank you for tje input .. I like to here that guys are running boost on a stock motor with little to no issues. Even if they are running 110 or better fuel it gives me hope for what I am trying to accomplish. I here a lot of info both ways .. I think the 2 stroke motor has alot of exhaust valve overlap with is inefficient but helps eliminate detonation .. I wonder if that has something to do with the rave valve mod I have heard mentioned on here in higher boost applications ??
 
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TheBreeze

Well-known member
Jul 23, 2008
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Sussex, Wisconsin
50/50 is very different than 94. Also, lowering compression kills spool time. Basically everyone in this thread is screaming "don't run straight pump". Add me to that list. 10:1 compression, and that turbo is going to take forever to spool up.

2000 feet and under, boosted carb sled, on pump fuel.... Scary stuff for sure.

Id be on 100LL.
 
N
Nov 11, 2015
31
3
8
Ottawa Canada
50/50 is very different than 94. Also, lowering compression kills spool time. Basically everyone in this thread is screaming "don't run straight pump". Add me to that list. 10:1 compression, and that turbo is going to take forever to spool up.

2000 feet and under, boosted carb sled, on pump fuel.... Scary stuff for sure.

Id be on 100LL.

i get it .. i know .. race gas way safer .. easier to tune .. and makes more power .. and when i say it like that it sounds dumb to want to run 94 .. but thats what i want to do .. if i wanted to run race gas or 50/50 thats what i would be doing . and who knows in a month from now i might have a melted top end .. or worse and you can all say i told you so :p but for now .. today .. im looking for info on how i can run a set up on 94 .. maybe 10:1 is to low .. some ppl say leave it as it is .. and some say no .. maybe 11.5 is where i should be aiming .. im just hoping that when it hits the dyno it is running good and making more power than it is now on 94 since where i ride that is all i can get
 
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Turbo11T

Well-known member
Nov 26, 2007
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Lake Crystal, MN
i get it .. i know .. race gas way safer .. easier to tune .. and makes more power .. and when i say it like that it sounds dumb to want to run 94 .. but thats what i want to do .. if i wanted to run race gas or 50/50 thats what i would be doing . and who knows in a month from now i might have a melted top end .. or worse and you can all say i told you so :p but for now .. today .. im looking for info on how i can run a set up on 94 .. maybe 10:1 is to low .. some ppl say leave it as it is .. and some say no .. maybe 11.5 is where i should be aiming .. im just hoping that when it hits the dyno it is running good and making more power than it is now on 94 since where i ride that is all i can get



Here is my opinion. Another way to get this done. The 9lbs of boost was I am sure a number that was for high elevation. Cutting the head you lose the fun of the sled. Why not run 3-4lbs of boost and 94 octane. The stock engine your elevation is making 150 hp. If you get 9-10hp per lb of boost that puts you at 180-190 hp. You may be pleasantly surprised at that boost level. If not it is a good starting point and you can work up from there and see where you start to detonate.


Also you are a smart person I can tell. A lot of ski doo turbo guys run 5-10lbs of boost at 8000+ feet. At that elevation the 5lbs makes the engine flow a little more efficient with a little extra and brings total pressure to 15.5 and 10 lbs to 20.5 total pressure. At seal level or close to it your 4 lbs of boost will be 18.5 total pressure.


Another thing is that the turbo that CPI uses is a journal bearing. While it is faster than a lot of ther journal bearing turbos it is still much slower to spool than a BB turbo. This on top of your head cut would make your sled very unresponsive.


So my advice. Get a wastegate and boost controller to start at 3-4lbs of boost and work your way up to find the limit on stock compression on 94 octane.
 
N
Nov 11, 2015
31
3
8
Ottawa Canada
That seems like some pretty solid advice .. wish I had though of tjat before I ordered my new wastegate lol .. at this rate I am going to have a shelf full of them lol .. I'm so excited to get this thing together and hit they dyno and see how it runs :) I have been away from home for 7 days working and just got home .. build and fab starts tomorrow morning :) wish me luck guys .. soon to be tje newest guy to the boosted sled family .. I want to take a second to thank all who have commented so far .. not always what I wanted to here but they have all made me think of things I need to do to accomplish my goal .. hopefully in a few weeks I'll have a reliable pump has turbo 2 stroke to smoke all my e tek buddies lol
 

bmiller1985

Active member
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Nov 30, 2013
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merrimac, wi
Do yourself a favor and read the post right below yours about most miles on a Silber. I had terrible luck with mine, switched to an impulse and nothing but smiles since

Sent from my Nexus 6 using Tapatalk
 

joshkoltes

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Dec 16, 2007
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I noticed that you asked for advice from turbo owners. 3 people have suggested to run avgas due to your elevation and boost level but then you say that you won't be running avgas. I have to ask-if 3 people with turbos advise you to run a gas, why won't you be running avgas?
I would be the 4th to advise to use AV gas.

fifth
 
N
Nov 11, 2015
31
3
8
Ottawa Canada
yaya .. lol you can tell me all you want im not going to run av gas unless i melt my top end first .. im going to build this setup to run on pump gas even if it kills me lol ,, i have been in contact with greg at jaws performance and man does he know his stuff ,, he is going to help me figure out what i have to do to achieve my goal.. and i will keep you all posted on things as they come along

now that i need to add a battery to the sled ill need a way to charge it . do i get the electric start harness for my sled pn 515175721 ? and if so where then do i hook the battery into the harness ? or is there a place i could charge it off the current non electric start harness ? electrical is not my strong suit
 
N
Nov 11, 2015
31
3
8
Ottawa Canada
Drill a hole in the top of your fuel tank and thread in a 90 you can attach a hose to.

ya i got a rubber gromet and 90 meant for a return line for a fuel tank at the local parts store for 11 bux and it worked perfectly .. just waiting on my exhaust flange to mount up the turbo .. got carbs all cleaned up ( kit came with carbs )thinking about upping the jet from a 17.5 to a 20 like i did in my sled before the turbo ..
 
N
Nov 11, 2015
31
3
8
Ottawa Canada
return line bung installed in tank, new rails ready to rock and back in the sled, and mocking up turbo placement .. i wish the parts would hurry up and arrive .. need a chin case seal before i can slap that back together and cant install oil tank till the chain case is in .. waiting on new oil pump anyway .. do you guys run an oil pressure gauge ? what is a decent pressure for the oil supply to the turbo ??? and should the oil pump be on a switch to be turned on before the sled or would having it turn on with the sled like it would be in a car be fine too ?

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