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Discussion Starter · #1 ·
Ok I am new to the Snowmobile sceen and I got a couple questions. I have a Polaris XLT 580 with I think a First Choice Turbo set up?

The electric fuel pump is not working. What fuel pump is it? Can I just get one from any fuel injected car or would that pump to much fuel?

I am afraid its gonna blow up and I was told it has had head work for lower compression. My compression is 86, 85, and 87psi and its hitting ten pounds of boost. Is that to much boost for this motor? It runs great up untill 3/4 throttle then it boggs but I think thats cause of the fuel pump?

Sorry if this dont make sense now that I am writing this my mind is blank lol! I will try to post up pictures of the turbo kit and fuel pump...
 

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Rick
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for one your compression is way low.
 

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Discussion Starter · #6 ·
I was thinking one from a Honda or something. I guess what I am looking for is how many gallons per minute the fuel pump needs to be?

What is normal and bad compression for these motors?

I assume its just the stock 580 pipe. After the turbo there is about a 8in muffler. I think its a matter of getting a fuel pump and getting it tuned in better. I did sync the carbs sense I rode it and it seems to rev up better. The Mag carb opened about a 1/8in before the middle started to move...
 

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Rick
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120 psi at least and was there a elec fuel pump on there? that sled stock should have a vacum one. but not sure since the turbo was added. but still that only works off the exhaust so why the elec fuel pump? i guess i just never seen this before. but unless you have injectors and stuff like that all you need is a stock pump for that sled which is like 40 bucks.
 

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Discussion Starter · #8 · (Edited)
Its got both, a vacuum fuel pump then a boost activated electric pump. The sled has a fuel pressure gauge and vacuum pump will hit and hold 8psi at full boost but sometimes the pump wont go over 4psi. I will take and post up some closer pictures of the fuel system tomorrow.

When I rode it I could only give it 3/4 throttle or it would bogg, but I was still beating my buddies 97 RMK 700 up hills. With that said I think the compression is pretty close to where it should be with the head work being done...
 

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Discussion Starter · #10 ·
Today I was able to get ahold of a guy that has installed these turbo kits. He says the fuel pump is a Holley pump that they use on there Pro Jection kits. He says if I am running 10lbs boost I need to have 20lbs fuel pressure at full throttle. Now the pump just needs to hurry up and get here!!!
 

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Rick
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it is still low compression. was it bored out at all? if so how much?
 

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Polaris Rider
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how many miles on the sled?
 

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it is still low compression. was it bored out at all? if so how much?
Indyryder you do realize this is a boosted engine right? He cant be running 120 psi if hes hoping to be able to use pump gas with 10 lbs boost! 10 psi equals WAAAAY more cylinder pressure than your getting with atmospheric pressure. I understand why you have the 120 psi number stuck in your head, but thats for naturally aspriated sleds. That goes out the window with these...
 

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Discussion Starter · #15 ·
Indyryder you do realize this is a boosted engine right? He cant be running 120 psi if hes hoping to be able to use pump gas with 10 lbs boost! 10 psi equals WAAAAY more cylinder pressure than your getting with atmospheric pressure. I understand why you have the 120 psi number stuck in your head, but thats for naturally aspriated sleds. That goes out the window with these...
I agree... I dont even think the crank could handle 120psi, 10lbs boost, and race fuel anyways :(

The sled has a exhaust temp gauge that goes from 0-2000 degrees. How hot is to hot for the set up i have do you think?
 

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edt temps shou;d not exceed 1250 degrees, and as for the compression cruzr is right turbo motors run on lower compression than a NA engine. 10 lbs of boost is a lot for that xlt!!! i hope that the crank is welded. and cruzr i got your message on here weeks ago and for some reason i cant read it!!!!!!
 

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Rick
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well i just learned something lol
 

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yeah w what i was gettin on about, is that i read that when you turbo a twostorke unles you have som form of exhasut valve, the turbo pushes a lot of air through the ports and right out robbing fuel economy and power, so what you need to do is make sure you ahve a good bit off backpressure, and what you can try is outtin a small reduce on the end of the exhats and see if you notice any difference. just some thoughts
 

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found this too:
Turbo Phazer History

I first built it in 1991 after being told that you could not turbo a fan cooled engine successfully. It took me almost two full winters to get it to operate half way decently but the original 485cc engine produced 132 hp on Dyno Tech Engineering's dyno. If you are old enough you may know of Jim Czycala who operated the Dyno Tech News for many years, a Consumer Reports type of publication. He also did all of the dyno work for Tim Bender who won Eagle River more times than I can remember.

I ran the 485 turbo Phazer from '91 to about '99 with great success. Basically, the turbo was an add on to a Bender ported Phazer engine that produced 85hp normally aspirated and 132 with the turbo at 13# boost. Once I replaced the original cast pistons I never once hurt a piston or anything else for that matter. Once I had a wrist pin bearing come apart at the end of a season but that was it. Never broke it which is a miracle considering the poor stock connecting rods in the Phazer and the less than stout crank but the turbo power is "soft" so it doesn't hammer like Nitros would. The key turned out to be the fuel system which I developed to deliver a constant fuel pressure above and beyond the boost pressure. I "gave" the system to Jim and it is now the standard for all turbo snowmobiles.

Eventually, 132hp was not enough so I decided to build the 650 engine. The attached narrative details what was involved. I also had to radically modify the chassis to fit the 650 engine which is about 1 1/2" taller than stock and had to be sunk in the chassis. Had a lot of trouble with the combustion chamber design with the larger engine and cooked a lot of pistons before I got a handle on it. Eventually got it to work pretty well but by then the chassis was totally out of its league. The small 8 pitch drivers and limited tunnel clearance meant a severe limitation on the picks that could be used and I had a lot of trouble trying to put the power to the ice.

Decided I needed to update the entire chaincase/brake/driveshaft situation and there is where it sits at the moment. The chassis needs major surgery to adapt an Artic Cat chaincase and driveshaft assembly rolled back to allow reasonable tunnel clearance. Also need a drag racing style skid frame to make it work right.
 
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