If you do any research on the carb I'm going to be using, the Mikuni TM40-6 or HS40, you'll see that it's also a carb that is used as a replacement carb on HDs as well. This carb is the predecessor to the Mikuni HSR series, which is likely the Keihin equivalent although the Keihin FCR series are flatsides. One thing I know about the HS40 is that the intake is the same size as the stock carb and the spigot diameter, while it is only slightly larger than stock, will fit the stock airbox plumbing without an adapter. That's not true of the HSRs. However, the 40mm may not provide the airflow you need with a turbo. I found a used one on Ebay for a reasonable price. You should be able to buy new from Sudco for under $300, if any of this peaks your interest.

While your observations are correct about the Polaris being in its torque band, you may still see a bog off the line. I just learned to give a little slower throttle than just jamming it to WOT and didn't have any problems, but was only true after I got the jetting right. However, until the machine completely warms up, that will not be the case. Just allow for a longer warm-up period.

 

Sounds like the HS 40 is probibly the best choice given fit and sizing . It should prove the best comprimize between top end power improvement and driveability

What RPM did it Idle at ?

When do you think you'll get a chance to try it ?

 

My ATV is up at my camp and I have to go up there the first weekend in March. If all my parts are in, jets and the 800 snorkel, I'll probably put the carb and snorkel on and give it a try. I've already dismantled the carb and cleaned it all up. I ordered a carb kit with the jets, which I'm hoping will be here for this weekend, so I can put it all back together. I'm going to go down one jet size on the starter jet, pilot jet and probably 2 sizes on the needle jet as a base line. I also intend to go up a size on the air jet (leaner). My 800 header pipe got here today and I'm going to ship it off to Jet Hot tomorrow. That should make it back in time for next weekend. I'd like to get all the mods installed before I start working on the main jet, but I can get the low and mid-range jets sorted out for sure. If this doesn't happen, it may be a while before I'm able to get back there. I'll keep you posted. Other's are probably curious how this turns out too. I'm not sure I understand your question on idle.

 

Sounds good !

I question the idle sped because it could be idled up to say 1400 -1450 rpm and with the idle mixture on the pilot screw just a tad rich this would produce less chance of a bog when the throttle is snapped open,..... not exactly an EPA approved setting but this would reduce the bog tendency

I talked to a guy I know that runs a " Blow through turbo setup "on a drag car and he claimes they require little or no accelerator pump shot because on a snap throttle test the impeller in the turbo creates a " choke " effect and puts an emeadiate draw on the venturi boosters to start the main metering system [ Makes sense to me ]

I called the techline at Aaen and questioned this bog issue and he confirmed it's never going to be 100 % but I'm willing to give it a shot because and I'm leaning toward the future turbo addition

Mentioning this he did say that the " blow through " carb/turbo setup is becoming more common [ sleds ]

To help get my WOT/ main jet mixture dialed in I'm going to us my " Barry Grant " exhaust temp monitor that we used on our turbo focus , it's a digital unit that has recall , I'll have to put the probe at they " Y " merge , I'll play it safe around 1200-1300 degrees

I have no idea how good the pistons are in the 700 [ probibly a cast hyperutectic type] so with 9.6:1 compression we'll keep it no more than 6 psi and total timming around 28 degrees as a beginning

Further down the road we'll get some better pistons and drop the CR to 8:1 and then put some better ignition that we can program and crank up the boost a little higher 12-14psi , 14.7 or 1 apmosphere added boost in theroy should double the HP in theroy [ will the pressed together crank take it ??????

Len.

 

oleman, what kind of coating you having done to the 800 pipen at Jet Hot ? I thought of having some type of coating to mine when i get it.
Jim

 

There are three options in the 1300 degree coating, sterling, flat black and grey. I've had their sterling coating on a few sets of headers and it's very durable. Because the sterling has a smooth finish, it seems it will clean up easier than the other colors, so that's what I'm going to have it coated with. I'm hoping it reduces heat radiating from the pipe around my leg, not so much for looks or durability, although these aren't bad side effects. Thanks for posting the part numbers on snorkel and other exhaust components I was lacking as well as the link to Asheville Motorsport. That made it too easy.

Lentech, a higher idle will certainly minimize the hesitation or mask it altogether. You'll need to modify the clutch accordingly. Your project sounds more than interesting and stuffing that turbo and the piping under the body cladding should present a pretty good challenge, so take lots of pics. I'm not sure what material the pistons are made of and I have my doubt about the stock bottom end, but with 14 p.s.i of boost your other limitation could be the drivetrain itself. You'll probably end making me want one.

 

whats the number or link for jet hot?

 

Oleman , I'd be glad to share this expeariance

This polaris twin looks like it was designed to be a workhorse [ 2 valve push rod ] more that something desined to make HP like a Kawasaki , but I think it been a parrell twin , and the layout in the machine , we can use to it's advantage with a Turbo

The Garret T-12 seems to have the specs I need

Clutching is an area I have absolutely no expeariance on so I'm gunna need lot's of advice


I enjoyed all your tech opinions as they have comfirmed some of my experinces as well


I'll keep you posted as we move along

Thanks ,

Len.

 

Go here Jet-Hot. There's primarily techincial info on the site in addition to the different coatings and color options. Follow up with the cost estimate and they'll give you shipping information and what not. They quoted me $85 less a 10% discount. The 2000 degree coating is $25 more, but not needed in my application. Locations are in MS and AZ.

 

Lentech, it's hard to beat the Heelclicker setup. It made a big difference in my quad.