Ulmer Turbo Max Boost

[nitris223]

What is the max boost I can run and 1600 ft elevation on a Ulmer Stage 2HE turbo for a nytro. The stage 2 HE comes with a 2854 garret turbo, intercooler and boost switch for 5 or 10 psi . I will be running a stock fuel pump. I want to delete the boost switch and go with a manual boost controller.
I think Ulmer told me the waste gate was set for 5.5 psi and I can't remember what he said I could run for max boost at my elevation. I here lots of guys around here running MCxpress kits at 7 -8 psi on stock fuel pump. It has been hard to get in touch with Ulmer because I have a hell of a time getting the phone lines to connect, usually takes about 30 tries before I get a ring tone, most times it is just dead air.

Could someone also plug the numbers into the boost/octane program and give me some figures on what octane I can run at what psi and what kind of hp I should be getting.. I played with it a bit but I don't know if I was entering the numbers correct. Not really sure what numbers I need to change in the yellow or white brackets. Sled is stock as of right now, no head shim or anything else done.

 

[mbarryracing]

nitris223,
There are way more variables that influence how much boost you can run than is comprehended in a calculator/program.
The biggest limiting factor on most kits is the stock fuel system, it can only support up to about 7 psi max before you'll start to see your AFR's drift lean, regardless of fuel octane or compression ratio's.
Not sure on Ulmer's stage 2 HE if he incorporated an aftermarket fuel pressure regulator with fuel return. If it does, then it will support fuel flow for higher boost levels but then you'll be limited based on the octane level of the fuel you are running and if you have stock compression.
If you are running 91 octane pump fuel and have stock compression, then you might want to again limit your boost to 7 psi max for detonation reasons.
Intake air temperatures have a huge influence on the detonation threshold and max boost level you can run safely, which is also not caught by any calculator. Ulmer's kit's have been known to run hot, so keep that in mind too.

 

[nitris223]

The stage 2 HE (high elevation) kit has the same components as the stage 2 minus the fuel pump and regulator and can be set for 5 psi for low elevation or 10 psi high elevation with a boost switch. The fuel controller is a PCV with PTI. I also ordered some extra heat sleeve material for the intake air tube and the turbo to intercooler tube to try and keep the radiant heat as low as possible. Hopefully this will help keep the air colder in the tubes. Installing a IP vent in the dash to help get the heat out from under the hood.
I am going to use Torco fuel accelerator and mix for 94 octane just in case the fuel is not what they claim at the pumps. I don't trust some of the gas stations where I can get fuel on the trails. I asked one gas station in town about how often the get premium fuel and he told me once every month or two. At $1.39 a liter I don't think they are selling much premium compared to the other gas stations on the outer edge of town where the trail system allows snowmobilers to access gas stations. Their fuel hopefully would be a lot fresher. Now that the fuel prices are dropping maybe a few more gas stations will sell a bit more premium. I don't see the prices staying low for to long.
Premium fuel in Canada is not supposed to contain any ethanol but I am sure some day that will change and I wonder if 91 with ethanol will work at the same psi as without ethanol. I don't know the effects of ethanol fuel and boost.

I want to be on the safe side of boost but also would like to get the horse power I paid for. I read somewhere that the front mount or mid mount turbo created more HP with lower PSI then a rear mount. Is this correct, I have searched and I can't find where I read that information.

So if the stock fuel pump is limited to 7 psi then if I set my boost around 6.5 psi max I should be safe at 1600 - 1700 ft and watch my AFR numbers to see if I am going lean on the top end.

 

[mbarryracing]

Actually it's the direct opposite, the front mount and mid mounts make less HP per lb of boost then the more efficient rear mounts because they don't utilize the stock headers so the engine automatically makes less HP naturally aspirated (adding boost to any engine just compliments what that engine already makes for HP) and also most rear mounts incorporate more charge air cooling via tunnel coolers, etc so by default make more HP via denser intake air.
The attraction to front and mid mounts was claimed quicker response, but over the last few years that myth has been dispelled. If you look at the trail kit market, the customer trend has been more towards rear mount types (Push, MPI, MCX, FPP, etc) and I think Ulmer even stopped making his own and now sells MCX. I haven't really followed much high elevation mountain stuff so can't say what that trend has been but if I was riding deep powder with long WOT pulls I'd want the most efficient turbo system that produced the coolest charge air temps.
If you are going to add the octane booster and running at the elevation your at, I'd feel safe running 7 psi all day long, just keep an eye on your AFR's because not all in-tank OEM fuel pumps are the same, there is variation in output capacity from pump to pump.

 

[nitris223]

Ulmer sent me a dyno sheet that shows a 8psi run. Also sent some other info for different boost / HP numbers. 6psi =195hp ,8 psi = 215hp and 10 psi= 235hp . It seems from what I can find reading is that 8.5hp per PSI is a good average of what guys are seeing. I hope this kit will make 180 - 190 hp.

 

[mbarryracing]

Thats sounds about right, the rule of thumb target for boosted sled motors is 10 HP per lb of boost, looking at numbers for Nytro's, Apex's, RX1's, Doo 1200's, etc.
For reference the dyno sheets posted for the FPP stage 1 kit shows 201 HP at 6.8 psi on pump gas, which is 9.7 HP per lb of boost based on using 135HP stock numbers.
However, more likely the Ulmer kit is probably actually making less than the typical HP per lb of boost because it has to make less base HP (unboosted/naturally aspirated) with that inefficient restrictive cast exhaust stub manifold, optimistically probably around 128-130 HP.

 

[nitris223]

So does Alpine and Impulse make less HP with their style of short header. It is longer then the cast header with the Ulmer turbo but still shorter then the stock header. I found a older Alpine rear mount kit where they had a different header. The kit was made by Trask Turbo and the header went from 3 into 1 I think before it entered into the tunnel. I know it only had one stainless steel flex coupler in the tunnel.
I went with the Ulmer kit because of the cast header was stronger then the other front mount headers that I was reading about. I didn't go with the Trask kit because the header is no longer being made and if there was a problem I would have to make something else work. Plus I needed to find a fuel controller for it.

 

[mbarryracing]

Hands down the Ulmer cast manifold will last forever, reason he developed that so it wouldn't break. It's a durable part.
Good question on the Alpine and Impulse headers, surely on paper they should make more HP but without doing a dyno comparison with just the headers (no turbo plumbing) then all we have data for is the stock headers that we know make 135HP. I'd venture to say that if Yamaha could have rated the Nytro at 140HP by a shorter header, I'd think we'd have that.
Food for thought... Excell's naturally aspirated header makes more HP than stock but it's a bigger diameter, same length though because it's a direct replacement.
But on the other hand, we are probably splitting hairs, a few HP one way or the other. I doubt I'd be able to tell the difference on those by the seat of my pants, because reality is we don't ride dyno's...LOL.

 

[nitris223]

I know Ulmer did some dyno runs at dynojet . I don't have a subscription so I don't know what sled it was on or what the chart showed for HP numbers. I keep saying I am going to get a subscription but most things like that I subscribe to I never use to its full advantage.

 

[nitris223]

I have a buddy that just picked up a 2009 XTX with a older MCxpress 180 kit on it that has not been updated to the 190 kit. That should be a good sled to compare with when I get around to getting mine installed. Just waiting on a few other items to show and about 6" of snow would really help.

 

[nitris223]

I looked hard at the FPP kit but I just couldn't swing it this winter and I have been wanting a turbo for 2 yrs already. Price was right on a used Ulmer stage 2 HE kit. Now that the CDN dollar has taken a dive it makes it even harder to buy across the line.

 

[mbarryracing]

Oh I hear ya, $$$ is hard to come by.
If you got a good deal, then all is good and so is that Ulmer kit. There are no BAD kits out there (with the exception of some cheapo cash grab kits).
Set it at 6-7 psi and be done with it, watch your AFR's. If you really want to compare, ride your sled back to back with your buddy's XTX MCX180 sled both set at the same boost level and then you'll know.

 

[nitris223]

That's the plan. It won't be a perfect apples to apples comparison because we have different gearing and mine being a 162 and his a 144. Not that I ever noticed any difference riding either sled in stock form on the trail as to track length. They should be close enough to get a seat of the pants feel.

 

[Jacob Sawchuk]

So i know this is an old post but is this the max psi the ulmer kit can get up to. Or is this just without doing shim kit studs and fuel pump and regulator. As well as if those three things can increase the hp as well as psi would you not need to use different injectors

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