chiaj144

iTrader: (4)

I'm having issues with my turbo'd ski-doo 1200. The sled runs great until it gets into boost then it falls on it's face. I'm showing 9lbs of boost, good AFR, have pressure tested the coldside for leaks, checked plugs, coils, turbo etc. What am I forgetting?
Basically I have boost, had to pull out a ton of fuel from a known good MAP which tells me I'm not making any power and have the sled running like a stock one with no boost now. The sled does feel like it starts to make power at 1 or 2lbs but anymore than that and it feels like I pulled a chute. I figure with all the experience on here somebody has had to have had a similar issue.
Help please I have a big trip coming up and really don't want to put my stock stuff back on.
Thanks, Carl.

P.S.- I've been trying to figure this out for two weeks, lol.

JoeNova

Ignore everything I posted before. I didn't notice what we were talking about.

Is it stock?

chiaj144

iTrader: (4)

So after getting some video of the gauges I found the sled was actually quit rich. The back pressure was blowing the waste gate open. I was showing boost on the gauge but it was just hot air as the turbo was way past it's efficiency range. Just thought I would update in case anyone else had a similar problem.

99tramsamc/fia

iTrader: (2)

What turbo?
Did you get it running?

chiaj144

iTrader: (4)

Yes it's working, just working on clutching now. Turbo is a Garrett 2860.

SSZ

what year is this sled? Is it a turbo kit you bought? If so who makes it?

99tramsamc/fia

iTrader: (2)

What kind of power?
Im doing a 02 800 polaris. Clutching seems to be the tricky part.
I see now it's efi

chiaj144

iTrader: (4)

It's a 2010 skidoo renegade 1200. It's a custom kit that put together. I thought it was fixed but it isn't. I didn't build the header and I think the header/waste gate is causing my issues. A 9lb spring is opening the gate at 0lbs. I put the stiffest spring in it and it opens at 4lbs. With my boost controller on it opens at 7lbs. Problem is that as soon as the gate opens I loose all power. Sled pulls fine until the gate opens. I can also build way more boost after the gate opens, just doesn't make power. I've tested/checked everything and tried two different gates. I think the waste gate is too close to the one header tube and its only bleeding boost from the one cylinder and not the other two. I'm going to relocate the gate to the exhaust housing to see if it clears up.

99tramsamc/fia

iTrader: (2)

Do you have anyway to check back pressure?
What turbine it?

chiaj144

iTrader: (4)

I have no way to measure back pressure yet. I've rebuilt the hot side and repositioned the gate just have to wait for my new clutch to test. So the sled makes great power until the waste gate opens. As soon as it opens I loose all power. It doesn't sound like it's opening fully. Kind of sounds like it's fluttering. Will go on the dyno next week if I don't have it figured out by then.

stevieturbo

When you say it loses all power.

Do you mean a total engine kill ? a power reduction ? failure of power to climb ?

What is fueling like ? Does boost stay at a certain level ? spark timing ?

And a wastegate is dynamic, it isnt just a simple open or close by a fixed amount. It will be a variable opening, and sometimes it can sound strange.

chiaj144

iTrader: (4)

Thanks for the reply. As soon as the gate opens it lays over. Doesn't quit just doesn't pull. Funny thing is I can still make more boost once the gate opens up. With a 9lb spring it would open the gate at 0psi and lay over but if I stayed in it I could make 10lbs of boost but not accelerate at all. AFR is a bit rich at mid 10's but I don't want to start to lean it out until I can figure out how much boost it's going to make. Timing is fixed by stock computer. Funny thing is if I unhook the reference line to the gate it will pull hard as soon as boost comes on until I decide to let off to prevent over boost.

chiaj144

iTrader: (4)

Here's a pic of the waste gate positioning on the original header.

stevieturbo

Draw a schematic of exactly how any signal lines, hoses etc are plumbed.

IronBlocked

What spring do you have in the gate, any restriction in the intercooler side?

chiaj144

iTrader: (4)

Will draw the lines out when I have access to a computer. I've ran anywhere from 6-15lb spring. The gate starts to open at 0lbs every time. I put my laptop on it tonight and it wants to make boost at 5000rpm at 10% throttle. Just poking down the trail I looked at the exhaust and it was glowing red. I'm starting to think the shop that shimmed my valves may have the timing off a tooth or so. No way this thing should want to make boost at 10% throttle. Maybe fuel is getting ignited in the header causing the early spool and glowing exhaust?

stevieturbo

Again I ask about ignition timing. You need to know what's going on here, not just assume it is ok.

But at 5000rpm, it wouldnt surprise me that there is enough exhaust energy to spool the turbo

But it makes no sense at all that the w/g would be opening at 0psi if you have 15psi springs installed

chiaj144

iTrader: (4)

There is no way to adjust ignition timing on the factory ecu. I've verified cam timing and it's correct. I performed a leak down test tonight and although it passed according to the gauge I had some leakage out the exhaust. I'm going to verify that I have the correct valve clearance and hope I don't have to pull the head for a valve job.

chiaj144

iTrader: (4)

Valve clearance is fine so it looks like I need a valve job.

stevieturbo

There may be no way to adjust, but that still doesnt mean it is doing what you want, what you expect, or what you think.

Hence confirming it isnt doing anything strange.

I highly doubt the problem is some leaky exhaust valves as that wouldnt explain the w/g opening at 0psi