Need help with turbo

[dmkhnr]

So my uncle has a push race gas turbo on his 08 m8 and after spending the last half of the season trying to chase down the sled bogging out we've finally got it running.
The problem is:
It pulls hard, skis off the ground, instant throttle response, but when it hits the deep stuff it falls on it's face.
It's pulling 9# of boost which holds, 12.5 a/f but only 39-42 mph track speed.

I've run it at 6#, all the way up to 12# and this is the case at all levels.

Any suggestions?

 

[mynewuseddoo]

Clutching? Rpm? Maybe more venting for fresh supply?

 

[WyoBoy1000]

That is some crappy track speed, I think I would call MM.

 

[dmkhnr]

We called him from the parking lot and was told that anybody who is telling you they get this high trackspeed is full of it. My ported M8 runs 42mph trackspeed and swaps marks all day with this race gas turbo.

 

[glassman]

Really sounds like a clutching issue to me. I pull 60 - 65 mph track speed in heavy snow load with stock gearing. Sounds like your not getting the power to the track.

 

[WyoBoy1000]

There is truth in that but when your 20mph down and swapping marks with a NA sled there is serious issues, What do you have for clutching.

 

[dmkhnr]

80# lt with red 305 prim
37/47 bdx with cat orange

 

[WyoBoy1000]

Whats it running for rpm, is the helix adjustable.

 

[dmkhnr]

The helix is not adjustable,
It runs 7900 rpm, I've seen it pull down to 7100 when under load but not all the time, we were thinking a rich condition was the cause of this.

 

[WyoBoy1000]

could be, maybe you should check for metal in the DD. Should not be pulling down and if it hits rpm it should slowly start to lean out.

 

[mmsports]

??

You called who?? That sounds like what Kelsey would tell you not me.

If you do not get 70 mile an hour track speed something is wrong.

We called him from the parking lot and was told that anybody who is telling you they get this high trackspeed is full of it. My ported M8 runs 42mph trackspeed and swaps marks all day with this race gas turbo.

 

[mmsports]

Sounds funny

So it sounds like you do not have power at top end whats dragging it down to 7100 is the question? Any chance of a boost leak?
80G stock or heavy tip?

 

[RACINSTATION]

x2 65-70mph up anything with that sled if it is set up right.

 

[dmkhnr]

Going to throw a stock 36 helix at it just for a trial and keep the 80# weights.

If I can get the track speed up, we'll give it more helix/shave some weight.

What is a good mountain setup?

Kevin, I didn't see the thread above where it said to call MM. It was Ken who we called.

 

[Vertical-Extreme]

Going to throw a stock 36 helix at it just for a trial and keep the 80# weights.

If I can get the track speed up, we'll give it more helix/shave some weight.

What is a good mountain setup?

Kevin, I didn't see the thread above where it said to call MM. It was Ken who we called.

You should be able to swing 80 gram weights no problem. I Wouk try a 44 or 46 helix with the 80's and the cat orange

 

[dmkhnr]

You should be able to swing 80 gram weights no problem. I Wouk try a 44 or 46 helix with the 80's and the cat orange

At 9000 elev?

I'm thinking 36/45 and 77#. If I pick up speed with the straight 36 It'll be a tell-tale sign that the original helix is too steep.

I got it straight from the horses mouth that MDS will have a set of weights that will work with the stock AC clutching.

 

[mmsports]

36

This is my mountain clutching and has been for 5 years now tried other always go back.
straight 44 or 48 stock orange spring
185/285 primary and MM 78-82 G weights heavy tipped.

Going to throw a stock 36 helix at it just for a trial and keep the 80# weights.

If I can get the track speed up, we'll give it more helix/shave some weight.

What is a good mountain setup?

Kevin, I didn't see the thread above where it said to call MM. It was Ken who we called.

 

[dmkhnr]

That sounds like what Kelsey would tell you not me.

I guess I missed this comment as-well.

 

[powder freak]

I have the exact same problem as your having. Pulls hard on the trail but when I hit the deep stuff I can't get any track speed but it still makes 8#'s boost. I've been reading some of the replies and decided to take a look at the clutching on my sled. I took the cover off the primary and pulled the spring out....in 2 pcs! Think that might have something to do with it? I'll test it out tomorrow but I think this might be the problem.

Good Luck.
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