Tuning Help Please

Radski30 · Nov 27, 2010

Took the Apex out today for the first time. Man, it felt easier to ride than my M7. It would side hill easy, carve and spin cookies, it felt really good to me.

However, that thing had no where near the power that my M7 has. I had it at 14 PSI, and it had a hard time in the deep snow. Wouldn't make it up some of the hills my M7 normally flys up.

I am new to the 4 stroke sleds.

A couple of things:

Stock Maverick Track
BD Turbo
2560 Small Turbo
Stock Rods and Pistons
Head shim(Don't no why this was put in, but ok)
Stock Clutching (except Weights)

Just curious, what can I do to get this thing screaming??? I do have a 174 3" Track and VE Tunnel coming. I am also going to roll the chain case.

What can I do to get this thing running good?

Thanks in advance

sledfvr · Nov 27, 2010

If you roll the chaincase it is going to feel more front end heavy. That turbo is maxed out at 14lbs. I'd upgrade to a 2860, less heat and more power. Also a 3" dump pipe right off the turbo and out the side panel helps reduce heat and run harder. The maverick track is about the worst turbo track out there. It peels over and just spins. Camo Extreme makes a big difference. Make sure your afr's are reading around 12.0 wide open so that your not too rich or lean. A 2860 at around 15lbs and these sleds start to come alive. You could run 12lbs on pump fuel with the shim. This should be a good start for you.

Radski30 · Nov 27, 2010

Thank You

Turk · Nov 27, 2010

2560 turbo is good to 22 pounds boost. Check your clutching & make sure your at least 10,600 rpm on a long full throttle pull.

http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT25/GT2560R_466541_4.htm

sledfvr · Nov 28, 2010

I was thinking it was a 2554. I thought that's what the smaller BD kits came with...maybe it was upgraded to a 2560?

EZmoney · Nov 28, 2010

You got a issue some where. Was it holding a 14psi? you also want around 10600 to 10800 for rpm. Your af should be 12.5 .Also Check make sure you have no leaks.check throttle bodies and make sure there on and hoses coming of turbo to the intercooler. check your exhaust for leaks,try to presure test the system That sled should kill any m7!

sledfvr · Nov 28, 2010

If its an older kit with a flex joint on the header then make sure that it isn't blown out or leaking.

zebiraross · Nov 28, 2010

That turbo is good to 22 psi AT sea level. If your running at 9-10K ft it's only good to about 15 psi. That compressor only has a 2.5 pressure ratio, and if you go over 16 psi you are out of the compressor map pushing out hot air.

dicey · Nov 28, 2010

could this be anything to do with the turbo?if your making 14#and are even close to a m7 there is something else wrong. What were you seeing for trackspeed?

Radski30 · Nov 28, 2010

dicey said:
could this be anything to do with the turbo?if your making 14#and are even close to a m7 there is something else wrong. What were you seeing for trackspeed?

My M7 is Turbo'd and it runs a consistent 90 to 100 MPH Track speed.

The Apex would only pull about 60 MPH in the deep snow up a hill. It was running around 16 PSI on the boost gauge.

It also sounded like it deto'd on the top. It kinda popped at WOT.

Don't get me wrong...Please. After riding this sled for the first time, I think I will put the M7 away for the year. It felt ten times funner to ride than my M7. Except for the power. I know that the power is there, it is just a matter of tuning and getting the system there.

How does a 2871 work? I have thought about sticking one on. Do I need pistons and rods? Do I need to move to 1000cc injectors, and a bigger fuel pump?

Again, I know these apex's are fast (I saw Zebs smoke all the 1200T at Fairview), and I know they are fun to ride. I just need a little direction on tuning.

dicey · Nov 28, 2010

ok ya didn't know the m7 was turboed, hows your rpms?

SLY · Nov 28, 2010

Popping on the top could be the rev limiter or lack of fuel. Lack of fuel will definitely cause a low power problem. You really should have no comparison to the M7, power wise

Turk · Nov 29, 2010

Really really sounds like your clutching is way out.

Wheel House Motorsports · Nov 29, 2010

put a real track on and get back.. I had a orignal maverick on my yamadoo and the thing was a pile of crap, it could spin it pretty quick, I just didnt get anywhere. the lugs just bent over and dint push the sled uphill.

justinkredible56 · Nov 29, 2010

Ski-Dooin it said:
put a real track on and get back.. I had a orignal maverick on my yamadoo and the thing was a pile of crap, it could spin it pretty quick, I just didnt get anywhere. the lugs just bent over and dint push the sled uphill.

I don't think the track is the culprit, although he is definitely going to see a BIG improvement when swapping it out. But he said he only saw 60mph track speed at 14psi. I would run over all of the turbo hoses/header/etc and then point my finger at the clutching. Power should be there but maybe the clutches can't keep up!

EZmoney · Nov 29, 2010

HAHA the guys says its popping or deto on the top end and you guys are telling him to swap tracks.:face-icon-small-con Get the sled running clean then upgrade! You running a bd box or pl? Lets start there and clutching.

JSCC · Nov 29, 2010

SLY said:
Popping on the top could be the rev limiter or lack of fuel. Lack of fuel will definitely cause a low power problem. You really should have no comparison to the M7, power wise

This is my guess as well, hit the rev limiter.
Radski, the snow we have right now is robbing a ton of power. Some what setup on top with sugar below. Both my TApex and M1T were struggling on the same hills they normally fly up. It is the snow. If you would have been riding the 7, I guarantee you would have thought something was wrong with it.

But as for the turbo, swap that out for a 2860 minimum or 2871 if you want. It will run much better with the bigger turbo.

Radski30 · Nov 29, 2010

Sounds good!!! I am looking at all the possibilities. Sorry to sound like a retard, but 4 stroke sleds are very new to me.

I have the Gen 1 BD box. it is not the ADA, and I will keep it that way. I have it in the shop and will check over all the joints to look for possible leaks. I am also going to put some pistons in it 10:1 and remove the head shim. I will also put a bigger turbo.

But, before I do all this, I am going to get her dialed in as it is, and familiarize myself with all the components associated with the sled and Turbo.

BTW, What track speed should I be getting with this set up? What is the Target?

JSCC · Nov 29, 2010

I have stock compression 2860, old style BD box just like yours. Depending on the hill I can see high 80's track speed or mid 70's, just depend on what kind of snow it is. This is at 12lbs.

Why are you doing pistons? Might as well do rods at the same time.

mattymac · Dec 1, 2010

alot of people are running the blue/white/blue yammi primary spring along with supertips, arctic cat green snopro secondary spring along with the shockwave helix.

proven combo for probably 95% of the turbo yammis out there!

Tuning Help Please

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