Boost-It settings

[TheYamMan]

Just out of curiousity what are everyones boost-it settings and what elevation and boost are you running?

Im still trying to work a few kinks out of mine. Ive talked with boost-it about it and they are very helpful. But im still curious what everyone is running.

Im running a Ulmer front mount kit with a 2860rs turbo and Water meth kit hooked up aswell.

My engine is shimmed and my boost is set at 15 pounds and im ridding at 1000-3000ft elevation.

The issue I ran into is a lean spot at low boost and a rich/bog at high boost.

 

[BigFish BC]

what is the sled doing,it almost sounds like you are adding to much fuel on the top end & dont have the box adding fuel soon enough

 

[TheYamMan]

I just Dialed back the top end and turned the fuel on earlier tomorrow ill try it again but on my last run I think I dont have enought weight in my primary may have been hitting the rev limiter aswell.

 

[BigFish BC]

cant remember my setting off the top of my head but they are pretty much what it comes from Neil at. i have to bump where the fuel comes on when i leave from town here, but i start at 100ft elev almost sea level.

 

[samsquatch47]

Set your rpm number to all zero till 7000. Then +7 from 7000 to 10000. My main is at 56. Threshold is at -3 ish I don't remember the exact but I know its in vacuum. Also turn on "LED @ 1%" this will light up the little led orange light on the box when the injectors start adding fuel. Easiest way to set threshold is:
Start threshold setting at the first neg setting below +0.1. Then cruise in a wide open flat area or trail and gradually speed up. Watch O2's and for the orange LED. Lower the threshold one number at a time till the lean spot goes away and the LED is now on where the lean spot used to be. Always put your 7000 and up rpm trim settings the same on a four stroke. And if you find your still fat or lean up top lower or raise your main a couple. This adjusts the whole fuel curve and usually the bottom end will still be fine. Saves u adjusting every upper trim setting one at a time. Also make sure "Lean disable" is turned off. It's it on and your trying to tune the box will dump a crap ton of fuel if it sees a lean O2 reading. It will catch it way before u will, then you will think its rich because it dumping so much! I find with the front mount u have to run a threshold setting in vacuum because the start building boost so early. Most rear most are at about +0.1 cause they are slower at building boost. This is what I've learned from tuning my impulse race gas turbo. Once you have it tuned you should only have to adjust the threshold setting up or down a couple. Main usually stays very consistent.
Hope this helps.
Dustin

 

[pelon]

I have my main at 100 and threshold is -10. It runs pretty darn good except for a low end (@1900 RPM) super quick burp. Neil says this is way to rich of a setting and I agree, but if I go lower it will start to lean out.

Alpine kit with the boost set at 10psi.

 

[samsquatch47]

I'm running main at 56 at 21 psi. Are you sure your fuel pump is keeping up or your fuel reg is working properly? At 56 and plus seven at 7000 an up I'm still at 11.7:1-12:1 air/fuel on a long wide open pull which is not lean at all. You shouldn't need more fuel at only 10 psi. What are your rpm trim settings set at? -10 is really early to add fuel too. It will run fine, but your losing a ton of fuel economy on the trail ride up.

 

[samsquatch47]

Neil sets fuel pressure at 44psi I believe on the yami's.

 

[TheYamMan]

Samsquatch47 those setting on my sled at 12 pounds worked perfect best AFR ive seen this season.

Thanks for sharing those settings.

 

[samsquatch47]

Right on man! Took me a whole weekend of playing around . Glad I could help!
Enjoy a smooth running sled and good fuel economy!

 

[pelon]

I'm running main at 56 at 21 psi. Are you sure your fuel pump is keeping up or your fuel reg is working properly? At 56 and plus seven at 7000 an up I'm still at 11.7:1-12:1 air/fuel on a long wide open pull which is not lean at all. You shouldn't need more fuel at only 10 psi. What are your rpm trim settings set at? -10 is really early to add fuel too. It will run fine, but your losing a ton of fuel economy on the trail ride up.

I have checked everything I can think of: I originally had fueling issues at boost, but Neil and I worked it out and figured it was an injector. I fixed that problem. Fired it up and its been running every since, except the main and threshold need to be set high/low. I have checked everything listed and replaced if I had a spare:

Fuel pump MSD (replaced it)
Injectors (replaced them)
Aeromotive Regulator (replaced it) -- always set at 44psi
Vacum/boost leaks
Wire connections etc.

A/F are:
13's at mid and high 11's to 12 at wide open.

Fuel ecenomy: On my last trip I used 4 gallons in just about 40 miles.

Trim numbers are set pretty close to the recommendations you gave in the previous posts.

I went out yesturday and tried your recommended settings from the previous post. It did nothing but stumble and go lean (15-16 a/f) when I needed fueling at boost

I do appreciate your input

 

[Northernboy]

I seem to have a similar problem, main set at 100 and runs good then no change and it starts to go really lean when I hammer it. I have a data logger installed too, and I can see the XIC isn't pushing the injectors as hard at that time. So I figure it isn't seeing the boost or RPM. So I'm going to re-plumb my boost signal to all three throttle bodies instead of just one, maybe this will give the XIC a faster and stronger boost signal. How is your boost signal hooked up?

 

[pelon]

My XIC sees boost and vacum from all three.

 

[samsquatch47]

I have checked everything I can think of: I originally had fueling issues at boost, but Neil and I worked it out and figured it was an injector. I fixed that problem. Fired it up and its been running every since, except the main and threshold need to be set high/low. I have checked everything listed and replaced if I had a spare:

Fuel pump MSD (replaced it)
Injectors (replaced them)
Aeromotive Regulator (replaced it) -- always set at 44psi
Vacum/boost leaks
Wire connections etc.

A/F are:
13's at mid and high 11's to 12 at wide open.

Fuel ecenomy: On my last trip I used 4 gallons in just about 40 miles.

Trim numbers are set pretty close to the recommendations you gave in the previous posts.

I went out yesturday and tried your recommended settings from the previous post. It did nothing but stumble and go lean (15-16 a/f) when I needed fueling at boost

I do appreciate your input

Hmmm... Well I guess every sled is different. The only other thing I can think of is to lower the "TPS Cut" a little and try it. That setting won't let the injectors add fuel after a certain throttle closing point. Meaning that if your just lightly on the throttle and your making a little bit of boost it won't inject fuel because it sees your below the set TPS setting. This would help the low end stumble but not the high rpm lean spot. Mine acted just like yours when Boost-it first installed the fuel system. But I believe we just lowered the threshold a tad into vac and lowered the TPS cut a little and all my settings were back into normal range. Something still sounds like its off to need your main that high, but every sled is different.

 

[samsquatch47]

Also forgot to mention you can go as high as 15-16:1 in the mid range in light throttle cruising. As long as its not falling on its face or stumbling it won't hurt your motor. Your sled stock will go that lean in a low load situation and so do modern cars trucks etc. Helps with Savin fuel on the trail ride up. Of course lower the threshold a bit if its stumbling and popping. I find sometimes on the same trail from one weekend to the next it might need to be adjusted do to different air. At 13:1 in the mid your right it will never stumble, just burn a little more fuel. These nytros are very forgiving to the amount of fuel they can burn and run fine.

 

[pelon]

I really do appreciate your input.

I was rolling stuff around in my head and I thought about the stock injectors. If one or more were not functioning at 100% then I would assume the boost-it injectors might take up the slack if the main fuel was set high enough. The stock injectors still fire under boost but need the boost-it secondaries to add just a little more --corrrect?

The stock injectors may be my issue at low RPMs. At about 1900 RPMs the motor stumbles and the a/f fluctuated rapidly from 15 to 16.5 ish.

?????

thanks again

 

[samsquatch47]

I really do appreciate your input.

I was rolling stuff around in my head and I thought about the stock injectors. If one or more were not functioning at 100% then I would assume the boost-it injectors might take up the slack if the main fuel was set high enough. The stock injectors still fire under boost but need the boost-it secondaries to add just a little more --corrrect?

The stock injectors may be my issue at low RPMs. At about 1900 RPMs the motor stumbles and the a/f fluctuated rapidly from 15 to 16.5 ish.

?????

thanks again

Yea at that low of rpm it really does sound like something that's not related to the boost it system. The nytros always do have a low rpm hiccup, a completely stock sled has it the stock exhaust just muffles it. I just can't judge how bad your hiccup is Online. Perfect example of this is a stock nytro with an aftermarket exhaust. You can really hear the crackle and pop on low rpm when the throttle is first cracked. You are correct the stock fuel system works as it did from the factory. That's the beauty of boost-it, the sled doesn't even know its not stock. So the low load, low rpm stuff should all be handled by the factory system. 1900 is barely engaged on the clutches so I don't think the sled will be making any boost that early. So the boost-it system should not be doing anything that early I believe. How did the sled run before the boost-it system was installed? How was the sled set up before? Was it boosted? stock?
Sorry for the million questions, just trying to help ya out.
I know every sled is different, but usually a sled that has to be set up way in left field to make it run is a red flag that there's another issue. Either it be with the stock or boost-it system.
Cheers!

 

[BigFish BC]

I seem to have a similar problem, main set at 100 and runs good then no change and it starts to go really lean when I hammer it. I have a data logger installed too, and I can see the XIC isn't pushing the injectors as hard at that time. So I figure it isn't seeing the boost or RPM. So I'm going to re-plumb my boost signal to all three throttle bodies instead of just one, maybe this will give the XIC a faster and stronger boost signal. How is your boost signal hooked up?

yes its always better to read off all three more consistant signal.

 

[Northernboy]

My bad...I was hooked up to all three throttle bodies.
I think my problem now is that the XIC is intermittently not reading the proper RPM. But it's really hard to see the display while riding and it doesn't happen all the time. I will be checking my green wire on coil lead. Any other ideas?

 

[samsquatch47]

Unless you have your lower rpm trim settings above zero the rpm won't matter. At zero in trim it won't add fuel until it sees boost. We set the trim to zero till 7000 because below that if there's no boost the stock fuel system can fuel it no problem. Example: coming back down a hill after climbing it. If it only worked on rpm then our sleds would flood themselves out in a low load higher rpm setting. So if your problem is below 7000 it's probably a threshold or boost sensing issue. Or your TPS cut is set too high, which will over ride all other settings and not let the XIC inject.