Need help sorting out boost issue

Scott & Heather · October 12, 2016, 04:09:58 AM

I'll ask Ken Cliff. I never wrote that down. Thing is, right now I'm getting amazing power. But he had to manually add fuel at lower boost levels. Which is meaning more smoke. I'd love to see it add fuel automatically and actually raise boost.

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luvrbus · October 12, 2016, 04:58:04 AM

If I recall they they use a 3 bar sensor(43 psi) most MAP sensors are 1 or 2 bars and I slept in my own bed last night not a Holiday Inn.With the smoke I think you are running to small of a A/R housing on the turbo those engine burn fairly clean when all the stars are in alignment

Scott & Heather · October 12, 2016, 12:23:58 PM

I had really no smoke to speak of until we tweaked the no-boost fueling numbers. But that's what it took to get power. I have not yet been able to get my hands on the silver leaf. We are in a different place nearly every week, so I'm still waiting for a quiet couple of weeks to order it and have it shipped

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blue_goose · October 12, 2016, 12:56:29 PM

Scott you are up against the same problem that I have had in the past. If you want fuel before the boost comes up you are going to smoke. There is no way to get around that. Ken, Martie and I have worked on mine for 3 years to keep the smoke down and still have power when you take off. I think my 50 series is as good as it will get now. It has been a tough job to get it to the point it is now.
When I had the 8V92 in my coach I never tried to change it. A little slow to about 10 miles per hr then it went fine.
Jack

luvrbus · October 12, 2016, 02:45:59 PM

Scott, you are dealing with a 2 stroke engine not a 4 stroke, the blower has a by pass valve either a mini by pass or full by pass valve that opens when the turbo boost reaches 6 lbs letting the blower spin freely.

If you have 14 lbs of boost on level ground at 1700 or 1800 rpm you are doing good.If you want a good setup with plenty of power less HP,less smoke and more torque less fuel usage,if you want the information can furnish it to you it is easy to get 1450 + ft lbs of torque from a 8v92 @ 450 hp or 475 hp @ 1300 rpm.

Remember you are dealing with a engine that has a air box any little leak in that section like a gasket on the inspection covers or bad air box check (drain) valves will affect your boost pressure

Scott & Heather · October 12, 2016, 04:29:32 PM

Jack, yeah it's been interesting watching ken work
With this beast. He's very good at what he does. Cliff, if you have the fuel table numbers or boi numbers, please do email me whatever you have. Ken is experienced but each engine is different and trying to dial this in has been a small challenge. I will reiterate, currently with fuel pushed hard before boost it drives like a rocket. I am not over exaggerating this. I passed trucks on some slight grades while accelerating from 70-75mph. It's unbelievable. Yesterday I pulled up on some steep ramps I made. These are the same ramps that I could never use with my mci 9 6v92 because it could never get up them. These are also the same ramps that my C3 couldn't get up without a running start just hoping I didn't fly right over the edge. Now, I press the throttle, black smoke ensues, turbo spools and bus climbs up the ramps without drama. From a stop, I have plenty of power to pull away from traffic lights with ease and actually stay with the flow of car traffic. It really is amazing. All while driving a coach that weighs 38,000lbs towing a truck that weighs 6500lbs. Crazy. I have no idea what my current MPG is. I'm scared to check.

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Beachfinn · October 12, 2016, 05:38:42 PM

If the power gets little too much, I could use few more hp 🤓
I'm at 28,000lbs plus a wrangler, and while not bad, it's 32mph over Rockies on I-70. Not heat issues though..

Anybody know of a guy who knows a guy close to AZ?

luvrbus · October 13, 2016, 06:22:51 AM

Ken is a master with the electronics he has helped me before,this 1 I think is going to need some different hardware if you are planning on running 475 hp, the 500 hp 8v92 even had different cams than yours for emission control (smoke)

blue_goose · October 13, 2016, 06:51:18 AM

When you get through with all your playing with the two stroke think about a good 4 stroke engine. My 102C3 only had 135,00 miles when I went to the series 50. Never would I go back.
The way you work it would only take a week end to make the change.
Jack

luvrbus · October 13, 2016, 08:17:47 AM

The 8v92 is not that bad of a engine

blue_goose · October 13, 2016, 10:36:53 AM

No Cliff the 8v92 isn't a bad engine. The problem it has is also yours and mine. It is old, now we need to get on with the new. Look who went to the 4 stroke, you, Ken and at least 25 more.
The 8V92 will be here when we are both gone, but still not as good as the 4 stroke.
Jack