NB-Snowgoer
Newbie
I'm new to the boosted sled scene but have been involved with boosted cars for some time. Bought a boondocker turbo'ed apex the end of last season and never got a chance to tune it or drive it. I'm a flatlander and I believe this sled was used in the mountains. Drove it shortly last saturday and acording to the way it was acting and a/f gauge it was severely rich. Would misfire under load, a/f was 14.5 -15 to 1 when starting out indicating raw fuel dumpng in exhaust, and then a/f would go to -10 to 10.5 after cleaned out a bit. Decided to go with boondockers "recommended starting out" fuel map tonight, and I would go from there. Boost is set at 12psi. head shim about 9-9.4 , on 91 octane. I am trying to get a good trail map before adding better fuel. Drove about 4 miles a/f staying between 10.5- 11.7, varying throttle, and load, stopped and header pipe and part of turbo was cherry red. It has heat wrap on it and you could still almost see through the pipe! The sled worked flawlessly, no breaking down or misfires. If it wasn't for the extremely hot pipe and turbo I was going to lean the map out to achieve around 11.8-12 to 1. So my ? is... is this normal? What should I be looking for? Is it fuel? Faulty a/f sensor? Any help or advice will be greatly appreciated. And yes, I have have spent countless hours searching this forum for info on boondocker turbos. Thanks.
HighSpeedLowDrag
Pro
15-1 is leaner than 10-1.
NB-Snowgoer
Newbie
I know that usually 15-1 usually indicates lean, but sometimes if you have a lot of raw fuel going by your a/f sensor, it will show lean even though it is rich. It will usually start to change the other way as it gets cleaned out or engine warms up.
rxrider
Jan-Ove Pedersen
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Here's the rule of thumb for tuning a boosted sled.
AFRs at:
Idle: 14.0-14.7
Engagement: 13.5
0 lbs boost: 13.0
5 lbs boost: 12.5
10 lbs and higher: 11.8-12.0
X2 on the raw fuel, but it usually shows way lean in a sled like 18-20, but it depends on the amount of raw fuel
Probably not, but you may have a lean condition initially, 14-15 afr under boost and high load would make the motor go lean popping and it will start braking up.
What better fuel are you thinking about?
The best way is to tune AFRs for the fuel you will be running most of the time.
AFRs at:
Idle: 14.0-14.7
Engagement: 13.5
0 lbs boost: 13.0
5 lbs boost: 12.5
10 lbs and higher: 11.8-12.0
X2 on the raw fuel, but it usually shows way lean in a sled like 18-20, but it depends on the amount of raw fuel
Probably not, but you may have a lean condition initially, 14-15 afr under boost and high load would make the motor go lean popping and it will start braking up.
What better fuel are you thinking about?
The best way is to tune AFRs for the fuel you will be running most of the time.
HURRICANE
TY 4 Stroke God
the red hot exhaust is an indication of retarded timing or advanced exhaust cam timing.Over fueling it will enhance the problem
NB-Snowgoer
Newbie
Thanks for the info on the settings. I never did any long hard pulls because I was a little nervous when I noticed the pipe. I'm running the boondocker programmer. What settings should I work on first? The sled doesn't seem to go rich until about 5 min of driving. I live in an area with no boosted sleds within 40 miles and those sleds are rear mounts. Not experiencing any popping or breaking down, but like I said I didn't hold it at 12 lbs for very long.
rxrider said:Here's the rule of thumb for tuning a boosted sled.
AFRs at:
Idle: 14.0-14.7
Engagement: 13.5
0 lbs boost: 13.0
5 lbs boost: 12.5
10 lbs and higher: 11.8-12.0
X2 on the raw fuel, but it usually shows way lean in a sled like 18-20, but it depends on the amount of raw fuel
Probably not, but you may have a lean condition initially, 14-15 afr under boost and high load would make the motor go lean popping and it will start braking up.
What better fuel are you thinking about?
The best way is to tune AFRs for the fuel you will be running most of the time.
NB-Snowgoer
Newbie
I have no idea if the timing has been changed. The exhaust will get really hot because the raw fuel will start burning in the header and turbo I suppose. Also, I'm planning on running a c-12 mix at higher boost running 660ft. I just want a good trail tune on 91 before I go that way so I can trail drive it a little. But if it is going to be that hot I'll limit it to 660ft. because I though it was going to burn.
HURRICANE said:the red hot exhaust is an indication of retarded timing or advanced exhaust cam timing.Over fueling it will enhance the problem
TurboTime
TY 4 Stroke Junkie
Call me. I may be able to help with your Boondockers settings. PM sent
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