SERT Adjustments for New Exhaust Pipes
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2nd Gear
Joined: Jun 2009
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SERT Adjustments for New Exhaust Pipes
I am new to HDForums so as a way of introduction I have been riding motorcycles for over 30 years, although, HD only for the last 6 years. I currently have a 2004 Ultra Classic Stage 4 Big-bore with SE Performance heads, SE forged high compression pistons, SE-257 cams, SERT, and SE slip-on mufflers.
For several reasons, I have decided to change pipes to a 2-1 type. I am also purchasing an AFR gauge since these pipes feature an O2 sensor port on the front pipe to monitor the Air/fuel ratio (AFR) a couple of inches from the exhaust port to facilitate tuning. Unfortunately, my SERT knowledge is limited and I have only loaded the SE prescribed map for the Stage 4 build and made minor adjustments to the idle speed. The pipe manufacturer recommends only making changes based on the AFR gauge readings since the typical dyno probes do not properly detect the gases.
Has anyone made a similar change in exhaust pipes? If so, how much change was required to the existing MAP?
Thanks!
For several reasons, I have decided to change pipes to a 2-1 type. I am also purchasing an AFR gauge since these pipes feature an O2 sensor port on the front pipe to monitor the Air/fuel ratio (AFR) a couple of inches from the exhaust port to facilitate tuning. Unfortunately, my SERT knowledge is limited and I have only loaded the SE prescribed map for the Stage 4 build and made minor adjustments to the idle speed. The pipe manufacturer recommends only making changes based on the AFR gauge readings since the typical dyno probes do not properly detect the gases.
Has anyone made a similar change in exhaust pipes? If so, how much change was required to the existing MAP?
Thanks!
Road Master
Joined: Jul 2008
Posts: 907
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From: Ontario
My 2-1 required a little more adjustment to the Volumetric Efficencies because my base map was for a typical 2-2 style exhaust. It has also required some more fuel than the base map at MAP 20Kpa below 2000 rpm. I also have closed loop capabilities on my bike so my tuning method is a little different than one that is tuned in open loop like yours.
I beleive to recalibrate your VE's due to your change in pipes you need to set your AFR to a constant value, then adjust your VE's until that is the value measured at your sensor. Once calibrated you can set your AFR's back and work with the bike to adjust it to be what ever you would like throughout your map. I think this is most acurately done on the Dyno with a sniffer in the absence of specific 02 feedback...
If you have an RB Racing style AFR indicator you can probably get something in the ball park by using your indicator, your tach, your feel for the bikes behaviour and checking the plugs.
I beleive to recalibrate your VE's due to your change in pipes you need to set your AFR to a constant value, then adjust your VE's until that is the value measured at your sensor. Once calibrated you can set your AFR's back and work with the bike to adjust it to be what ever you would like throughout your map. I think this is most acurately done on the Dyno with a sniffer in the absence of specific 02 feedback...
If you have an RB Racing style AFR indicator you can probably get something in the ball park by using your indicator, your tach, your feel for the bikes behaviour and checking the plugs.
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2nd Gear
Joined: Jun 2009
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Well I am glad that my pipes will not be available for 4 weeks now. I obviously have a lot to learn. I appreciate your response. Someone suggested an excellent dyno tuning shop to me today. I would like to be able to ultimately tune my own bike; but, I am sure the learning curve is severe. Do you have any suggestions for some good technical manuals on SERT tuning? I have the SERT manual loaded on my computer along with the SERT software. I will study the tables and manual. Also, would I be able to change the pipes and safely ride it to a dyno without damaging the engine?
Thanks again!
Thanks again!
Road Master
Joined: Jul 2008
Posts: 907
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From: Ontario
That SERT manual is a pretty good read. I checked it out once cause its similar to my TTS system. Short rides with new pipes won't harm your bike. Especially because you had previously had it tuned to your build and are only out by style of pipes alone.
Road Warrior
Joined: Mar 2008
Posts: 1,691
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If you're going to put all that money in then you might as well pay for a dyno tune as well. Get someone like Doc to tune it for you, or get him to recommend someone for you in your area. Then you can play around all you like and restore the professional tune when you're done. It'll take a good tuner 4-5 hours to tune the bike. It'll take you 40-50 hours assuming you pay for some dyno runs in there. That's time actually productively tuning and doesn't include driving to some secluded road out in the country for a street test. So, realistically, it's a hobby for the next couple of years.
If you haven't ordered the gauge yet then you want a logger like the WEGO III from DTT. Unless you're going to take a video camera to film the gauge it's about useless for tuning. You could use it to tune for fuel economy, but not performance. Fuel economy is steady state cruising down the highway. Performance is cranking the throttle open and climbing through the rpms. Doing that requires at least a log. Get into that and you'll find it isn't the torque measurement you need the dyno for but rather you need it for controlled test conditions. The torque measurements is really mainly needed for setting your timing. It can help with understanding how afr relates to power, but that really has nothing to do with the build and you can just read about that. Getting the desired and actual afr to match is where the real work lies.
If you haven't ordered the gauge yet then you want a logger like the WEGO III from DTT. Unless you're going to take a video camera to film the gauge it's about useless for tuning. You could use it to tune for fuel economy, but not performance. Fuel economy is steady state cruising down the highway. Performance is cranking the throttle open and climbing through the rpms. Doing that requires at least a log. Get into that and you'll find it isn't the torque measurement you need the dyno for but rather you need it for controlled test conditions. The torque measurements is really mainly needed for setting your timing. It can help with understanding how afr relates to power, but that really has nothing to do with the build and you can just read about that. Getting the desired and actual afr to match is where the real work lies.
Thread Starter
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2nd Gear
Joined: Jun 2009
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Thanks for the good information. I plan to talk with the dyno shop early this morning and will continue my tuning education. I will also check out the WEGO III from DTT. Since I am new to the forum, I do not know who Doc is. I am in the northern VA area.
Road Master
Joined: Jul 2008
Posts: 907
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From: Ontario
You won't find him here any more. But you'll still get lots of good references for him if you ask around. I would recommend him as well. You can find him on the austrailia HD forum but I think he is out of Florida.
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Road Warrior
Joined: Mar 2008
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Yeah, he's in Florida, but regretably I don't have contact information for him. He trains tuners and keeps track of people's experience with tuners. The thread on the TTS above might have contact information for him since he sells the units.
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Road Warrior
Joined: Mar 2008
Posts: 1,691
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I found contact info for him. HDMD Tuning Center, HDMD88@yahoo.com, 352-242-9616. He keeps track of people's experience with tuners and can recommend a tuner for you. Since you have an interest in tuning I would suggest you make sure you can get the files from all the runs and a few of the intermediate tuning files. It would be a great learning tool. You can download WinPEP from DynoJet to view the dyno run files. Logs off the ECM would be nice too since that's mostly what you're going to see with DIY. Personally, I would be willing to pay an extra $100 if they provided all that.