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Dyno Test of Drilled Stock Mufflers & Fueler

18438 Views 30 Replies 13 Participants Last post by  magoo
I did some Dyno Testing of stock mufflers vs. drilled with and without a Fueler. I'm at home right now so I don't have the Dyno Charts to actually post, but here's some numbers to contemplate;
All Stock 82.1 HP, 70.7 TQ
Drilled Mufflers 84.4 HP, 71.5 TQ
Interestingly there is a LOSS of torque between 3050 rpm and 3600 with the drilled mufflers and stock Fuel curve. the sound is very Triumph or Norton like with the 3/4" holes, I like it.

We ran the stock mufflers with our Top Fueler, this is actually made for us by Dobeck Performance (the guy who invented & owned Dynojet).
The peak torque didn't change and the peak HP went up .7 More importantly the torque from 2500 to 3250 went up a little as did HP from 5500 on up by a couple. Much smoother from 2500-3500 rpm.

Drilled Mufflers with the Fueler. The Peak HP was the same as without the Fueler at 84.4, peak TQ was 72.1. The important thing here is Torque at 2500 was up 4-5 Ft lbs and it basically gained 2-4 all the way through the power band. The same was true for the HP.

Now some interesting notes. The Top Fueler was run "Out of the Box" which comes actually optimized for the standard 1200 Sporty. Unfortunately the A/F Sensors in the Innovate Motorsports meters on the Dyno went a bit haywire after about our 15th run so we decided to hold off "Tuning" until we could get them re-calibrated.
The stock bike showed readings of approx 14.7 around 4000 rpm to 13.3 at 6750, with a very lean 18.3 at 2500 when the throttle was whacked to start the run!
The fueler as delivered was 13.6 at 2500 when whacked (showing that our "accelerator mode" was working well, and that is where we saw the largest power increases) to 14.0 at 4000 and 13.0 at 6750, which tells us that we need to do some adjusting to get a bit more power out of the bike.
We will do some more testing soon, when the A/F meters get sorted out.
The other interesting thing was we monitored Oil Temp and Cylinder head temp. Between the stock fuel curve runs and the Top Fueler runs we only saw about a 5 degree drop in both temps! Granted the Superflow Dyno has very good Air Flow with fans that blow air at the motor that increases with the "Road Speed" of the run but that actually simulates what happens on the road.
As soon as I can get it back on the Dyno I will tune it for 12.5-13.3 across the board and see what we get, we are expecting, based on experience, to see another 3-5 HP and Ft Lbs across the board.
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Thanks for posting this. Really looking forward to what you come up with as you explore this further.
Good stuff Don, really pleased to see some more R&D going on. Be interested to know what happened with your sensors. I'm using the 5 wire Bosch sensors with the LM1s. How were you taking the readings with the undrilled mufflers? Did you use the existing sensor bosses, or drill the headers and put in another bushing? Did the calibrate function on the LMs not work, or was it a sensor malfunction?
What correction factor are you using? SAE, STD, or DJ ? What gear are you using for your testing?
Sorry for all the questions, but I'm out on a bit of a limb over here and you're the only one I know using a similar setup to me. I'll be starting my XR R&D testing soon and it would make sense for the benefit of others, for me to present things in the same way as you. There's likely going to be some differences anyway, but if I use 4th gear and SAE and you use 5th gear and DJ, or vice versa, the differences will be substantial on the numbers even though the percentage gains or losses will be the same. What do you think? I'll go with what you've already started with and then we've got a "standard".
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Good stuff Don, really pleased to see some more R&D going on. Be interested to know what happened with your sensors. I'm using the 5 wire Bosch sensors with the LM1s. How were you taking the readings with the undrilled mufflers? Did you use the existing sensor bosses, or drill the headers and put in another bushing? Did the calibrate function on the LMs not work, or was it a sensor malfunction?
What correction factor are you using? SAE, STD, or DJ ? What gear are you using for your testing?
Sorry for all the questions, but I'm out on a bit of a limb over here and you're the only one I know using a similar setup to me. I'll be starting my XR R&D testing soon and it would make sense for the benefit of others, for me to present things in the same way as you. There's likely going to be some differences anyway, but if I use 4th gear and SAE and you use 5th gear and DJ, or vice versa, the differences will be substantial on the numbers even though the percentage gains or losses will be the same. What do you think? I'll go with what you've already started with and then we've got a "standard".
The LM1's are set up with probes that go in about 20". Not as accurate as sensors according to some but it allows us to test any exhaust system. We think the failure was in the sensor that is in the one of the probes, possibly both!
We ALWAYS run 4th gear on the Super Flow. We usually quote the DJ correction as there are more Dyno Jet's out there than anything else so it makes the numbers a little more comparable.
Blimey, whats the chances of that happening in both???
I use the tubes as well (same sensor in the end). Most of the EFI bikes i do use a 2 into 1, so I need to be in the headers to map both cylinders individually. Not everyone wants me to drill the baffle on some mufflers to get the probe in front of it. I use 4th gear also and use SAE as a CF. Not a problem to use the more common DJ factor though. Thanks for your input Don.
I know with our setup you can print out all three readings SAE, STD, or DJ for every run at anytime. Pretty cool I'd say.
Yup, same as that. I had some weird AFR readings at the upper end of the RPMs this week. Ran the Direct link data log file back and turned out I'd maxed out the injectors.
Dyno runs

You should try a run with no mufflers and see what you get.

Chow Don
G
Yup, same as that. I had some weird AFR readings at the upper end of the RPMs this week. Ran the Direct link data log file back and turned out I'd maxed out the injectors.
Boz,

Did you max out the injectors on an XR, or on another bike? I only ask, because mine are running in 80% range delivering 12.5 at WOT.
You should try a run with no mufflers and see what you get.

Chow Don
I actaully started a pull with no mufflers just for kicks and it fell on it's face so I aborted the run
Boz,

Did you max out the injectors on an XR, or on another bike? I only ask, because mine are running in 80% range delivering 12.5 at WOT.
Hey Phaedrus, no, not my XR, I'm still gathering a few more parts while I wait to make a time slot.
This was on an 09 FLHX with a 113 I've built. I was experimenting with air cleaners, throttle bodies and injector sizes. I'd gone back to the stock 4.35 injectors, which were running at 80% and then dumped the SE aircleaner after discovering it made 5hp more with just the back plate. I put the SE heavy breather on which also fattened and increased the torque, and then started adding fuel. The power dropped and the AFR went all over the place on both cylinders and I found that I was running 82% and 86%. Put the 5.3's back in, reflashed, and it all worked again.
Scratched my head a bit first though, thought my sensors had buggered up initially. Being able to record and play back all the ECM activity on the monitor after a dyno run is an absolute godsend. For a dyno operator, that Direct Link is a seriously good bit of kit. Out of interest I had also previously swapped the stock injectors front to rear. The AFR was different in most areas. They might well be matching injectors at peak flow (which never happens in use), but they are not matched anywhere else. Probably the main reason canned maps are so inconsistent from bike to bike.
The XR runs the same injectors as the other Sporties, 3.89 I believe, so I think I'll be pencilling in slightly larger ones once my R&D starts to take shape, if you're already seeing 80%.
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Streettracker

Thanks for the info. Much appreciated as a fueler and drilled stock mufflers are all I plan to do.
G
We ran the stock mufflers with our Top Fueler, this is actually made for us by Dobeck Performance (the guy who invented & owned Dynojet).

Streettracker,

I was wondering about the Top Fueler. I googled it and found one sold by Patriot and then googled Dobeck and found a different fueler. Patriot sells a track model and a street model. Which did you use?
How to order

Hi streetracker. I sent you a pm and it says you exceeded the max message amound. I then tried sending you an email and have not heard back from you. I am interested in buying a fueler. How can i get one from you, assuming you are still selling them.
I did some Dyno Testing of stock mufflers vs. drilled with and without a Fueler. I'm at home right now so I don't have the Dyno Charts to actually post, but here's some numbers to contemplate;All Stock 82.1 HP, 70.7 TQDrilled Mufflers 84.4 HP, 71.5 TQ Interestingly there is a LOSS of torque between 3050 rpm and 3600 with the drilled mufflers and stock Fuel curve. the sound is very Triumph or Norton like with the 3/4" holes, I like it.We ran the stock mufflers with our Top Fueler, this is actually made for us by Dobeck Performance (the guy who invented & owned Dynojet). The peak torque didn't change and the peak HP went up .7 More importantly the torque from 2500 to 3250 went up a little as did HP from 5500 on up by a couple. Much smoother from 2500-3500 rpm.Drilled Mufflers with the Fueler. The Peak HP was the same as without the Fueler at 84.4, peak TQ was 72.1. The important thing here is Torque at 2500 was up 4-5 Ft lbs and it basically gained 2-4 all the way through the power band. The same was true for the HP.
If I understand everything that I just read correctly (which does not happen often). A stock XR1200 with a fueler and drilled mufflers will make more torque and horsepower then a stock XR1200 with a fueler and no drilled mufflers through out the entire rev range from 2000 to 6800 rpm ?

Inthered
What size holes are typically being used with the best results.
If I understand everything that I just read correctly (which does not happen often). A stock XR1200 with a fueler and drilled mufflers will make more torque and horsepower then a stock XR1200 with a fueler and no drilled mufflers through out the entire rev range from 2000 to 6800 rpm ?

Inthered
Yes, but very minor differences.
This is awesome, Street. Would you be willing to post your best settings for your Top Fueler for those of us running that setup? :whistling:
This is awesome, Street. Would you be willing to post your best settings for your Top Fueler for those of us running that setup? :whistling:
The set up that comes pre programmed in the Top Fueler was pretty much dead on for So Cal with drilled mufflers. (And it was the same setup for the non drilled mufflers as well)
I did some Dyno Testing of stock mufflers vs. drilled with and without a Fueler.

As soon as I can get it back on the Dyno I will tune it for 12.5-13.3 across the board and see what we get, we are expecting, based on experience, to see another 3-5 HP and Ft Lbs across the board.

streettracker;

Were you ever able to finish this project up (i.e., as noted at the tail end of your original post)?
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