Loss of low end torque with slip on.

[Sulli]

I recently received and installed my Huzar exhaust.  Location is good, sound is great, however, I am 100% sure I have lost low end torque.  I will pull Huzar off this week, and replace OEM to ride them back to back.  Has  anyone else experienced this?

[Dougie]

3 hours ago, Sulli said:

I recently received and installed my Huzar exhaust.  Location is good, sound is great, however, I am 100% sure I have lost low end torque.  I will pull Huzar off this week, and replace OEM to ride them back to back.  Has  anyone else experienced this?

Nope. Is anything stuck in the exhaust (packaging or something)? Dislodged a sensor? 

[jdub53]

No seat of the pants power change when I installed my Huzar and I'm using both dB killers.

[Sulli]

Nothing lodged in exhaust.  I have the one db killer installed (is it directional, would that make a difference?).  I did not purchase the exhaust to gain power, would have to decat to do that.  My goal was to prevent damage on tip overs to swing arm and hanger.  However, I did not expect a drop on low end torque.  LIke I said will swap out Wednesday and run back to back, if its not all in my head, the stock exhaust will be staying on.  I was curious if anyone else had experienced this.

[Sulli]

1 hour ago, Dougie said:

Nope. Is anything stuck in the exhaust (packaging or something)? Dislodged a sensor? 

I just noticed you said dislodged a sensor.  What sensor would this be?

[Dougie]

17 hours ago, Sulli said:

I just noticed you said dislodged a sensor.  What sensor would this be?

Lambda sensor on the exhaust, for example. Top or bottom? Anything controlling fuelling. 
nothing restricting fuel flow? Or blocking airflow. 
have you tried the old can again yet? Could it be as simple as it just feels weaker? More noise for same throttle and speed as it were?

[Sulli]

I do not believe, the slip on and mid mipe involve any interaction with sensors, so I do not believe it's a sensor issue.  I do have the Huzar db/flow reducer at the end of the slip on, which I guess could be an issue?  Anyone else install this? I do not have the second db eliminator which is inserted in the end of the slip on installed.  I guess it could all be in my head, however, my butt dyno says otherwise.  I am off tomorrow will pull db eliminator out, run it to see if there is a difference, if not I will put stock exhaust back on and test, to be sure.

[Ray Ride4life]

Taking out a dB killer would take away low end power. More flow is good for top end but for low end you want back pressure which is created by a dB killer.
With a performance exhaust you also want a performance air filter because in order to exhale more you have to inhale more.

[Sulli]

I have heard the back pressure argument more than once, however, it seems improved flow would improve the bikes performance as a whole.  My biggest concern is that no other T7 rider with the Huzar has commented about a reduction of low end power.  So either my butt dyno is off or it isn't.  When I switch out the pipes tomorrow, I will know for sure.

[Ray Ride4life]

Your butt dyno doesn't give you any numbers.
Try to pop a wheely at different rpm's and/or gears and do the same with the OEM if you don't want to put him on a real dyno.
In my time heard a lot of people say they gained power with the new sporty exhaust but when they put them on a dyno it often turned out they where missing some.

[Hibobb]

@Ray Ride4life it is the placebo effect. Put some go-fast item on and you think it goes faster. Heck, if i change the oil and wash/wax mine I think it goes faster. 

[Canzvt]

Putting a pipe on a T7 in itself will NOT increase performance. It WILL de-restrict backpressure slightly and make the bike run a bit leaner, hence the possibility of a torque decrease in that RPM range as these bikes are super lean to begin with to meet emissions regulations. Opening up the intake/exhaust system WITHOUT changing fueling will typically result in a performance degrease. That magnitude of the decrease has a bunch to do with your elevation, temp, specific bike, and how sensitive your butt dyno is.

[Larson627]

I have experienced a considerable shift in power with more free flowing exhausts on other bikes pushing the power curve up in the RPM's, but there is another phenomenon to consider here as well, and that is the noise to power ratio. If you are using your ass to measure HP, it is hard to ignore the calculations your ears are adding to the mix. If the bike is substantially louder than before, but not measurably faster, it might feel slower than it did when it was quieter. I have often found this with loud exhausts. My Camel with the db killer removed makes the bike feel like a turd, but I am pretty sure that is just because it is making way more noise than power. 

[Canzvt]

When I fitted my Camel (original high outlet config), it was lean down low. Meaning at 2000-4000rpm partial throttle, it would hesitate when you applied throttle. When I added my Uni (Aussie) filters, it made it worse (as it should!!) as it was opening up the intake and exhaust breathing restrictions. 2WDW tune, and the world and my T7, got much better!

[Sulli]

1 hour ago, Hibobb said:

@Ray Ride4life it is the placebo effect. Put some go-fast item on and you think it goes faster. Heck, if i change the oil and wash/wax mine I think it goes faster. 

It's quite the opposite, sound is awesome, however, low rpm, it feels slower.

[Hibobb]

8 minutes ago, Sulli said:

It's quite the opposite

@Sulli Yes, when I went back to the beginning, I saw that was what you were talking about. I believe you and you are the exception to the norm. No one likes to admit they made things worse....

 

As Ray and other have mentioned, it is a balancing act with Air-in/Air-out/Fuel and most all the HP power comes at higher RPM's. Yes, there are exceptions to this put I am speaking on general terms.

Changing just one item usually just screws up the balance and you get a net loss HP.

 

For me.... the T7 has more than enough power. To tune it to what I liked, I just went up a tooth on the counter shaft sprocket. Again, this is just what "I" wanted, and it is not for everyone. If I ever smash up my muffler I may go to a high pipe, just to protect it a bit. Stock noise/sound is fine for me, I don't like loud bikes.

[Sulli]

I agree stock pipe noise is fine.  I do a lot of trail riding  and the bike goes down periodically, so change to the Huzar was purely for damage limitation.

[Sulli]

I ran the exhaust with the disk db killer/flow restrictor, then with the addition of the bolt in db killer, then, without any.  I cannot say other than noise, that there was any dicernable difference.  Then I pulled the the exhaust and replaced the OEM.  The difference was night and day.  With the OEM, the low end pull throughout the gears, is crisper and sronger.  Not satisfied with just my opinion, I recruited a long time riding buddy, proceeded to pull the OEM, installed the huzar and had my buddy ride with the same configurations as above.  I then pulled the exhaust and had them ride the OEM.  They were 100%  sure the OEM achieved better power throughout the gears low down in the rev range.  So the stock is back on and here to stay.  As I mentioned before, I do a lot of offroad riding and one of the sweetest parts of the T7 is that crisp low down torque througout the gear range, its where my bike lives when I am off road, and I would not trade that for anything.

Edited June 23, 2022 by Sulli

[Dirtbandit]

Sulli , By chance is this for sale on eBay? If so wish I read this thread prior to bidding. Ugh.

[DT675]

On 6/23/2022 at 12:11 AM, Sulli said:

I ran the exhaust with the disk db killer/flow restrictor, then with the addition of the bolt in db killer, then, without any.  I cannot say other than noise, that there was any dicernable difference.  Then I pulled the the exhaust and replaced the OEM.  The difference was night and day.  With the OEM, the low end pull throughout the gears, is crisper and sronger.  Not satisfied with just my opinion, I recruited a long time riding buddy, proceeded to pull the OEM, installed the huzar and had my buddy ride with the same configurations as above.  I then pulled the exhaust and had them ride the OEM.  They were 100%  sure the OEM achieved better power throughout the gears low down in the rev range.  So the stock is back on and here to stay.  As I mentioned before, I do a lot of offroad riding and one of the sweetest parts of the T7 is that crisp low down torque througout the gear range, its where my bike lives when I am off road, and I would not trade that for anything.

Thats the exact results I would expect.  Unless your going to get a full tune I dont like aftermarket exhausts at all.  They look better, thats it. (I get the getting it up and out of the way thing, too) I did the exact same thing with a Honda CRF250L recently.  Mine was stock, my buddies had a PowerCore4 on it without DB killer/ no tune and his was gutless compared to mine.  It made a Shet tun of noise but was gutless.  I eventually went to a FMF Q with DB killer and full tune and that went pretty well.  Was the best of the 2 worlds but was still too loud...

[Sulli]

I believe the power curve has been altered, I am sure in the higher rev range it pulls better, however, off road is my priority!  Sounds great, however, also too loud for my living environment !

[Simmons1]

1 hour ago, Sulli said:

I believe the power curve has been altered, I am sure in the higher rev range it pulls better, however, off road is my priority!  Sounds great, however, also too loud for my living environment !

Surprised you think its too loud.  With both DB Killers and Spark arrestor, I think its quieter than the stock muffler. YMMV

[Ray Ride4life]

I have a K&N air filter and removed the inner part of the snorkel yesterday and i have a MIVV Dakar.
Didn't ride with the partially snorkel removal, just K&N and MIVV are not bad but i have a Rapid Bike Evo on it's way.

[Cruizin]

On 6/20/2022 at 12:02 PM, Sulli said:

I recently received and installed my Huzar exhaust.  Location is good, sound is great, however, I am 100% sure I have lost low end torque.  I will pull Huzar off this week, and replace OEM to ride them back to back.  Has  anyone else experienced this?

I have a Wings exhaust, felt a little loss at first, might have just been mental, but I had @2 Wheel DynoWorksflash my ECU and I got back a jolt of low end power and what feels like more top end power as well. Remember, these bikes are already kind of lean from the factory, opening up the exhaust makes em even more lean. Try an reputable ECU flash. Worked for me.  I also removed snorkel and run an oiled foam air filter. 

[Sulli]

Maybe this is the route to go.  What was the cost?