Horse Power

[matt]

So next year when I have cobra exhaust off and stock exhaust on with possible truck stack mod I will have gained 8-10 horse, Dam the bike goes sweet already and 8-10 horse is a pretty nice increase. Question is will I actually feel that in the butt dyno?   Thank Matt

[theredark]

I would think so.   You could always get the dyno done with the current exhaust and again with the new one.   I had Naults in Manchester do one last year.

[Hoser]

I picked up six horse and a couple foot lbs tork just by putting Grumpy's tips on my stacks.  Hoser

[Tropic traveler]

Butt dyno at my house says the Cobras on Kim's '98 cost it noticeable HP.
Both the '97 & the '99 are glasspack equipped, butt dyno say both will walk away from the '98. Big flat spot in the acceleration curve with the Cobras.
BUT.... the wife likes 'em & they do sound awesome, so they stay.   

[Ricky-D]

Don't forget to mention the accompanying loss of mile per gallon.

***

[Momz]

Remember that it is TORQUE that gives you the acceleration you feel when you twist the throttle.

Torque is a measurement and HP is a calculation based on that torque measurement.

Proper Dyno calibration and warm up are key to an accurate torque measurement. And not all Dynos will give the same readings. Measuring the exhaust air/fuel ratio is key to properly setting up a motor for an exhaust change/swap.

I've had my bikes Dyno'ed at different times with varying results. And I have torn apart the stock exhausts to find how restrictive they really are. All three of my Valks have non stock exhausts ( one has Cobra 6 x 6, one has glasspacks/stacks, and one has a completely unmuffled system made from the OEM unit).

I firmly believe that contrary to popular thought, that the 6 x 6 when properly jetted will produce at least the same or more torque than most systems used on our Valks.

[Len]

My Cobra 6 x 6 pipes had a noticeable flat spot during hard acceleration that came in at approximately 6k RPM.  This went away with installation of the long Cobra baffles, K & N filter, and Carb. work done by Patrick's Custom in Augusta, GA.  Now it pulls until it hits the rev limiter.
Nothing else I have heard sounds like a Valk with open Cobras, but I enjoy long rides and the drone was a serious problem...baffles eliminated the drone. (Made the neighbors happy too)

Thanks to Art in SC for the cut done Cobras!


Pat will dyno tune the bike later this year.

[pancho]

I firmly believe that contrary to popular thought, that the 6 x 6 when properly jetted will produce at least the same or more torque than most systems used on our Valks.

hey Momz, I'm wondering what turned out to be the proper jetting for your Valk with the 6X6 system, and how you determined that?? I have played some with mine, but did not do any rejetting when in the carbs,, no dyno either,, seems to burn correctly, but still thinking about it.

[Dag]

There are tons of Butt Dynos claiming power gains from one kind of muffler over another, always take these claims with a grain of salt. The mind can make good things better then they really are, meaning a very sweet sounding muffler will trick you into thinking its faster because you enjoy it more. Only way to know for sure is to look at a real dyno.

Muffler backpressure is going to have the biggest unfluence oh your power band shape. A more free flowing muffler will provide more gains higher up, but could result in a loss of the lower end torque.

Here is my result.
Viking Exhaust
Viking needles / springs
Dynatek Ignition Module
Dial-A-Jet (secondary fuel system)
 

[Hoser]

Mighty good numbers, Dag.    Hoser

[Momz]

I firmly believe that contrary to popular thought, that the 6 x 6 when properly jetted will produce at least the same or more torque than most systems used on our Valks.

hey Momz, I'm wondering what turned out to be the proper jetting for your Valk with the 6X6 system, and how you determined that?? I have played some with mine, but did not do any rejetting when in the carbs,, no dyno either,, seems to burn correctly, but still thinking about it.

I bought my 98 Valk from a dealer, but I knew the previous owner. He had the Cobras installed along with their jet kit. But spark plug readings show that it has been properly jetted.

It is also modified by using I/S carb springs, an I/S ICM, polished intakes, simple ECT mod., a K&N air filter and raised the front of the gas tank to increase flow to he airbox. It is fast, not as fast as some, but faster than most.

And as Dag mentioned, back pressure effects torque at lower RPMs and less backpressure is better at higher RPMs.

[pancho]

Good info guys,, seems to be the same combo of things I have heard mentioned a few times before.

I agree with Hoser, Dags numbers show he has his running great and a good combination of mods, although I wonder about that secondary fuel circuit. I have used one before on a single carb Harley,, but six of them?? I wonder if it was a chore to dial them in??

[Dag]

wonder if it was a chore to dial them in??

That was actually the easiest part.
http://valkyrienorway.com/Dial-A-Jet%20NEW.html

I have installed DAJ on 6 Valkyries and a few other bikes. It just works very good.
Great improvement on throttle response.
Best spent money on my Valkyrie 

[matt]

Hey Dag,,  Ya I saw that system from you I have looked into it I really like the system, hopefully next mod after exhaust (wife feels morg and other bills need to be paid first)  Nice seeing you back on

Matt

[pancho]

wonder if it was a chore to dial them in??

That was actually the easiest part.
http://valkyrienorway.com/Dial-A-Jet%20NEW.html

I have installed DAJ on 6 Valkyries and a few other bikes. It just works very good.
Great improvement on throttle response.
Best spent money on my Valkyrie 

Interesting setup,, pretty straight forward to install. The one I have used was caused a Thunderjet, a previous version of this   http://www.thunderproducts.com/thunder_powerjet.htm    I think six of these might be a nightmare to get synced up with the variable adjustment.