Quiet versus powerful

[David Jackson]

A couple of interesting items come up as I read all the various posts. One is that fuel injection seems to be more sensitive to intake, exhaust, cam, etc. changes than carburetors might be; or possibly the reality is that fuel injection can be tuned so precisely, in ways I cannot even begin to fathom, that it may seem to the uneducated layman (me) that changes with a fuel injection system can have far more detrimental effects if the fuel injection system is not retuned than would be the case with a carbureted engine.

Anyway, that's one point. However my other point relates to my '01 Dyna, which has a carbureted engine and it relates to power versus noise. I read in one of your recent posts, Mike, that from now on you are going to be sensitive to the noise issue in your recommendations to motorcylists. I can understand that perfectly well and I wonder why some of the manufactuers of those big, ugly, carbon cans which supply muflers to Japanese sport bikes do not supply them for HD? Those little rockets really go, yet they don't make anything like the unholy din (to those who hate bike motors) which our HDs do. It should be obvious to all by now that there is so much abuse by silly riders of open exhaust systems that Big Brother is going to come down on us hard one of these days. Plus, its just plain rude to make so much noise in inappropriate places. I used to have CHs way back when, with factory straight pipes; and I used to ride them very carefully in built up areas so I made very little noise. It is possible to do that, but many people don't even try.

And so ... back to my bike. 113" kit, HTCC CNC Ported Heads, maybe changing to 260 cams, 51mm CV, with the HD gadget installed which gadget allows choices between different advance curves and starting points (the SE Pro Adjustable Map Ignition System); I have two pipes I own and have not decided which to run. One is a V&H ProPipe. I have both baffles and in an earlier post you recommended I use the quieter of the two; both for noise and for improved mid range rideability. Understood.

The other exhaust set I have is one with the stock header pipes and the SEII slip on mufflers. I used that combo with the 103" setup and liked the look, the sound (sounds more like a Harley to me than the Pro Pipe 2 into 1, and it seems so quiet I installed the extra horn from HD), and the midrange; however I could tell I lost some real power up top.

If I were to use that set up with the 113" combo as above;

1) How much power would I be likely to lose versus the Pro Pipe? (I don't want to lose so much power I simply defeat all my efforts with heads, displacement, cams etc to get better performance)

2) Where would you recommend someone start with the tuning, i.e. jetting, and igintion curve and initial spark timing?

And, of course, inasmuch as I like the look of two seperate pipes is there another combination of header pipes and slip ons which would make better power than what I have without being too noisy?

(P.S. My cases should be coming your way shortly for the breather mod we have talked about.)

Regards;


David Jackson

[Mike]

Anything that changes the amount of air or how it is processed by the motor requires the fuel injection to change accordingly. Since EFI is computer based, it only knows to do what it is told by the ECM and therefore must be told what to do with air flow changes. Carb's are signal based, respond to air flow changes and to a degree compensate for those changes. It has been argued that cams with a lot of overlap upset the EFI's ability to be properly compensated to correct AFR (especially with common or single runner intakes vs. segregated runners). In practice we've found that tuning can adequately managge this to the degree that it is not an issue for the bikes owner. In other words, the HP gains more than outweight any problems associated with overlap/intake crossflow/reversion. It can be argued that EFI is better at managing these problems because of it's ability to specifically target tuning. That's why torque dips do not appear as deep with EFI bikes vs. carb.
We are struggling with the power vs. noise issue realizing that quite bikes may not achieve the hp levels of loud bikes. Your point is well taken that why spend money on things to raise hp when the pipes will not allow it's realization. Your point about import bikes is also true but H-D guys just do not want really big mufflers, which is what will be needed to achieve both quite and HP. We've known this for a long time but who wants to build pipes no one will buy. Perhaps that time is near but it will take a paradym shift in rider attitude and exh. manufactures design philosophy. The good news is that shift is already becoming aware in that people are making it part of their discussions.
The hp losses of one pipe vs the other are difficult to predict but expect 5-10 at high rpm, better 2-4k numbers and better average numbers with the quiter pipe. Lets not forget that the porting, camming and carb.rules all still apply, just concentrated at lower RPMS.
Start with 220main jet, 52 low speed, rich needle (if you buy the tuners kit), 28 degrees total timing from 3k+ progressing evenly from 12 degrees to 28 from 500-3000 rpm. Detonation will dictate how much advance the motor will accept and this will be the tuning guide. These are WOT settings only and the rest of the range will have to be done either on the dyno or on the road. A load control dyno will be the best tool for complete setup.
I've checked to make sure we had the reed valves in stock and all is good for the case mods.
Regards, Mike

[David Jackson]

HI Mike;

This is a current (May 5th) addendum to a pretty old thread.

My bike is still not together; partly because I kept changing my mind about motor components and partly because of the little missing piece of the puzzle here and there. I have another bike (FLTHCUI) I can ride, so life does go on!

Anyhow; I went to this thread because I remember we were discussing various exhaust alternatives for my bike. I bought a used D&D Boarzilla but the techs tell me it won't fit my Dyna; the muffler bracket hits the swing arm and the muffler itself interferes with the saddlebags (2001 FXDXT) so even if I can get another bracket the pipe won't work with my bags. So ...

I now have the SE HTCC CNC Ported heads with SE Bigger Bore cyls and proper pistons for the heads, (113"), Bobby Wood 408G grear drive cams, the stock 5 speed, the Latus case breather set up, balanced flywheels, the Wood modified 51 mm CV carb, and a choice between two pipes; one is the stock headers with the SEII slip on mufflers, and the other pipe is the V&H Pro Pipe. When discussing these choices previously I was planning to use higher rpm cams than the 408Gs.

If power I spent lots of money to get will not be completely wasted I could probably go with the SE slip ons; partly because they are not nearly as loud as the V&H (or the Boarzilla, for that matter, which I did not necessarily think I could stand forever). Previously you mentioned a loss of 5 to 10 hp at top end, and a possible gain in the 2K to 4K rpm range with the SE slip ons instead of the V&H. I wonder if that would be all bad with a low end cam like the 408G?

Would you have another exhaust system suggestion/recommendation?

I was considering a couple of other alternatives some months back; one is the Super Trapp 2 into 1 and the other is the Cycle Shack one piece with the large diameter header pipe. Do you have any thoughts on either of those?

I have spent many happy hours checking out the various dyno results with different pipes but none are exactly what I have for parts.

Thanks for any advice and/or recommendations you can give!

Regards;

David Jackson

PS Did you get the book?

[Mike]

Thanks for the book info, just have not got toit yet but definetly intend to. The good 'ol Cylce Shack 2" "M" pipes really work great and would be a good choice at a very low price. Be sure to get the tappered duals with removable baffles so that tuning can be done with baffle mods. (all the big HP charts advertised with these pipes are with cut or no baffles). Of course as always, modifying the baffles means more noise.
Thanks, Mike

[David Jackson]

Hi Mike;

Good luck with the book! I guess the info in it is pretty much old hat by now; but it is fun having old books; I should know as I have shelves full of them.

Thanks for the good info on the pipes. Cycle Shack certainly seems to be a lot of bang for the buck. You are not the only one with a high opinion of them.

Since I wrote you I have picked up the bike. The Boarzilla I bought does not fit, however; so I rode it with the stock header pipes and the stock HD SEII slip ons. From past post I guess that may be costing me 10 hp; but the upside is that my ears were not ringing from loud pipes after a 2 hour ride as they were oftentimes with my Pro Pipe. In fact those HD SEII slip ons are so quiet that I installed the extra HD horn so I would not be invisible to car drivers.

I am not just sure what I should do about the high hp exhaust system situation; having my ears not ring is worth something, and as you have commented in the past, noise we make on our bikes is an issue; so maybe I won't do anything but Cycle Shacks surely are tempting even for a short time!

Is there something different about the M pipes from the ones on Cycle Shack's website now? They show two styles of one piece two into two pipes with the larger diameter header pipe; slash and tapered. I understand the tapered part and I understand the removeable baffle part; just don't understand the "M" part.

Thanks;

David Jackson

[Mike]

The "M" pipe is what we used to refer to as the larger diameter/removable baffle. Cycleshack may have changed the designation or my memory may just be getting "soft".
Regards, Mike

[David Jackson]

Hi Mike;

Thanks for the info on Cycle Shack M pipes. I will give them a call. Maybe it says "M" on their web page and my lazy eyes did not see it.

For any forum readers who have D&D pipes, apparently there are some situations where there are clearance problems. The head of the company, named Dave, apparently is aware of this and has made up some adapter kits which consist of spacers and longer bolts. Unfortunately as of this date (May 20, '06) he is out of the US and unavailable. However he will return one day they say and then I can learn more about the spacers, etc. Just FYI if any readers have those pipes.

Mike, I doubt you would care to repeat what you mentioned before about HP and TQ loss/gain with my SEIIs and stock header pipes, but if you have any more thoughts on them I would love to hear what those are. I am not a racer or anything but do hate to give up too much power I have paid so much for; but I am also sensitive to the noise issue, both for me in terms of ear damage and ringing in the ears after a ride, and to the public; as you have mentioned a long time ago.

Is there anyone you know of who makes quieter mufflers with large diameter header pipes? I know S&S is making something for the Touring bikes and maybe they will get to Dynas some day. Have you tested any of those?

I believe we also discussed a little bit; alternative muffler situations. I have written to some of the muffler companies which make those big ugly cans for import bikes but none seem to have any interest in H-Ds. I wonder why? As you have said, sooner or later the noise issue is going to become an even bigger deal than it is now.

Regards;

David Jackson

[Mike]

We've been playing with the CALIBER systems lately and these, so far, seem to be a good compromise between sound and power. Their touring system is very similar to the Rhinehart true duals and performs about the same but slightly less load. We have not had a chance to test their other systems (softail, dyna. etc.) We also have yet to setup our DB test station (I have all the parts, just need to get the time and set up methodology).
Thanks, Mike

[Mike]

I mistakenly referenced Cobra exh in my above reply, but should have said Caliber. I edited the reply to be correct. Apologies for the error.
Mike