Another Supertrapp question (s)

Hey guys. I have this supertrap header 4-1 (see pics below) It was originally on my bike at one point. The previous owner replaced it with the 2-1 set I have on right now. He said that he replaced the supertrapp because he liked the dual exhaust sound better. I asked him if he ever rejeted and he said no. the bike right now it's running great, the plugs are all tan and my valves lash (clearences) are within spec.

I know some of you will probably say "oh no, his bike is running good, is he gonna swap his exhaust for the supertrapp?

Errr. yes, at least I think I am.

I read some posts regarding the supertrapp set up and how to tune it.

based on what I have, which is the set up the PO had on my bike, the disks look pretty dark and sooted. That leads me to believe that he was running rich and was quiter than what I now have because he had less plates than what he should have had on there in the first place.

I want my exhaust louder than whaty it is now. I am thinking about swaping to the supertrapp, but I don't know what sound to expect from it.

Does anyone know?

Also,my disks have these groove/kinks/ridges on them. Are the disks supposed to all line up with the ridges or are they supposed to be offset to increase flow? Mine are the one that have the one stud in the middle holding all the disks.

I only have 8 disks, I think if I was to order more disks to lean ut the mixture, I would need a longer supertrapp stud so I can fit more disks in, correct?

this is what I have.












My goal is to make the exhaust louder, but I also want a deep sound. Will the suppertrapp acomplish this?

Obviously I know I can get it as loud as I want, but my inquire is wether I can achive this sound after I tune the supertrapp with the correct amount of disks. I don't want to have to go with bigger jets, just so I can tune the exhaust to the sound I want. I want the exhaust to be tuned to optimim performance.

I will greatly appreciate your anwers and comments.

 

Hello, xulf.

The discs on my Supertrapp mount with 6 screws through the holes in the discs. If you look at the disks, you can see that will result in the notches lining up in a row. Offseting them would allow slightly more flow, but making the center bolt tight enough to keep them from slipping would probably bend them.

My discs were sooty just like yours when I first got my bike. It also has pod filters on it. A thorough carb cleaning and adding 6 more discs resulted in a proper mixure setting. The condition of the plugs is a better indicator of proper engine tune, though.

As far as exhaust note, I like the sound I get from my set-up. Mine is an 1100, though. Has a nice deep rumble at idle. Really gets angry after about 6 grand on the tach. Sounds like the big, mean, older brother to my 750! You can get more discs from Dennis Kirk, and a few other outfits, I believe. Do some plug chops first to see where you stand. Just going to 4/1 doesn't mean you have to rejet automatically.

If your plugs show it's running rich, order at 6 discs to start. One or two won.t change much, but the increments are small enough to really let you get it dialed in. It does make it louder as you add more discs as well. No one will mistake you for a Harley, though. And yes, adding more discs would require a longer mounting bolt. My set-up has 13 discs, but, as I noted above, also has pod filters, as well as larger main and pilot jets.

Hope that helps. Mike

 

Thanks Mike. I will look into getting more disks soon and the longer mounting bolt as well. yeah, I read that I shouldn't have to rejet if the exhaust is tuned properly. But if I go for sound (louder) then I'll probably have to rejet.

 

ItsMikey,

Are you getting your discs directly from Supertrapp? My bike was dropped previously and I'd like to replace my bent discs and add some so I can dial my mixture screws back a tad. Currently I'm running 8 discs (I think).

Xulf,

If you change your mind, I'd like to buy your Supertrapp setup.

 

Hey Sushi. How do you like the sound of your supertrapp. What can you compare it to? is it a deep sound or a rice rocket. And don't lie just to get me to sell you my set up...LOL

On these bikes, the mixture screws IN is richer and OUT is leaner?
I've only worked on holleys and webers, where IN is lean and OUT is rich.

 

No, in is leaner, out richer.
I like the idea of a tune able muffler, you can make it louder or quieter depending on your mood.

 

It is without a doubt, rice-rocket sounding. All the sport bikers tell me they like the sound of my bike but I would have preferred the lower note. It is also definitely louder than stock sounding. It has kind of grown on me over time though.

I was disappointed to read in this post that adding baffle plates makes it even louder but richer running. I didn't want that. I don't dare remove any plates to quiet it down because I had a hell of a time getting it rich enough without re-jetting the carbs as it is.

I swear I'm not telling you this just to get your rig. Perhaps someone with a 4-1 MAC or Kerker setup can chime in and tell you what theirs sounds like. I've never heard anyone's bike but mine. I will see if I can get some video/audio this week and post it so you can hear.

 

Sushi, I got more plates from Dennis Kirk. Adding more plates makes it louder and LEANER, not richer. If you are running rich now, you can add some more plates and be good to go.

 

That is what I read also. directly fromt he supertrapp website. More disks = louder/leaner. Less disks = quieter/richer. Thus mine having only 8 plates looks really sooted and from what the previous owner told me, it was quieter than what I have now. I think I made up my mind, and when I get some extra $$ flow I will order me some more plates and a longer bolt.When I checked Deniss Kirk all the had was the plates without the notches. and I did not see any kits that came with a longer bolt, but I guess I can use a hook type bolt sold at home depot or ACE hardware.

 

Ahhhhhhhhh ok. That's good news for me. I want to REMOVE some discs, quiet things down a little and I can dial back my mixture screws to compensate.

Who is Dennis Kirk and how do I contact him? I want to replace my discs with un-bent ones.

 

Dennis kirk is an online bike shop with a huge catalog. here is the link I found: http://www.denniskirk.com/jsp/common/Frontpage.jsp

So you are going to quiet down/run richer therefore you're going to adjust your mixture screw in, correct? That makes sense.

 

That's correct. I had to dial way out just to get rich enough to run safely so dialing IN will be cake.

I think I have like 8 plates so I'll start off by removing 4 and see what happens.

 

So with 8 plates is pretty loud? I have eight right now and it looks like the previous owner was running slightly rich, and he said it wasn't as loud or did not have the rumble these 2-1 I have in right now had.
Can you count how many plates you have in your supertrapp? I would like that info for reference.

 

I'll count 'em up when I get home. I'm not POSITIVE that I have only 8 plates. It may be more.

I had to dial WAY out beyond 2.5 turns on a stock set of carbs to get rich enough. I've heard that if your mixture screw tension springs are weak, that you can vibrate the little screws right out of their threads if you're dialed out far enough. That hasn't happened to me, but like I said, I'll be glad to tone it down a little, and be able to dial my screws back in some.

I doubt the kind of change I'm looking to make will alter the bike's performance much. Maybe I'll buy your stock exhaust if you sell.

"loud" is a relative term. I'm not fond of really loud noises to start with. My bike may not be considered loud by other people. I've had compliments on the sound though. Plus, I live in a townhome so population density is high and I'm trying to be courteous to avoid nasty memos from the Condo-Nazis. I am actively trying to sell my place now so I hope to be in a single family home by the end of the year where I won't have to worry about it so much.

 

hey sushi, did you count them disks yet? I'm getting eager here.

 

Xulf 13,

I have one of these SuperTrapp systems myself and have never adjusted it. I am going to check ine and see how many disc I have because I suspect I could benefit from some fine tuning.

 

Thanks Gehiv, I want a start base. i want to know what most are running. Mine only has 8 disks and I suspect I need to have 12 or more. But I first want to hear what most are running.

 

i ran a super trap on a tt500 and a dr650 the tt a while ago and i remember it had the extension bolt and i believe 14 plates and the longer rear cone
this was dirt only and noise didn't matter
the dr had 8 plates and the shorter rear cone, noise was a factor
6 plates in the dr changed top end performance for the worse
12 plates was too loud, i didn't change any jets and mixture screws aren't
real critical on one cylinder thumpers
the long or short cone will change the exhaust tone

 

thanks Polock, by the look of mine, What kind of cone do I have?

 

that is the short cone or what they used to call a 2-stroke cone
i looked up their catalog and in universal fit they list 2 stroke kits and 4 stroke kits but have no picture of the difference
the 4 stroke cone was about twice as long, same basic shape
might have to give them a call
mine had a short stiff spring under the the nut that holds the plates in
oh yea the plates should nest into each other

 

Thanks again man.

 

Sorry man. Work and reserve duty overloaded my a--. Ok, I definitely have 8 plates not including the final cover plate on the end. I do not have a cone like the photo that you have posted. It's just a flat plate with a slight dome. It looks normal, I don't think it's anything that a PO fabricated.

 

Thanks Sushi. I have 8 on mine as well. I think I will try to do the swap here in a few weeks and see how loud mine is with the type of cone I have on mine, and see how it sounds and so a few runs and check my plugs. Thanks a bunch Y'all

 

Oh, thanks for the reference to Dennis Kirk. I'd never heard of it and found many tempting, affordable exhaust options for our bike.

 

We have them @ Summit Racing also.

330-630-0240 ask for Tom

but not until Thursday.

I'm on vacation!