Sharkey....just saw this.....I did this so far,but need more backpressure still IMO....also Im deconed too.

i want to somehow block off more of the air coming around the square metal arear.....i noticed mine is still loud as hell,so i dont think Im actually doing much here with my setup...as 99% of the airflow comes around and thru the outer baffels

Dan

 

ok - see how the edges of the baffle have started to fold out? what I see is if you folded the edges of the baffle out the washer appears to be to big... I remember seeing a piece of angle iron - about 1" X 1" and had a washer tacked onto one end. the center of the washer was filled in with the piece of angle iron. Then I think it was tacked to the baffle, or maybe screwed on - not sure on that. so the best tune would be with the correct size washer.... sound close?

I think I saw a thread with this mod but can't find it.

 

good info, thanks.

This must be why I was told to fold the ends of the square baffle out to the inside of the cone to block the air flow. This way all the air is forced through the center and the "lollipop" washer acts as an anti-reverberation tool to help with performance and backpressure.

I think I got this correct???

when we had the '07 DX on the dyno I held a piece of wood over half the end of the TH. well I tell you what, the sound was LOUD and "On the money" and the ponies went up 2-3 points. holding the wood over the end is about the same as folding out the edges and putting a "lollipop" in the center.

what do the members think?

 

The only mod I did was to turn them red hot on Gracies Sporty, it was running a bit too lean that day

 

There's something about the 08 engines that is different IMO. The 08s and open pipes are much harder to tune for, and to tune out reversion (even in open loop). I had a thunderheader on my 06 that was tuned once, and ran perfectly for a couple of years with no reversion, and never a decel pop. Now with the 08 I hear complaints almost every week.

I'd be curious for one of the EFI guru's to jump on here and speculate.

 

Rich Products will be releasing a map for the '08 models with the SERPT tuner. they will be e-mailing me the map ASAP and I will have it for any members to use....

 

Bent my baffle flanges to the outer walls as much as I could right after I got it (I've had TH on other bikes). Running semi topless with Race fueler not SERT dynoed at Gail's last year 110 at rear wheel can't remember tq. Max said not quite as loud as CFR. Still loud but kicks in fantastic around 5K rpm. No decel pop either.

 

If I could find a good way to quiet it up some, I'd be a buyer. I very much like the look and the sound - it's just too loud for the regular long runs I do at highway speeds.

 

Hey guys...

Ok today I messed with a plate i was trying to bolt into the TH to increase backpressure.....but most all combonations that totally got rid of all backfiring resulted in top end power loss....the torque was amazing but just wouldnt breathe well for top end...

so I decided to just try the CRUSHED BAFFLE technique,that I had heard of before and similar to what Sharkey is talking about....this is different then the above washer pics I had tried too.

well,from the small amount of testing between rainfall today,i definitely think there is more power with the baffle crushed and pressed to the outsides(see pics below)....I think there may be a slight sacrifice on hi top end power but there is much more punch in bottom and mid,most likely pulling more torque numbers due to more backpressure,definitley can FEEL it!....

Here is a "crushed" thunderheader baffle(center 4 sided metal piece).....with my THunderheader DE-CONED it was pretty easy to do with a large long screwdriver and hammer,however im not so sure it would be as easy with a stock TH and cone.

this does LITTLE to quiet down the THunderheader,but then again i love it loud,this is all about power and reversion for me.

Dan

 

I have had no backfiring with my setup. I have done no mods to the thunderheader. I run a PCIII and amsoil flter. I still have the top on the airbox. I'm not sure why I don't have any backfiring but I'm glad that I don't. The only problem that I have is stallng when I pull in the clutch.

 

I still have the top on the airbox. I'm not sure why I don't have any backfiring.

That's why you don't have backfiring. Dan your baffles look too restrictive for me, but if they work then that's good. From what I understand a washer that is 2/3 to 3/4 the size of the exhaust exit is that you should have. Although looking at your baffle maybe that is correct in volume, just a different shape.

I'll be playing with a reversion washer when I get home. I designed one for my powerline that worked 99.9%, shouldn't be an issue with the TH. My only problem was the washer liked to heat with the exhaust and usually broke off, maybe I need something heat treated.

 

you definetly seem to be on to something here Dan...

are the 4 holes from the screws holding in the old washer set-up? I will be talking with Rich products on the map this week...

maybe they will ask for a members bike to dyno????

 

I agree if you have your TOP ON and intact(stock not SEMI) then you probably will not get any backfiring ever....you are not as FREE FLOWING as being topless.

I got some test time in tonight with crushed baffles,and there is definitely more torque for sure,3500 downward its more like an airhead now,lots of grunt!...i think up around 7500-9grand though she lacks abit,due to limited airflow probably....

Id say for typical day to day riding and not hi speed running i really like the baffle crush.

also i know its tough to see,but where the baffles are crushed there is still some space for airflow around the crush,hard to tell in pics though.

Im running a LEANER MAP now too so that might be another reason shes abit sluggish up on top end.

I wish i still had a stock LID around,id like to try a stock lid just for kicks.

Dan

 

tt

 

Holy thread resurrections batman!!!


Lol...

R

 

Yeah - I'm just trying to see if anyone anywhere has come up with an effective baffle to significantly quiet down the Thunderheader, since they come up for sale periodically - because they are painfully LOUD!