Im trying to get some advice from pros here. I recently upgraded my 09 street bob to SS 110 kit. Heads ported/machined by Dave Mackie compression 10.7 I already had Woods TW-8-6 cams in my bike and left them. HPI 55mm TB w/ 5.3 injectors and new Thrashin AR 2-1 exhaust. My builder tuned with Power Vision and I thought numbers would be better not that they are bad. 122/121 Id like the torque to come on sooner and thought it would and pull harder than it does. See the dyno sheet.
I posted this over at HD forums and got some feedback, just trying to some more digging on this.
I spoke with a known tts mastertuner who said bring it after breaking in the engine. He said could be my cam. Id like to get some input on what others think here. Thanks!
I've never heard of that exhaust. It is a full length system? Sometimes the stubby little two into ones can hit the curve hard like that on the low/mid range.
Good money that pipe is the problem.
That's not a typical TW8 torque curve; it's nothing like mine was.
Nothing wrong with the TW8 or the PV and no need to replace it with a TTS. Dump that exhaust. A lot of these companies coming up and just welding some pipe together without doing any testing or having any concept of what makes an exhaust work. If you want that custom stainless look, have Burns design an exhaust for you and then have someone weld it up for you.
I just looked at the exhaust website. Looks like they have several baffle options. Don't know which one you have. Maybe a different one might help.
Quote from: Nastytls on April 11, 2019, 06:33:20 AM
That's not a typical TW8 torque curve; it's nothing like mine was.
Nothing wrong with the TW8 or the PV and no need to replace it with a TTS. Dump that exhaust. A lot of these companies coming up and just welding some pipe together without doing any testing or having any concept of what makes an exhaust work. If you want that custom stainless look, have Burns design an exhaust for you and then have someone weld it up for you.
Agreed I have essentially the same set up except I have GMR heads it made 134/125 with a short RB LSR pipe slight torque dip down low but that 8 pulls all the way out the back door Guess I agree it's the pipe
I looked up the pipe and it appears they did some sort of testing with Fueling. It has a familiar look to it. There are several baffle / options available with that pipe. It may need an experienced Dyno tuner to straighten it out or to find the problem with the combination of pipe components. Maybe one of the FXR guys on the site have some experience with the pipe and will be willing to offer some helpful insight.
https://www.thrashinsupply.com/products/thrashin-ar-system-exhaust-fxr
A local dealer uses that pipe a lot with the M8 Softails, I just bought a Fat Bob there. The Dyno guy was trying to sell me on a build and offered a lot of Dyno charts for me to view. Most of the charts had similar dips though not as bad. I did notice the pipes with the " dog ball baffle" had a better looking curve.
Whenever I see a cheap pressed 2-1 collector as oposed to a decent fabricated merge collector, I question the quality.
Info on the "AR chambers"
https://patents.google.com/patent/US6336471 (https://patents.google.com/patent/US6336471)
Regardless of patents and reversion theory that is still a big dip, similar to V&H big radius 2 into 1 sheets I've seen, maybe pipe alone or pipe and components, any of you dyno chaps seen this pipe?
Well, Dave knows what's going on with heads so I would rule that out, secondly that cam at 10.7 to 1 is probably one of the best power producing cams available if you don't mind a little associated sound from the valvetrain. So that leaves the pipe which I have never heard of and likely the problem. Even with the pipe not being the best I would be willing to bet it is VERY lean in that dip area as well.
I'd put a supermeg on it, keep the PV
Quote from: harpwrench on April 12, 2019, 06:32:06 AM
I'd put a supermeg on it, keep the PV
If you live to be a 100 you won't get better advice than that!!!
Just listen to what everybody here and hdforums has told you. Your exhaust sucks.
Lot of advice and appreciate all the feedback. I do have the dog baffle in this pipe. Is it possible if went with different baffle would make that much difference?
I spoke to a local tuner who has tuned with this exhaust and did say the dip is this exhaust. But would the pipe alone cause torque coming on late?
Anyone recommend good pipes for my set up to get more torque?
Quote from: kd on April 11, 2019, 07:17:05 AM
I looked up the pipe and it appears they did some sort of testing with Fueling. It has a familiar look to it. There are several baffle / options available with that pipe. It may need an experienced Dyno tuner to straighten it out or to find the problem with the combination of pipe components. Maybe one of the FXR guys on the site have some experience with the pipe and will be willing to offer some helpful insight.
https://www.thrashinsupply.com/products/thrashin-ar-system-exhaust-fxr
Yes i have the more aggressive dog baffle in there. Im going to call Thrashin and aee what they say. I was hoping a good tuner could make it better
Quote from: harpwrench on April 12, 2019, 06:32:06 AM
I'd put a supermeg on it, keep the PV
This pipe you think is better than thunderheader? Will it add more torque ?
Dragula 2
Quote from: mickblues on April 12, 2019, 11:08:34 PM
Quote from: kd on April 11, 2019, 07:17:05 AM
I looked up the pipe and it appears they did some sort of testing with Fueling. It has a familiar look to it. There are several baffle / options available with that pipe. It may need an experienced Dyno tuner to straighten it out or to find the problem with the combination of pipe components. Maybe one of the FXR guys on the site have some experience with the pipe and will be willing to offer some helpful insight.
https://www.thrashinsupply.com/products/thrashin-ar-system-exhaust-fxr
Yes i have the more aggressive dog baffle in there. Im going to call Thrashin and aee what they say. I was hoping a good tuner could make it better
A few posts up BVHOG chimed in, he can tune, a good tuner could probably lessen that dip, but without spending the coin to find out there is no way to know for sure cause of the pipes unknown characteristics, at least around here. It might be a good pipe :nix:
Supermeg is a good pipe, tunable, not all like the sound.
W8 works well 3K-6K. This is why sometimes they start their runs at 2500. Makes it look better.
If you really are at 10.7:1 compression and everything was assembled properly your cold cranking compression should be about 200 psi at near sea level according to Big Boyz calculator. I would at least start there before spending $$$ on new pipes.
Quote from: BVHOG on April 12, 2019, 06:27:04 AM
Well, Dave knows what's going on with heads so I would rule that out, secondly that cam at 10.7 to 1 is probably one of the best power producing cams available if you don't mind a little associated sound from the valvetrain. So that leaves the pipe which I have never heard of and likely the problem. Even with the pipe not being the best I would be willing to bet it is VERY lean in that dip area as well.
Was hoping a good tuner can fix the dip and torque curve. Does the pipe need a certain amount of back pressure
Quote from: tdrglide on April 13, 2019, 07:04:18 AM
If you really are at 10.7:1 compression and everything was assembled properly your cold cranking compression should be about 200 psi at near sea level according to Big Boyz calculator. I would at least start there before spending $$$ on new pipes.
I don't think ill be changing that exhaust I just got it so I'll have to get the tuner to look at and see if he smooth out the curve and hopefully get more tq earlier on.
Unfortunately, folks spend their money on a pipe prior to realizing what actually works.
Quote from: mickblues on April 13, 2019, 03:08:11 PM
Quote from: tdrglide on April 13, 2019, 07:04:18 AM
If you really are at 10.7:1 compression and everything was assembled properly your cold cranking compression should be about 200 psi at near sea level according to Big Boyz calculator. I would at least start there before spending $$$ on new pipes.
I don't think ill be changing that exhaust I just got it so I'll have to get the tuner to look at and see if he smooth out the curve and hopefully get more tq earlier on.
If it was me, the first person that expressed an interest in the pipe would get to make an offer. :nix: You could spend more in dyno time than the difference on a new pipe. You may be able to recoup most of what you paid while the pipe is newer and then get into a known performer. If you are after performance your selection is more limited.
The SuperTrapp Fatshot exhaust for dynas look sweet...
Quote from: mickblues on April 15, 2019, 01:28:02 PM
The SuperTrapp Fatshot exhaust for dynas look sweet...
:up:
Try the better baffle first.
Quote from: joe_lyons on April 16, 2019, 06:30:03 AM
Try the better baffle first.
Better baffle for my current exhaust? I spoke with thrashin and they said I shouldn't change baffle one i have is best one
Quote from: mickblues on April 18, 2019, 05:27:16 PM
Quote from: joe_lyons on April 16, 2019, 06:30:03 AM
Try the better baffle first.
Better baffle for my current exhaust? I spoke with thrashin and they said I shouldn't change baffle one i have is best one
There are 2 dogball baffles which one do you have?
this is my TW8 in a 107" with a dragula 2 pipe. initial dip is because it goes dead fat (10:1) at low rpm where i haven't tuned it yet.
My 107 with Woods 8-6 with D&D Fatcat, torque for days! :baby:
Quote from: JTCreeper on May 22, 2019, 09:01:15 AM
My 107 with Woods 8-6 with D&D Fatcat, torque for days! :baby:
Which baffle do you have in the Fatcat?