Upgrading to True Duals
#11
At the risk of repeating myself, I will repeat myself; see #3.
If you are dead set on TDs, Rinehart is the way to go; the only three stepped headpipe available; all others are two steps. However, it won't matter, you will loose torque and the bike won't be as rideable. I like the RH TDs and run them on my 107". which is soon to be a 103" and I am thinking I might need to dumpt the RHs in favor of a Propipe ot Theader.
As someone has noted, there are no heat issues with the 88" and the "Y" pipe; never has been.
Bottom line is that an 88" motor, particulalry a stock or Stage I motor, is just too small to benefit from true duals.
Keep the head pipes, clean up the inside of the "Y" connector and replace the mufflers with the older SEs, Rush, Cycle Shack, V&H or Fullsac slipons. If you are looking for a set of the older SEs, PM me, I am pretty sure I have a pair squirreled away and will sell them for a very reasonable price.
If you are dead set on TDs, Rinehart is the way to go; the only three stepped headpipe available; all others are two steps. However, it won't matter, you will loose torque and the bike won't be as rideable. I like the RH TDs and run them on my 107". which is soon to be a 103" and I am thinking I might need to dumpt the RHs in favor of a Propipe ot Theader.
As someone has noted, there are no heat issues with the 88" and the "Y" pipe; never has been.
Bottom line is that an 88" motor, particulalry a stock or Stage I motor, is just too small to benefit from true duals.
Keep the head pipes, clean up the inside of the "Y" connector and replace the mufflers with the older SEs, Rush, Cycle Shack, V&H or Fullsac slipons. If you are looking for a set of the older SEs, PM me, I am pretty sure I have a pair squirreled away and will sell them for a very reasonable price.
#12
I've never come across that before! I've used TDs on an 80" Evo, a stroked 89" Evo, as well as my 107". Each worked perfectly well from a riding point of view. How big does a motor have to be to benefit? And what is that benefit?!
#13
There are exceptions to any rule but generally speaking any stock or Stage I 88" motor in a good state of tune with the OEM exhaust will see a torque dip with true duals. The dip will be off idle and usually will require engine rpms to exceed 2000 rpms to overcome. IMHO, 107", perhaps even 110" is what I would consider large enough that there would be no loss of torque perhaps an improvement with TDs over OEM exhaust. Dyno data will bear this out. I think your previous post addresses the benefit of alternative systems to true duals.
The H-D OEM exhaust system, particularly the head pipes, actually work very well.
#14
That's a fair statement. Its been several years since I had an 88, and it didn't have nearly the heat problems the 96 bikes do, but it would get warm on a hot summer day.
Whenever someone on the forum mention TDs anymore, the usual chorus of "you'll lose low end torque" comes up. Here's a guy asking a question about how to handle a planned change to his bike, and almost immediately comes the answer to the question that wasn't asked.
B.S. I've got Rinehart TDs on my bike, and there is no loss of low end torque, when compared to the original headers. Other systems might offer a little more on the low end, but compared to the original system, no loss at any rpm.
I ran Samson TD fishtails on a 88 evo bike. Didn't have it dyno'd, nor was I concerned about it, but there was no loss or gain that you'd notice SOP.
The stock Y-pipe is a piece of crap, but it can be made to work better by removing the restriction.
Whenever someone on the forum mention TDs anymore, the usual chorus of "you'll lose low end torque" comes up. Here's a guy asking a question about how to handle a planned change to his bike, and almost immediately comes the answer to the question that wasn't asked.
B.S. I've got Rinehart TDs on my bike, and there is no loss of low end torque, when compared to the original headers. Other systems might offer a little more on the low end, but compared to the original system, no loss at any rpm.
I ran Samson TD fishtails on a 88 evo bike. Didn't have it dyno'd, nor was I concerned about it, but there was no loss or gain that you'd notice SOP.
The stock Y-pipe is a piece of crap, but it can be made to work better by removing the restriction.
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Usefulnut (04-27-2020)
#15
Originally Posted by boogaloodude
Whenever someone on the forum mention TDs anymore, the usual chorus of "you'll lose low end torque" comes up. Here's a guy asking a question about how to handle a planned change to his bike, and almost immediately comes the answer to the question that wasn't asked.
Originally Posted by boogaloodude
B.S. I've got Rinehart TDs on my bike, and there is no loss of low end torque, when compared to the original headers. Other systems might offer a little more on the low end, but compared to the original system, no loss at any rpm.
I ran Samson TD fishtails on a 88 evo bike. Didn't have it dyno'd, nor was I concerned about it, but there was no loss or gain that you'd notice SOP.
I ran Samson TD fishtails on a 88 evo bike. Didn't have it dyno'd, nor was I concerned about it, but there was no loss or gain that you'd notice SOP.
Originally Posted by boogaloodude
The stock Y-pipe is a piece of crap, but it can be made to work better by removing the restriction.
Last edited by djl; 08-12-2011 at 08:44 AM.
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skills (04-28-2020)
#16
show me your dyno charts that show a loss of torque at any rpm using a Rinehart True Dual system compared to a stock exhaust system on a 88, 96, or 103. If it's as prevalant as you say, you should be able to produce several charts.
Last edited by Mike; 08-11-2011 at 05:58 PM.
#17
I appreciate all the advice. I don't have a big concern over the small loss of torque. I have yet to find a road that my bike has not made it down without stumbling or feeling under powered. I definitely am looking for a sound change over the stock pipes and SE mufflers. I am not necessarily on a budget just trying to avoid outlaying $1500 at once. It seems easier to swallow that kind of money over several changes rather than one; i.e., my wife won't bitch as much. What is the easiest way to tell if the SE mufflers are the old style versus the new? A friend and fellow rider seems to think they are the older SE slip-ons.
#18
I appreciate all the advice. I don't have a big concern over the small loss of torque. I have yet to find a road that my bike has not made it down without stumbling or feeling under powered. I definitely am looking for a sound change over the stock pipes and SE mufflers. I am not necessarily on a budget just trying to avoid outlaying $1500 at once. It seems easier to swallow that kind of money over several changes rather than one; i.e., my wife won't bitch as much. What is the easiest way to tell if the SE mufflers are the old style versus the new? A friend and fellow rider seems to think they are the older SE slip-ons.
#19
http://harleytechtalk.org/htt/index....html#msg417102
BTW, my torque loss comments were specifically directed to 88" motors in stock or Stage I configuration. IMHO, 107' or 110" is the displacement size that may benefit from true duals.
Last edited by djl; 08-12-2011 at 10:05 AM.
#20
If you are so confident, produce the evidence! My TDs certainly had a drop off in torque until they got into their stride at around 4k rpm.