Duals vs. crossover
Cruiser
Joined: May 2005
Posts: 144
Likes: 0
From: St. Johns, MI USA
RE: Duals vs. crossover
Well I got the dyno run done.
95 Cu IN
Crossovers: Max HP = 82.2 Max Torque = 90.6
True duals: Max HP = 78.6 Max Torque =86.2
I lost if you read only the top end.
But between 2600 RPM and 3500 RPM there is very little difference and that is where I run on the highway. I have more at 2800 RPM, then it crosses over at 3000 RPM to go lower. It is close untill 4500 RPM then about 4 HP & TQ difference.
Ed
95 Cu IN
Crossovers: Max HP = 82.2 Max Torque = 90.6
True duals: Max HP = 78.6 Max Torque =86.2
I lost if you read only the top end.
But between 2600 RPM and 3500 RPM there is very little difference and that is where I run on the highway. I have more at 2800 RPM, then it crosses over at 3000 RPM to go lower. It is close untill 4500 RPM then about 4 HP & TQ difference.
Ed
Seasoned HDF Member
Joined: Dec 2004
Posts: 8,978
Likes: 34
From: Cedar Point, NC
RE: Duals vs. crossover
After spending a day with HDWRENCH while he did my 98" kit, we got to talk about this. He teaches dyno stuff at MMI, and believe me, he knows his poop.
Anyway, he told me basically what has been summed up here...the True Duals are great for Top End, but not so great for the low end...putting the baffles in the Rineharts will help with the low end, but to get the BEST performance, you obviously need 2 into 1, and the next best would be a stock crossover type configuration, and then the true duals.
He told me that on the dyno, the stock configuration with a set of SE slip ons will outperform a set of Rineharts. BUT, you have to tune it on the dyno to get the perfect tune, obviously.
Everything else is a swag.
Mac
Anyway, he told me basically what has been summed up here...the True Duals are great for Top End, but not so great for the low end...putting the baffles in the Rineharts will help with the low end, but to get the BEST performance, you obviously need 2 into 1, and the next best would be a stock crossover type configuration, and then the true duals.
He told me that on the dyno, the stock configuration with a set of SE slip ons will outperform a set of Rineharts. BUT, you have to tune it on the dyno to get the perfect tune, obviously.
Everything else is a swag.
Mac
Cruiser
Joined: May 2005
Posts: 144
Likes: 0
From: St. Johns, MI USA
RE: Duals vs. crossover
Bare with me I am trying to post my dyno sheet. Now we will see if it works.
Yes it does. The blue line is with V&H and crossover. The red line is V&H with true duals.
[IMG]local://upfiles/2381/7371C921157440F3BCBD65A0933D8466.jpg[/IMG]
Yes it does. The blue line is with V&H and crossover. The red line is V&H with true duals.
[IMG]local://upfiles/2381/7371C921157440F3BCBD65A0933D8466.jpg[/IMG]
Seasoned HDF Member
Joined: Dec 2004
Posts: 8,978
Likes: 34
From: Cedar Point, NC
RE: Duals vs. crossover
Interesting...not what I expected.
The Tq stays pretty tight between the two until about 3100 and then the true duals seem to pull slowly ahead...
I would have expected the Tq to be better down low for the cross overs and then get better for the true duals... at the high end...
Same for the HP...
With the exception of the 2800 range, the cross overs killed the true duals.
Was this the final tune for both? Or was this just the initial with both? Were any adjustments made to Ve and ultimately the AFR for best tuning?
Mac
The Tq stays pretty tight between the two until about 3100 and then the true duals seem to pull slowly ahead...
I would have expected the Tq to be better down low for the cross overs and then get better for the true duals... at the high end...
Same for the HP...
With the exception of the 2800 range, the cross overs killed the true duals.
Was this the final tune for both? Or was this just the initial with both? Were any adjustments made to Ve and ultimately the AFR for best tuning?
Mac
Cruiser
Joined: May 2005
Posts: 144
Likes: 0
From: St. Johns, MI USA
RE: Duals vs. crossover
ORIGINAL: pilot1996
Interesting...not what I expected.
The Tq stays pretty tight between the two until about 3100 and then the true duals seem to pull slowly ahead...
I would have expected the Tq to be better down low for the cross overs and then get better for the true duals... at the high end...
Same for the HP...
With the exception of the 2800 range, the cross overs killed the true duals.
Was this the final tune for both? Or was this just the initial with both? Were any adjustments made to Ve and ultimately the AFR for best tuning?
Mac
Interesting...not what I expected.
The Tq stays pretty tight between the two until about 3100 and then the true duals seem to pull slowly ahead...
I would have expected the Tq to be better down low for the cross overs and then get better for the true duals... at the high end...
Same for the HP...
With the exception of the 2800 range, the cross overs killed the true duals.
Was this the final tune for both? Or was this just the initial with both? Were any adjustments made to Ve and ultimately the AFR for best tuning?
Mac
I think you might have read it wrong the cross overs are better all the way through. Blue line crossover / red line true duals.
There are no adjustments made to my EFI bike. I only have the stock 95ci in software it it.
But look at the air fuel ratio. It is all over the place with duals.
Now I have a problem the dealer that did the BB does not have a dyno and warrantys the engine but can not do any race tuneing. The dealer that has the dyno can do race tune but then the warranty goes out the door with both shops.
Any race tuning will void my warranty.
Ed
Seasoned HDF Member
Joined: Dec 2004
Posts: 8,978
Likes: 34
From: Cedar Point, NC
RE: Duals vs. crossover
You're correct, I mis-typed...I meant they were tight until 3100 and then the crossovers pulled ahead...that would make more sense with the sentence after it...
AFR is all over the place...
I wonder how it would do with a tune...
Mac
AFR is all over the place...
I wonder how it would do with a tune...
Mac
Cruiser
Joined: May 2005
Posts: 144
Likes: 0
From: St. Johns, MI USA
RE: Duals vs. crossover
My dealer that has the dyno can tune the bike but I have to buy the race tune kit first then they will tune it but........................ out goes the warrenty.
I thought you miss typed it because you contradict yourself later.
Ed
I thought you miss typed it because you contradict yourself later.
Ed
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Seasoned HDF Member
Joined: Dec 2004
Posts: 8,978
Likes: 34
From: Cedar Point, NC
RE: Duals vs. crossover
Just went through this with my 98" kit. I bought the SERT, and now I need a dyno. I have a map on there that "feels" good, but you don't really know until it's tuned.
I gave up on the warrantee. The bike is stout...if I have a problem with some other part of the bike, it will be covered under warrantee just none of the stuff that I messed with.
Mac
I gave up on the warrantee. The bike is stout...if I have a problem with some other part of the bike, it will be covered under warrantee just none of the stuff that I messed with.
Mac
Grand HDF Member
Joined: Nov 2004
Posts: 3,917
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From:
RE: Duals vs. crossover
Now this might not help much but Gerald told me that the optimum AFR on a Harley is 13.7, and if I'm correct, shouldn't it stay consistent through out the whole run.
Also on the V&H system, it doesn't mention on the website if they are of stepped design or not.
I also have a book where they compared Rineharts to some other exhaust including a 2 int 1 system by D&D, The 2 int 1 won but by very little, I mean very little, so I think that a good design in a system will also help such as the Rineharts.
Also on the V&H system, it doesn't mention on the website if they are of stepped design or not.
I also have a book where they compared Rineharts to some other exhaust including a 2 int 1 system by D&D, The 2 int 1 won but by very little, I mean very little, so I think that a good design in a system will also help such as the Rineharts.