Author Topic: D+D Exhaust for EFI Enfields  (Read 22946 times)

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72westie

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Reply #15 on: August 22, 2012, 06:35:14 pm
Just got off the phone with him, I didn't see your post quick enough Scotty, so I wasn't able to ask that question.

The pipe is a stepped head pipe, 1 5/8 out of the head to 1 3/4. They have a 2 1/4 full length heat shield back to the muffler, that is what gives the head pipe that big look. He said they tried a bunch of different sizes and this was the best set-up.

The muffler has a long louvered baffle in it. There is no packing on it, you can put packing on it and it doesn't change the sound very much.

They had a local customer loan them his C5 to do the R+D on it. He was having a hard time hitting 70mph on the freeway, now he is hitting 75mph no problem.
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2009 AMA Vintage 50's #1 Plate
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ace.cafe

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Reply #16 on: August 22, 2012, 08:23:58 pm
Does this use the O2 sensor, or what?
Home of the Fireball 535 !


72westie

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Reply #17 on: August 22, 2012, 10:06:01 pm
The pictures show the wire from the O2 sensor hanging there, but I forgot to ask specifically if it does use it.
2001 Royal Enfield Bullet 500 Race Bike:
2008 Ahrma Classic 60's #1 Plate
2009 AMA Vintage 50's #1 Plate
2010 AMA Vintage 50's #1 Plate
http://www.bgmotorcycle.com


ADB

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Reply #18 on: August 23, 2012, 03:19:47 pm
I was curious about the 02 sensor as well.


BRADEY

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Reply #19 on: August 23, 2012, 05:53:51 pm
Nothing against the D+D exhaust sytems personally, but my C5 can hit 144 KPH /90MPH on the OEM stock torpedo. Take into account 10% error on the clocks, it is still 80MPH. I can easly cruise 70MPH all day long. I cannot comment on how much quicker D+D would hit those speeds though :)
I would be interested in more real world data.


Ducati Scotty

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Reply #20 on: August 23, 2012, 06:38:15 pm
+1.  I can hit 85mph on the clock on my dead stock C5, 70 is a piece of cake.  That said, I love the look of reverse cone mufflers so this still gets my interest.

Scott


Hobbydad

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Reply #21 on: August 23, 2012, 07:19:56 pm
I agree on the C5 top speeds, I think 85 on a stocker isn't a problem. It may be maxed out but it can do it. Bradey hit it on the head though, it may change how quickly you can get to the 85. Reguardless I agree with Scotty, I like the look and am still interested, especially in the blacked out unit. If I can put that slip-on on my pipe from Hitchcock's I'll seriously consider it. The first day I rode after taping my pipe the efi muffler from Hitchcocks started turning colors.
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Ducati Scotty

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Reply #22 on: August 23, 2012, 07:29:36 pm
My EMGO reverse cone is turning yellow in spots.  At first I thought it was just because I didn't clean off my grubby paw prints before I ran the bike but now I can see that the yellow spots are aligned with the internal baffles.  I think any muffler that runs gases next to the outer shell is going to turn color.  These bikes just run lean and spit hot gasses.  This is why I'm thinking of ceramic coating whatever system I end up with black.

Scott


SimonT

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Reply #23 on: August 23, 2012, 11:53:22 pm
Hey mate... Guessing you are in the US.

Would shipping to Australia be prohibitively expensive?


72westie

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Reply #24 on: August 31, 2012, 04:11:32 pm
Sorry for the delay. They do use the stock O2 sensor and EFI systems.

 :D
2001 Royal Enfield Bullet 500 Race Bike:
2008 Ahrma Classic 60's #1 Plate
2009 AMA Vintage 50's #1 Plate
2010 AMA Vintage 50's #1 Plate
http://www.bgmotorcycle.com


boggy

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Reply #25 on: August 31, 2012, 05:29:24 pm
80MPH. I can easly cruise 70MPH all day long.

Why am I still messing around with this slow-jam AVL engine?  I coulda sworn I was doing at least 70 on the highway but my chase-car informed me I was only kissing a low 60.

Exhausts looks cool Westie.  That's an impressive gain.  Bet they sound fantastic.
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ace.cafe

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Reply #26 on: August 31, 2012, 05:50:53 pm
Sorry for the delay. They do use the stock O2 sensor and EFI systems.

 :D

Cool!
Thanks. That's what I was hoping for.
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72westie

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Reply #27 on: August 31, 2012, 06:33:04 pm
I will go double check today, but I think the rev-limiter kicks in at 5K on a stock 2010 C5 and its only pulling 77 MPH on a dyno with no wind resistance at that RPM. Unless you have a big C/S sprocket, I think you speedometer is very optimistic.  ;)

If you were to by-pass the rev limiter, it still has some speed left I think.
2001 Royal Enfield Bullet 500 Race Bike:
2008 Ahrma Classic 60's #1 Plate
2009 AMA Vintage 50's #1 Plate
2010 AMA Vintage 50's #1 Plate
http://www.bgmotorcycle.com


barenekd

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Reply #28 on: August 31, 2012, 07:36:37 pm
Quote
I will go double check today, but I think the rev-limiter kicks in at 5K on a stock 2010 C5 and its only pulling 77 MPH on a dyno

My G5 rev limiter kicks in at 5900 on a dyno, about 92 MPH with a 17T sprocket. My bike will quit at about 84 in the real world though, not by rev limiter, more like horsepower limiter.
A C5 at 5000 RPM should still be doing about 82. What tires do you have?
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« Last Edit: August 31, 2012, 07:40:21 pm by barenekd »
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Ducati Scotty

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Reply #29 on: August 31, 2012, 07:39:31 pm
It can't kick in at 77.  My speedo reads 85mph when topped out in fifth gear, I'm not hitting the rev limiter and my speedo can't be that optimistic.

Scott