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[HUBBARD]

Boy oh boy......[highlight]this could get ugly if the "Led Sled" [/highlight][highlight]chits the bed and gets smoked on her own home turf.[/highlight]

[DCFIREMANN]

 158hp WOW

[DCFIREMANN]

Stopped by Zippers to see what was going on with Punkin. Not much she was sitting over in the corner next to a rocket Dyna they have been working on. I did ride her with the new cams installed. Very impressed with the throttle response. I do have a dyno sheet with the new cams installed. I tried to scan it last night but I am missing part of the program for my new 4 in one1 printer. The numbers were (if I remember correctly) 98.6 H/P and 110.9 TQ. The Tq curve had a hudge dip in it but jumped up quickly. This is an inherent problem with the Thunder Header. There is a fix for it but they did not bother with it. Also the numbers are SAE CORRECTED!!!!!!!!

Be Safe

THE DAWG

[RATKING]

Hello DAWG,

   I always enjoy your posts.  I am curious about your comment regarding "the big torgue dip" that is common with the Thunderheader, and the "fix" for it.  I was under the impression that generally the 2 into 1 pipes produced the best overall performance on the V-Twin (especially low end torgue), and that the Thunderheader was the best of these 2 into 1 exhaust systems.  I know that the Thunderheader is using 1-3/4 primary piping which is the same size as standard EVO an TC stock exhaust.  Generally speaking, smaller diameter primary with longer length, would mean great low-end torgue.  Couple that with the Thunderheader collector system and anti-reversion characteristics, I am surprised that there is a low-end torgue problem.  I know that some of the other pipes with the large diameter and/or stepped primary primaries are looking for peak horsepower and torgue readings.  These pipes do not really help you with power in your normal 2-4000 RPM driving range.  

   The Thunderheader only comes in one pipe size (1-3/4) and was introduced when 80 ci EVO motors were the latest technology.  It was my understanding at that time that the Thunderheader was a true performance pipe and that there was infact a torgue dip in the lower RPM range.  But I wonder if that holds true with the Screaming Eagle motors that are almost 30% larger in displacement (103 ci).  With 80 ci the Thunderheader is a high-end pipe; with 103 cubes and the higher throughput of the CVO motors, the Thunderheader is actually more of a low-end pipe.  

   I have always read Harley V-Twin exhaust dyno comparisons with great interest, as the differences in performance between different styles and makes were dramatic.  Is there a consensus as to whose 2 into 1 pipe is the better performer for 103 displacement motors in the 2-5000 RPM range?  For a cam, I will be going with the RedShift 575 grind, perfect for my RPM range.  I have not seen any dyno comparisons in the magazines lately; are there any good magazine articles out there?  By the way, what is the "fix" you are referring to?

   Just for reference, I have a 2005 SE Fat Boy that I put a Thunderheader on and tuned with a SERT.  The performance improvement was dramatic.  The same amount of throttle and time that used to get you to 2800-3000 RPM now blasts you to 4000 RPM.  It is really running beautiful, and you cannot beat the Thunderheader sound.  Really appreciate the feedback.  Thanks  
      

[DCFIREMANN]

RATKING thanks for the reply.

The Thunder Header has always had the low rpm TQ dip( around 2000 rpm) even with the Evo motor. It is a quick dip and pulls up quickly. I am at the firehouse today and can't give you the numbers where the dip occured. It was fast and TQ droped about 5 ft lbs if I remember correctly. It also pulled up to 98 ft lbs at 3000 rpm on my bike.

The fix for the TQ dip is very easy. The V Girlie got to see the fix and wondered what is was for and she actually understood the fix. You drill a 3/8 hole on the bottom of the pipe near the rear but in front of the cone insert a 3/8 bolt with a nut inside and out so you can lock it when you are done. You then redyno and screw the bolt in the pipe till the dip goes away. I don't know how it works but it does.

Be Safe

THE DAWG

[Street Stalker]

Well here it finally is...

[AUSSIE_FLSTFSE]

Well here it finally is...

[Street Stalker]

Aussie Mike,

Do you know if your first run with higher numbers was a corrected (SAE) or non-corrected (STD) dyno run?  Your second run numbers after the cam swap may be corrected instead and that could be why your numbers appear to have gone backwards... [smiley=nixweiss.gif]

My guess is that might be it as you said it does feel stronger than before

[AUSSIE_FLSTFSE]

Aussie Mike,

Do you know if your first run with higher numbers was a corrected (SAE) or non-corrected (STD) dyno run?

[tunedse2]

Aussie Mike,

Do you know if your first run with higher numbers was a corrected (SAE) or non-corrected (STD) dyno run?

[AUSSIE_FLSTFSE]

Here is the sheet

[AUSSIE_FLSTFSE]

For those with poor eyesight

[Twolanerider]

Here's a brief ride report on the new cams after covering some miles.  Have returned now from a trip that put 3500 miles on the motor; mostly highway.  Trip was supposed to be a bit more miles but this was enough to really get a handle for what the bike "felt" like after the cams' installation.  

So far as cruising long hours on the highway is concerned it's a great combination.  Tons of pull right where you want it and when you want it.  It's a much much better combination in the mountains than it was previously.  Not downshifting nearly so often.  For Interstate miles the engine feels perfectly at home at 75 in 6th.  It's even very happy at 70 in 6th.  It would not have been before.  

So, without worrying about numbers of any kind; but simply speaking to how it feels as a cruiser now, I am very very pleased.  It's just a very nice feeling combination that cruises down the road in a manner like it should have coming from the factory (but didn't).  The bike is much more of a pleasure to ride now and actually even a bit less "work" to ride as well.  Even more glad I did it now after the trip than I was when I first got on it after the work was completed.

[JR]

Excellent report Buddy! [smiley=xyxthumbs.gif] Glad to see ya posting again, was getting a little worried about ya. [smiley=cherry.gif]

                                                                  JR [smiley=banana.gif]

[Twolanerider]

Excellent report Buddy! [smiley=xyxthumbs.gif] Glad to see ya posting again, was getting a little worried about ya. [smiley=cherry.gif]

                                                                  JR [smiley=banana.gif]

Thank you JR.  Appreciate it  [smiley=drink.gif] .  Bike is even all cleaned up from the trip finally and ready to eat bugs again.  How you liking the feel of the yellow bike since getting the work done?