Exhaust Tuning?

[MisterCinders]

Shopping for some random bits on Amazon, and I noticed this item:

http://www.amazon.com/Vance-Hines-Exhaust-System-Tuning/dp/B007GMQY0K/ref=sr_1_15?s=automotive&ie=UTF8&qid=1335450614&sr=1-15

It's a set of inserts for the exhaust system that supposedly adjust your exhaust flow for tuning. Sounds like another option to augment jetting issues with a V-H pipe.

With pods and a 4-1, I continue to fiddle with my jetting and floats, etc. In my case, I am pretty close, but have trended towards rich even though my set up should have me fighting lean issues. Not sure that these inserts would be useful to me, but I'd never seen this kind of thing before.

Has anyone ever used one of these kits? Do they work or add anything to the jetting process?

[spyug]

Do they work or add anything to the jetting process?

More unnecessary complications I would think. Tuning exhaust is one of those real esoteric arts requiring some complicated equipment and a ton of experience. Not for the uninitiated and I don't think some inserts are going to be easy to figure out how to use to the best advantage.

I'd pass and just stick with what you are doing.

Good luck.
Spyug

[tkent02]

Some bikes (the last of the RD 400s, the new BMW inline four) use a throttle plate in the exhaust, it closes partially at low RPM to increase torque. On the BMW it is computer controlled, on the old RD it was operated by vacuum or something?. Both of these systems it opens wide for high RPM power.

You could get more grunt with this restrictor in place, but you would lose more on top for sure. If you didn't want the high RPM kick you wouldn't have a 4-1 pipe anyway, would you?

[AJ]

The big claim to fame for the Supertrapp disc system is you can add or remove discs to adjust back pressure. My old Sportster is quite sensitive (and I'm at 14 discs, I think).

I just replaced my 1100's monster 2.5 inch clear ID Kerker glasspack with a new 1.5 inch ID core that has greatly enhanced the bottom end torque (plus muffled sound, which was the primary purpose of the change).

If your system is pretty well tuned to your liking, that kit probably won't do you much good. I think you'd get the most benefit if you were already running a very large diameter exhaust and wanted to experiment. Doubt you'd see much effect if you're running a standard sized V&H pipe (that's what it looks like in your photo).

[MisterCinders]

Yeah, this doesn't look like something worth messing with. I am pretty sure the jetting situation will sort out in this next iteration.

The bike was already running pretty well with my previous jetting selection, but it had a lingering richness issue. I'll just keep fine tuning the carb jets.

Thanks for the background on this exhaust tuning stuff though.

[Billy Ricks]

Did you do a jet kit or are you struggling with the stock needles?

[MisterCinders]

Did you do a jet kit or are you struggling with the stock needles?

There is no jet kit for my bike. The stock needles are adjustable though. Right now I have the jets at

Pilot - 15
Fuel Screw - 1 turn out
Air Screw - 2 turns out
Mains - 122.5
Needle - 4th clip down (2d highest needle position)

Been wrestling with the float levels and some sticky floats, but I think that is sorted now. Need to change the oil and filter (gas mixed in when carbs flooded) before I can run the engine to test the new settings. Should have my new oil filter today to button up the bike tonight or tomorrow.

Fingers crossed.

[Billy Ricks]

There is no jet kit for my bike. The stock needles are adjustable though. Right now I have the jets at

Pilot - 15
Fuel Screw - 1 turn out
Air Screw - 2 turns out
Mains - 122.5
Needle - 4th clip down (2d highest needle position)

Been wrestling with the float levels and some sticky floats, but I think that is sorted now. Need to change the oil and filter (gas mixed in when carbs flooded) before I can run the engine to test the new settings. Should have my new oil filter today to button up the bike tonight or tomorrow.

Fingers crossed.

I should have realized you have VMs. For some reason I was thinking CVs. Float levels have a big effect on mixture.

[sparki]

that v&h tune thing is for their drag pipes to move the power afaik