Yes, the best with the baffles is the W118's and the best without the baffles is the W158's.

The most power is no baffles, with the W158's, but that might be a little louder than some like.

Being centered in the hole/evenly gapped vs. a little uneven shows no difference on the dyno, and our butt dyno's can tell the difference either.

The key functions that increase the power are:

1. The LEAST amount of resistance to the flow of exhaust coming out of the engine...resistance is like putting the brakes on the engine.

2. The least amount of energy pulse reverting and heading back up the pipe to run into the exhaust gasses.

The rounded part of the TTI pointed toward the engine, along with the sinusoidal wave shape of the TTI, reduces the resistance to the flow, and actually helps speed it up with a type of Venturi effect.

The cupped part of the TTI pointed toward the atmosphere catches the majority of the reverting energy pulse, preventing it from traveling up the pipe.

Back to the W158's with the baffles...even though you are getting part of the benefit, as you butt dyno told you, there is too much resistance to the flow of exhaust coming out. You will like the results of the W118 with the baffles even better.

 

Me again! I;m just putting the w118s in but it looks to me like the threaded bit isn't long enough? I assumed you position the round bit in the centre of the flow, but note you say it doesn't have be.

However, if I use a nut on the inside then I dont get enough thread sticking through for a nut to go right over on the outside? So do I leave the nut of the inside and just pull the round baffle up against the inside of the exhaust itself?

 

I would dispense with the washer and grind the tab on the baffle down until you can get a full nut on the outside. Just a thought.

 

I've wound the inner nu edown level with the top of teh baffle and managed it that way. By way of constructive crticism, anotehr half inch of thread would have allowed perfect positioning and lock up and an easier tidier job. But I do note DK say it doesn't affect it on the dyno.

 

Not for nothing,but I bought a set of the smaller ones(158's ?) for my Softail w/ V&H Longs.Thought they were too small,and put them in my wife's Shadow 750 instead.W/O telling her what they are supposed to do,she was blown away with the difference in throttle response,and transition from low to mid.Her words, not mine.Now that I've cut 4" off my longs, I wonder if they'd do the same?

 

hi , i received my W118 TTI , getting them put in on Wednesday , will let you know ...

 

118W ... sorry ...

 

Well i got some saddle time today. Rolled out of my drive and was pretty much stuck in heavy traffic from home to central London, but even then I could tell wha an improvement these are.

Some times at small throttle openings, say an 1/8th to a 1/4 turn when lane splitting, I found the bike had an almost flat spot or vagueness when feeding in small amounts of throttle. That seems to have gone now. I'll have a better impression of them when i ride out of heavy traffic but the bottom end improvement is undeniable.

 

Wow, I found the sweet spot for me! The 118s with the standard short shot baffles works very well and is a great balance between noise and power, or at least the one that suits me.

I always felt the short shots were just too loud for where I ride, so i tried the V&H quiet baffles. These do quieten it down a bit and the blocked end seems to have some of the effect TTIs do, as initially I felt i had slightly improved bottom end. But I also felt I'd lost some top end? I got used to it though and stuck it out for most of the summer.

But the real kicker was the QBs took away that unique Harley burble as you pull away, you know that inimitable sound that only Harleys have! It was still there of course but had lost its bite. After hearing a few other Harleys I knew I needed that sound back.

So the standard V&H baffles were fitted with w158s, but as I was told by DK this wouldn't be ideal as they work best with the baffle removed. So I got the 118s and now I couldn't be happier.

The pick up is much better and there is a noticeable boost in bottom end. Also being back to free flowing the bike feels quicker overall. So, yes, I am now a happy chappy!

 

Congrats on your install and improved performance.

Yes TTIs are not just a hype that some people claim on here. It works if properly fitted and an inexpensive mod. It does fill those flat spots in low-mid range torque.