I will vouch for a good 2-1 system, with the 475 cam the exhaust change is a major seat of the pants feel. I even went as far as adding 2 wing nuts in right at the merge of the headers and use them for tweeking that tq curve. I am not sure what the impact would be 117vs 120
Which 2-1 did you end up going with? I have a decatted stock header with the crossover completely removed with a smooth cap welded in place with a Khrome Werks 4.5" muffler, which I believe is the same as the MK45 right side muffler. I've played around with the db reducer baffle, adding some more holes to the blunt end of the baffle, & started off without it, it did bring up he low end TQ with the 475, it is very sensitive to the right exhaust & back pressure.
Which 2-1 did you end up going with? I have a decatted stock header with the crossover completely removed with a smooth cap welded in place with a Khrome Werks 4.5" muffler, which I believe is the same as the MK45 right side muffler. I've played around with the db reducer baffle, adding some more holes to the blunt end of the baffle, & started off without it, it did bring up he low end TQ with the 475, it is very sensitive to the right exhaust & back pressure.
sounds like you experienced the same as me, I ran the capped stock head pipe before but I made my own 2-1 using 2” primary’s and that is where I picked up the 9hp 7tq.. could some of that gain be from the added time on the dyno, yes it’s possible because it was re tuned when the head pipe was swapped. I used a 4” stainless tube with full sac baffles that I played with the holes.
Thanks for the replies so far. I’m thinking since I already have the bike coming apart, and I’m trying to be cost effective, I’m keeping the 117 kit. I’ll run this setup with the decatted stock pipe (May do a Dyno run with plugged crossover for kicks and comparison) for a year or two until I’m ready to do it all again. At that point, I may do 124”, throttle body, and a bigass 2-1 exhaust.
sounds like you experienced the same as me, I ran the capped stock head pipe before but I made my own 2-1 using 2” primary’s and that is where I picked up the 9hp 7tq.. could some of that gain be from the added time on the dyno, yes it’s possible because it was re tuned when the head pipe was swapped. I used a 4” stainless tube with full sac baffles that I played with the holes.
I'd love to see some pics of it, did you use the stock header as a pattern to get the bends right?
No the stock bends were copied first and then I tested the resistance with a volume/backpressure fixture we use at work. Out of the 3 headers this is what had the best flow from flange to merge. Built the first one you see in the picture out of steel and went straight to the dyno to see what we gained or lost. Each primary tube is 15” before they merge. I will try and find my stock header with the cap that put in so you can see that also.
Gentlemen, pro tip. Always thoroughly check your parts BEFORE you tear your bike down. I went through them when I first got them, but didn’t realize they sent me mis-matched cylinders. Now I can tack another week or two into this build time...
Last edited by Trainwreck43; 12-23-2018 at 09:53 PM.
Gentlemen, pro tip. Always thoroughly check your parts BEFORE you tear your bike down. I went through them when I first got them, but didn’t realize they sent me mis-matched cylinders. Now I can tack another week or two into this build time...
I’m very sorry to hear this and apologize greatly. We will take care of this straight away. Please send an email to travis@fuelmotousa.com with all of your information, we will overnight you the correct cylinder so you have it as soon as possible.
I’m very sorry to hear this and apologize greatly. We will take care of this straight away. Please send an email to travis@fuelmotousa.com with all of your information, we will overnight you the correct cylinder so you have it as soon as possible.
Mistakes can happen, it's how you take care of those mistakes that make you stand out from the rest. It seems that you can't ask for more than that !!!!
12-20-2018, 02:02 PM
