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MAC 4 into 2 Exhaust System

  • Thread starter Thread starter cberkeley
  • Start date Start date
C

cberkeley

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When I really got into my GS650GL project, I soon realized the need to replace those homemade and deteriorating exhausts (essentially straight through pipes with automobile resonators and turn-out tailpipes..... who knows where the backpressure is). I was always partial to Turn-Outs and Slash-Cuts over the standard Megaphone systems installed by the manufacturer. In my research I came across MAC who offered two choices for the GS650 series, these being four into one megaphone, and four into two turn-outs. Also, I noted there’s precious little information out there on these products.
I decided to go ahead and order the four into two turnouts Mfg. Part No. 003-0808, which I received today and opted to write some preliminary information which I hope may assist those trying to make similar decisions.
Searching the web I found that cyclepages.com had the cheapest price ($290.66) and they were very nice to work with and they were prompt in their response. The package consist of a large corrugated box of dimensions are 36”x16”x8” and contains the right and left headers (individually packaged in transparent plastic bags) and a smaller partitioned box 25”x9”x4.5” which contains the right and left turn-out style baffles and two clamps with attendant bolts, lock-washers and nuts (everything in individual clear plastic bags). All items nicely chromed except for the bolts, lock-washers and nuts which are typical nickel-plated steel (I will change these out to stainless). I was a bit disappointed to find some surface rust inside the pipes and baffles and have not decided what I should do about this situation.
New header flanges are supplied and are already installed on the header pipes. They are nothing more than chrome–plated steel stampings of a shape/footprint similar to that of the OEM product.
I was told by the vendor that re-jetting the carbs would not be necessary with this system as MAC engineered it such as to replicate the backpressure as obtained with the OEM exhaust.
The bike’s going to the shop next week for a top-end rebuild (awaiting the gasket set and rings) and to drill and re-tap two broken exhaust bolts in the head. Once I get that done, I will ride the bike for a few days with the present exhaust, then mount the new exhaust, compare and post my impressions along with some pics (sorry, no dyno, this will be all subjective):-D
 
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MAC system

MAC system

I'm thinking of going the same route, so keep the impressions coming -looking forward to it mon!

Did it allow you to keep the centrestand installed?
 
I'm thinking of going the same route, so keep the impressions coming -looking forward to it mon!

Did it allow you to keep the centrestand installed?

Although I have not installed it yet, from just offering it into position I foresee no problems with the centerstand.
 
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MAC says that it needs no modifications and will not be in the way of the centerstand, passenger pegs, etc.

Do any of you have sound clips of what these sound like? I'm really thinkin about getting some for my GS850.
 
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