SuzukiSavage.com - Print Page

SuzukiSavage.com
/cgi-bin/YaBB.pl
General Category >> Rubber Side Down! >> Will a Larger Header Pipe Reduce Low RPM Torque?
/cgi-bin/YaBB.pl?num=1628520704

Message started by d3adrock on 08/09/21 at 07:51:44

Title: Will a Larger Header Pipe Reduce Low RPM Torque?
Post by d3adrock on 08/09/21 at 07:51:44

I'm thinking about getting a custom header pipe built for my Savage that would follow Lancers recommendations of 1.65 ID pipe (1.75" OD).

My bike has a stage 3 cam, 10.5 piston, mikuni VM carb, and a delkevic muffler (which I wish was a but quieter)

My main concern is that the shop I'm working with said it would destroy my low RPM torque, which is exactly my favorite kind of torque!

So, does anyone know if that is true or is it baloney?

Thanks for any advice!

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by Gary_in_NJ on 08/09/21 at 09:21:32

That is true in theory. I think DragBikeMike has actually done some testing if you look at his performance threads.

Have you done any porting to the head? You'll get more bang for the buck with that effort. If the exhaust port hasn't been derestricted, then header pipe diameter wont matter anyway.

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by d3adrock on 08/09/21 at 09:23:40

supposedly the shop did. Although I'd have to take it apart to look. if they didn't I would port it myself anyways.

Would you happen to know where dragbikemike did that comparison? I looked for a bit but couldn't find it.

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by Fast 650 on 08/09/21 at 11:07:19

Look in his evolution of a hotrod thread. He tested a larger 2 inch MAC pipe with a 1.79 inch ID against the stock pipe. Low rpm torque loss even with that huge pipe was so small that it isn't really noticeable . These engines respond well to port work along with a bigger pipe and less restrictive muffler.

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by d3adrock on 08/09/21 at 11:33:42

I must be the worst forum searcher ever, because I looked there and I still couldn't find it.

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by Ruttly on 08/09/21 at 11:56:16

You have already changed the dynamics of your engine by changing cam , piston , carb & muffler. Now it needs the larger header. It will have a different powerband and torque curve. Don’t worry you will like it !

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by d3adrock on 08/09/21 at 11:59:10

I guess I just have to find someone to bend one for me, which is easier said than done.

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by DragBikeMike on 08/09/21 at 15:17:50

D3, you will find that the stock header works amazingly good for as small as it is, but a larger header works great too. There really isn't any appreciable impact on low speed performance with the BIG header (nothing you will feel with your butt dyno). The bigger headers have a significant impact on top end performance.

I did tests comparing the stock header (1.3" ID) to a Mac header (1.79" ID). Those tests were extensive, comparing the effect of the header when installed on a stock head, ported head, hotter cam, larger carb. In every instance, the two headers performed very close to each other. You can find all the specifics in Parts 3, 4, 5 & 7 of the Evolution of a HotRod series. I have included the links below.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1623048749

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1625732492

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1626391255

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1627891507

Please tell us more about your setup. That 10.5:1 piston, is it the new Wiseco flat-top piston. Did you experience any problems with installation regarding valve-to-piston interference? Do you like how it runs?

Title: Re: Will a Larger Header Pipe Reduce Low RPM Torqu
Post by d3adrock on 08/09/21 at 16:11:49

Holy cow, a response from the man himself. I'm honored. Thanks for those links. I will definitely do a deep read of those.

Yes, I installed the flat top 10.5 wiseco in 95mm for a grand total of 666cc (I'm tickled silly by that and I will never stop telling people)

I actually did end up with my valves slamming into my piston. Cost me a pretty penny to fix.

Pretty sure it was the mechanics fault for the initial install, but I've already paid so whatchagonnado?