My wanna be 750 rat bike bobber

[Stormstyles]

Ok so I have been doing some work on it here lately got the exhaust done. And Yes it is very low I know. but here it is some pics for you...

[drhach]

I'd kill for a roomy, heated shop. Some day. Nice work on the header.

[Big T]

Nice work, but it'll probably run like crap. There's a reason the head pipes on a 4-1 run all the way back under the bike.

That being said, I'm kinda brain dead tonite.

I think you need longer pipes to get any torque. May be Ray or someone will correct me.

[makenzie71]

Exhaust construction is a lot more than pipe length...he'll have all kinds of issues with that one for all kinds of reasons...but I don't think performance is the number one concern with this machine.

Do keep in mind that you HAVE to have a certain number of degrees of clearance just to move a bike, right Stormy? If this is meant to be looked at before anything else, then it's on an awesome road, but if you intend to ride it in the real world please do keep the geometry acceptable...not just for your safety, but ours as well.

[rapidray]

With the pipes that SHORT before they merge, it will have POOR torque. Also, the lengths are VERY unequal adding to the bad. I suggest you get a 4 into 1 from someone to at least measure the primary lengths to get an idea where to start. Also, the way the pipes all merge together has a HUGE effect on scavenging, or in your current pipe, the LACK of. I highly recommend you look at other systems, WITH a tape measure in hand & try again. I do commend you on your effort & desire but just recommend you do a little more homework. Ray.

[Stormstyles]

Exhaust construction is a lot more than pipe length...he'll have all kinds of issues with that one for all kinds of reasons...but I don't think performance is the number one concern with this machine.

Do keep in mind that you HAVE to have a certain number of degrees of clearance just to move a bike, right Stormy? If this is meant to be looked at before anything else, then it's on an awesome road, but if you intend to ride it in the real world please do keep the geometry acceptable...not just for your safety, but ours as well.

Yes this is just a look at bike. Not looking for the performance side. Now I am really low on this bike and dont think it will corner for sh** lol. Really dont want to corner it. This bike was given to me to build for myself and do some reaserch on. I build custom cars professionally and YES I do know that the header does need equal lengths. Built a ton of them for our cars.
But I would like to know or maybe have some help form you all on being able to build a correct header for this and one other. I will be building another one after this one soon prolly for next season.

Most of my clients like radical stuff so thats why its setup that way. I appologize to all the hard core GS guys if I have offended anyone. But this is my interpretation of what a metric bobber will look like.

Plus the price was so right...

[drhach]

I think there is a big difference between building something that will compete and something that you're just going to ride to the bar. I think RapidRay is correct from the standpoint of someone who builds race bikes. In that world, .01 seconds matter and building an engine that doesn't capture that potential is a really bad idea. I think it is fair to say that your bike will not run to its full potential using that exhaust. It also won't handle to its full potential using that frame. You've also made it clear that you're looking for a hot rod.
If you want to build an exhaust like the ones that are commonly used, you probably could copy existing design. However, I thing that your bike will run "good enough" the way it is.

[Stormstyles]

I think there is a big difference between building something that will compete and something that you're just going to ride to the bar. I think RapidRay is correct from the standpoint of someone who builds race bikes. In that world, .01 seconds matter and building an engine that doesn't capture that potential is a really bad idea. I think it is fair to say that your bike will not run to its full potential using that exhaust. It also won't handle to its full potential using that frame. You've also made it clear that you're looking for a hot rod.
If you want to build an exhaust like the ones that are commonly used, you probably could copy existing design. However, I thing that your bike will run "good enough" the way it is.

I totally agree with you. Thank you for your comment. You hit it on the head. I might in the end change the exhaust and some others but the real essence of the bike is a bobber style, but with that said it might accually might be better built with something other than rat style

[Rake]

I totally agree with you. Thank you for your comment. You hit it on the head. I might in the end change the exhaust and some others but the real essence of the bike is a bobber style, but with that said it might accually might be better built with something other than rat style

I like where you are going with this, at least for the stated purpose. That said Rat's are grown not built. For good rat bike ideas check out http://ratbike.org/

[drhach]

I totally agree with you. Thank you for your comment. You hit it on the head. I might in the end change the exhaust and some others but the real essence of the bike is a bobber style, but with that said it might accually might be better built with something other than rat style

Reciprocating IC engines respond well to tuning. They also tolerate a lot of slop. Think about the old Model T's. Far from the latest and the greatest in tuning, yet they ran just fine. They smoked, polluted and chugged and sputtered, but they went down the road and many people drove the crap out of them.

It used to irritate me, but I had a fluid dynamics teacher who used to say that the IC engine was developed by "tinkerers" while turbine engines were developed by "engineers". Man that used to make me mad.

[Mark Harrop]

I think it looks good bro...

If you are not expecting it to run with the 'busas, I think it will get down the road OK with those shorty pipes. Post a video after you fire it up, and crack the throttle a couple of times!

[Stormstyles]

I will do it for you guys. Now the exhaust is done I can send the engine out for build. Using a 750 bottom end and an 850 top end. Hope it works.

[Big T]

I will do it for you guys. Now the exhaust is done I can send the engine out for build. Using a 750 bottom end and an 850 top end. Hope it works.

That should be a bolt on - if you search the site, someone posted up how they did it. It gives you a nice torquey engine that should offset some of your tuning issues.