Gen II exhaust on gen I, am I imagining more power ?

Dehning

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I've owned my 2003 for about 18 months now, I went through various slip-ons before I settled on some Microns. I've got a K&N air filter, PAIR system is removed and a PC3-USB running a generic aftermarket air-filter + slip-on map. Bike ran pretty good, felt proportionately right compared to my Blackbird & VFR800. I also replaced the complete 2003 head with one from a 2006 to fix an oil leak recently.

I laid it down a couple of months back and got some new Chinese fairings which looked and fit great but one the Microns got a few good scrapes so I needed something else. I stumbled on a set of brand new Yoshi's on craigslist for a great price which were simply labeled as "for Suzuki". I called the seller and he said something about GSXRs and when I told him this would be going on a Gen I he believed it would fit perfect. I picked them up and took them home and to my disappointment discovered that they didn't fit. When I looked up the model number I saw that they were for the Gen II. I considered hacking them up to make them fit but decided rather to try my luck finding and fitting a Gen 2 header system. I found one for $30 on ebay and got it all hooked up a few weekends ago. Everything fit fine except the mounting lug behind the sump doesn't match and the belly wing will have to be trimmed a bit to make it fit. It definitely sounded and looked different but I really didn't have much time to play with it. About a week ago, I removed the Yoshi street baffles because it was a little too quiet.

After that long preamble, here's the part that's got me scratching my head; the bike seems to have significantly more power low down in the rev range, and I'm talking about enough that it feels like a different bike. It pulls hard from very low revs too, open the throttle wide at 1500 RPM and it pulls unbelivably well - certainly WAY better then the Microns and Gen I header. I have not removed the CAT in the Gen II header and the only downside I have found so far is that the Yoshi's are cooking my feet.

So is there any good reason that Gen II headers with Gen II Yoshi slip-ons would make significantly more power than the old stuff?
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High res pics here.
 
So is there any good reason that Gen II headers with Gen II Yoshi slip-ons would make significantly more power than the old stuff?

no
 
Dnt know my man- I'm trying to install a Yosh R77 on my 05 bike now. I've got a full Yosh TRS system. Hopefully I can use part of the full system to make the R77 fit. Its been done, I love the look of the R77 on the Gen I.
 
Strife, you have FIOS? If so, what package? I just ran the speed test and we seem pretty close :)

I believe I have the 25/25 business class fios package.

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Also,isn't there issues with the mufflers lining up with the rear pegs? You didn't show any pics of that location.
 
No CAT on a Gen I.
Not getting as much technical info as I had hoped from this thread.
I'm going to assume that the Gen II header's must flow slightly better than the Gen Is (otherwise Suzuki wouldn't have changed them) and that the Yoshi's just provide better low down torque than the Microns do.
 
No CAT on a Gen I.
Not getting as much technical info as I had hoped from this thread.
I'm going to assume that the Gen II header's must flow slightly better than the Gen Is (otherwise Suzuki wouldn't have changed them) and that the Yoshi's just provide better low down torque than the Microns do.

Suzuki changed the header to flow better with the gen2 engine, but obviously because they had to add the catalytic converter.
I gutted the converter on my gen2 because it was cooking my feet. It is restrictive and the bike runs smoother at high rpm and is sluggish low in the rpm. It's noticeable it takes a second for the empty chamber to pressurize and then the engine suddenly picks up.
The difference in the 2 gens headers is subtle at a glance when compared, aside from the converter.
My personal experience has been that a muffler(s) can make a noticeable difference. Even when comparing 2 that look very similiar.
For example, a friend of mine has an 05 gsxr 1000 and he put a Yoshimura slipon on it. It looked and sounded good, no real noticeable performance gain. He later put a Two Brothers slipon on it, and it killed the low end power, and there was no denying it(both with stock tune). He put the Yoshi back on and the low end power returned.
To compare the 2 mufflers they were very similiar in length and inside diameter, so it was strange to feel such a noticeable difference. I'm not knocking the Two Brothers either, as both pipes are quality and would have dyno tuned well.
We all know that a good dyno tune corrects lean/rich spots and adds/subtracts timing where needed to make a bike perform it's best. Swapping exhausts around on a stock tune is a gamble, some are just going to run better at certain or all rpms than others.
I think you just have an exhaust combo that your bike likes.:beerchug:
 
So the Gen2 bolts up the same excepts on the hanger and the belly wing has to be modified?
 
So the Gen2 bolts up the same excepts on the hanger and the belly wing has to be modified?

Exactly correct, you also need a short bolt to plug the O2 sensor hole (I found one Home Depot and cut it short) and I ended up trimming back the fairing by the Cat.
 
My question is this- I have a FULL YOSH TRS SS SYSTEM- can I just use the headers to fit a Gen II YOSH R77?

I'm not sure I follow... Do you have a full system for a Gen II ? If so then yes, it should bolt right up to a Gen I with the exception of the lower tab and assuming the pipes follow the same course as the OEM pipes. The hangers will sit in a slightly different position on the mufflers too.
 
Strife, you have FIOS? If so, what package? I just ran the speed test and we seem pretty close :)

I believe I have the 25/25 business class fios package.

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My plan is 15/5 that I am paying for but that has been the speed I've been getting for over a year now.
 
Maybe the increased back pressure from the cat giving you more grunt down low?

I've read that 'back pressure' is a misnomer and that a good exhaust system has more to do with keeping the momentum of the air leaving the engine intact as well as timing the reflected shock waves re-entering the combustion chamber from the exhaust side. Whatever it is, it seems to be working well :thumbsup:
 
I'm not sure I follow... Do you have a full system for a Gen II ? If so then yes, it should bolt right up to a Gen I with the exception of the lower tab and assuming the pipes follow the same course as the OEM pipes. The hangers will sit in a slightly different position on the mufflers too.

No- I have a barely used GEN 1 Full TRS Yoshimura System. Was hoping i could use the headers off that exhaust and piece together the rest with the GEN II pipe and mid-pipe. I really don't want to sell this exhaust if I dnt have to & buy a Gen II and it won't fit. You think it would work? You're the man so I'm asking for your help:thumbsup:

If anything- hopefully it sells on ebay here soon and then I'll start from scratch. Thanks for the help ahead of time

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