You are right and in that Topic bellow , i find some contradictory informations compared with the ones in the one i was referring to above , so there might be some mistakes somewhere it seems !
i found another topic here , named 93-95 vs 96-97 exhaust :
https://cbrforum.com/forum/cbr-900rr...xhaust-125764/

In that topic I found yesterday , a guy says that unlike what was said in the other topic about 93-95 and 96-97 exhaust compatibility ,
about the 3 bolts pattern changing between 94-95 and 96-99 , AAKK'?À'´´´that the 3 bolts patterns is the same from 93 to 97 and that it would just be the exhaust hanger which is'placed differently !
That said'i am a bit lost between all these contradictory informations , cause as you say , i bought an Akrapovic full exhaust Racing system and it was specified to be compatible with any bike between 93 to 99 , so i don't see how the exhaust hanger would be different on the 96-99 compared to the 94-95 , unless the wakrapovic Full exhaust Racing system does not use it , so it is not a problem for it if there is a difference !
and about the 3 bolts pattern , the guy says they are the same from 94 to 99 as he put a 96 muffler on a 94 header / collector .!

I 'd like to find some definitive answers about those bolt patterns cause some say it's rotated 20° from 96 to 99:compared to 94-95 , whereas others say it is exactly the same !

My Akrapovic Full exhaust Racing system for my CBR900RR doesn' t have any mid pipe as you can see bellow on the picture .

The reason why i might want to replace hat Akrapovic Ful Racing system on my bike is because since it was insralled, replacing the stock header / collector ( not sure if it was totaly stock ) and the Mig dual output muffler that was installed previously , i hear the engine sound totaly differently, muxh louder and witha different sound when above 3000 to 4000 rpm and it really bothers and disturbs me !
I took back my bike to my usual workshop,where they do all the maitenance on my bikes but they didn't find any problme on it except they did not really hezr the sound i talk about or only in static as they are in the center of Paris'where there is'luch traffic jal and in very small streets , so they can't really try the bike past the second gear and not really over 4000rpms .
Withe the previous Exhaust system i did not have the weird noud sound coling frol the engine !

 

Ok I see the Akra mimics the OEM exhaust, that said you should be able to fit and aftermarket can onto the Akra combination header / mid pipe as long as the diameters were the same, but even then you can get sleeves that adjust the diameter. I am sure a Yoshi would fit on that as it has the spring hooks.
It would then be trial and error with a header (and mid pipe) / can combination that you would be happy with.... an expensive way to go.

If you were happy with the original set up then I would suggest fitting that back on.

 

I was not particularly happy with the previous'one but at least î did NOT have that loud weird engine sound that came along with the installation of the Akrapovic full'exhaust system !
i suppose there must be something in the header / collector that makes the engine sound like that !

 

I meant " i did NOT have that engine sound before installing the Akrapovic full exhaust system " ( i had forgot the NOT in the post above but i just corrected it ).

Sincerly this engine sound is a Mystery to me and i don't understand why i have it now since the Akrapovic has been installed , whereas i was expecting to be really happy with that Akrapovic full exhaust system, so i want to understand what's going on !

Unfortunately , there is no Yoshimura available for sale new , for those years of CBR900RR !
I already have a hard time trying to find a yoshimura or Akrapovic full exhaust system second hand for my GSX-R 750 k8 as it seems they rarely appear for sale second hand in good condition ( for any of my bikes except maybe sometimes for the ZRX1200) !

 

If you are looking to carry on experimenting you could try the Delkevick exhausts
https://delkevic.co.uk/s/Honda/CBR90...EBLADE%20/1995
Not in the same league as the Akra, but do get good reviews and have new build systems available.

It could of course be something as simple as the old exhaust set up was overly loud and masking the engine sound that was there all along

 

It could have been but unfortunately i don't think it was ! Lol
i am sound ingeneer and as many sound ingeneer who have listened to music in studio for many years , many have gone a bit deaf or have the ears very sensitive what is called to have an hyper accousia and that is what i have , so i am quite sensitive to sound level/ pressure and i would have felt if it was the case .
For example , i could not ride my GSX-R 750 K8 with the SC project GPM2 which was installed on it when i bought it , when it did not have the db killer on the muffler, so much it was loud !
i had to put it on .
And when i bought the CBR, i did not felt the exhaust / muffler was that loud , it was not .

 

"Sounds" like it's time for a different bike.

 

No, i like this bike , so i hope i will understand what's going on and find a solution .
At worst , i will change the exhaust but the Akrapovic full exhaust was not cheap to buy new, so if i could find the reason why i have this sound and find a solution to get rid of that problem without changing that full exhaust , i would be happy !
I was so impatient and eager to install that full exhaust to get the good Akrapovic sound and extra performances , that obviously i was disappointed and surprised of the result !
Apart from that , i love this bike and i also spent some money to have it serviced as it should and have all the maintenance done that the previous owners did not do for many years it seems ( apart from the most basic things ) , so i would like to really enjoy it as , she and i deserve !

Unfortunately , it's winter , so not the best time of the year to ride ( it's been raining nearly all the time in Paris for weeks !) and also, i just had a flood in my basement which damaged the gas boiler , so i haven't had any hot water nor heater for 2 weeks now ( and no water at all for a few days ) , whereas the gas boiler has been replaced barely a year ago , because of a much bigger flood , where all my floor ( ground level ) was drawn in water up to 40 to 50 cm and the streets as well , just because of 3 or 4 hours of rain , what had not happened in such quantity during the last 30 years !
So i have to deal with those problems first despite the fact i also have some problems with the company which installed that gas boiler .....
I hate winter for riding a bike even if i do ride in winter , knowing i don't have a car anyway .

 

Thanks for your answer !
Yes , i heard about the Delkevic exhaust , they are not as famous as the yoshimura or Akrapovic but they might sound good and some seem to have a good look !

I just sent them a message ro have some infos about them , so i will see what they answer me !

There is Also Black Widow which makes a header/ collector/ tail pipe with a lot of mufflers that can be used with it and on which you can remove the 3 bolts part to install others silencers than theirs or the ones compatible wit the OEM one But I could not find their sound level yet .
I don't really know the quality of this brand and the sound they have ( nor which is better between Delkevic and Black Widow) but when i see they seem very light due to the fact the metal thickness is quite thin , i am a bit afraid they might be too light to have some good low end ( as the weight of the exhaust has some consequences on the sound ).

 

Had a little chuckle (laugh) about which one is better due to the current UK / French strained relationship.
Yes they are definitely second tier when compared to Akra, probably not far off Yoshi if price is a guide.

Delkevic are UK made and come with a 5 year warranty and do have a very good reputation, Black widow on the other hand are Chinese made and only come with a one year warranty (I think). The chrome quality seems to be more variable with the Chinese products.
So for me the UK made one would be better, but that of course that is a personal choice

I sent Delkevic a query a while back asking why they have changed the design of their header pipes for the F4i as they has removed the small link pipes between #1&2 and #3&4 down pipes. To which they answered that on their testing they did not notice any difference between the designs and sent dyno pictures of the comparison. So they do seem pretty clued up with what they are doing.

****this is not a Delkevic Sales Pitch, just my personal observations********