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02 F4i with Yoshimura RS3 slip on...

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by the joose, Nov 14, 2005.

  1. Hi there,
    I have a 2002 Honda f4i, and after reading every review on the internet, that told me the yoshimura was good for a couple of extra bolt on hp, and a great sound... I bought a carbon fibre rs3 on ebay.

    After installing it with a six pack and kicking it over, I had a grin bigger than texas... this thing sounded great. But I wasn't going anywhere except to the fridge and the lounge that night, with another beer and a remote control.

    The next day when i rode out of my driveway, my grin started to fade... f*%$ me this thing is loud!... I mean it sounds great, but have i just painted a target on my back?!? I decided I should be a little conservative on the throttle till i get out of suburbia at 6am on a Saturday morning.

    Then i found something that wasn't mentioned in any article or review i've read online... not only at low revs, from around 3-4000 rpm, (from memory) does my once puring cbr seem to choke spit and splutter... but where the hell did this flat spot come from!!! wind the throttle on gently and it doesn't want to know about it, but open it up enough and it launches.

    I got on the M4 to see what happens in a straight line, and my grin started to return. But the pros didn't outweigh the cons.

    I called my local honda dealer, and asked if they could remap the stock computer to suit the new exhaust, and the short story is that they couldn't. I'm still unsure if 'THEY' couldn't do it, as in the staff didn't have the knowledge how... or if it simply cannot be done.

    They did suggest an aftermarket computer, but that was going to cost me another $700 or so... Now the stock pipe is back on, and my hondas alot happier... and alot quieter. And the yoshi exhaust is wrapped in a blanket in the garage.

    I dropped into a yamaha dealer the other day, and asked if they had any thoughts on the flat spot so that i might try and put the yoshi pipe back on, and they suggested a k&n filter to solve the problem. I smiled and said thanks and walked away, thinking that all i need was a $140 air filter that made my bike run lean, therefore hot and with a flatspot and cranky low rev range.

    Now that you know my 'entire' story... do any of you have any ideas or experience with f4i's, yoshi rs3's, remapping existing computers, or aftermarket computers, aftermarket air filtersm and whether the end result is worth the effort in the first place...

    thanks. the joose.

  2. Power commander is what you need.

    You can add a K&N filter to allow it to breath more but if you want optimum performance you will need to build a custom map for it. PC's are great, you just plug it into your laptop and you can see it working "live".

    I had a PC on the SP1 and uploaded a series of maps till I found a good one that I was happy with. Most dyno shops can build you a map but will charge big dollars for teh privelage. Worth every cent imo.

    Some of our partners offer you a member discount too ;)
  3. What he said. You've got a finely tuned piece of engine there, and you can't change something as major as how the air gets OUT of the engine without also changing how it gets IN.
    Without labouring the point, your local dealer would probably have told you this before you did your dough on eBay.....
  4. I think the bigger problem lies in the fact that the exhaust manufacturer insists you wont need to remap it. Thats what they all claim for the slipons ive seen...
  5. thanks...

    thanks guys, the cheapest I've found the pcIII-usb online so far is $550... anyone know where i might find one cheaper? I think i read somewhere last night that the power commander can optimise performance up to around 15% to 20% compared to the stock ems which is quite often only set up around 70% of optimum... is this true? can anyone actually confirm this... is it just another sales pitch? worth the cash? Or is the opinion that i should leave well enough alone...
  6. i have an 01 cbr with the same can and i had a k&n and powercommander fitted and tuned by Phill Tainton racing.

    it makes a hell of a difference, not only in performance but also in fuel economy (i got an extra 70kms a tank out of it)

    it cost about $900 all up but it was worth every penny (thats for filter, power commander, fiting and dyno tuning)

    and you think your can is loud, try cutting 100mm off it to make a stubby, now that is loud
  7. I have a 04 ZX6R with the same exhaust, and yes, its damned loud...

    Never thought of getting a computer, I was thinking of taking it to someone for additional baffle... But then again... I ride bikes well, but I know stuff all about how they work...
  8. Well they didn't actually lie.... You can use it without a remap... It may run like crap, but it will still work. :LOL:

    Yoshi's are one of those pipes that will not run anywhere near as good as it can without a remap, it can actually make the bike run worse.

    An aftermarket exhaust on a fuel injected bike will nearly always benefit from an aftermarket air filter and a remap at the same time. Can cost as much as the pipe itself.

    I have a carby in my bike, and I didn't want to spend all the money at the shop to get it rejetted. I did it myself for a fraction of the cost, and learnt a lot about the bike at the same time.

    It's easier with a fuel injected bike, get a powercomander and download a new map from their web site. Your setup sounds like a fairly common one, and I would be surprised if they didn't have a map on their site.
  9. a power commander it will be... now let's just wait and see how good these puppies really are...
  10. You definitely need an aftermatrket computer, such as the Power Commander. It will allow you to tune the engine for more power. Definitely do some good research on who is going to tune it. An engine is only as good as its tuner. ;)
  11. fwiw, my slip on yoshi rs3 and powercommander on my 02 f4i is something to smile about. the fluff is replaced by a snap, and i unexpectably caught myself napping winding it on further up the dial, more than once... my next question will be about brakes...
  12. Nice glad to hear you sorted it out