Air box mod and gutted cat? yes no?

markmcc21

markmcc21

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Hi all, iv booked my bike in to get my ASI blocked, ASV shorties, K & N and Mivv suono fitted on tue. my question is whilst its in should i do the airbox mod and/or drill out the cat? iv read varied opinions but i need to know if it is worth getting it done (as its a permanant mod) as in whats the gains? more power? smoother delivery etc? Will it result in a fail during MOT here in UK? just a simple yes or no from the guys who have experienced pros/cons will be appreciated.

p.s Iv booked it in for a dyno run tomorrow to see power before and ill do it again once things are fitted also will chat about poss PC3 with custom map but thats about £240 and then £100 for a custom map so might leave buying one for a while till i save up!

Thanks for any advice guys
 
I can tell you that the airbox mod and Cat gut are worthwhile simply because of increased flow. I have done all the mods and I have noticed considerable low and midrange improvement. I am using Graves velocity stacks, And reflashed my ECU as well. The throttle response is like it should have been to begin with for my 06. I don't have any dyno runs to confirm this, I'll leave that to those who care about it.
 
is the ECU flash the same as remapping a cars ECU? so in principle its a different and cheaper way of making the most out of the aftermarket kit compared to what a PC3 can do? sorry not really clued up on the ECU flash :(

cheers for the advice mate.
 
markmcc21 said:
is the ECU flash the same as remapping a cars ECU? so in principle its a different and cheaper way of making the most out of the aftermarket kit compared to what a PC3 can do? sorry not really clued up on the ECU flash :(

cheers for the advice mate.
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The reflash is exactly that, I had mine done at a place that specializes in cars.
You give them a list of mods, And they load a file that has those parameters since they are common mods they are pretty spot on. I am very pleased with mine. For about the same money you can get a one time fix. You can eliminate the Exup servo and O2 sensor without getting check engine lights, Eliminate rev limits whatever you want pretty much.
 
markmcc21 said:
Hi all, iv booked my bike in to get my ASI blocked, ASV shorties, K & N and Mivv suono fitted on tue. my question is whilst its in should i do the airbox mod and/or drill out the cat? iv read varied opinions but i need to know if it is worth getting it done (as its a permanant mod) as in whats the gains? more power? smoother delivery etc? Will it result in a fail during MOT here in UK? just a simple yes or no from the guys who have experienced pros/cons will be appreciated.

p.s Iv booked it in for a dyno run tomorrow to see power before and ill do it again once things are fitted also will chat about poss PC3 with custom map but thats about £240 and then £100 for a custom map so might leave buying one for a while till i save up!

Thanks for any advice guys
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Gut the cat: YES,,, but it may not pass gas analyzer testing, I'm not familiar with MOT.
Airbox mod: YES,,, Should have no effect on MOT or any other government testing, it'll just give a boost in power with slightly more intake noise.

At some point, when you get a PCIII or V, remove the flies and/or get an FCE. This will give a nice bump in midrange ummphh!

BTW: The airbox mod is cheap to reverse. A new airbox bottom is about $25 here i the states. The cat gut is a different story.

Looking forward to your before and after dyno results. See if you can get a printout of the Air/Fuel too.
 
I don't get why people say you can't do the flies w/o a pc3 or 5. I've gutted, cut the airbox, blocked the ais and cut my flies down and haven't flashed or put in a pc3/5.

would it benefit me, sure, but does it hurt not to have it, no. My bike runs much better than stock w/ no side effects that I can feel.
 
X2. Yes you can, without the PC. Would it be even better? Yes. But is modding the airbox, cutting the flies, and blocking the AIS and adding an exhaust more awesome then stock? Hell yes. I've been running mine like that for years and it's great.


Sent from my iPhone using Tapatalk
 
Octupi said:
I don't get why people say you can't do the flies w/o a pc3 or 5. I've gutted, cut the airbox, blocked the ais and cut my flies down and haven't flashed or put in a pc3/5.

would it benefit me, sure, but does it hurt not to have it, no. My bike runs much better than stock w/ no side effects that I can feel.
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I guess I can't speak from experience, I got my PCIII before I did the flies and FCE. But looking at some of the few A/F charts that people have posted, and hearing all of the complaints of a bog and poor performance after messing with the flies and without a PC, I decided to get the PC before any mods to the flies, or adding the FCE.

However, I did run slip-on, cat gut, airbox mod and High flow filter without a PCIII and had no issues what so ever. The bike ran better then stock and sounded much better then stock.
 
cheers fellas, il post on here tomorrow what bhp im producing after the dyno and then some pics with the stuff fitted and hopefully results of 2nd dyno. im going to run the bike for a short while and see if i need the pc3/reflash. as for the airbox mod and cat gut, im going to get them done as most seem to sway towards then against.

Phil_RC_1 just been reading some of your comments about flies and fce, would you suggest standard or modified flies with an ivans fce or just totally removing the flies and no need for the fce? if totally removing them fixes the glitch then thats a super cheap mod, fce are around £170 :( cheers
 
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markmcc21 said:
cheers fellas, il post on here tomorrow what bhp im producing after the dyno and then some pics with the stuff fitted and hopefully results of 2nd dyno. im going to run the bike for a short while and see if i need the pc3/reflash. as for the airbox mod and cat gut, im going to get them done as most seem to sway towards then against.

Phil_RC_1 just been reading some of your comments about flies and fce, would you suggest standard or modified flies with an ivans fce or just totally removing the flies and no need for the fce? if totally removing them fixes the glitch then thats a super cheap mod, fce are around £170 :( cheers
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You can read a wealth of posts about this subject here on the forum. But my opinion, the FCE is designed to work with cut flies, that would be the tried and true route, and that's what I have. I have no experience running no-flies, however, many here have no flies and swear by it, but no flies won't get rid of the jerky fuel-cut, only the FCE is proven to fix that issue consistently. If you read the ECU reflash threads, a lot of people say that the reflash did not get rid of the fuel-cut issues.
 
ill look into buying a FCE and the modified flys then. once they arrive and fitted ill get the PC3 fitted with a custom map. think ill do 3 dynos, 1 before, 1after the airbox mod, filter, gut cat and slip on and the 3rd after the cut flies, PC3 and custom map. should see some interesting results!! cheers for your advice.
 
I did the airbox mod and flies and slip on all at one time, but I appreciated the mods much more after I got a pcv. Mu bike runs way better because of it and it was worth every cent
 
cheers, what made you go for no flies? i take it for your bike no flies was better then cut flies? iv got an 06 bike would you say the best option for me is a FCE and cut flies? tbh i dont really feel this snatch but iv never ridden the way to try feel it. iv only covered 400 miles on it so far. thanks
 
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