Exhaust won't stop popping / banging..

  1. Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.
    #1
    It's usually people asking how to get their car to pop and bang, But this time it's the other way around.

    Obviously I didn't mind a few pops on gear changes / down rev.. But since I changed my MAP sensor to a brand new one, the pops are just simply annoying.

    When slowing down / down rev - when It hit's 1750rpm it constantly pops and bangs until 1500rpm..

    I know it's only 250rpm.. but at cruise speeds it seems i spend most of my time around 1750rpm.

    If i'm cruising @ 30-35mph in 5th the rev's are at 1500-1750.. Therefore if I let my foot of the throttle to engine brake upto junctions or to match other drivers speed it pops n bangs everytime.

    Engine braking down a hill - constant pops and bangs.. I thought it might clear itself out after a 50+ pops.. but nope, pops all the time.

    So finding myself either coasting or changing gear to stop it..

    Was slowing down for a roundabout last night, doing 25mph with it banging like mad.. and a police car stopped at the other side of the road and turned around to pull me.

    4-2-1 to race center to 3 inch backbox

    Would putting a CAT back on stop these pops? Or is it just something i'll have to put up with?

    (would like to add the car is running 10x better with the map sensor + no EML - But all these pops can't be good for my valve seats etc?)

    Any ideas / input would be great
  2. Regular Poster Joined: Oct 2012 Leeds, West Yorkshire Posts: 389
    #2
    hi mate
    Did you try it with the CAT back on?
  3. Established Member Joined: Mar 2012 Posts: 1411
    #3
    Quote:
    Originally Posted by ady_saxo View Post
    hi mate
    Did you try it with the CAT back on?
    lol .. . ..
  4. Saxperience Post Whore Joined: Apr 2011 Posts: 9100 Amazon green VTR 16v, Inferno RS clio 182
    #4
    Yes the cat will help. However I had to alter my FPR to get it to stop, but not the 3.5 is back in it pops and bangs like mad even with a cat in
  5. Established Member Joined: Jun 2011 Bridgnorth (Shropshire) Posts: 2001 Jdm Dc2 Integra
    #5
    Don't you run with no lambda sensors whatsoever? That might be why
  6. Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.
    #6
    Quote:
    Originally Posted by Gandi699 View Post
    Yes the cat will help. However I had to alter my FPR to get it to stop, but not the 3.5 is back in it pops and bangs like mad even with a cat in
    Ah right! I am running my 16v on 3.5bar FPR - but read on here that the ECU can alter +/- 20% fueling for idle etc, and 3.5bar with std 16v injectors is enough flow for 135-140bhp.

    I thought on the overrun aka downrev that no fuel is sprayed ? So shouldn't matter on fuel pressure?

    Sums it up - even with a CAT on it's going to pop and bang! I need a daily driver.. This isn't very road friendly any more haha.

    Jones - I wasn't running any lambda's, but I have both lambda's plugged in and working now - the car run's 100% just the annoying constant pops on the down rev.
  7. Saxperience Post Whore Joined: Apr 2011 Posts: 9100 Amazon green VTR 16v, Inferno RS clio 182
    #7
    try a cat, and silencer mid section with baffled backbox. I ran a 3 bar and it stopped the popping and banging but I'm gonna give it another go tonight and see what happens, see how the 3.5 performs
  8. Saxperience Hardcore! Joined: Mar 2008 Posts: 31279 Citroen Saxo VTS, S60 D5
    #8
    Mine pops and bangs quite loud with a cat in still. A silencer would probs kill the pop/bangs off imo. When i used to have my silencer in i dont think i ever heard it pop or bang.

    4-2-1>cat>2"s/s
    1 user thanked this post:
  9. Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.
    #9
    Ill be on the look out for a silenced centre section then!

    Cheers all for suggestions.
  10. Saxperience Hardcore! Joined: Nov 2005 Coventry Posts: 17782 Fiesta ST150
    #10
    standard system would sort it out lol, silencer and cat will help but it will still happen, just wont be loud
    1 user thanked this post:
  11. Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)
    #11
    I would say you are simply over fueling your car with the large FPR.
    Why do you need that? Whats your full engine spec.

    I would be checking for borewash as well.
  12. Saxperience Post Whore Joined: Apr 2011 Posts: 9100 Amazon green VTR 16v, Inferno RS clio 182
    #12
    VTS was 3.0 bar wasn't it? Same as the s2 rallye
  13. Established Member Joined: Jun 2011 Bridgnorth (Shropshire) Posts: 2001 Jdm Dc2 Integra
    #13
    ^^
    Yep vts runs 3.0 bar standard
    vtr runs 3.5 standard
  14. Saxperience Post Whore Joined: Apr 2011 Posts: 9100 Amazon green VTR 16v, Inferno RS clio 182
    #14
    Think ill swap mine back then tonight
  15. Established Member Joined: Dec 2008 Bournemouth/Ringwood Posts: 1259 Black Mk2 VTS
    #15
    Quote:
    Originally Posted by saxova View Post

    When slowing down / down rev - when It hit's 1750rpm it constantly pops and bangs until 1500rpm..

    I know it's only 250rpm.. but at cruise speeds it seems i spend most of my time around 1750rpm.

    If i'm cruising @ 30-35mph in 5th the rev's are at 1500-1750.. Therefore if I let my foot of the throttle to engine brake upto junctions or to match other drivers speed it pops n bangs everytime.

    Engine braking down a hill - constant pops and bangs.. I thought it might clear itself out after a 50+ pops.. but nope, pops all the time.

    So finding myself either coasting or changing gear to stop it..
    I have this exact situation. I have supersprint 421, supersprint straight through race centre and a kam racing backbox on my vts.

    Can anyone shed any more light into why this may happen? Im not too clued up about what people are saying about FPR and things like that.
    I love the sound of the exhaust system so don't really want to put a silencer or cat converter back on.

    I also do have my engine management light on due to a dodgy lamda sensor, Could this be the reason its pops at 1750 revs? Is the popping at 1750 revs causing any damage?

    Cheers
  16. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #16
    simply put, there's too much fuel in there.

    they will not damage your valve seats, they happen in the exhaust.

    if the lambda is buggered, that will cause it.


    damage caused depends on how long you ignore it, worst case is a worn out engine from too much fuel in the bores.
  17. Established Member Joined: Dec 2008 Bournemouth/Ringwood Posts: 1259 Black Mk2 VTS
    #17
    Quote:
    Originally Posted by welshpug View Post
    simply put, there's too much fuel in there.

    they will not damage your valve seats, they happen in the exhaust.

    if the lambda is buggered, that will cause it.


    damage caused depends on how long you ignore it, worst case is a worn out engine from too much fuel in the bores.
    thanks for the reply. will get a new lambda sorted soon!
  18. Established Member Joined: Jan 2009 killin,perthshire Posts: 1561 Audi a3 1.8sport,kawasaki zx9r c2,Yamaha R1 track
    #18
    Sorry to hijack

    Do most people who fit aftermarket cams and get a remap,keep the std 3bar fpr or do they fit a 3.5/4 bar fpr as well as the remap?

    I know some people fit uprated fpr when they don't bother with a remap,to stop the engine from running lean at higher rpm's.

    Cheers
  19. Saxperience Forum Bum Joined: Dec 2008 Lancs Posts: 4124 JP4S'd R.
    #19
    Have since put a 3 bar reg on / both lambdas are still working / Still no EML after all this time

    BUT it still pops. If it's not damaging anything, I'll put up with it

    WULL - people usually keep STD injectors if they're getting it mapped as the extra fuel needed at higher RPM will be mapped in

    People who aren't wanting a remap usually up the fuel pressure to compensate, obviously isn't ideal, but better than standard.