unrestricted exhaust effect?

[Goldie_7]

quick question due to some argument......
my engine was mapped after a rebuild, gt35r, bla, bla. i believe WITH my exhaust bung in, which fairly restricts exhaust flow. and since its been back on the road this year, i\'ve been running it WITHOUT the bung. when on the track, especially when coming out of a corner at full throttle in 2nd, the car would splutter and spit losing power until i let off the throttle a bit and then pull fine. (is this a bit of detting). it would also hesitate from around 6k upwards. so i\'ve now changed my 02 sensor (which had a dodgy connection, don\'t think it was down to that though) and put the bung back in, and it pulls perfectly (a lot smoother).

My question beeeeing....do you think this will have caused damage?! Some say yes, some say no.....just not sure if it\'s been detting?

[michaeljohnrx7]

Hi, sorry to reply in this thread but not sure how often you check old posts, but is there any chance you can send me your mobile number to my email address  (michaeljmckenna69@yahoo.co.uk) so I can organise meeting you this  coming monday when Im heading up to aberdeen for my offshore survival  course,  for the rx7 fd parts I had contacted you about previously?

[m1tch]

What mods does the car have? I know that on Prof\'s FC it ran higher boost with the bung out vs with the bung in with the same boost settings, the spluttering you might have experianced is fuel cut due to the boost level? Or indeed ignition breakup, depends on what ignition booster you are using on your setup.

[wolfie1]

if you had it mapped with the bung in will it not be boost cut due to the system having more flow?

[BlitzBoy]

cant believe the tuner mapped the car with the bung in! big fail imo.
without the bung your map is now running dangerously lean, u lucky it has not gone pop.
Get the thing remapped asap

[Prof]

Agree with Blitz 100% - bunged exhausts should be mapped without the bung in so you know there is enough fuel when the inevitable higher boost hits.
 
I know that I get a similar stuttering effect sometimes - caused by deliberate overfuelling for the upper cells in the map, but the problem is the same effect could be caused by det / too lean / ignition breakup - and unless you can monitor the engine when this happens you won\'t have a clue which it is.