Rep Power: 0

i was driving yesturday at 6.5 psi with a tuned e-manage( not for my civic tho.. this is from a type R boosted)...
anyways i was driving around.. car runs fine, no more skipping while booting it or anything... anyways... I gunned it ona straight away... in 1st gear and in the middle of 5-6 rpm... I ehar a LOUD BANG!!!! from under the car... i thought the girl beside me slid her seat back and it hit the back or something... literally the "whole" car shook... I was like wtf.... the noise came from under so i thought that it could only be backfire... doesnt happen that often only when I gun it... now.. my question is...
Is this normal? what should I be concerned about???

FYI: I did not put one of those flame throwwer thingies... just a 2.15 straight back exhaust... let me know what ur hypothesis' are.. thanks

 
Rep Power: 342

a normal back fire should not violently shake the car like you described.

You might wanna make sure you didn't blow anything. Does the car still perform the same?

 
Rep Power: 297

i got a friend that drives a srt-4 that does the same thing when racing.... the only reason his does that cause his car runs and tuned to be rich when boost kicks in... so when he lets off the gas theres still excess gas in the system which in turn detonates the excess fuel in the downpipe.. when hes racing u can see under the car the area it detonates.. it does that around the connection link right after the downpipe which is held together with a screw and spring... i guess thats what the spring is good for besides helping with the vibration and stuff

 
Rep Power: 350

Sounds like it's rich and you could probably stand to use some ignition tuning.

 
Rep Power: 0

thanks every1 for help.. yah i need to get my e-manage tuned..