pbn85

iTrader: (8)

I dont know if I should post it here or in the 5th gen section. Either way Im sure the mods will move it if necessary.

So I had my hotshots installed yesterday. I bought them used but they only had 1k miles on them. Install was good except for the fact my mechanic needed to relocate a few bungs. Fitment was good otherwise. Upon start up the car sounded good. So I left the shop and heard this really loud noise coming from underneath the car. more like a fluttering noise. So I drove back and let him drive it. No leaks btw. He heard the noise and we found out it got really pronounced driving uphill. While driving he noticed another noise...pinging. he didn't worry too much about this b/c he said the comp. is not used to the new mixture and it will take some time to adjust. he told me not to worry about it.

We got the car back on the lift and checked everything. He shook the flex section and it made some noise. Maybe thats what the bees in a can noise was. But from what I remember that was only common on warpspeed and budget ypipes. I did not expect it to be with HS headers. Anyway, the noise has to be coming from the flex b/c we checked everything else. My car has no more cats, not even the main one. So thats ruled out as well. I dont know if I should exhaust wrap the flex or buy a lined one from cattman and weld that in place. Here is why Im posting: Cattman flex sections are 2.5inches and 10inches long including 1 inch end caps on both sides. Can hotshot headers handle this? I know the regular flex section on HS is no where near 10 inches long...

Also..the car drives like crap. I got my vafc today and Im hoping a tune will get the car to run better. Its actually feels a bit slower, sluggish off the line. My mpg has not gone down though...btw Im going to get a street tune with a wideband 02..not a dyno tune

Overall the car is really loud...too loud for my taste. I will remove the test pipe and if its still loud then I will take out the cattman bpipe as well. Heres a clip of the how the car sounds.


[IMG][/IMG]

NmexMAX

iTrader: (22)

Cut and pasted twice ,

Anyhow, give us the basics. Do you have any SES lights? If so, what are the codes? Where/why did he add new bungs?

pbn85

iTrader: (8)

no codes thank god...he welded in bungs for rear o2 sensors

Im just curious about using a 10 inch flex piece on the ypipe of the HS. I never read about HS flex's going bad...

MOHFpro90

iTrader: (11)

Are you running O2 sims or something since you have no cats? Just curious.

Sorry I cant help with the flex Q, but I would say its fine. Not sure though.

NmexMAX

iTrader: (22)

It's not a matter of the HS headers being able to 'handle' a larger flex section. All that will do is add a little more flex to the engine during load. Nothing adverse, IIRC my CM flex section is about that length (makes sense since it is Cattman) I don't see a reason for any problems to arise using a longer flex section.

Explain this flex section noise a little better, or post a clip from outside teh car. What kind of noise did it make when the mechanic 'moved it around' ?

pbn85

iTrader: (8)

the bends on both ypipes are different...thats why I asked if a Cattman flex section would fit.

I will try to post a sound clip today...but Im thinking of getting exhaust wrap to wrap around the flex section only. Any adverse consequences by wrapping the flex section? I know the noise will not completely go away but it will be subsided

NmexMAX

iTrader: (22)

There have been mixed reviews/opinions of wrapping a flex section. Some say the noise goes away with it, some say it damages the section even further due to excessive heat build-up. I have never wrapped any of mine, but if it were an option, I wouldn't do it.

Also, why 'bandage' the problem instead of looking further into it and finding out where exactly and why the noise is coming from.

It's almost like when you thought your pre-cats went out. You always asked why, but never went and found out on your own.

pbn85

iTrader: (8)

edit: nevermind..I just off of the phone with a Summit Racing tech and he advised against using exhaust wrap b/c it gets hard over time which would defeat the purpose of a flex section.

Guess I will just get one from Cattman

nismology

iTrader: (8)

Moved.

pbn85

iTrader: (8)

thanks

So yes even Brian Catts agreed with me in his email. He said there is a chance his flex section may not work on my HS b/c the bends of the pipe are so different than the cattman. Guess I will go to a custom exhaust shope (meineke?) and get one of their lined flex sections.

Im getting the car tuned on saturday...contemplating between a street tune w/ a wideband o2 or a dyno tune. Both have its advantages...except I really want some before and after numbers so a dyno it will be.

As for the noise...it only comes on with firm acceleration, not if I gently accelerate. Even more reason to believe it could be the flex? The only reason Im making speculations about it being the flex is b/c the car was already on the lift and my mechanic shook it...made an abnormal noise and I cant describe it. There were no leaks and everything was bolted up air tight with a special sealer. The fact that that very morning when I brought the car in and it sounded normal also leads me to believe its the flex section. When Im driving the noise can be described as "fluttering"...not sure if that helps. I cant even take a sound clip b/c my phone does not pick up the noise from inside the car and when I have the phone outside the car all you can hear is the wind.

What also leads to believe its the flex is that when revving at idle it makes no noise. This is probably b/c air is not traveling through it as it would when driving.

Dave B

Get rid of the test pipe ASAP. Those things cause all sorts of nasty noises and there aren't any real gains.

Child_uv_KoRn

iTrader: (7)

I like the deep growl gains

NmexMAX

iTrader: (22)

I hated the rasp.

maxspeed96CT

iTrader: (9)

Im not sure what noise your talking about. The headers just make the ar run louder, as far as ping and it just seemed noisier to me too after the install

Your flex maybe used for more than 1k like the guy said and is just shot ?


As far loudness, I went from test pipe to cat and wasn't happy, felt a loss in performane and response , and the cat made it sound more like a 4cyl , now I have the test pipe agian , when I drive slow and keep the rpms low its pritty good, at WOT is suprises and scares anyone around the car .

slickrick

iTrader: (12)

you sure its not the b pipe rattling against any heat shields?

n3985

iTrader: (36)

+1 or the cross member?

pbn85

iTrader: (8)

positive...car was fine that same morning. Plus, my mechanic took off ALL heatshields so we could isolate the problem to the flex.

Also...when the car is "cold" the flex does not make any noise. When its warmed up a bit and the exhaust gases start flowing thats when the noise comes. I guess the metal expands when warm. I really wanna know if anyone with hotshots has the flex problem...are HS flex's lined?

maxspeed96CT

iTrader: (9)

doe it sound almost like the valves or just cheap piping? dunno but i dont think its the flex

pbn85

iTrader: (8)

no way cant be the valves..I have a brand new engine

Brian said the cause is turbulence originating in the 2-1 collector and a lined flex will fix it. My engine is in great condition so its def. not that. And like I said, prior to the headers the car was sound.