No Muffler = Really Bad?

[LI03SI]

HI I got my car last week from the body shop and I got the JDM BC3 kit on it so the stock exhaust wouldnt fit through the rear bumper. This was wednesday night (Thanksgiving Eve) so I couldnt bring it directly to a muffler shop to get it done. So in the mean time I drove it somewhat (maybe 50-100 miles) with no muffler on it. I also dont have a resonator since I have a 2.25 inch midpipe

So to get to the point. IS this really bad for my car? B/C on Friday night at about 7 o clock after driving all day after I had put a muffler on it at about 7 am - MY OIL pressure light came on just as I was pulling up to work. So I got out and let the car sit for a second and checked the oil and It Had none. So I got in the car to drive it home and I backed up, then when I went to put it in first gear, just as I hit neutral the Tach dropped wayyy low to 200 rpms and then went up to like 5-600 and idled there, so i pulled the car back into the parking space and called my friend and had him bring me fully synthetic oil. I dumped a quart in and then drove her home and she ran fine for the 2 mile drive. Then when I got home I changed her oil immediately with castrol fully synthetic 5w-30.

Now this is when I found out that the body shop had changed my oil, so I am wondering if there could be 2 Possibilities here.

1- Is that I burnt a valve or something b/c I didnt have the proper back pressure running it with no exhaust?

2- I have been running fully synthetic mobil 1 since 5000 miles on my car and now it has 18000, COULD the possibility that he changed it back to regular oil have fucked up my motor? B/c I have Heard that once you go synthetic you cant go back

[oogy-boogy]

Hmmm....Sounds like the shop that did the oil change forgot to put the plug in until after they poured the oil in. I don't see how there's any way the lack of oil was affected by the lack of exhaust. Probably just mechanic error.

I would definitely reset your ECU...

-Pull out the positive terminal
-click over the ignition to the accessory switch until all power is gone
-Let the car sit for 10 min
-Reconnect and allow it to idle for 15-20 minutes with nothing else on (AC/radio, heater, etc).

Take her for a ride and see how it runs...;)

[silver]

having no muffler will only cause your car to be loud. your motor doesn't require back pressure...period no matter what anybody tells you. as for the oil problem, i'd go with the plug idea, it may not have been tightened, did you notice any oil spots on the ground when you were parked. as for the funky idle, sounds like nothing, you probably just had the clutch near the friction point which caused your idle to drop.

[LI03SI]

What about switching from synthetic to regular oil? I have heard the the seals tend to swell up or something to that effect when you put the regular oil in it.

[ahhhonda]

After you put a quart of oil in, did you check to see what level showed up on the dipstick? In other words, do you have any idea how low you were on oil? Were you checking your oil level regularly, and how often were you getting your oil changed? Just wondering..

As for the exhaust, I agree with the others, it's not going to be related..

Switching from regular to synthetic and back shouldn't have created any major problems like that either. They both lubricate, it's just that synthetic is better at it.

[downhil]

Originally posted by silver
your motor doesn't require back pressure...period no matter what anybody tells you.

our engine may or may not, yes (i dont know); but some, like a turbo rotary do require some.

[FreakSoft]

Did it sound good. I think I want to do this to my car on purpose to get a deeper sound without the ugly tin can. I could never place a huge coffee can on my car and still be able to stomach driving it.

[LI03SI]

It only took about 3 seconds for the oil to drain out, and then it just trickled... it coulnt have been more than a quart or 2 left.

I hated the sound of it with no muffler... sooooo loud all the time, no quiet at all. I put a flowmaster dual exhaust muffler on it.. ones that split for like camaros and shit and then got 2 3" stainless steel tips and had them welded onto the pipe.. it looks really good and i love the sound of it with my CAI when i get on it.

[KickerSi]

Having the muffler off will only lead to less restriction of the exhaust. And Freaksoft. it does sound good with it off and you can feel a little bit more power.




...your motor doesn't require back pressure...period no matter what anybody tells you.

Sure buddy, take of the midpipe and see if your car doesn't need backpressure. Or better yet, take of the exahust manifold and burn some valves. Who ever told you that was wrong!

[ConeCrazy02]

Take off the muffler, burnt off the plastic cover for your lower rear control arm. Heat it long enough and apply enough force to the lower rear control arm and it just might break off.

[silver]

Originally posted by KickerSi
Sure buddy, take of the midpipe and see if your car doesn't need backpressure. Or better yet, take of the exahust manifold and burn some valves. Who ever told you that was wrong!

the midpipe doesn't create back pressure, it affects the velocity of the exhaust. the exhaust manifold is just a log manifold whose whole point is to conserve heat to quickly light off a catalytic converter and save space. the aftermarket header that you buy makes power by using resonance tuning to create a low pressure wave pulse during the overlap period, nothing to do with backpressure for power gains. the only real way to drop your back pressure is through the changing of mufflers.

there is always going to be natural backpressure through the exhaust system all the way from the exhaust stroke, we do not need to add any more back pressure than there already is. and according to your idea, all race cars should be burning valves since they are running on next to nothing in terms of back pressure.:confused:

[rs_1101]

the diffrence is racecars have short, big exhaust setups. when you have 6 foot pipe, some interesting resonance nodes build up, and can travel up the headers, and yes you could burn valves, or worse, suck them. fortunatly our car should be able to ecu its way into compensation for this. i dont think its too big a worry, but it can happen. at least youve got your cat in there to muffle alittle.

[silver]

Originally posted by rs_1101
the diffrence is racecars have short, big exhaust setups. when you have 6 foot pipe, some interesting resonance nodes build up, and can travel up the headers, and yes you could burn valves, or worse, suck them. fortunatly our car should be able to ecu its way into compensation for this. i dont think its too big a worry, but it can happen. at least youve got your cat in there to muffle alittle.

he was talking about taking off pretty much the entire exhaust piping from the manifold back, making it much shorter than 6ft. maybe i was too vague with my statement. no additional backpressure is needed. this is really pointless to argue about, just open up a physics book and look at a motor and form your own opinion. i have never burned a valve nor had one burn on a motor that i have worked on, many of these motors dialed in at about 1.5psi of backpressure.

where in oc are you from(off topic)?

[rs_1101]

from costa mesa. if your going on saturday ur welcome to roll with us!!

but yea, most of my friends are musclecar guys, and that can be a problem with older motors that i know of is the danger of a resonance node wandering up the header and sucking a valve. its like a once in a blue moon thing, or maybe it just happens to larger displacement motors.

*edit* my bad i didnt see that you were in florida.. wrong orange county.. theres one in cali too!

[silver]

i'd love to go but i'm in florida now:) i used to live in fullerton up until earlier this year.

yeah i have heard that regarding some chevy motors, but those had carbs on them so it i would assume there would be a difference. i can't say that i've ever done anything other than an oil change on an american car, but i've built 100's of japanese motors and cars.