I think its loose gears and anyone tried no mufflers?

[87whitevert]

My question comes from my setup and whether or not it is worth to change. I currently have 4.10 gears in my '99 cobra and have no mufflers on the vehicle. This sounds amazing but I have to say that I believe I am loosing some torque . I also feel a small thump most of the time when I put the transmission into gear and when I let off the clutch. Now I have replaced the transmission about 5 months ago and am pretty sure it is not the U-joints so I believe the issue is with the rear end and something being loose but I don't know them that well.

Question one is if the rear end is loose would it be from the gears being worn so buying a new set of 4.10's would fix it? or would it be in the rear end and I have to rebuild it? How much should these costs installed/fixed?

Question two is by replacing the straight pipes with mufflers, say just 40 series Flowmasters, will I greatly feel an increase in torque? Has anyone else tried this setup, having no mufflers, and decided to go with mufflers?

 

[chrisbudl1]

if you are sure that the sound is coming from your rearend, it could be the crush washer or something like that. I just had my gears installed 2 weeks ago, and we reused all the stock spacers. Luckily we got it right the first time. it sounds like something isn't mateing up right, but don't take my word on it, I am new to all of this stuff. Unfortunately if it is in the rear end, you have a mess coming. Good luck

 

[chrisbudl1]

I would imagine that you would feel a little difference if you put mufflers back on. does it smoke a little when you rev it? my friends 03 gt did until he got mufflers put back on it. depending on which muffler you use, you should be able to get the same kind of sound you have now only a little cleaner.

 

[87whitevert]

muffler

yea it does sometimes smoke when it has not been started for a while and I dont think its blue smoke (oil). I think I would feel a bit increase in torque after putting the mufflers on but I am still not sure.

 

[doogz]

Man, i'm surprised you like the sound!

FWIW: http://www.andersonfordmotorsport.com/media/rumble.htm

A dyno shootout of popular mufflers. This was done on a 347, but an interesting read.

 

[CobraFangs]

Have you ever heard of something called "back pressure"? That refers to the amount of pressure and torque being generated when the car accelerates. Too much back pressure or too little is a bad thing. Playing with the exhaust can effect this quite a bit. Before I got my 03 Cobra...I had just 98 V6 Mustang. It had 4 Cats on it, which was robbing me of some hp, so I was going to remove 2 of the Cats, but before I did I check a few things out and talked to the ones who do my mod work for me, and they explained that, that exhaust was made to work with those 4 Cats, and that taking to off could cause a problem with the back pressure. I never did take them off. Same is true with the mufflers, you may be causing something to not just run the way it should without them on.

 

[6000FTSVT]

you are losing torque. I had an 02 GT with magnaflows took it off when I traded the car in and straight piped it lost TONS of torque. when the exhaust exits the engine and hits the cats it loses velosity and then just trickles out the remaining 7 ft of pipe. when you have a properly functioning exhaust it should create a vaccum in the pipe. so when the exhaust valves open it creates a siphon effect and the gas going out the tubes PULLS the exhaust out of the cylinders. therefore making more room for fresh air. the normal name for this process is scavenging. want good sound and power o/r pipe and good catback. nuf said