jg 368 48

today my dad bought a new bmw x5 (the 4.8). i drove it today and it's really nice. there are some things on it that i wish my 99 rx300 awd had. however, they're mostly small things i dont really care about. one thing i really liked is the way the engine sounds when driven. it's got a pretty deep sound that i think is cool. it also accelerates much faster than my car (as expected for being bmw's biggest SUV). i know that there's probably no way to make my car go as fast as a new x5 4.8, but is there a way to make my engine sound like it? it's hard to explain i know it's a crazy question and ill probably be over it in a week or so, but at the moment im really curious. any suggestions?

jg 368 48

to make myself more clear...whats a good way to make my car have that nice, soft rumble that im talking about? muffler tips? i have no clue! any advice?

Lexmex

One of my neighbors has a 4.8 and it does fly. The torque is quite incredible. I have been urging him to come over to the track with it, but sadly no.

I also am very aware of the sound if makes, so I know what you are talking about.

A few things:

1) Easiest thing to do: Remove the air resonator (picture below is one from TunedRX300). You will find this piece on the driver's side below the headlight and behind the front bumper. There are a couple of screws you have to remove below to get it at it and then two more screws on clamps that you have to remove to get it out. Removing this device will give you a little more oomph and will result in a nice intake sound, especially, at 3,000 RPM+.

2) Direct flow muffler- it is not all just more power, but getting a direct flow muffler will also result in a nicer sound.

3) Tips- For power they do nothing and rarely can they do much for sound. However, if you can find a a tip with single entrance that turns into a u-shape with a double out, this can give a nice rumbling tone to complement the direct flow muffler. Only other thing that can be done is to turn the muffler tips downward (such as I have on my RX300), but this is so the sound is a tad quieter instead of waking up the neighborhood.

4) Resonator- That fat tub piece after the catalytic converter weighs a lot. Removing it will give a nice rumble, but will set off car alarms and cops. Now, I have an aftermarket resonator, but even with the one that I have, it still makes noise. Plus, playing around with removing and replacing the stock resonator is a hit/miss thing that costs $$$.

5) As far as playing around with catalytic converters and precats, unless they are damaged (like mine have been over the years given the bad gas down here), don't touch them. Even a high flow cat won't do much for sound given the stock resonator. I plan to get a wider Magnaflow cat in the future to accommodate the turbo, as the current one won't be sufficient with regard to emissions for that kind of setup. Though as I mentioned before, with my current one, I pass voluntarily the emissions down here without issue.

6) Bigger tubing- ah...now we are getting somewhere. If you take a look at my exhaust system below, making a y pipe after the resonator is a cost effective method of delivering more power and better sound. You can get a muffler that will take in two pipes and shoot it out one exit. Mine is a double/double. However, best suggestion is to get a wider pipe, 2.5 inches is sufficient from the resonator up to the muffler.

jg 368 48

alright thanks for the tips! how does the first thing (the thing to be removed from the below the driver side headlight) change the sound? my car will still b completely functional without it right?

Lexmex

This is another location of where it is and the bullhorn modification I later did in that location to throw in more air.

You will have no problems without it, but as far as changing the sound, is has a slight growl to it. I don't know how better to describe it. Not quite a roar though.

jg 368 48

ok...how much do u think a company would charge to take off that one thing? i dont know how to do anything. i dont even know how to change the windshield wiper fluid (had to take it to an automotive company).

Lexmex

It's not hard at all. All you have to do is remove a few screws on the plastic cover underneath and get at those two screws shown in the picture of the resonator.

jg 368 48

ok thanks...how much would the correct muffler tip cost? do u have to have it installed? how much would the direct flow exhaust cost (approximately (+ install))? thanks!

Lexmex

Well, it depends on the muffler. Some of those nice Rod Millen Mufflers (others can comment on it), cost several hundred dollars. However, something like a Magnaflow can can be had for under $200 USD. My first post-stock muffler was an APC Intimidator that down here cost a little over $200 USD, but up in the states would surely cost less.

The Rod Millen system was excellent since it required no welding, just removing some bolts a little bit behind the original muffler. However, any other will require someone who knows how to weld. I have no idea what the labor might run in the states, but down here, el cheapo is about $25 USD and the guys at Hangar 1 will charge $50 USD to non favored customers. However, labor prices are lower down here.

Tips generally runs under $100 USD, usually under $50 USD in the USA and usually require welding. However, some are the type where one just 'screw' them on and the pressure of the screw keeps them attached.

salimshah

By changing intake and exhaust, sound wise, you get something different from your start point, but that may or may not be better (or closer to desired).

As an example, I switched the exhaust on my GS to LTuned. In our family, the launch sound is very much liked ..... but at crusing speed there is a persistant drone in the cabin. So now our family is divided on the "how good it sounds" .

So if you are adventurous, go ahead, but my suggestion would be, sit in vehicle and see for yourself if that is the change you want. How things sound is all subjective. There is a difference between harsher and deep growl which depends upon intake and exhaust plumbing + damping of the cabin etc.

Just the sound of closing the door in BMW sounds very different as compared to Lexus.

Lexmex, if I am not mistaken is driven to extract every ounce of power and the change in the sound is a side-affect. Others may have a different objective, leading to a different compromise.

Salim.

Lexmex

Salim you are right.

The main area where I see sound can radically change for the worse is with the removal or modification of the resonator. It has to be done right or

jg 368 48

o ok. wow this leaves me with some choices to make! i think i'll probably do something with the muffler. seems to be the easiest thing to do to give me a different sound. now i need to figure out an effective thing for power! yesterday there were two cars that dominated mine. one was a nissan sedan (i think maxima) and the other was i think the smallest ford pickup truck. i was flooring it (going speeds i wish to not speak say ) and they went flying past me. i had the extra power button on and everything. still they went flying past me like nothing. what should i do for a drastic increase that wont cost a fortune!!

Lexmex

A Maxima will rip you whether the new or last generation. I can beat a last generation V6 Camry with ease (maybe that will give people a hint on a 1/4 mile time at sea level). Not sure what type of Ford truck you were racing. Some Ford trucks can give me issues, but it depends on which model.

Anything you can do with the exhaust will help. If you are willing to do a y pipe behind the resonator using a twin 2.25 inch piping like you see on page 3 of my cardomain page below with a direct flow resonator (you can use a 2 in and 1 out muffler), that is a big start.

For an intake, try the Weapon-R Secret Intake. Best thing yet that I have seen commerically produced. However, TunedRX300 developed a lower air intake system, which I modifed (I showed this in the earlier shot) and that will shove a good dose of air into your engine.

My idea to modification is a step by step approach so one learns what each part does.

jg 368 48

how does the Weapon-R Secret Intake work? i went to the site (about $200 or so), but i dont understand where it goes. is it hard to install? is it something that goes on the outside of my car or somewhere under the hood? thanks

jg 368 48

ooh yeah i forgot to comment on the truck. i'm not sure what it was. it didnt look like that nice of a car at all. maybe the smallest pickup or something...nothing u would expect to have a lot of power. i tried finding it online but i couldnt find anything that looked similar. it might not have been a ford, but i think it was. not sure, but it beat me bad :-(