Listen to this contraversy

I work at Auto Zone and I heard more crap (literally) about cars than I could even think up. I was talking to one of my fellow employees about how I may get a custom exhaust and a flowmaster muffler. Then everyone makes faces at me and says that flowmasters are only for domestics and I'm like what the hell, any part can be used on any car. Just like how the brand of spark plugs you use doesnt matter. They were trying to say that you cant use denso's in domestics because they wont work as well, and how boschs arent good for imports because the way theyre made. Mufflers are mufflers and spark plugs are spark plugs. The make and how theyre made and what theyre made of is what matters. I'm planning on getting Denso Iridiums in my civic and if not I'm getting Bosch Platinum +4's and theyre all like boschs wont work in your car. I'm sick of hearing all this crap. Plus most of the people I work with make fun of me because i bought a civic (theyre all rednecks). On sunday I sold 8 Denso Iridiums to a guy with a 96 Crown Victoria with a police engine at 12.99 a plug. He wanted the best and i gave him the best. Plugs are plugs, mufflers are mufflers. What works best works best no matter what kinda car.

just a heads up, platinum 4s suck dick. platinum isnt as good of a conductor as some, its just made to last a long time. plus, unless you have some MAJOR mods and i mean major as like 20+ psi, then just use NGK V-Power spark plugs. you will not notice any difference from the super expensive plugs besides about $15 more in your wallet.

I saw a big difference in plugs. Platinum 4's made my Prelude run like crap so I went back with NGK's.
I work at Advance and I disagree with you on the spark plugs issue. Muffler wise I don't know or care.

The reason those Bosch platinums make your car run like crap is because most of them are non-gap type plugs. They have multiple electrodes and the power of the spark is just random. With a stock NGK plug you gap it to a certain amount and the spark is consistent and will run nicely. Most hardcore drag racers still run stock plugs. Anyone who is a slightly good mechanic can change a set of plugs. I would never leave plugs in my car for 30,000 miles or whatever the platinums are supposed to go to. I change my plugs about once a year and keep them fairly fresh. Its like $4 for a new set so not a big deal.

I agree in that some parts are more for domestics and vise versa. Like when I see a domestic with something rice on it, it makes it a millon times worse. a mustang with an aluminum wing is just asking for it. But this is just me, do what you want with your car, after all, it is yours

yeah I ran Bosch Plat's for about 10 mins... the car ran like crap. NGK-R work well and I been using Zex Plugs in my B16 and that works real well I find.

bosche is good for Euro cars

dunno what your talking about bosch plat's work great for me. i dont think its much of a big deal they are just plugs. not gonna really make to much of a difference.
i just dont think flow masters belong on imports. and the same for domestics.
no real reason just always kinda though it was rule of thumb.

I agree in that some parts are more for domestics and vise versa. Like when I see a domestic with something rice on it, it makes it a millon times worse. a mustang with an aluminum wing is just asking for it. But this is just me, do what you want with your car, after all, it is yours

Hell when i see an import with a aluminum wing i think he is asking for it. I hate alluminum wings, lol. Import, Domestic, whatever it may be on, lol.

I agree I put the bosh plat 4 in mine and they work great. It feels like my throttle response is better and I get a smoother idle. I guess it varies from engine to engine like every other mod. No two engines are the same.

Flowmaster makes all different types of mufflers, for all different types of cars. The 50 series was the type used by people driving Ford Tempo's (I was a Tempo guy) and other smaller domestics. I think the 60 series is the import model, go to www.flowmaster.com it will show all the types

sum it up people who don't know there shit make shit up. morons like that also tend to spread there B/S as info to even lesser informed therefore getting many to belive crap like that.

OEM all the way. ;)

OEM all the way. ;)

W3rd...

And when your Bosch plugs fuse themselves to your aluminum head from burning too hot you'll switch back to the NGK's you should've put in to begin with.

Been there, done that...

i ran the +4's also in my d15 and they actually improved my gas mileage and acceleration, just like the box said, ive not had a problem at all with them.

but it is true that some plugs will work better in different cars, cause of the conductor materials.

Precious metal plugs tend to not run well in Honda's (except newer coil on plug types) with stock ignition systems because the stock ignition is not very powerfull.

It may have a high voltage with the regular plugs, but if you switch there may be too much V drop (or dampning of the high side or any other thing) across the coil to get a good spark.

Mufflers are all about back-presure kids, imports need more and domestics need less, its that simple :2cents:

you're retarded. no engine needs backpressure. please dont spread ricer boy myths when you dont know wtf is going on. thanks.

Mufflers are all about back-presure kids, imports need more and domestics need less, its that simple :2cents:

Man what are you smokin all cars need a little because if u dont have any ull end up sucking ur exhaust back into the pipes if u downshift like when ur tryin to slow down. People with fart mufflers or whatever u wanna call em think theyre car gets faster but they end up losing horsepower because their pipes are too big. And anyways it doesnt matter what kind of car u have all cars are made in the same concept basically, it doesnt matter whether you drive an import or a domestic.

Oh yeha I had Bosch Double Platinums in my Ford Probe and I felt alot of difference by doing just a tune-up with them. I also slapped an MSD ignition coil in there so maybe that helped alot too. But I was really satisfied with them.

+4's....hehe where do i begin...... my old 95 escort as well as my old turbo b16 would eat right through the center electrode. there would be a hole about 1/8" deep! swithced back to ngk's never had a problem. but then again the +4 is the only plug that could keep my old datsun from fouling out. i say oem all the way!

Spark plugs do make a difference, it may not be big but theres still a difference.

http://www.importreview.com/reviews/BoschVSNGK.html
http://www.importreview.com/reviews/densoVSbosch.html

I've tried different makes of plugs in over 12 Civics from SBCs (in stock and race trim) and everything through to 4th gens. Anything OTHER than NGK is useless in them. You couldn't pay me to put anything else in including Bosch. They dont have the life of NGK or the reliability in Hondas. In non-jap designed cars they work fine in my experience.

As stated by others: OEM all the way.

you're retarded. no engine needs backpressure. please dont spread ricer boy myths when you dont know wtf is going on. thanks.
who's the retard, cars do need backpressure. and it is true, smaller engines need more backpressure than a larger engine

first off... no engine needs backpressure, what they do need is flow velocity. huge difference. And different parts for imports and domestics doesn't make any sense at all cuz imports now use v8s(toyota tundra) just like some domestics use inline-4s(chevy cavalier), so there is no one piece that is only for domestics. Its pretty damn sad when those guys working at the auto part store dont have a clue what they're talking about, cuz there the ones selling me parts for my car

who's the retard, cars do need backpressure. and it is true, smaller engines need more backpressure than a larger engine

YOU ARE

back pressure (two words) is bad. You can measure it if you want to, just hook a pressure gauge to your manifold.

Why it is bad:

When the exhaust valve opens, exhaust is forced out, but not all of it, the small amount still in the quench zone remains. Higher pressure (aka back pressure) = higher density = more exhaust. This exhaust displaces the fresh charge on the intake stroke. On the intake stroke there is a vacuum, so the exhaust remaining expands and fills a larger area. By decreasing the back pressure you can decrease the amount of exhaust left in the cylinder.

However, too large and you risk loosing velocity. Velocity is important because the [exhaust] gas flowing through the manifold will create a sort of column of mass, when gas is no longer being added to the column, it creates a slight vacuum between the end of the column and the exhaust valve. The valve opens and this column helps to evacuate the cylider better. Headers are designed to allow all 4 cylinders to work in unison to get an even better scavanging effect. Care must be taken when chooseing a design for an exhaust system to preserve this effect (header design, primary size, secondary size, piping diameter, and muffler design)

With a turbo the pressure on the head side of the turbine will always be higher than the pressure in the outlet of compressor, here pressure can not be reduced, so flow is more important. After the turbo a large exhaust system will help. Generally the larger the better, but the largest that will fit on our cars is 3"

-Dustin

you're retarded. no engine needs backpressure. please dont spread ricer boy myths when you dont know wtf is going on. thanks.

http://files.automotiveforums.com/gallery/uploads/82015/negative4.jpg

Ok. I work in a preformance/fabrication shop and moderate the 88-91civic/crx forum over at metroareaimports, yea i have no idea what i'm talking about sorry :screwy:

ok if back pressure (sorry i missed the space bar the last time) was bad, then how can too large of an exhaust cause loss of power? b/c you have lost too much back pressure thats why. you are contradicting yourself. i'm not saying you want a lot of back pressure, but you do need some.

Its pretty damn sad when those guys working at the auto part store dont have a clue what they're talking about, cuz there the ones selling me parts for my car

You talking about me man? Nah Im just kidding dude. You dont have to know about cars to work in an auto parts store just to tell you the truth. What I knew when i first started working was basics and how to change oil and easy stuff like that. But you should see some of the dumbasses that come into Auto Zone adn try to sound all smart. Some fucker came in and was acting like he was all cool and was like "my car is dual over head cam, becuase it says D O H C on my engine and thats means dual overhead cam" I just stared at him like he was a dumbass for a minute and tried hard not to laugh in his face.

Cars do need a little backpressure by the way, its one thing when you run open headers, but when youve got piping youre trapping all the exahust inside them and if they dont flow fast enough, the engine sucks the fumes back in and thats when it goes like rrrr hr rr hr hr hrr rr and it sounds like its sorta studdering, thats a bad thing. Not enough backpressure=bad. The reason big v8's dont need as much backpressure is because theyre blowing out so much exhaust that it doesnt matter.

fucking i give up, if you are too fucking retarded to read what I wrote, and maybe look up some of the multiple sylable words in a dictionary, then i don't fucking care if you want to be wrong so bad. be wrong, and i'll just sit here and laugh to myself while your car is slow.

Note: my previous post is based on, and can be verified by, any engine flow analysis program (ie: virtual four stroke).

Me proving why your wrong: V8s and I4s both hate back pressure, it is bad on any engine, v8's typically have larger primary tubes than i4s because they displace more per cylinder than i4s. If you use too large of system on any engine you will decrease the velocity of the air, therefore decreasing the momentum therfore decreasing scavanging. Momentum is mass X velocity, mass can not be increased, increase velocity to increase scavanging. higher velocity = lower pressure, a properly sized tube will have as low of pressure (or less) than an engine running on an open head. Running open header decreases torque because mass is decreased, open atmosphere is basically infinite diameter piping, so all velocity and mass are lost at the point where the exhaust exits. This does not mean you should have an 8ft tip on your exhaust, because there is a point where you are pushing the exhaust instead of creating a scavanging effect.

-Dustin

:loser:

stepped headers is all i can say for scavanging....do a lil reasearch....

i wasn't talking about you hilikus, i was talking about those other guys you were referring to. Its ridiculous to think that a specific spark plug/muffler would work better for import/domestic because there are import v8s just like domestic v8s and there are domestic inline-4s just like there are import inline-4s. So to say a specific spark plug or muffler will only work well in a domestic is absurd. Those are the same people that think honda stickers give more horsepower.

I've been using Bosch Platnium plugs in my '89 1.5L dx hatchback for about a year now and I find them to be the same as the stock NGK plugs. Lately the car has been shittin' bricks but I chaged the plug wires with a set of bosch wires and it runs normally. As with mufflers, I know i'll just stick with having the sock one, or none at all!

I'll throw in my experience with Bosch :thumbsdow - I got those silly Platninums and then ended up changing the cap/rotor/wires, cuz it was running awful and I figured "the plugs are brand new, I must pulled something loose with the wires...turns out my $20 Platinum plugs were the issue. After probably an unnecessary $80??? and then $4 worth of NGK's later :thumbsup:
I had trouble finding NGKs and used Champions for a while too and never had any issues with them, but now we finally seem to have a few auto parts stores that carry them so I am NGK all the way..

As stated earlier - three letters - OEM

stepped headers is all i can say for scavanging....do a lil reasearch....

Was that directed at me?
Most stepped headers consist of either two tube diameters (single step) or three tube diameters (double step). We have heard of people building headers with as many as four steps (five tube diameters used in the header tubes) but question if any gain came out of all that extra effort and expense (we'd bet money that they actually LOST power - by reducing the exhaust gas velocities excessively - by the addition of these extra steps). (http://www.headersbyed.com/stepped.htm)

-Dustin