TravisCadello

Ok, after my engine swap on my 92 civic sedan dx. i ran the car a few days with open headers, only the downpipe on and is sounded sweet. dc sport headers is the only upgrade. well 2 weeks later im putting the exhaust back on because people are telling me it will run faster with the exhaust. well i put my exhaust back on or just welded it back on and Immediately i noticed a good 15hp diffrence. it is waaaay slower with the exhaust on i can hardly do a burnout now lol. why is it that people always say you lose power with open headers?

alphalanos

headeR. you have no downpipe youre NA. What motor do you have. With no exhaust you basically have no venturi effect. If youre turbo then open DP is a good thing.

TravisCadello

Its a D15B7.... and what do you mean i have no downpipe? Cause i do.

1.5Slowmatic

a down pipe is what is bolted to the exhaust housing of a turbo, you have a 2pc header im assuming, which has no down pipe, just an upper manifold and than the lower piece that has the 2-1 merge section

TravisCadello

I guess its a 2 piece header. I've always called the lower piping the downpipe. anyways back to the question, Why do people say a car is faster with a exhaust and open headr make you slower?

blkegcoupe

back pressure

00b20vtecoupe

its a friggen d15 and ur running an open header??? lol and stock??? all ur doing is giving ppl a headache!!!

Juan_Mitosis

I've heard that open header might give you slightly more torque, and RUIN top end horsepower. Maybe thats why you can do burnouts, and it feels slightly stronger.

If you think it sounds sweet. . . well, good for you. But its TERRIBLY loud and annoying for the rest of the planet, specially if the open header is on a 15/16 second car, where there's not much to watch when all the most noise is going on.

If you like it that much. . why don't you try a cutout?

E-cutout https://honda-tech.com/zero...age=3

DIY Cutout

https://honda-tech.com/zero...age=1

turbojdmhatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00b20vtecoupe &raquo;</TD></TR><TR><TD CLASS="quote">its a friggen d15 and ur running an open header??? lol and stock??? all ur doing is giving ppl a headache!!!</TD></TR></TABLE>
but it sounds mad tyte yo muh downpipe is da sweetness yo!!1!!!
get a clue

San-Wan

if u got a stock b-series used a good header thats 4-1 for horsepower or 4-2-1 for torque and used 2 1/2 or 3 inch diameter piping prefibly mandrel bent, to the axle back and a good quality muffler like greddy,apexi,hks,etc..anything thats real jdm with a 2 1/2 or 3 inch exit...it helps on power, sound quality, and look...the purpose is to have it open but also use back pressure is what u need..your not on boost so the downpipe idea u think makes power but the sound is playing tricks on you..

TravisCadello

[freak] Yea! I love the sound. and the car isn't completly stock. it has a stage 1 cam not sure what kind and the bottom end was rebuilt with high compression pistons. 70mph to 105mph i beat a 2000 civic si. and my friends 5spd civic ex single v-tec 2000 i smoke him every gear. and this is in a sedan and im spanken 2 doors with better engine. B18's in 93 tegs i spank nasty. so im proud of my lil D15 so i run open header. not only that it sounds sweat is hell!

turbojdmhatch

sweet man so that 100whp is crazy

TravisCadello

Hell yea!!! lol this car is slow to me. but it surprises me with other Hondas. I used to own a supercharged 1993 ford probe gt 5spd so yea, its a down grade for me. a D15 is a nice gas saver though!

00b20vtecoupe

hahahahahahahahahaha

San-Wan

i cant disagree with that...i got a d15b in my ek hatch and is kinda heavly modified and still and N/A setup..and i didnt spent a **** load of money either...i save mad gas cause its tuned with hondata..and i ran 14.2 at atlanta motor speedway..and 13.7 on nos and i get better gas mileage then my volvo s60 r and its faster...hows that for a single slammer...and i got a k20 waitin after i run low 13's just for the fun of it...

cleansi

i very much find hard to belive you took a si unless some thing was seriously wrong with his car ive owned 15+ d series motors and just a cam ? any dohc vtec motor would smoke it.that 109 hp just doesent cutt it

jimmy o.

my d15 with open header sounded like garbage the only reason i did it becuase i put exhuast on my car

ddd4114

Any reduction in backpressure will result in torque gained throughout the powerband. The trick is maximizing exhaust gas velocity throughout the usable portion of that powerband.

i_am_a_black_man

open headers = +15 horsepower?

**** man [freak] the headers, open head= +30hp

Hanmin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by San-Wan &raquo;</TD></TR><TR><TD CLASS="quote">if u got a stock b-series used a good header thats 4-1 for Top end power or 4-2-1 for low end power and used 2 1/2 or 3 inch diameter piping, Preferably with the cheap and stupid bend , to the axle back and a good quality muffler like greddy,apexi,hks,etc..anything thats really expensive. with a 2 1/2 inch or cop attracting exit...it helps on power, rice quality, and look...blah blah blah blah </TD></TR></TABLE>

helped you out=]
The difference I see can think of is, a small hp increase from 2" to open headers. But with that 2 inch and a non coffee can muffler, you won't be getting the stupid modified exhaust ticket from your local police officer

TravisCadello

I asgree. i never thought about even racing this lil single cam till i messed around with my friends 2000 ex single v-tec and i spanked him. after that i wanted to keep my open headers lol. and that dam si on the highway the whole front end jumped up nasty and i punched mine and 70 to like 105mph i was ahead half a car and he finnally caught me at 115mph and was slowly pullen on me. he even had a head start and i caught him fast. im not making this **** up. i put my exhaust back on the other day and my homeboyz dam D16y8 spanked my ***. 0 to 70mph i was ahead till 2nd gear and then he started pullen a little bit. before with open header i beat him by 2 cars easilly.

alphalanos

Street racing is not an accurate way to measure power gain. Those cars you mention are so close in power to weight its going to be a drivers race. single cams are slow (unless boosted)

Ryanwill86

wow

thumper64

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alphalanos &raquo;</TD></TR><TR><TD CLASS="quote">single cams are slow (unless boosted)</TD></TR></TABLE>
Why is it that the SOHC engines are slow? I agree with you, but I don't understand why they make so much less power. Are they meant to be economy engines, so they're built to be slow, or is it the engine's inherant design that limits it?

Considering that the valve train, block and head are lighter and there are less moving parts to cause drag, wouldn't they actually make more power if they could flow the same and had better cams? Honda should have been able to squeeze the same 160hp out of a D16 as a B16. They'd probably have to have beefed up the bottom end for the RPMs and change the head and intake to get more flow, but it's not like it would have been hard.

I'm not knocking the D series. They serve their purpouse as fuel efficient motors, but why couldn't they make a SOHC that performed like a DOHC?

ddd4114

How about the F22A? Bisi kinda liked that one.