glocknesmonster

Ok Iam running a bonez test pipe to n1 dual exhaust. And was wondering how much more h/p and Is it worth it to go with r/b headers to straight pipe (i.e. 3 inch) all the way threw to the tail pipe. B/c my cousin has an 87 just like me with all the mods the same wich are intake,street port,racing clutch,9 lb flywheel,ngk plugs,wires,and no a/c.(i.e. all done by the same shop to.) but is running headers and straight pipes all the way threw.
Well one day we where on the highway going like 40 and both punched it and he went zooming past me. So i was like WTF this shouldnt be that big of a differnce.So it got me wondering is it that much more h/p or is my car not running or tuned right. Also my plugs,fuel filter, and every thing else is fine so know power loss there. Where else could I be losing power.

rotarygod

iTrader: (1)

Headers make a huge power difference over the stock exhaust manifold. Some people say otherwise, but it's true. They especially make more power throughout the entire powerband. Don't think only peak power. There isn't really much point to a 3" exhaust. 2.5" is more than enough for what you are doing. Bigger isn't always better and this is a good example. If you were running a peripheral port engine with a megaphone collector you'd benefit from a larger exhaust but don't worry about it. It is very possible you have something wrong with your car but headers make can make a big difference.

Agent_D

iTrader: (2)

i agree, but if you want power out of your header, go with AWR or SDJ for them, sure more expensive, but worth much more power.

also you sure your 5/6 ports are working?? or open?? and if its S5, your VDI??

glocknesmonster

Ok thanks. To make sure a got this right my test pipe is 2.5 inches like u said not a big differnce. But a header compared to a test pipe at same diameter is a big difference right. Also what could be wrong. Runs smooth throught whole power band just seems not as much power.
Another time we went for a ride in each others car punched it from a stop to 3rd hard in both cars and his had wich seemed a lot more put you a$$ in your seat. Ig you know what i mean. One other thing my car runs very rich what would be the right thing to do to lean it out a little. about 13 miles per gallon but isnt this about ave.

Agent_D

iTrader: (2)

yea, a full 2.5" is all any n/a FC needs, unless, as posted above, you have a peripheral port or something crazy.

there could be several reasons, his car may have a fresher engine, making more compression, some FC's, I and others have noticed, are factory freaks, some just run like mad and others just normal.

the header will make a significant difference and may put you just where your friends car is at, or a bit better, a straight 3" from header isnt exactly the best route, your exhaust setup with a header should make more power/torque throughout the power band, over the straight 3". also, if he is running an RB and you get an SDJ or AWR, you should make more, talked to the guy at SDJ and he said on a dyno their header was making 9-12hp more than RB consistently on several different cars.

glocknesmonster

whats awr or sdj. Its an s/4 both of them. And the 5th and 6th port thing I think its blocked off or something. I took it to the shop who rebuilt my engine and expressed about the 5th and 6th ports b/c i read it on this site and he said they where done right for max h/p. But i think they are blocked off. Is this the right way. And Iam dumb where whould I chech to look the left side facing car?

glocknesmonster

Ok you convinced me Iam getting a header and running 2.5 all the way threw. Also iam under the consumption r/b are the best.

Agent_D

iTrader: (2)

the passenger side right above the exhaust manifold. removing them isnt exactly the best on stock ports, someone posted some information about it creating an unwanted intake air turbulence at the port, althought ive driven cars done both ways, wired open, and completely removed, it doesnt feel any different.

www.sdjmotorsports.com
www.awrracing.com

the SDJ is 450
and the AWR 550

Agent_D

iTrader: (2)

RB are good, for what they are, their a great quality header, and priced right, but others have designed better ones that make more power. you get what you pay for

RotaryDreamz

iTrader: (29)

just buy the RB headers and have it custom welded to yer straight pipe... i kno people that had it done and they felt a good increase... let us kno wat setup yer running and how you like it...

glocknesmonster

k. thanks for all the help and quik response. so know differnce if wired opend or blocked off sounds good will keep mine blocked off. I know iam a pain but if the sdj is just a little more than r/b about how much more h/p. And can u put a number on how much more power the r/b header is compared to what I got.

glocknesmonster

Hey thats a good idea DREAMZ b/c I all ready have a test pipe wich can be a straight pipe and is 2.5 inches. Just have some one cut and weld. good stuff.

Agent_D

iTrader: (2)

if you want to have it cut and welded you wont see the same increase in power as if you had it bolted to say, an RB pre silencer or a corksport test pipe.

glocknesmonster

Why's that seems weird. Just wondering learn something every day. B/c if u think its still going straight threw at the same rate.

Agent_D

iTrader: (2)

just search, i dont have the articles or explanations anymore or i would post them.

exhaust pieces are sold for a reason, and R&D has been put into most things, if it was best to have a single piece exhaus system, well you get the idea, we'd all have single piece exhausts from engine back.

glocknesmonster

ha iam dumb i just thought they didnt make single pices all the way threw b/c the box it would come in would be huge and no company would deliver it. LOL.

Agent_D

iTrader: (2)

yea if you search for exhaust articles on scavenging and velocity and tuning you'll find a lot of stuff.

Agent_D

iTrader: (2)

http://www.yawpower.com/jantech.html

http://www.yawpower.com/febtech.html

there are a few

glocknesmonster

thanks.

Agent_D

iTrader: (2)

no prob my setup is the one in my sig, Mind Train header, RB 2.5" pre silencer and Apex'i N1 single

my wifes car pulls pretty nice too, Mazdatrix true dual, the older style with 2 pipes all the way back, and a pre silencer on each pipe. very quiet and agressive at low RPM's and of course loud rotary at high rpm's, pulls very smoothly, even with the 5/6 ports closed it does ok, i zip tied open her VDI just need to get the 6 ports working or removed lol