Header Question

[GTS]

Hi Guys

What are the pro/cons between a 4-2-1 design and a 4-1 design?

I'm asking becuase I don't know much about a header and this will most likely be my next mod.

[BigVinnie]

4-2-1 design is made for low to midrange torque engines. The KA seems to utilize this type of design the best. 4-1 design headers are mostly for high rev engines like the SR20, or even smaller displacement L series engines. Design feature is extremely important for the way power will be delivered in the power band. The main focus of the header is to magnify that power by controlling the exhaust pulses to fine tune it's power band. 4-2-1 breaks pulses numerous times making scavaging more effecient at lower RPM's. 4-1 design only breaks pulses enough so that the engine can utilize scavaging at higher RPM's. The KA isn't a good achiever on the 4-1 because it's shift point is relatively at 6000RPM, and power drops significantly after 5600RPM. 4-1 is best used on an SR because it revs and peaks a bit higher. Peak power is about 6000RPM and then begins to drop power slowly till about 7300RPM which should be the shift point for the SR.
It's just what makes the engine more effecient.

[GTS]

4-2-1 design is made for low to midrange torque engines. The KA seems to utilize this type of design the best. 4-1 design headers are mostly for high rev engines like the SR20, or even smaller displacement L series engines. Design feature is extremely important for the way power will be delivered in the power band. The main focus of the header is to magnify that power by controlling the exhaust pulses to fine tune it's power band. 4-2-1 breaks pulses numerous times making scavaging more effecient at lower RPM's. 4-1 design only breaks pulses enough so that the engine can utilize scavaging at higher RPM's. The KA isn't a good achiever on the 4-1 because it's shift point is relatively at 6000RPM, and power drops significantly after 5600RPM. 4-1 is best used on an SR because it revs and peaks a bit higher. Peak power is about 6800RPM and then begins to drop power slowly till about 7300RPM which should be the shift point for the SR.
It's just what makes the engine more effecient.


wow, thank you very much for your insight.
i guess i'll be going 4-2-1 design.

any specific brand names that you would recommend?
i've also heard that it is IMPOSSIBLE to find a header for the KA without modification, can you provide more insight ?

[BigVinnie]

any specific brand names that you would recommend?
i've also heard that it is IMPOSSIBLE to find a header for the KA without modification, can you provide more insight ?

DC sports and HOT SHOTS need no modifying what so ever, and install is relatively easy (for OBD1 KA's). Although either of these 2 come with a $300 plus price tag, but are well worth the investment for the power they deliver. I personally own a dc sports and have had no problems since it's install almost a year ago.

Although if you have an OBD2 KA you will need the OBD 1 EGR TUBE, you will need to cap the AIV port, move teh O2 to the collector, and get a CAT to bolt to the collector to the exhaust.

[theicecreamdan]

who fuckin told you that its "impossible" to find a header that fits?

[S14DB]

My OBX fit flawlessly. Been running fine for over 2yrs now.
http://img.photobucket.com/albums/v108/S14DB/240sx/Header2.jpg

[aaroneezee]

whats the primary and secondary diameter for the hotshots and dc? ive always wanted to know this.

[projectRDM]

OBX is a stainless copy of the Hotshot for less than half the price. I wouldn't recommend anything else after installing two of them recently. Great fit, power gains, looks, and quality build.

[cgguy]

Anyone ever dyno'd these products? Just wondering what the gains (or losses) would be.

Also, for all you guys running them what other exhaust modifications have you added? I'm assuming at least a catback?

[S14DB]

http://img.photobucket.com/albums/v108/S14DB/240sx/Dyno/DynoCompare.jpg

[GTS]

who told you that its "impossible" to find a header that fits?


a member of my local 240 club, he could be simply ignorant, who knows.

I just wanted to get some answers, and so far, this thread has been great
looks like i'll be looking for an OBX header...if it's that much cheaper than Hotshot

[GTS]

Hey Guys

I was lookin around Ebay..

http://cgi.ebay.ca/OBX-EXHAUST-HEADER-HEADERS-95-98-96-97-NISSAN-240SX-S14_W0QQitemZ8052347939QQcategoryZ33631QQrdZ1QQcmd ZViewItem

is this what I'm looking for? It's a 4-2-1 design right?

I couldn't find a hotshot header on ebay to compare.

[S14DB]

Yep, That's it.

[importnut]

I can say that I'm really happy with my OBX header. The only problem I had with it, was that it didn't come with an adaptor to work with my early '95, 3 wire O2 sensor. I took it to an exhaust shop and they set me up.

The only beef I have, is that it was made for a 240 with stock engine and transmission mounts. The Nismo trans mount moved everything up so high, that the header will hit the bottom of the car....but seldomly. Between that header, the 3" cat and exhaust, my 240 pulls much stronger.

Here's my install:

Header Install (http://importnut.net/240header.htm)

-Alex S.

[koukidough]

those obx headers looks so clean

[BigVinnie]

OBX is a stainless copy of the Hotshot for less than half the price. I wouldn't recommend anything else after installing two of them recently. Great fit, power gains, looks, and quality build.

I am not saying that you are wrong they do look similar, but there not the same. Runner 4 to the OBX header is at an uneven length to it's runner 1 compared to runners 4 and 1 on the hot shots( the hot shots will obviously make better HP and torque numbers. You can put the 2 headers side by side and can tell that the runnner lengths to the OBX aren't the same length from runner 4 to runner 1. The hot shots is much more genuine, and I would say makes better numbers on the dyno. Some OBX aren't that well crafted either and some people have noted problems connecting the EGR tube. OBX defenitely won't show the same gains as the hotshots, but if people don't care about that 1-2 HP loss (compared to HOTSHOTS) to save $200 then I would say go for it.

[S14DB]

Splitting hairs to me.

[atom]

Just for clarification, the OBX is a copy of the old hotshot design. Hotshot has since revised it making a bit better design wise IMO. I think the DC sports is still the best design wise, it has a nicer merge on runners 4 and 1.

[GTS]

can anyone post some links to hotshot headers?
i can't seem to find any on ebay.

[axiomatik]

why are you only looking on ebay? why not look at Hotshot's website?

http://hotshot.com/hotshotheaders/ns3010.html

[GTS]

why are you only looking on ebay? why not look at Hotshot's website?

http://hotshot.com/hotshotheaders/ns3010.html


because I'm that poor :)

thanks for your help

[wangan_cruiser]

i have a 1st gen hotshot header the two piece style. anyone have this? whats the gain after installed? i havent got the chance to install it since i got it =)

[wangan_cruiser]

I can say that I'm really happy with my OBX header. The only problem I had with it, was that it didn't come with an adaptor to work with my early '95, 3 wire O2 sensor. I took it to an exhaust shop and they set me up.

The only beef I have, is that it was made for a 240 with stock engine and transmission mounts. The Nismo trans mount moved everything up so high, that the header will hit the bottom of the car....but seldomly. Between that header, the 3" cat and exhaust, my 240 pulls much stronger.

Here's my install:

Header Install (http://importnut.net/240header.htm)

-Alex S.





dont they crack? i heard they crack on the long run. correct me if im wrong

[S14DB]

dont they crack? i heard they crack on the long run. correct me if im wrong
You're wrong. Had mine installed for over 2yrs with no problems.

[BigVinnie]

because I'm that poor :)



A guy that owned a Lambo once told me..... "If you are poor, performance isn't for you then. To go fast cost money, lots of money".........
Just remembered that off the top of my head........

[projectRDM]

Just for clarification, the OBX is a copy of the old hotshot design. Hotshot has since revised it making a bit better design wise IMO. I think the DC sports is still the best design wise, it has a nicer merge on runners 4 and 1.

^ Bingo. I should have been more clear, but the people who would differentiate or even know Hotshot has had a few revisions are few.

[BigVinnie]

This is a pic of the finished and revised HOT SHOT Header.
http://img295.imageshack.us/img295/2940/hotshotheaderforka24de9js.jpg
Here is a pic of the OBX header.
http://img197.imageshack.us/img197/560/obx9194240sxheader9xr.jpg
Hot Shot by far is smoother and like I said earlier has equal length runners.

Just for the hell of it, pics of my DC Sports.
http://img351.imageshack.us/img351/7471/dcsportsheader042wg.jpg
http://img351.imageshack.us/img351/8713/dcsportsheader036pj.jpg
http://img351.imageshack.us/img351/6587/dcsportsheader024ar.jpg
http://img351.imageshack.us/img351/9200/dcsportsheader018ir.jpg
http://img351.imageshack.us/img351/2941/dcsportsheader4wu.jpg

[Pacman]

What is the exhaust sound after the header is on? I have an Apexi N1 75mm-85mm exhaust and I lik ehthe sound of it now. I don't have a silencer either.

[S14DB]

Louder and deeper.

[SpeedMonkeyInc]

My brother had an OBX on his S14 with an Apexi N1 and it really had a nice sound. Not really deeper on my brother's car, but a more "intense" sound. Good stuff.