i already have a 15% pulley but would like to get more hp/tq out of my mini at low mid rpms and pass a smog test. can i do both with an aftermarket header ..... like obx? i've heard that obx headers are a good bang for the buck?

 

Does OBX make one for an 07 yet????????

 

it's a convertible supercharged (not turbo)... so i think all the mechanicals are the same as the 1st generation hard top.

 

i don't wnt to open a can of worms, while the obx header is a great addition and certainly adds a certain degrees of seat of the pants feel... i can say, and i have some proof, the obx header isn't the best out there

what else have you done, i wouldn't do a header unless i already did the catback... along with an intake...

 

[quote=kyriian;2069792]i don't wnt to open a can of worms, while the obx header is a great addition and certainly adds a certain degrees of seat of the pants feel... i can say, and i have some proof, the obx header isn't the best out there[quote]


You wont be "opening a can of worms" , the obx is only $200 give or take. Of course it wont be the best out there, but if you find another header that makes more hp/tq for under $500 than consider it sold. To tell the truth you wont see much gains from a header unless its flow matches with a head etc. RMW has a head/header combo thats nasty IMO.

Jack

 

I have yet seen ANY type of comparisons/data that favors 1 header over another.

 

I'm with kyriian on one hand(it's the hand that says:" get a catback and intake,then header")

Those little pitiful stock pipes dont need more air shoved thru them

I also have experience with the obx. It seems to have started to finally"settle in"- me likey.

On the hand that seeks fun -
I say live it up! obx-check !
cai of yer chosing-check!
exhaust -check!
Death to stock!
-unleash the beast and start boltin' stuff on.

It's quite exciting when you do compound mods.
One thing I have figured out:If you enjoy making your car more of a performer,you will get to it all eventually......cuz its hard to stop once you start.
as for smog tests....well ......there are peeps out there that will hep ya out wit dat.

 

well, i can tell you this much, 3 years ago, header-less and crank pulley-less, i pulled 183 whp on a hot day

last year, with the obx header, stock cat, 2% crank pulley, i pulled 181, more importantly, toque went from 159, to 156

not exactly earth shattering reduction, i mean there's plenty of other factors, but a source told me, ports on the obx is smaller than stock... im taking it off and doing the measurements once the snow decides to stop

which has lead me to believe, the mid range increase is there, but it might end up costing more than you think

just my 2 cents worth

 

No comparisons, but there is data. Especielly when its matched up correctly with other parts.


Jack

 

you lost power?

 

But theres to many variables, temps, humidity, engine wear etc. Especielly if the Dynos were a year of each other. There are plenty of Dyno charts showing the OBX making great gains.


Jack

 

I respectfully disagree with a couple things in this thread. First off, I'd say the OBX header give more seat-of-the-pants improvement than a cat-back, and it's cheaper as well. I know the usual route is a cat back first, but I used the OBX with the stock exhaust and it does make a noticeable improvement in mid range torque. On the other hand, when I added the Skunk-2 cat back (= Invidia w/plain tips), there was nothing but more noise until 5000+ rpm.

Secondly, the OBX does not have smaller inlet ports than stock.

 

i do agree with that, that's why i said i didn't want to open a can of worms with my statement, i guess my point is, your mileage will vary...

ultimately, no matter how much intake and exhaust we can do, its the head that's the bottleneck, you can open an intake path, more air will go in, but the amount of air going in is limited by your port sizes, same as exhaust, we can agree on that no?

 

indeed

 

the minute you match up to "other parts" - then its not possible to separate the contribution of each part - and thats why I say there is no comparison data.

 

You are correct. Way too many variables - one you did not raise was the belt.

 

If one had budget constraints - I would do an OBX header w/ 1-ball.

I had the obx/1-ball and later swapped out the 1-ball to a cat back - I doubt I gained any significant additional power but got more sound and sexy new tips

 

at this point, all i was considering was s/c pulley, cai, header, one-ball and most importantly... a custom tune by jan @ rmw. what do you think my hp & tq will be after doing all of the above? by the way, anyone know if the obx header will pass a smog. someone that was selling it mentioned it was "carb exempt".

 

The header should be able to pass, as long as you use the stock cat, or equivilant. Don't go for any "High Flow" cats, as they probably won't pass.

 

I disagree - the stock cat should work fine w/ those mods.

Here too the data is unclear. How much more flow is necessary ? and which after market cats provide the extra free flow required for our cars. Take a summit catalog as an example and you read "high flow" but to what? Each vendor quotes different things and its virtually impossible to compare.

 

Too hard to tell what you will pull, Im at 198 with just %17, CAI, exhaust and untuned. Waiting to se what jan can pull out of it. Every car is diffrent.

 

198, is that crank or wheel?

As long as you use a stock cat i dont see why the OBX header wouldnt pass CARB.

 

At the wheel....strong car FTW

Jack

 

why did you decide to go with a 17% pulley (instead of a 15%) and did you upgrade your injectors?

 

I just didnt want a %15 and i didnt want a %19 so i got %17 . No im running on the stock 340's but up top i am very very lean. I have 380's in a box next to me, i think when i get tuned by jan im going to go ahead and get the 440's put in, so if anything else gets added in the future there fuel already there to play with

Jack