It's me again. I know last time I posted a new topic it really started a fire with folks here, and it may have burned some bridges. Sorry 'bout that. Didn't mean to ruffle so many feathers. But it looks like that one has died out so it's time for something new.

I'm collecting parts for a mild, low-end torque building LN2 to try for better mileage and drivability from my S-10. I've gotten alot of good help here before on what to go with ( Thanx, Mad Jack! ), and now I need something very crucial to this build: A proper header. So far all I can find is 4-1 ball-socket types that from what I've heard are meant more for high-end RPM power. From what I hear a 4-2-1( AKA: Tri-Y ) would be more suitable for my application. But it seems no-one makes one from what I've seen. So, I'm left with this: Get a friend with the fabrication skills that have built good ones for others to produce one for me. I have just one problem: He needs to know what the primary & collector dimensional numbers need to be ( Length, diameter ) ! And this is a Try-Y, so the step diameter & primary adjoining fork-tube angles are needed too. It is critical that he knows this otherwise it's wasted effort and metal. I know others here have bought ones meant for the J-car app & I don't want to seem a pest but if you know these dimensions on the J-car app please tell me. This is the only way I can get one & I'd hate for this to be half-assed. Can you help?

Go beyond the "bolt-on".

Actually, a longer header is for higher rpm power, and a shorter headder is for more streetable mid range gaines. The 4-1 style will probably work just fine. A 4-2-1 style header like your talking about will move your powerband higher than it sounds like you wan't.

Weebel wrote:Actually, a longer header is for higher rpm power, and a shorter headder is for more streetable mid range gaines. The 4-1 style will probably work just fine. A 4-2-1 style header like your talking about will move your powerband higher than it sounds like you wan't.

I do not know why you would say that. I have always been under the understanding that a 4-2-1 is better for tourqe than a 4-1.



FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

Weebel wrote:Actually, a longer header is for higher rpm power, and a shorter headder is for more streetable mid range gaines. The 4-1 style will probably work just fine. A 4-2-1 style header like your talking about will move your powerband higher than it sounds like you wan't.

Sorry to inform you, but the longer tube headers are more for low end torque. A shorty header is more for high rpm horsepower. Primary tube diameter determines the torque peek, while the primary tube length determines top end horsepower peek that a header will help develop.

The collector acts basically the same and will have a big affect on how well the header develops the torque and horsepower. Most all of the street headers made for the Cavaliers have very poor collectors, i.e., very short (4"!) and narrow (2.25"!), with a ball socket right at the end.

The primary length and diameter of the PaceSetter header for the 2.2L/2200s are actually quite good for the power-band a mildly modded Cavi normally operates. What kills the output of the header is the collector. Cut the collector off about 1.5" above the collector and put a 2.5" 4-1 collector that is over 8" and replace the PS down pipe with a 2.5" pipe with a flex coupler in it. Then run a reducer to the 2.25" hi-flow cat and exhaust and you'll have an awesome street exhaust.

Michael, you can get just as much torque and horsepower through a properly designed 4-1 header. I know there are very few headers for the S-series trucks with the 2.2L/2200s and they are very expensive.

Send me a PM with the year of your S-10, what machine work (including any head work) you have or are having done, what rocker ratio and valve springs you have or are getting. With this info, I can help you design the header for you needs along with sending you some other info to maximize the low to mid-range output of the motor.

Well Jack, you have a better understanding of the LN2 than most seem to, so here it goes:

'94 S-10 LN2 w/ 4L60E & A/C. Factory tow pakage w/ 4.10 gear. No knock sensor & no exemption from the IM240 emissions test by me.

It's all stock, yet I'm forced to run 92-octane to prevent knock for reasons that totally elude me.

No machine work, yet. If I do I'll follow Mr. Dave Vizard's performance w/ economy advice on the exhaust side ( Race port shaping, larger valve...). But somehow I doubt it will come to that.

I'll be following your Crane rocker advice and go with gold 1.6s after I find where to get a cover spacer and how to grind the cover for clearance. Maybe even do the LN2/LT-1 lifter build-up.

Springs will remain stock since Notec pointed out they would do just fine with the stock cam & Crane rockers.

I'm totally on-board with the flex-tube idea since I've worked in a exhaust shop ( Car-X ) after college and know that is way better than a straight flange or ball socket.

I'm looking to do a CAI, or hopefully an actual FAIS, since I once fabbed one onto an '85 S-10 with an TBI "Iron Duke" & 700R4 and a K&N replacement filter. The only other mod was 2.25" Flowmaster 40-series fitted at the shop I worked after the cat. Got 25 mpg clockin' 75-80 in it while goin' to Bowling Green, KY for the Buick Nationals. Believe it!

So that's the jist of it. Hope it's enough for you to work with. Forgive me if I put this here instead of in your mailbox, but I'm guessing by PM you meant parts manifest. You know what I'm aiming for with this truck so my hopes are on you, Jack. Good luck & god speed with this thing.

Go beyond the "bolt-on".

Long headers and lakers are for high rpm, and shorty style are for lower rpm. It's always been that way. The less restrictive your exaust is, the higher up the power gains are, I thought everyone knew that. The problem is finding something in between thats right for your engine and how you want it to perform. Maybee a longer header works well for mid range power on a 2.2, but if you put a shorter one on there, it's not going to move your peak HP farther up the powerband than the longer one, it will just flatten out your power curve more, making it pull more evenly throught the powerband, wich in turn lowers your peak HP RPM. Basically, as long as you don't go to far, the more pipe you have between the engine and the collector, the higher your peak power will be, it's all about exaust velocity.

Longer header= less resistance to flow, wich means a higher rpm (more exaust flowing through the pipe) is needed to promote nominal exaust velocity.

I'm probably gunna get flamed for this, but I know I'm right.

gotta love all the trash in here

long tubes depending on their primary length , run a wider rpm range

shortys in a narrow rpm

mids are in between the shorty and longs

tri-y are a mid range header , and usually pick up more low end than a long tube , where the long tube will be close , with alot more top


each primary tube diameter and length for each application and usage , varies from vehicle to vehicle , not 1 is identical , and you make 1 change and you through the rest out the window as to whether it will work right or not

then you run into alot of work testing and remaking and retesting , 70% of the headers out there are designed to fit the vehicle , and allow a easy install over having to custom make something , and the keep it simple stupid reasoning , usually make good gains

to many excessive bends in a pipe restrict air flow , and will cause a loss of power , over a similar product with less bends

for your S10(which shouldnt even be in this sections asking questions for WRONG VEHICLE TYPE FOR THIS BOARD) there isnt alot of choices for headers for the 2.2 , and as far as i know , pacesetter is 1 of the few and is a CARB approved header

Well I try to get help where I can, and since the LN2 primarily sees use in the J-body, I figured this would be as good of place as any to get help in my situation. And guys, if you knew about sonic tuning ( Weebel ) you'd know that a longer tube uses sonic-reversion to aid the evacuation of the cylinders at a lower RPM than a short tube, which aids in the production of power by 1): Prevention of dilution of the fuel/air mixture entering the cylinder and 2): Aiding the flow of said mixture into the cylinder during the period of cam overlap. With a short, stock profile cam a longer tube of the proper diameter will work prefectly with the low frequency pulses of the exhaust at low RPMs. A long tube is also helpful with a BIG cam with alot of overlap in the same ways mentioned in order to aid in low-revs operation, but again the tubes must also be of proper size as to not choke the engine at higher speeds. The same rules apply to intake manifold design, only the intake's tuning relies more on runner length to time the pulses right for the cam's intake valve open event at a given RPM ( If I remember right ). The beauty of a Tri-Y header is help synchs all the exhaust pulses together to aid in overall scavaging. True, I could go with pre-fab header, but is the EGR fitment on these " CARB exempt " headers? I sure don't see one and my truck relies on it to prevent knock ( Remember, no knock sensor! ). Hey, a new message just came. Think I'll go check it out now.

Go beyond the "bolt-on".

Ehhh....this could go on forever. I was just making a generalization when it comes to off the shelf headers. Basically, if your going to by a longer off the shelf header, make sure your car can make use of it, thats all. I'm not trying to start any huge arguments or anything. I wasn't talking engine specific or custom built, just mass produce like pacesetter, or magnaflow, and what not, which is what most people do, I I thought you where doing the same. Yea a custom built header when done right will work better, and you can get away with making a longer one and still keep some mid range power if you know what your doing, and if its specifically built for mods done to the engine. Most mass produced headers are desinged for stock engines and you cant really make use of a larger off the shelf header unless your engine has been modified to make use of it (more aggressive cams, or higher red line ect..).