local custom made headers ? how good or bad is it ?

[Blackedout86]

hello, can anyone please enlighten me about custom made headers, i cant get any aftermarket headers. Would it be better to ask local shop to replicate catless stock header but slightly increase its size, or just remove the cat on the stock header ?

i have no clue about air flow on the header, but i can see that my local shops can't do Mandrel Bend which means they just cut small pieces of pipe and weld it to replicate the stock header's curves, does it really affect the power ?
Thanks before

[humfrz]

Originally Posted by Blackedout86

hello, can anyone please enlighten me about custom made headers, i cant get any aftermarket headers. Would it be better to ask local shop to replicate catless stock header but slightly increase its size, or just remove the cat on the stock header ?

i have no clue about air flow on the header, but i can see that my local shops can't do Mandrel Bend which means they just cut small pieces of pipe and weld it to replicate the stock header's curves, does it really affect the power ?
Thanks before

Question: Why can't you get an aftermarket header?

If you can't get an aftermarket header and your local shop has limited fabrication capabilities, I would suggest you just leave it alone.


humfrz

[86MLR]

Find a 17+ header and either just knock out the cat (what I did) or cut the cat section out and replace with a pipe section.

Easy and cheap, and typical gains to alot of aftermarket headers.

Plus you can keep the OEM heat sheilds.

Simples

[Mr.ac]

It all depends how the bends are made.
If it's just a cheap old pipe bender then the flow won't be as good.
If they have a good mandrel bender then it's pretty much what every aftermarket header uses.

Not sure how good local shops are but, if he's into Motorsports and has a good rep for making dyno proven results then why not?
If it's just some hole in the wall muffler shop, eh, it's your call. Who knows.

[Brink]

Originally Posted by Mr.ac

It all depends how the bends are made.
If it's just a cheap old pipe bender then the flow won't be as good.
If they have a good mandrel bender then it's pretty much what every aftermarket header uses.

Not sure how good local shops are but, if he's into Motorsports and has a good rep for making dyno proven results then why not?
If it's just some hole in the wall muffler shop, eh, it's your call. Who knows.

They wouldn't be making bends.

they just cut small pieces of pipe and weld it to replicate the stock header's curves

[SuperTom]

the cat is the restriction on the stock headers. I wouldn't just gut the cat though. A gutted cat has a lot of turbulence. I would just have him weld in a straight pipe in place of the cat

[Blackedout86]

Originally Posted by humfrz

Question: Why can't you get an aftermarket header?

If you can't get an aftermarket header and your local shop has limited fabrication capabilities, I would suggest you just leave it alone.


humfrz

The car is quite rare in my country, so its aftermarket products are very limited, and shipping them from outside the country is just too complicated and expensive, im just looking for a simple and cheap alternative

[Blackedout86]

Originally Posted by 86MLR

Find a 17+ header and either just knock out the cat (what I did) or cut the cat section out and replace with a pipe section.

Easy and cheap, and typical gains to alot of aftermarket headers.

Plus you can keep the OEM heat sheilds.

Simples

Originally Posted by SuperTom

the cat is the restriction on the stock headers. I wouldn't just gut the cat though. A gutted cat has a lot of turbulence. I would just have him weld in a straight pipe in place of the cat

Can you give an comparison example of the catless stock header with aftermarket ones ? Is it as good as Borla uel, for example.

Or even better, is there a dyno numbers on this mod alone ?

[86MLR]

http://www.ft86club.com/forums/showt...76#post2420676

You will need a mini cat until you get a tune so you don't throw a code.

I got one of these >

Lots of km, both hwy and general trashing around, no codes.

I really need to get a tune though, and a pipe welded on.

My mate replaced his catless OEM header (with a pipe welded in) on his 2015 with a SME header, cost him about $1000, after tuning there was a few extra hp up top, but he believed the money wasn't worth the few extra hp.

He reckons he feels no noticable difference anywhere in the rev range.

And yes it was tuned.

I was looking at headers before I talked to him, now, I'm just gutted.

But, this is only one example.

[x808drifter]

I could have sworn someone made nearly this exact thread a few months back.....

[Lantanafrs2]

[QUOTE=Blackedout86;3156382]Can you give an comparison example of the catless stock header with aftermarket ones ? Is it as good as Borla uel, for example.

No, it isnt

[Blackedout86]

Originally Posted by x808drifter

I could have sworn someone made nearly this exact thread a few months back.....

i think i've seen the other thread, but the tested car is supercharged and has many other mods, i just want to know the numbers on removing the cat alone, on stock car.

edit : one more thread with similar topic has the tested car modded with e85 fuel

[86MLR]

LOL

Anyways, IRT modified OEM header, if your happy spending over 1k$ there are better options.

If you are at the pointy end of the field, there are better options.

If you want a performance mod for minimal cost and "most" of the gains, you cannot go wrong with a modified OEM header.

If by chance you want that extra couple of hp up higher in the rev range, or more torque in the mid range, buy a EL, UEL, long runner, short runner, small pipe, big pipe, 4:1, 4:2:1.

There are enough headers out there to pick where you want what IRT the hp/torque a header will give a NA FA20.

Me, I looked at my 17 OEM runner and secondary sizes and lengths, I asked around at the track and did alot of googling, luckily for me I had a mate who did the hard work and the cash outlay on this, from all of this I came up with my decision of what would give me best bang for my buck, $150 for the modified OEM pipe, or over 1k$ for a couple more hp up top, I chose the $150 option.

In the end do whatever the hell you want, as long as your choice is based on sound engineering and not just what people post on the interwebs.

Edit: plus money saved will go on dyno time for ECUTEK (when I pull my finger out of my arse and get it tuned, + rev match, I'm rubbish at heal/toe)

But don't listen to me, I'm just a crazy old hoon posting on the interwebs ��