Factory Headers vs Stainless and Aftermarket

[grego0o]

After some issues in the weekend I am tossing up whether or not to commit to either a set of Tomei Headers, Sinco Custom Set of Headers or going back to Stock Headers after my Stainless Set blew to pieces at Alexandra Road Hill Climb and left my car sounding like a tractor...

I'm currently running a EJ25 with a GT3540 .63ar and around 19 Pounds of Boost and wondering whether the stock headers would flow enough to take this? Engine Mods are below for anyone wanting more information.

V10 EJ25 rebuilt with:

100mm Oversized Wiseco Forged Pistons

Eagle Forged Rods

ARP Race Bearings

ARP Headbolts

Hyperflow Stage 1 Sump

Torque Solutions Aftermarket Solid Engine Mounts

Beatrush High Performance Solid Gearbox Mount

Stock EJ20 SPEC C Heads

Custom 6 Puk Clutch with a 2800lb Pressure Plate to handle the power

Garret GT3582R (Gt3540) with a .63 AR with V Band for easy install and removal

Custom Braided Oil Feed and Return Lines

50mm GFB V Band External Wastegate (plumbed back of course)

Aftermarket 4-2-1 Stainless headers

Custom Up pipe twisted to fit the GT3540

4" Stainless Intake off the Turbo to a 4" HKS Mushroom Filter

Modified Trust Stainless 3" downpipe,

Full Stainless 3" exhaust with small tip for stealth

Link ECU Boost Controller

Link G4 Plug in ECU

Link Fuel Pressure Sensor and Oil Pressure Sensor tuned in with the link to avoid anymore engine failures! (fingers crossed)

Standard Tank Fuel Pump as Lift Pump

1.5 Litre Surge Tank

Bosch 044 Fuel Pump

Split Fuel Rail

Sard Fuel Pressure Regulator

850cc Top Feed Injectors

Flipped V7 Manifold (Painted Hulk Green)

Custom Intercooler Piping to work in with the flipped manifold and new turbo (all black silicon joiners)

600x200 Tube and Fin Intercooler

Aftermarket Alloy Radiator w/ Black Silicon Radiator Pipes

Remote Oil Filter Kit with/

12 Row Oil Cooler

Custom Transmission cooler

2 Litre Catch Can Setup

Does anyone have any information on the Flow of Stock Headers vs Aftermarket? Any Dyno Sheets of Before and After?

Has anyone used a set of Tomei Headers or used Sinco Customs?

Greg

[gotasuby]

We talking factory twin scroll or single scroll

[Scoobydoo]

You could possibly ask STM about some aftermarket ones that Falgoon had on his V7, and he supposedly took of and/or replcaed them with other ones.

This information was 2nd hand though and don't know how accurate or reliable it was, but I was tempted to get them when I had my V7, but never followed through with it.

This was also probably close to 2 years ago now as well.

[Fastfour]

I've warped the flanges on my factory twin scroll headers

[B4 2000]

I have Tomei headers on my legacy (i believe they are Toemi) and they are bloody great quality and freakn heavy. I'm sure they are far better than any other aftermarket ones you'll find.

compared to the SYMS and SSR ones, they much better quality (for my naked eye)

[gotasuby]

 Fastfour said:

I've warped the flanges on my factory twin scroll headers

Your not having much luck with your car

[Fastfour]

Nope I'm not. Had some thicker ones laser cut. Just need to weld them on.

[B4 2000]

that's them, they were on marc's car and now on mine

[grego0o]

 gotasuby said:

We talking factory twin scroll or single scroll

Single Scroll.

[Stoffa]

Talk to subzero 5ubzero sp? He was running sinco custom ones. needed his car to make them though. made out of mild steel so less prone to cracking

[sl8r]

with 2 litre heads

[madmike]

I would stay away from stainless ones.

They seem to be okay on the road but i have noticed on Subaru's they dont generally stand up to the heat of track work.

[ODB]

 madmike']

I would stay away from stainless ones.

They seem to be okay on the road but i have noticed on Subaru's they dont generally stand up to the heat of track work.

[quote name='Stoffa said:

mild steel so less prone to cracking

[ADIKT]

Looking to go equal length? or you wanna keep it sounding like a subaru?

[Tony]

 madmike said:

I would stay away from stainless ones.

They seem to be okay on the road but i have noticed on Subaru's they dont generally stand up to the heat of track work.

Depends what sort of stainless they are made from. Lots of slip joints and HPC coating seems to help.

[funkytown]

Mine seem to have gone fine to date too

[grego0o]

 ADIKT']

Looking to go equal length? or you wanna keep it sounding like a subaru?

From my readings I don't think that makes a difference in power out put..

[quote name='madmike said:

I would stay away from stainless ones.

They seem to be okay on the road but i have noticed on Subaru's they dont generally stand up to the heat of track work.

/quote]

Depends what sort of stainless they are made from. Lots of slip joints and HPC coating seems to help.

This is true also, the quality of stainless will depend on the the length of time before they crack... Mine have done 50000ks so lasted a while before falling to bits so they did pretty well!

[lachlan]

http://www.dirtyolbc.co.nz/community/topic/738-port-n-polish-factory-manifold/

port an polish factory offering . + naisoc cross pipe compo

[Stoffa]

I think you'd want to stick with a proper header at the power your making, the GT spec ones seem to have a good name for themselves

they even make a set with EWG V-Band setup http://gtspec.com/product/gtspec-ss-gen-ii-racing-exhaust-manifold-wrxsti-impreza-w-ewg-44mm-setup

or if you just use an adaptor on top of a factory mounting point up pipe $699US is not too bad http://gtspec.com/product/gtspec-gen-ii-racing-exhaust-manifold-uppipe-ej20ej257

I do love love the look of the Tomei ones though

[grego0o]

 Stoffa said:

I think you'd want to stick with a proper header at the power your making, the GT spec ones seem to have a good name for themselves

they even make a set with EWG V-Band setup http://gtspec.com/product/gtspec-ss-gen-ii-racing-exhaust-manifold-wrxsti-impreza-w-ewg-44mm-setup

or if you just use an adaptor on top of a factory mounting point up pipe $699US is not too bad http://gtspec.com/product/gtspec-gen-ii-racing-exhaust-manifold-uppipe-ej20ej257

I do love love the look of the Tomei ones though

I wonder if a v band between headers and up pipe would be effective? I've heard the flanges warp out on the stainless sets ( have seen funkys do it )

I wouldn't be using the up pipe from these kits either.. It would be my custom made one, but would want single scroll entry for less fuss when adapting my current up pipe.

[BT]

As Tony said slip joints and HPC...

[madmike]

 funkytown said:

Mine seem to have gone fine to date too

Apart from the flanges warping you mean...

I did a season of Road and Track with no problems...

Then they just started warping and cracking.

To the point that one slip joint slipped out completely. (Cheers to Tony for helping fix that BTW!!)

[funkytown]

Mine were welded on mild steel. not stainless so get the facts straight.

Oh and ive melted 3 uppipes.. none of them stainless mounted on my stainless headers.

[funkytown]

Oh and the flanges that go agaiast the heads that came on these headers when i bought them.. are still flat as a die.

Only the parts i changed along the way going twisted has moved

[ADIKT]

 grego0o']

Looking to go equal length? or you wanna keep it sounding like a subaru?

From my readings I don't think that makes a difference in power out put..

[quote name='madmike said:

I would stay away from stainless ones.

They seem to be okay on the road but i have noticed on Subaru's they dont generally stand up to the heat of track work.

/quote]

Depends what sort of stainless they are made from. Lots of slip joints and HPC coating seems to help.

This is true also, the quality of stainless will depend on the the length of time before they crack... Mine have done 50000ks so lasted a while before falling to bits so they did pretty well!

Yea but some people are a lil fussy over how their car sounds lol