Long Tube Header Dyno results & Photo

[richardholdener]

PS-This is why I don't like to provide photos of the prototypes since they don't represent what the production piece will be.

Originally Posted by Yoda

does any1 one see that it is spit at the top. Never seen that on a header before. Was it a mistake or did it crack?

[thepaidtraveler]

Don't wory about posting prototypes Rich. Some people need to realize that this is what is considered a rough draft and not the final product.

It takes time to test and develope.

[Yoda]

i had a question and you answered its no biggie. Better you show the prototype so we can see where your going if we are to invest in it. It makes me feel alot more comfortable in investing in a product form some1 i dont kno or has heard about(others might have but not me). I am not a fan of word of mouth from people establishing others credibility. And i kno its a rough draft. Just wanted to kno if its a part of the design or not and its purpose.

But again thank you for taking the time to R&D all these parts for our cars.

[jkuchta]

So....will this system be available in 304 SS?

[richardholdener]

We are checking on pricing bbut it will likely be aluminized or coated mild speel to keep cost reasonable. 304 SS might nearly double price.

Originally Posted by jkuchta

So....will this system be available in 304 SS?

[jkuchta]

Keep me posted....I'd pay extra for a 304 SS header that will last a while.

Thanks again for creating these parts for our car!

[Treyz]

subscribed

[AznGouki]

I'm definitely interested. It's rusting that really worries me.

[NonStopTuning]

Another excellent thread. Great job Richard!!!

[rob323]

Richard, is there any provision to allow for the twisting of the motor? Flex joints etc?

[WolfWings]

Originally Posted by AznGouki

I'm definitely interested. It's rusting that really worries me.

Honestly I'll pay the $1100 if it came in a good stainless steel instead of mild steel, but I live in the edges of the rust belt where the automated car washes are enclosed, heated, and get more business during winter from people grabbing the underbody wash than they do during the summer. :-)

[jkuchta]

I want the stainless most because it can put up with the higher heat of trackdays a lot better.

[WolfWings]

Originally Posted by jkuchta

I want the stainless most because it can put up with the higher heat of trackdays a lot better.

That's flatly wrong. Both have a melting point north of 2500 degrees farenheight. Mild steel and 304 stainless steel both don't give a damn, most mild steels are in fact good up to 2700 degrees F, same as 304 stainless steel. High-carbon steel's are the ones that melt around 2000 degrees farenheight. Both also conduct heat almost identically, so there's no difference there either. Coat the mild steel version if you're concerned about heat-containment for track use.

Only reason to go with 304 SS on an exhaust is for rust prevention at exhaust temperatures or for cosmetic reasons. It may be possible to wrap and coat an exhaust to get the same rust prevention as 304 SS, but it's one of those "do you trust the coating to be water-tight and road-salt-proof, versus being able to rely on the underlying metal?" concerns.

[ddongbap]

Originally Posted by richardholdener

The oxygen sensor positon has no effect on the air/fuel ratio. You can run the sensor stuck in the end of the exhaust or in one individual tube, as long as each cylinder is runing the same-the readings will be identical. Not sure what you mean by lower readings or giving the impression of more power or performance. The dyno does not read impressions-it reads real numbers generated by the motor.

Unless you're missing fuel injectors in two of the cly. jk=]

[WolfWings]

Originally Posted by ddongbap

Unless you're missing fuel injectors in two of the cly. jk=]

Not how it works. Only diesel engines and direct-injection engines have individual fuel injectors 'in' each cylinder. Most have multiple injectors to equalize the air/fuel ratio across the cylinders, but even if you have a single fuel injector fail it should cause a global drop in overall fuel available, with a minor to major additional localized drop on the closest cylinders to the fuel injector that failed. The global drop should still be picked up regardless of which exhaust runner the sensor is in.

And then there's cars that only have SPFI (one injector for the whole engine) instead of MPFI, and even among MPFI there's sequential (one spurt per cylinder timed with the intake stroke to fine-tune the air/fuel ratio beyond just flattening it across all cylinders, what all super-modern engines like our Yaris use, admitedly maximized local effect from a single failed injector), simultaneous (timed spurts from all injectors at the same time, pure air/fuel levelling across all cylinders, least impact from a failed injector), and batched/hybrid that fires injectors more often than needed (more than once per stroke), but vaguely synced with the intake cycle, usually I've seen that only on engines that also have a waste-spark ignition system or V engines to simplify the ECU logic and use a wiring harness that just Y-forks to each bank for the injectors instead of running individual control circuits for each injector.

[gboezio]

Actually Mild steel is a better material than 304 SS to handle the heat cycles, when 304 is heated the carbon combine with the chromium to form chomium carbide witch make the metal brittle.
304 is good for post headers exhaust systems since the temp is lower, I'd say to get the steel headers and coat the inside and outside, they will last long enough.

Or... make one out of 321 SS the alloy is stabilized with Titanium, it's hell expensive and rare like pope's crap, a costly option for an economical car IMO.

Just 0.02 $

[jkuchta]

Gboezio and WolfWings....you're both about half right.

Stainless and Mild steel both have high melting points, but Stainless conducts heat far less than mild steel, making it much better for exhaust applications. Also, stainless is much less susptable to scaleing and errosion than mild steel, making it even more superior in this application.
As far as embrittlement...while it will happen, the reduced fatigue strength of 304 will still be higher than that of mild steel, making for a stronger header.

A good site to look at is : http://www.burnsstainless.com/TechAr...s_article.html

I understand this is a site for a company that makes exhaust products, but this is also one of the most respected names in the industry. Feel free to fact check.

I'm still in if the header is made in 304 SS.

[RacerFreakXXX]

think it will sound like this?

tein yaris