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Forced Induction SystemsDetailed discussions regarding cold-air intake systens, superchargers, turbo chargers, and other induction systems for your vehicle.
This is a discussion thread titled "Doug Thorley 5.7L Headers", within the Forced Induction Systems forum, part of the Technical & Vehicle Assistance Forums category.
Alright dammit, what the hell are we supposed to do for traction... I mean really...Ive got CAI and exhaust and Im already roasting them at will, add another 48ftlbs and Im up sh*t creek.
I want them though...
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2007 Toyota Tundra
5.7L V8 2wd
RC/SB
Mods: Tint, Flowmaster exhaust, Sport sill plates, Sport decals, Sport pedals, Chrome handles, Alpine speakers
Wow, so many questions. Ok, it does not really change the sound too much, a little deeper but not much. They are mild steel coated in ceramic and available in chrome right now. The stainless steel would have cost too much money and no one wold want to buy them.
As for the dyno charts and pictures, we have nothing to hide with our product. I am a Mechanical Designer here at Jardine/ Doug Thorley and I am very proud of our product. It is excellent workmanship and development. Such considerations as firing order, equal tube length, and REAL TRI-Y design. I am not at my desk right now. But our header compared to the stock one has MANY differences. The stock one is stamp mild uncoated steel with NO equal length tubes and dumps right into cats. When they are that short there is no torque and slow response. The best place to get our headers right now is through URD USA.
Our headers undergo pressure testing to make sure all welds are good and leak free. Flanges are think 3/8" laser cut steel. They are ground flat AFTER being welded to insure a proper seal. We also use factory Toyota style crush gaskets because they work the best. Why change it? Our ceramic coating is the best money can buy, its 5 mil thick on both sides and provides excellent durability and heat protection. They wont blue and wont rust.
I will get a picture of the stock manifolds tomorrow so you guys can compare. We have nothing to hide about our products and I will be glad to answer any other questions you guys have.
Oh, and yes we do have headers for the prior years, we are currently producing them.
I don't have a new Tundra, but I do like to see industry experts coming here promoting their products and answering questions. Kudo's to Thorley and welcome aboard...
What are the peak gains? Id love that much more low end, but i dont wanna sacrifice top end either.
Have a look at his graphs on the first page of the thread. The top end gains are modest at only a couple horses, but certainly nothing is sacrificed as the gains are still positive.
Whats the difference between those headers and the stock Tri-Y headers?
As for that dyno graph it appears that torque management may have kicked in below 4k RPM's. I think that its only fair to judge that graph from 4k+.
As I said in a previous post, the stock Tri-Y have many pitfalls. For one they are uncoated mild steel that has been stamped. The tubes are all VERY short and not of equal length. And the Tri-Y, the collectors are so close together that it does not take full advantage of the scavenging effect of the Tri-Y. Thus our reason for saying ours is a "True Tri-Y".
As for this torque management, I have not heard of this concept. And if it was true, then our headers would not have made such a difference below 4K as you say. These motors don't have a VTEC like Hondas and kick come special valve lift at high RPM. They VVT-i, but not to be confused with VTEC. The 5.7L takes advantage of dual overhead cams that truly lets the motor breathe compared to the GM and Ford guys with 2 or 3 valve. And I will be the first one to say that it is impossible to try and tweak a stock motors ECU. We don't do tricks and gimmicks like that. We give all the facts straight forward. We have nothing to hide!
No they're not, they're stainless steel.
Being as they're regular 4 into 2 into 1 welded tubular headers, what exactly is stamped?
By normal definition it is stainless yes. But 409 stainless? It is one of the worst types of stainless to use. It will still corrode and a magnet will stick to it. Anybody who knows a minor amount of metallurgy knows this. The stainless we use on our motorcycles is 304, which is one of the best. 409 stainless is like saying a Hyundai Tiburon is a sports car compared to a Corvette which is 304. Still both stainless, but one is superior. By our standards, it is not stainless. Take a look at the stock manifold in the picture. You can see all the stamped parts and the tubes that are as short as 3 inches!! Not good for superior performance, but better considering past years of truck manifolds.
The stainless we use on our motorcycles is 304, which is one of the best.
And Tundras?
Quote:
It is one of the worst types of stainless to use. It will still corrode and a magnet will stick to it.
That's open for debate, in the past I've done quite a bit of fabrication and welding with it in the heavy truck and equipment field and never found much fault with it.
That's open for debate, in the past I've done quite a bit of fabrication and welding with it in the heavy truck and equipment field and never found much fault with it.
With heavy equipment, not automotive. Ask any Metallurgist what they think of 409 versus 304. And 304 of heavy equipment makes sense because there is sooo much material, it would not be smart to use tons of 304 where 409 could do the same job, 1 inch thick 409 has years before rust will do any damage, but when its .065" thick, it can corrode through very quickly without proper coating.
What am I debating again material ballistics for again?
Re: Doug Thorley 5.7L Headers
Not good for superior performance, but better considering past years of truck manifolds.
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