Doug Thorley 5.7L Headers

[07Sport]

The whole 4000rpms argument is ludicrous. The faster 60 foot times, the better. If we have more low end tq to get off the line faster, it will substantially improve 1/4 times. Imagine lowering a 2.2 60 foot time to a 1.9. Granted for 2wds some type of traction aid will probly be needed, but that will translate into at least .3 faster in the 1/4, probly closer to .5. Also, given that the headers will heighten gains from exhaust and cai the increase will be exponentially increased depending on accompanying mods.

[ToyCrazy]

Originally Posted by tickin'tundra

In your case- no. Running around with your foot on the floor will have a bigger impact on your gas mileage than changing out the headers...

If these headers offer more efficient exhaust scavenging than the stock headers then there is indeed a possibilty of gas mileage improvement. I don't think it the 2-3 MPG improvement that was implied earlier, but based on the design difference it should offer better mileage, but that is not a fact until extensive testing could prove it.

Thanks, I just want to make sure the headers won't hurt my gas mileage.

[LSKustumz]

Originally Posted by Barberdan

You will get no 1/4 mile improvements because the speed at which the engine operates almost entirely to accomplish it's quarter mile the quickest is not improved by these parts. With an automatic transmission, boosting low end response only helps when you can achieve wide open throttle at those engine speeds and Toyota 6spd transmission doesn't hardly allow this to ever happen. You will notice though that you can get a little more oomph out of the engine before it decides to downshift. Could save even more gas than the percentages of gain shown in the dynos if you get hold a single higher gear position in a hill climb.

Just to hopefully teach someone with their eyes open: Peak horsepower(and average HP in powerband if you want to be specific) is all that matters in engine output charts if you can use up all your traction in the dig. A boost in low end HP or torque can do nothing to improve a vehicle such as this(in a drag race standpoint).

With a good enough launch(easy with a manual, a bit trickier with a automatic) The vehicle engine should never operate below 4000RPM or even 4500RPM using the Tundra 5.7L in this example. Boost output below this range just simple won't appear in a drag race because the engine never used that operating range. Before you start asking the reason why you don't use the Sub 4000RPM range off the line either is that you jumped into this powerband with tire spin, a little is usually a good thing.

I find this is getting beyond the point now. But for the sake of the argument and clarification so other people aren't mislead, you are wrong. If you think that the engine should never operate below 4K, you really have another thing coming. Not only will you get premature engine wear, but you just don't know the philosophy behind drag racing. It is getting out of the hole the fastest. If you launch at 4,000 Rpms, your torque converter will fail, put tremendous stress on the drivetrain, and you will just sit and spin out. Not to mention you will hit redline in 1,000 RPM. I would like to see a drag race like that!! It wont be a very good one!!

As the poster previously said, this will increase your 60ft. times and lower your overall time in the 1/4. If you don't think headers especially of this quality will help, then you will not be successful at the drags. Have you ever been to the strip? Have you ever raced? We should tell all the big block guys out there to put their stock manifold logs back on that they will will not see and improvement in their 1/4 times. 5.7L V8 are not meant to REV. They are meant to build torque from idle. This is why Toyota put in a V8, and not a turbocharged 4 cylinder. The 4 cylinder can produce as much power, but not nearly as much torque. Do you see what I am saying? Or am I wasting my breath? Torque is what gets WORK done, HP is the rate at which the work gets done. If you don't understand this most basic Physics statement then I will try to explain it a little better.

Either way, for everyone else. They will improve your gas mileage, but like other posters have stated, it is truly dependent on your driving habits. And if you do love planting your foot to the floor all the time, then you will love these headers because they punch back!!

[LSKustumz]

No, they will not hurt your gas mileage. We generally see a range of 1-3mpg better when people put on JUST the headers. But have not seen the data on these since they are so new.

[Burger Steak & Eggs]

Originally Posted by LSKustumz

THY-560Y

Interested in these.

Are they shorties or full length?

Mild steel with ceramic coating?

What is the primary diameter and collector diameter?

Do they bolt up to the stock exhaust or some fabrication needed?

Cost?

(Thanks for taking the time )

[v8Toilet]

Back a few years ago $600 for 409 stainless steel short tube headers like these would be about market price but these are not stainless steel. I'm curious as to what is the actual difference in price between 409 stainless and mild steel and 304 stainless? Is it really hundreds of dollars?

409 Stainless steel does not rot out like was previously mentioned. It tarnishes and gets some surface corrosion but it does not rust. In fact it should last much longer than the life of most vehicles. 409 Stainless steel is much better than mild steel and that is why most automotive manufacturers use it in their exhaust systems. Mild steel on the other hand will rust out if just one piece of that coating chips off and once the cancer starts it's all over in a short period of time especially if you live in the snow belt; I know this based on personal experience with coated mild steel headers.

The other thing that was not mentioned was how does the cost of coated mild steel compare to uncoated 321 or 304 stainless steel headers? If I remember right coating headers used to be about $200 + $600 = $800. If you can make 304 stainless steel headers for $900 than I would say that is the better deal because 304 stainless steel would last forever.

One other important thing is the collector design. Do you use a merge type collector like JBA uses for headers on the first generation truck or do you use the less expensive open collector like the one onside the collector of the SSautochrome headers for the first generation trucks?

As far as craftsmanship those headers do look nice!

[Barberdan]

Originally Posted by WannaRedTundra

Im not trying to pick a fight or say youre wrong but Im just asking for clarification. How could we run a quarter mile while operating at above 4500 RPMs without modifying the tranny? Doesnt that only leave us 1500 RPM to work through? I just dont think my truck operates that high strung when I floor it. But I guess I could be wrong, have been in the past..

I'm sorry but I'm talking to people that don't honestly know how power works and how drag racing takes place. You have lived by rules of thumb too long and havn't broken things down yet. The reason the motor won't operate below 4500 RPM is tire spin as soon as you launch. You'll start at 1500RPM but immedietly be spinning tires and jumping into the powerband around 4500RPM. Adding more power down where there was tire spin offers no 1/4 miles improvements unless you need more tire spin than you had stock. Not the case if you can launch it properly.

[Barberdan]

Originally Posted by 07Sport

The whole 4000rpms argument is ludicrous. The faster 60 foot times, the better. If we have more low end tq to get off the line faster, it will substantially improve 1/4 times. Imagine lowering a 2.2 60 foot time to a 1.9. Granted for 2wds some type of traction aid will probly be needed, but that will translate into at least .3 faster in the 1/4, probly closer to .5. Also, given that the headers will heighten gains from exhaust and cai the increase will be exponentially increased depending on accompanying mods.

If you acquire gobs of traction and have the lousy torque converter to rely on taking off I can see where boosting the low end can provide improvements in the 60ft times and overall 1/4 mile. Not incredibly important still since you can launch heavily if you know what you're doing in even a stock Tundra and you stay around the Sub 4000RPM range for such a brief moment. Rest of the race through all the gears in certainly above 4000RPM.

[low c1500]

Originally Posted by v8Toilet

Back a few years ago $600 for 409 stainless steel short tube headers like these would be about market price but these are not stainless steel. I'm curious as to what is the actual difference in price between 409 stainless and mild steel and 304 stainless? Is it really hundreds of dollars?

409 Stainless steel does not rot out like was previously mentioned. It tarnishes and gets some surface corrosion but it does not rust. In fact it should last much longer than the life of most vehicles. 409 Stainless steel is much better than mild steel and that is why most automotive manufacturers use it in their exhaust systems. Mild steel on the other hand will rust out if just one piece of that coating chips off and once the cancer starts it's all over in a short period of time especially if you live in the snow belt; I know this based on personal experience with coated mild steel headers.

The other thing that was not mentioned was how does the cost of coated mild steel compare to uncoated 321 or 304 stainless steel headers? If I remember right coating headers used to be about $200 + $600 = $800. If you can make 304 stainless steel headers for $900 than I would say that is the better deal because 304 stainless steel would last forever.

One other important thing is the collector design. Do you use a merge type collector like JBA uses for headers on the first generation truck or do you use the less expensive open collector like the one onside the collector of the SSautochrome headers for the first generation trucks?

As far as craftsmanship those headers do look nice!

In simple terms, the higher the number, the better the SS alloy will withstand heat damage.

[FiveOh]

Originally Posted by LSKustumz

I find this is getting beyond the point now. But for the sake of the argument and clarification so other people aren't mislead, you are wrong. If you think that the engine should never operate below 4K, you really have another thing coming. Not only will you get premature engine wear, but you just don't know the philosophy behind drag racing. It is getting out of the hole the fastest. If you launch at 4,000 Rpms, your torque converter will fail, put tremendous stress on the drivetrain, and you will just sit and spin out. Not to mention you will hit redline in 1,000 RPM. I would like to see a drag race like that!! It wont be a very good one!!

As the poster previously said, this will increase your 60ft. times and lower your overall time in the 1/4. If you don't think headers especially of this quality will help, then you will not be successful at the drags. Have you ever been to the strip? Have you ever raced? We should tell all the big block guys out there to put their stock manifold logs back on that they will will not see and improvement in their 1/4 times. 5.7L V8 are not meant to REV. They are meant to build torque from idle. This is why Toyota put in a V8, and not a turbocharged 4 cylinder. The 4 cylinder can produce as much power, but not nearly as much torque. Do you see what I am saying? Or am I wasting my breath? Torque is what gets WORK done, HP is the rate at which the work gets done. If you don't understand this most basic Physics statement then I will try to explain it a little better.

You make a lot of statements here that really discredit your opinion. Making statements like 5.7L V8's are not meant to 'rev', truly shows your lack of knowledge. The cylinder layout and displacement have very little to do with capacity to rev. To find that out you would look at bore/stroke ratio and valvetrain configuration.

What the other guy was trying to get across to you was that you are only below 4000 rpm for a very short time in a drag race. This is right after launch when you are in first gear and already fighting for traction (with stock rubber). Adding more power here will not significantly improve 1.4mi times. Once you are out of 1st gear, you are running in the upper ranges of rpm and out of the range where your headers make power gains.

[tonylop33]

Here is how TS handles group buys.

FAQ: TundraSolutions.com FAQ

[thumbster]

Originally Posted by LSKustumz

If you are complaining about cost of the headers now at $600 which is far cheaper than any other competitor, which there is not any. But 321 steel will expand and contract differently than the metal on the head and cause leaks, crack welds and jump the cost up A LOT. If you have not seen the raw material cost of stainless lately than you are assuming too much. As I have said before, I'll say it again, other metals are just not suited for the application. So if you think $600 for mild steel now is a lot, make them 321 and see the price up to $900-1000!! Everything will have to be tig welded, and will be much more brittle and susceptible to corrosion. Nothing worth a GOOD amount horsepower will not be easy. This goes for anything. Our headers combined with an intake and exhaust is the best bang for buck horsepower you can get!!

I like the design of these headers, BUT....

If welded correctly (tig or mig), 409 is superior in durability to mild steel and will therefor handle more heat due to it's higher carbon content. It is the material of choice for heavy duty truck exhaust systems because of this durability. How do I know this? I have been tig/mig welding custom exhaust systems on airplanes, cars and boats for 20 years and have never had a weld fail on any header or exhaust component, even on a turbo application - period. It all depends on the filler material, welding technique used, and you have to back shield the inside of the tubing when you weld it. One of the main reasons toyota had problems with the older tundra's manifolds were the way they were welded - welds were done way too hot for the sake of production speed, causing them to crack right at the tube flanges on the heads. Expansion rates only matter when you use dissimilar metals for your flanges and tubing. Most header manufcaturers use mild steel flanges even though they use 409 or 304 stainless tubing. Inconel (321) is obviously cost prohibitive and totally overkill on a street vehicle, hence the in my last post.

Even the best coatings will eventually wear off in time, so using stainless steel of any grade will at least keep the whole thing from rusting apart prematurely. Like I said before, since the labor costs for installation will be high, I would like know they won't rust apart when the coating eventually fails. Mild steel is only used in exhaust systems for one sole reason - cost reduction.

When the internal coating fails (which you can't see from the outside) you will have surface rust on the inside of the header. This iron oxide can contaminate the O2 sensors causing them to fail prematurely. Even JBA makes their headers mainly from 409 steel and they don't cost more than the Doug Thorleys. If these headers were at least made from 409 steel, I'd purchase them in a heart beat, coated or not.

[jkd]

Couldn't agree more, Thumbster. Another thing to consider, the stock stainless headers are heat-wrapped to protect all the components in that confined area and most aftermarket headers are well known for barbequeing the starter, etc, after a period of time. If you take a look, even the stock ones are agony to remove and install so if a starter, etc, fails due to aftermarket headers, with the extra labor involved, flat-rate gets thrown out the window and it's going to be strictly time and materials payed for by the customer, not a Toyota warranty issue.

[mike100]

I think thumbster answered his own question..Nobody can make tig up decent set of stainless pipes because the welds fail. I would never buy another set of stainless myself (because I do my own labor).

[LSKustumz]

Ok, well I hope everyone had a good weekend!

I have seen MANY different posts on here about the racing concepts. I don't need a lesson on drag racing. That is not my profession and something that I really don't know much about. I would like to learn more, but thats what I do in other threads. I appreciate the banter to bump the thread but please, lets keep on the subject at hand. It is an awesome truck, don't get me wrong. But talking like these things are gonna be on strip in February at Pomona is a little far fetched for most people. They are not drag trucks nor intended from the manufacture to do so. If you want a exhaust that flows top end and give you the up-most top end performance, get some zoomies installed and gut your cats and remove all the charcoal cannisters lol. Fact is, these headers are great for the daily driver looking for better street performance and towing. We have to conform to C.A.R.B. and also make them affordable to the consumer. It kills me when people think that it is easy to make performance on all the newer cars and trucks. And fact is, it is becoming tougher because of smog restrictions, and warranty issues. If we were concerned with the drag strip performance of these, they would not be the same. And the fact about materials for the headers, there are many different opinions on materials. But you don't mess with what is working. Doug Thorley has been around for 50 years. We are not JBA or any other exhaust shop that blows through town every 2-3 years. We trust our methods because they have worked, and continue to work. We want to make an affordable performance add on for the aftermarket enthusiast. And our method has proven just that.

I am always open to answering questions about our headers. Whether it is something critical or not. Thats what I am here for, positive or negative scrutiny, I am here to answer directly to the consumer.