!!Doug Thorley Headers 4.7L V8!!

[sumday]

winter to summer blend change?

i think the claims about mileage increases with headers is more hype than reality

 

[atalarico]

winter to summer blend change?

i think the claims about mileage increases with headers is more hype than reality

I could have sworn I saw most everyone with DT headers claim a 2mpg bump! Ah well. I knew it was too good to be true. There is definitely a power bump though, but I've been a good boy and try not to abuse it when I'm trying to compare apples to apples mpgs.

 

[That_Titanium_4RNR]

I could have sworn I saw most everyone with DT headers claim a 2mpg bump! Ah well. I knew it was too good to be true. There is definitely a power bump though, but I've been a good boy and try not to abuse it when I'm trying to compare apples to apples mpgs.

You would probably only see a difference if you had a MAJOR exhaust leak, and even that difference would probably be very slight if at all. Mine has a bad leak and is 4wd. My gf's mom has a 2wd v8 and hers doesn't leak and has nearly identical mpgs

 

[blackoutt]

Too hard to calculate a mpg change with so many different variables in fuels, temps, terrains, adding bigger tires, more wind resistance, hauling more or less shtuff. The biggest header gain I found was just in driveability/response and also less downshifts on slight grades on the interstate (with stock size tires and gearing).

 

[atalarico]

You would probably only see a difference if you had a MAJOR exhaust leak, and even that difference would probably be very slight if at all. Mine has a bad leak and is 4wd. My gf's mom has a 2wd v8 and hers doesn't leak and has nearly identical mpgs

Mine was major and getting worse. It sounded like a poorly tuned v12 Merlin engine, and exhaust would come in the cabin when at a stop or standstill for too long.

So yeah, I was hoping to see some improvement.

 

[atalarico]

Too hard to calculate a mpg change with so many different variables in fuels, temps, terrains, adding bigger tires, more wind resistance, hauling more or less shtuff. The biggest header gain I found was just in driveability/response and also less downshifts on slight grades on the interstate (with stock size tires and gearing).

I get that, which is why I'm taking the weekly average of similar trips to the mountains combined with my commute. I'll let it average out longer and see if goes up from there.

 

[Jason B]

[MENTION=9]Jason B[/MENTION] makin it happen!

Happy to help, it's been a long road and you guys helped make all this happen too!

Long vs short some say the long tubes are better for high-end power while the short tubes have more low-end response but it depends on what article you read, some actually say the opposite. The tube diameter seems to make a larger difference in performance.

The biggest difference, specific to our application, is that the DT short tube headers don't have a flange welded to them, which means you can add cats to them but you have to make a jig and get them welded in the correct position to match up to the factory piping. These new long tubes travel all the way to the flanges, deleting the cats, so these are purely 'bolt on'. No need to pay a welder or spend a bunch of time getting it set up.

Dyno numbers between the two might be interesting but they'll both be way better than stock.

Very good reply. Glad I didn't need to type that out Main reason was to eliminate the need for welding and many guys on here want to install themselves at home. Now, the shorties are for those that live in a state that makes you have cats, etc. But some states only care if you have a check engine and it doesn't matter if there aren't cats, but you can fix that with the CEL eliminators I sell, which are cheap!

what makes you think that the shorties with correct cats wouldn't pass inspection?? I am in NC and they currently still do emissions testing and I was planning on running shorties with cats welded on and stock y-pipe

You can do that, I sell both the short and the long. You'd just need to CEL eliminators, but better yet I can sell you high flow cats with the shorties that each give about 7 hp per cat over the factory cats, and no check engine with the cels.

Doug Thorley 03-04 SHORTY headers ORDER LINK

Doug Thorley 05-09 SHORTY headers ORDER LINK

For those that want LONG tubes and the DT Y pipe, call or text me at 717-319-2100 - I'm here all weekend too. EVERYTHING now in stock again!

 

[sumday]

You can do that, I sell both the short and the long. You'd just need to CEL eliminators, but better yet I can sell you high flow cats with the shorties that each give about 7 hp per cat over the factory cats, and no check engine with the cels.

so even shorties with cats need cel elimnators???

 

[Toyrundrive]

winter to summer blend change?

i think the claims about mileage increases with headers is more hype than reality

Can confirm: rig weighs 6000lbs, got at least 2mpg increase from headers, high flow cats, and a super 50

 

[That_Titanium_4RNR]

You can do that, I sell both the short and the long. You'd just need to CEL eliminators, but better yet I can sell you high flow cats with the shorties that each give about 7 hp per cat over the factory cats, and no check engine with the cels.

So the cel eliminators you're talking about are the "extender" style right? Where the space the o2 sensor away from the airflow? Also if I would need these for the stock cats then I would definitely need them for aftermarket ones. Yeah when I'm ready to buy I will definitely be hitting you up and checking out some different options.

 

[Jason B]

so even shorties with cats need cel elimnators???

It's 50/50. But 100% if you go with high flow cats with the shorties. I sell them and it's not big deal. You only need (2), I have them in stock, and $24 shipped to your door. Most people call me to order these as they have questions and it's a big purchase and I explain everything to them over the phone. I have awesome high flow magnaflow cats that work with these and give 7hp extra PER CAT!

Can confirm: rig weighs 6000lbs, got at least 2mpg increase from headers, high flow cats, and a super 50

Yes, you didn't hear wrong! I've had others tell me 3-4 more MPG highway, on stock tires, cruising at 65 mph. Again, this was HIGHWAY. Everyone has been pleased with the gain in MPG. Not sure what other poster wasn't seeing the same. I'd pull the negative on the battery to reset the ecu for that.

So the cel eliminators you're talking about are the "extender" style right? Where the space the o2 sensor away from the airflow? Also if I would need these for the stock cats then I would definitely need them for aftermarket ones. Yeah when I'm ready to buy I will definitely be hitting you up and checking out some different options.

Yes, well, I have pics of them installed. They are cheap and do the trick luckily.

ANYONE THAT WANTS TO ORDER, call or text me at 717-319-2100 - I have pics of the extenders too. Long tubes and Y pipes IN STOCK.

 

[dropspace]

FWIW I did not get a CEL and did not use the eliminators. DT Shorty headers and magnaflow high flow cats.

Full custom exhaust all the way back, not sure if that matters. The shop that did it specializes in Toyotas so maybe they knew how to space the sensors correctly. I also probably got lucky.

Shared album - Jonathan Stevens - Google Photos

 

[sumday]

looks like a nice setup...loud?

 

[dropspace]

Shared album - Jonathan Stevens - Google Photos

It blew the phone over at the end but you get the idea haha.

Its fairly quiet at idle, sounds mean when you stand on it.

overall its night and day with power and throttle response from stock. I tow a lot and really enjoy the added torque. Not enough data yet on any MPG increase, but that wasn't my primary goal.

 

[Formidable]

That sounds amazing. Love the way this V8 opens up with exhaust mods

Shared album - Jonathan Stevens - Google Photos

It blew the phone over at the end but you get the idea haha.

Its fairly quiet at idle, sounds mean when you stand on it.

overall its night and day with power and throttle response from stock. I tow a lot and really enjoy the added torque. Not enough data yet on any MPG increase, but that wasn't my primary goal.

 

[aaronmjr]

I hope I don't have to anytime soon, but if my stockers crack, I'm totally going this direction. They look and sound amazing!

 

[Marfy]

What exhaust is that? Mine is way more raspy.2007 Toyota 4Runner - V8 - Clyp

 

[Ed_C]

FWIW I did not get a CEL and did not use the eliminators. DT Shorty headers and magnaflow high flow cats.

Full custom exhaust all the way back, not sure if that matters. The shop that did it specializes in Toyotas so maybe they knew how to space the sensors correctly. I also probably got lucky.

What exhaust is that? Mine is way more raspy.2007 Toyota 4Runner - V8 - Clyp

I'm going to guess Magnaflow X-pipe with Dynomax Race Bullet mufflers

 

[Jason B]

I hope I don't have to anytime soon, but if my stockers crack, I'm totally going this direction. They look and sound amazing!

No check engine lights. I know how to make these work with no codes with just about ANY setup too. I also, now have the LONG TUBES in stock, which need NO WELDING but those won't ever be carb approved for CA obviously, but some still do them in CA somehow. IF you want long tubes and the new Y pipe, call or text me at 717-319-2100 or order below.
Alot of time and work to get these done but was all worth it.

Calling all V8 owners that want a high flow Y-pipe!!! I can do it. Need your help!

Doug Thorley 03-04 headers, SHORT AND LONG TUBES

Doug Thorley 05-09 headers, SHORT AND LONG TUBES

Also, the Gibson catback, which pairs great with these headers, also on sale!

Gibson 4th Gen exhaust

 

[sumday]

FWIW I did not get a CEL and did not use the eliminators. DT Shorty headers and magnaflow high flow cats.

Full custom exhaust all the way back, not sure if that matters. The shop that did it specializes in Toyotas so maybe they knew how to space the sensors correctly. I also probably got lucky.

got a pic of the headers with sensors?