- Thread starter
- #21
They did tell me that they (URD) have a cat back exhaust system going into production soon for the GX460, so they are paying attention to the GX460 market.
GX460 headers (1 Viewer)
- Thread starter giovanni
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That’s good news!
What kind of gains is URD hoping to see with a full exhaust system? Seems like there is a lot of opportunity to improve power output from this engine, but I have't looked into what the low-hanging fruit would be.
- Thread starter
- #24
They didn't say at all, and I don't think they have any stated gains for the other 4.6l or 4.7l applications that they do have headers / exhaust for.
Building the 4.6 / 1UR-FE is hard to find info on, but I did read some things that lead me to believe there's 30 or 40 hp to be gain by freeing up the exhaust flow.
I'm certainly no expert here, but seems reasonable. Take a look at the exhaust manifolds and they are obviously restrictive compared to any modern performance application.
Building the 4.6 / 1UR-FE is hard to find info on, but I did read some things that lead me to believe there's 30 or 40 hp to be gain by freeing up the exhaust flow.
I'm certainly no expert here, but seems reasonable. Take a look at the exhaust manifolds and they are obviously restrictive compared to any modern performance application.
r2m
Richard
To gain 30-40 hp, I would assume one would also need to open up the intake with some type of low restriction induction system like an air cleaner, snorkel, turbo, super charger, etc. In my experience, to be able to get a freer flowing exhaust you have to have a freer intake. You can only exhaust what is coming in through the intake. You have a 6" straight pipe coming right out of your exhaust ports on your heads, but it won't help if you only have a 1/2" intake manifold. Okay, so I'm exaggerating a wee bit here, but hopefully the point is made.
Taking it a step farther, that's why many will "port" their heads, to make the intake and exhaust ports larger to allow larger diameter intake and exhaust manifolds. And they'll even polish these ports to allow a smoother, less restricted air flow in and out of the piston chamber (cylinder), but I'm getting a little carried away now.
Please forgive the redundancy for any hot rodders that already know this.
But more back to the topic, I'd like the added ponies, but it's hard when it might compromise good 'ol Lexus (Toyota) longevity. After all, isn't that why we buy these? Because they definitely are not the best looking SUV, best MPG, best technology, nor most modern... But they are comfortable and do last forever!
- Thread starter
- #26
The general assessment that I read was that the intake system was capable of flowing much more than the exhaust on this engine platform. The injectors have enough bandwidth headroom to put in a little more fuel too, so there *should* be some real gains.
I've never seen a free flowing exhaust compromise reliability - the problem comes when you start jacking up compression, running very aggressive timing, forced induction, etc.
I've never seen a free flowing exhaust compromise reliability - the problem comes when you start jacking up compression, running very aggressive timing, forced induction, etc.
IMO: Not hard to believe that Lexus left motor in a relatively detuned state for reliability
I see the tuners in Russia get around 30 extra HP with tunes. Not sure of torque. Granted it appears the tune is based around a complete removal of emissions a well.
Let browser translate
www.drive2.ru
www.chiptuning-remap.com
IIRC... someone mentioned on GXOR a tuner that felt that 30-40HP was doable without any exhaust changes.
I see the tuners in Russia get around 30 extra HP with tunes. Not sure of torque. Granted it appears the tune is based around a complete removal of emissions a well.
Let browser translate
Прошивка Lexus GX460 URJ150 Denso 89663-60E74
Прошивка для автомобиля Lexus GX460, кузов URJ150, двигатель: 4.6i бензин, 1UR, блок управления: Denso, версия программного обеспечения: 89663-60E74, в прошивке отключен контроль катализаторов (Е…
www.drive2.ru
Готовые прошивки
www.chiptuning-remap.com
IIRC... someone mentioned on GXOR a tuner that felt that 30-40HP was doable without any exhaust changes.
Not headers but while we are on the performance subject
www.suprastore.com
XAT Racing Exclusive 3URFE 1UR-FE 3UR Performance Camshafts
Now that we have finished our run of UZ VVTi cams, we're gearing up for performance parts for the latest Toyota V8s, the UR series! Our initial batch will be a group buy. We will need 6 sets sold to get it going, and after that, expect pricing to go up. These cams will be for anyone looking to...
So full exhaust + tune + EGR delete may yield anywhere from 50-90bhp? That’s pretty impressive. Getting close to 400bhp and likely over 400tq would really improve the 460 by a large margin. Plus it would be mega fun in a straight line.
r2m
Richard
Hate to be the wet blanket here, but so often horsepower and torque are spewed out like fishermen telling stories of just how big their catch was.
They're always using a rubber ruler to measure their catches.
Unless I see graphical proof, it's really hard to take seriously exactly how much HP is hitting the rear wheels.
Which brings up another point, is HP being measured at the drive shaft (read: higher numbers) or at the rear wheels, which is what really matters.
Heck, even manufacturers stretch their engine size and horsepower rating a wee bit.
They're always using a rubber ruler to measure their catches.
Unless I see graphical proof, it's really hard to take seriously exactly how much HP is hitting the rear wheels.
Which brings up another point, is HP being measured at the drive shaft (read: higher numbers) or at the rear wheels, which is what really matters.
Heck, even manufacturers stretch their engine size and horsepower rating a wee bit.
A lot of claims that the 1UR-FE was used in the 2008-2011 GS 460 in middle eastern markets and rated at 347HP in that application. I thought most manufacturers started rating at the wheels by the late 70s/early '80s? No idea how others rate. I'm curious to see what others do for these mods... I'm keeping mine stock in that department.
Pricing is AUD
I see the cylinder heads are the same for the 1UR-FE and 3UR-FE
www.oemvehicleparts.com
Perhaps a way to connect 3UR-FE designed headers using 3UR-FE manifolds bolted to 1UR-FE?
2007-2017 Toyota Cylinder Head 11101-38H20 | OEM Vehicle Parts
Cylinder Head - 1110138h20. Genuine Toyota® Parts & Accessories. Manufacturer Warranty. From the Dealership to your Door.
www.oemvehicleparts.com
Perhaps a way to connect 3UR-FE designed headers using 3UR-FE manifolds bolted to 1UR-FE?
- Thread starter
- #36
I saw that supercharger - tempting. 
On the 3UR headers potentially working ... that doesn't solve the vehicle specific fitment issue so not sure that helps much. It is surprising that the heads are the same p/n!
On the 3UR headers potentially working ... that doesn't solve the vehicle specific fitment issue so not sure that helps much. It is surprising that the heads are the same p/n!
Not a wet blanket. Need to determine what the driveline % loss is then we can use the brake horsepower / flywheel horsepower then calculate the power at the wheels.
Another question is has anyone dyno’d a low mileage / new GX460 to get a factory baseline? This is all in my wheelhouse coming from modding fast cars, may not know much if anything about off-roading but I know speed. I’d love to see a sample size of GX460’s of varying years all with low mileage to see what the actual output both crank and wheel power would actually be. I’m willing to bet these are detuned a decent amount for reliability.
No, still rating power at the flywheel.
Unfortunately .... I can't remember seeing any 460s dyno'd. A chance there are some test Tundras with 1UR-FE that may give some idea even though official engine ratings are slightly different.
I was confusing the old net versus gross HP ratings.
I was confusing the old net versus gross HP ratings.
I'd be surprised if headers, cams, exhaust, and intake got more than 30hp.
Bumping this thread. So I’m interested in possibly pursuing this either in Q4 or in early 2022. The air injection ports are for the SAIP? Could one simply delete that altogether? A good less restrictive exhaust along with a less restrictive intake and an ECU tune should give us a reasonable boost in performance as a good first step before forced induction.
