Bgw70

you are correct outside of the USA before 2005. In the US it was 300hp due to SAE rating system.

U.S. automakers continue to use SAE net ratings, but in 2005, the SAE issued a new standard, J2723, which clarified and amended the existing methodology, among other things requiring that a suitably qualified independent observer be present during the rating procedure. Some engines measured under the new “SAE Certified Power” guidelines ended up with lower ratings than before while a few other actually ended up with higher ratings. In most cases, the engines were not actually altered in any significant way; the changes were in the test methodology. Most if not all manufacturers now use this methodology for the U.S.-market cars and trucks.

https://ateupwithmotor.com/terms-tec...et-horsepower/

Wolfhouse

This is all very interesting to learn, and ill make sure to double-check my facts better in the future, sorry for posting misinformation.

That being said, what I've found after doing more research is that the German and other European automakers use their own standard. How separate/different are these measurements from the new SAE? If they are different, do cars like the M6 really put out as much as they say they do? I believe it is called DIN testing and is similar to the way we used to test circa 1972, based on Gross HP?

OBP

Dunno about the M6 but on German cars, I do believe the hp rating on my CLS550 is inaccurate. MB declared it as 402 or so and tuners who have worked with this engine ( M278 v8 4.7 twin turbo ) did dyno tests etc after their tuning which yielded 520+ or - hp for a tuned CLS550. . Working backwards and after applying what they expected their tuning should have produced for such an engine ( subtracting their estimated hp gains for the tune ) the deduced hp pre tune for the engine in my CLS is about 430-440. So MB is mis-declaring the output on my engine but I doubt anyone is going to be upset about that. I'm perfectly good with it. To try to bring this back on topic though, wonder whether the LC500 engine really puts out what Lexus says it does. Have not test driven an LC but I did test drive an RCF in the past - same engine I think as the LC ( please correct me if otherwise ) and it feels pretty good from a seat of the pants dyno.

Bgw70

what standard did your Dynometer shop use for the hp rating?

Wolfhouse

I brought this up on this thread as I found it relevant to the varying calculations, and whether it is possible/reasonable to compare the SC to other foreign manufacturers or if the HP would be higher or lower, and which is the most accurate measurement.

Kira X

iTrader: (24)

I wish the 3UZ came with more power stock. I have an LS430 and would like to add an SC430 and LX470 to my collection. I installed a bigger exhaust on my LS and it didn't do a whole lot. The only way to get serious power out of these engines is through a turbo or supercharger.

OBP

will send PM cos we are getting off topic - I know where your logic might be going and I thought of that too but dunno the answer for sure.

hotrodsrj

I thought I would chime in here on the original question. Horsepower formulas are pretty basic in-so-far as four-cycle, gasoline, internal-combustion engines. It all boils down to these variables regardless of turbos, superchargers, injected, carbed, whatever? The basic horsepower calculation takes these into account: type of fuel (ie gas, methanol, nitro), cubic inches, peak power rpms, volumetric efficiency, compression ratio, If you change any one of these you will change the hp!

bacardi11

iTrader: (1)

guys do not use a tubo or charger on your 4.3 430sc you are looking for big trouble.
21/2" exh. setup is the best only 2 free flowing cat. x pipe free flow mufflers you can use free flow res. also headers OBX are nice.
this will give all you need and you will be A HAPPY CAMPER
Stainless Steel exh. the best but no cheap

NocGTR

The 3UZ was designed when the Japanese was still under the "Gentleman's agreement" of 280 hp maximum output.
That is why everything was 280 hp back in the days.
I think Nissan was the first one to "break" that agreement, then everyone follow after.
If you look at the Nissan Skyline GTR back in the days, it claimed 280 hp on paper but when put on a dyno they were all making over 300 hp.

So Lexus basically tune the engine to make that 280hp, then tune the rest to make torque.
The result is an over engineered and reliable engine, that is packaged relatively well in terms of size and weight.
Toyota try not to use any technology that isn't well tested and proven; they aren't early adaptor like the European are.

If you look at Audi who was the first adaptor for FSI (direct injection) technology.
Great on paper because it makes much more power, burn cleaner, and all that other good stuff.
Then you see cars like Audi S5 and the Audi RS4 V8 all have intake valve carbon build up after only 10,000 miles.
Great on paper, works perfect in the lab... Not so well in the real world and certainly not something I would want in my car.

Enjoy the 3UZ engine, it is one of the best V8 ever made if you ask me.