# De-tuned 280 HP engines by the japanese government?



## S14240SR (Aug 20, 2004)

I heard that the japanese government only allows cars in japan to have no more than 280 HP. If skylines in other countries are pushing close to 330hp stock (which is what I heard) then what does japan do to restrict the extra horsepower?


----------



## Joel (Jun 11, 2003)

nothing. 'officially' they have 280ps. 'Unofficially" they dont.


----------



## tougedrifter (Sep 17, 2004)

the whoel deal is complicated. but its not imposed by the japanese government. it was a gentlmens agreement between japanese and european auto makers basically saying that they wont put street legal cars under production with more than 300 horsepower at the wheels. which is why the sti and the evo and skyline barley skim the surface. "officially" GT-R's have 276 to the wheels, but put it on a dyno and youll see low-mid 300 horses.


----------



## Pete-flint (Jul 29, 2003)

Air intake and exhaust inhibit performance on most home market cars. First mods are new induction kit and a straight through big bore exhaust system with possible de-cat.


----------



## ReVerm (Jan 13, 2003)

tougedrifter said:


> the whoel deal is complicated. but its not imposed by the japanese government. it was a gentlmens agreement between japanese and european auto makers basically saying that they wont put street legal cars under production with more than 300 horsepower at the wheels. which is why the sti and the evo and skyline barley skim the surface. "officially" GT-R's have 276 to the wheels, but put it on a dyno and youll see low-mid 300 horses.


Good news for us though is the still not widely known fact that some Japanese companies are officially beginning to ignore the 280ps restriction for cars sold in Japan. The Japanese Market Honda Legend (Acura RL in the US) is amongst several new(er) cars now sold in Japan which claim 300ps official output.


----------



## Token Moron (Mar 28, 2003)

its not a law...its just an "agreement". no one is holding the japanese market from producing more than 280hp


----------



## ReVerm (Jan 13, 2003)

cHoPs said:


> its not a law...its just an "agreement". no one is holding the japanese market from producing more than 280hp


The first part is true. However, it is also an undeniable fact that Japanese manufacturers have been following this "agreement" (albeit loosely at times) and have been limiting the output of their products (de-tuning, as some call it) because of it. It is also fact that the original agreement stated that Japanese auto manufacturers which grossly violate the 280ps restriction would be barred from certain PR events. Even if it wasn't law, there were reasons for manufacturers to abide by the rules they set.


----------



## Zen31ZR (Mar 24, 2004)

In any case, the 280 Hp "restriction" not been followed since the early-mid 90s. The Supra TT at 300 Hp, the 3000GT at 320 Hp, the 300Z TT at 300 Hp, the list goes on......


----------



## ReVerm (Jan 13, 2003)

[email protected] said:


> In any case, the 280 Hp "restriction" not been followed since the early-mid 90s. The Supra TT at 300 Hp, the 3000GT at 320 Hp, the 300Z TT at 300 Hp, the list goes on......


You guys are missing the point. There's a difference between going a bit over without telling anyone and being able to release 400ps machines without having insurance companies and competing manufacturers glaring down at you for your actions.


----------



## BII (May 13, 2004)

tougedrifter said:


> the whoel deal is complicated. but its not imposed by the japanese government. it was a gentlmens agreement between japanese and european auto makers basically saying that they wont put street legal cars under production with more than 300 horsepower at the wheels. which is why the sti and the evo and skyline barley skim the surface. "officially" GT-R's have 276 to the wheels, but put it on a dyno and youll see low-mid 300 horses.


THe WRX is also limited by homologation/HP limits imposed by WRC rules. WRC cars are limited to only 300 HP.

This gentlemen's agreement is similar to the rule GM had for its divisions back in the 60s, that no intermediate size cars were allowed to have a V-8, it wasn't a law or anything, but Delorean added one as an option to the Tempest and started the Muscle car era. Maybe if one Japanese maker blatently breaks the agreement (like a 400HP car) the others will be forced to do it as well, like with what happened with the GTO. I doubt it, given the conservative nature of the Japanese auto-makers' management.


----------



## tougedrifter (Sep 17, 2004)

[email protected] said:


> In any case, the 280 Hp "restriction" not been followed since the early-mid 90s. The Supra TT at 300 Hp, the 3000GT at 320 Hp, the 300Z TT at 300 Hp, the list goes on......



the horsepower restriction was to the wheels i thought. because the 300z TT was at the same spot as the skyline at 276. maybe its at the flywheel :?.


----------



## Kouki S14 (Dec 24, 2004)

It was 280hp at the wheels.
Recently the agreement has been overlooked by a few companies and it appears that soon everyone will forget about it.
Even though some supras and 300zx's have been over the 300hp mark, on paper they all said 276hp.


----------



## Zen31ZR (Mar 24, 2004)

Kouki S14 said:


> It was 280hp at the wheels.
> Recently the agreement has been overlooked by a few companies and it appears that soon everyone will forget about it.
> Even though some supras and 300zx's have been over the 300hp mark, on paper they all said 276hp.


 On Japanese paper, maybe. On American paper they are as I stated.


----------



## tougedrifter (Sep 17, 2004)

[email protected] said:


> On Japanese paper, maybe. On American paper they are as I stated.



haha thats because us americans are stupid when it comes to cars. they market cars with numbers at the crank so it looks like they have more useable power than they really do.


----------



## BigBlueR32 (Sep 29, 2004)

tougedrifter said:


> haha thats because us americans are stupid when it comes to cars. they market cars with numbers at the crank so it looks like they have more useable power than they really do.


Just exactly...


----------



## Zen31ZR (Mar 24, 2004)

In that case, the actual Hp rating on the American version of the Mk-4 Supra was 326.
The horsepower measurments are all taken in the the same area, IE the flywheel, it's simply the difference between metric Hp and SAE Hp. You don't beleive me , google it........


----------



## TSXtacy (Jan 15, 2005)

Well unofficially, the HP limit was lifted by the new Honda Legend (Acura RL). The government allowed for them to market it as a 300 HP car. Good move, now Nissan can really exploit their resources for the new GT-R :cheers:


----------



## GTES-t (Jan 2, 2004)

[email protected] said:


> In that case, the actual Hp rating on the American version of the Mk-4 Supra was 326.
> The horsepower measurments are all taken in the the same area, IE the flywheel, it's simply the difference between metric Hp and SAE Hp. You don't beleive me , google it........


It's not simply the difference of metric/SAE hp. The Japanese "agreement" is for 280 PS (metric HP) which equals just over 276 HP.
Tougedrifter is right, Americans easily fall for the HP figures. Whithout knowing what they truely are. Most vehicles are sold in the US with a bhp (brake horsepower) figure, the power at the crankshaft.

Now, the Japanese "agreement" was never made for a specific hp test location or conditions. So, most Japanese high hp vehicles are sold with the whp (wheel horsepower) figure, the power at the drive wheels. 

Now, take a factory GTR, put it on a dyno, and it will usually beat the 276hp. This is due to one other trick the manufacture does, they take their final PS figure, if it's over 280, they factor in power loss due to road friction, wind, etc. and amazingly, all the Japanese perfomance vehicles match 280ps exactly, on Japanese paper.


----------



## Zen31ZR (Mar 24, 2004)

GTES-t said:


> This is due to one other trick the manufacture does, they take their final PS figure, if it's over 280, they factor in power loss due to road friction, wind, etc. and amazingly, all the Japanese perfomance vehicles match 280ps exactly, on Japanese paper.



Road friction, wind and etc does not cause a _loss of power_ , it simply increases "road hp", the power required to keep the vehicle moving at a steady speed on a flat surface at a certain mph. It used to be tested at 30,50 and 70 mph, not sure what it is now. The only place power losses can actually occur after the engine, is in the drivetrain.


----------



## TSXtacy (Jan 15, 2005)

[email protected] said:


> Road friction, wind and etc does not cause a _loss of power_ , it simply increases "road hp", the power required to keep the vehicle moving at a steady speed on a flat surface at a certain mph. It used to be tested at 30,50 and 70 mph, not sure what it is now. The only place power losses can actually occur after the engine, is in the drivetrain.


 :thumbup: 

well said! simply physics, basically. Higher the Friction Force is, the higher the Applied Force needs to be.


----------



## GTES-t (Jan 2, 2004)

[email protected] said:


> Road friction, wind and etc does not cause a _loss of power_ , it simply increases "road hp", the power required to keep the vehicle moving at a steady speed on a flat surface at a certain mph. It used to be tested at 30,50 and 70 mph, not sure what it is now. The only place power losses can actually occur after the engine, is in the drivetrain.


I'm aware that these do not cause an actual power loss from the vehicle. I was speaking in general terms. 
This is how Japanese companies used to manipulate their power figures to fit within the "agreement" though. That way they could say that the power was "equivalent" to 280ps on the road (known in the US as "rolling HP"), after these factors, even though it would dyno higher. It's the same basic concept used in weather with wind chill. It may be 50, but due to wind chill it feels like 45.
Here's an example of a calculator for figuring out the amount of aerodymanic and rolling HP required.
http://www.bgsoflex.com/aero.html



TSXtaxy said:


> well said! simply physics, basically. Higher the Friction Force is, the higher the Applied Force needs to be.


That's the problem, physics are not simple. As you said, the higher friction force, requires a higher applied force. 
Since, you're figuring this out for a vehicle's max hp, you do not have any more hp to apply. So the extra HP required to overcome that drag and friction, can be calculated as a Rolling HP loss.


----------



## Zen31ZR (Mar 24, 2004)

GTES-t said:


> I'm aware that these do not cause an actual power loss from the vehicle. I was speaking in general terms.
> This is how Japanese companies used to manipulate their power figures to fit within the "agreement" though. That way they could say that the power was "equivalent" to 280ps on the road (known in the US as "rolling HP"), after these factors, even though it would dyno higher. It's the same basic concept used in weather with wind chill. It may be 50, but due to wind chill it feels like 45.
> Here's an example of a calculator for figuring out the amount of aerodymanic and rolling HP required.
> http://www.bgsoflex.com/aero.html
> ...


 "road Hp" losses alone would not bring such a car as say, the TT Supra, in line with it's supposed 276-280 whatever Hp rating. Road Hp on that car, even at 70 mph, was supposedly less than 25. Less than 20, if I remember right. Most regular cars total less than 20 road Hp. Only SUVs and very heavy high Hp luxury sport (SL55 AMG) cars have gone higher. Wind resistance is a big factor in road Hp, the Supras slick shape keeps it from losing too much.


----------



## GTES-t (Jan 2, 2004)

Looking at the Supra figure you posted earlier. You shouldn't have to factor in the road HP. As you said, it's at the flywheel, so it doesn't factor in the drivetrain loss. The power loss through drivetrain is usually anywhere in the range of 15-25% depending on who you talk to.
Giving the 326 bhp the 15% loss, that makes around 49 hp drivetrain loss. That gives it a 277 whp figure, which is pretty much the 280ps.
That fits right into the Japanese on paper figure.

The R34 GTRs were being driven right off the showroom floors, and dyno'ing around 300PS or more. These are cars that they did the extra factoring of road hp, so that they would be 280PS on paper.

These are just how the Japanese manufactures got their cars to fit in under their 280ps "agreement." I'm not saying they didn't fudge the figures a bit to do it (claim more drivetrain power loss, more road hp effect) because it's well known that they did.

Otherwise, it'd just be an amaxing coincidence that the 300zx tt, Skyline GTR's, top end Supras and NSXs all have exactly 280ps in Japan... on paper!


----------



## Marty01 (Dec 20, 2004)

interesting read up.. indeed 

but this is NOT limited to Japanese production cars

lest we forget the domestics fudging the numbers for insurance reasons...


1969 Camaro Z28 with for example...


----------



## Zen31ZR (Mar 24, 2004)

GTES-t said:


> Looking at the Supra figure you posted earlier. You shouldn't have to factor in the road HP. As you said, it's at the flywheel, so it doesn't factor in the drivetrain loss. The power loss through drivetrain is usually anywhere in the range of 15-25% depending on who you talk to.
> Giving the 326 bhp the 15% loss, that makes around 49 hp drivetrain loss. That gives it a 277 whp figure, which is pretty much the 280ps.
> That fits right into the Japanese on paper figure.
> 
> ...


With the AWD, though, drivetrain losses approach 20% or more. I've seen Skyline dynos of 325 to 368 Hp, _all stock, no mods_. But that's _ON THE GROUND_, given the nature of how a dyno works. That's _after_ drivetrain loss occurs, because the dyno reads the Hp transmitted to it's rollers, in this case the ground. You can't _fudge_ that. I would say it's more like the Japanese just have been outright lying for years, and the Hp agreement was pointless, since they've apparently not paid much attention to it anyway......


----------



## tougedrifter (Sep 17, 2004)

[email protected] said:


> With the AWD, though, drivetrain losses approach 20% or more. I've seen Skyline dynos of 325 to 368 Hp, _all stock, no mods_. But that's _ON THE GROUND_, given the nature of how a dyno works. That's _after_ drivetrain loss occurs, because the dyno reads the Hp transmitted to it's rollers, in this case the ground. You can't _fudge_ that. I would say it's more like the Japanese just have been outright lying for years, and the Hp agreement was pointless, since they've apparently not paid much attention to it anyway......



neither did many of the european car manufacturers who were the other party in the agreement. both sides took alitlte from the agreement, but they stayed around the same area.


----------



## ReVerm (Jan 13, 2003)

[email protected] said:


> With the AWD, though, drivetrain losses approach 20% or more. I've seen Skyline dynos of 325 to 368 Hp


Wow. Where did you see that? I have never seen 368awhp for a stock GTR coming out of a properly calibrated AWD dyno (which tend to do strange things with ATTESA equipped cars even when properly set up).


----------



## GTES-t (Jan 2, 2004)

I've never seen stock GTR's dyno that high. I was in Japan 4 years, and the highest I've seen a stock GTR dyno was 320ps, and that was because the front driveshaft was disconnected. Other then that, all the awd dynos averaged around 300ps. Which puts Nissan the right area to fudge the numbers with rolling hp loss.


----------



## Zen31ZR (Mar 24, 2004)

You should have seen the outrageous dynos for R34s, then. 330-350 from the Vspec II and upwards around 400 for the Nur. This is, granted, recalculated to engine (IE flywheel) Hp, but with over 330 at the wheels. Maybe in range for fudging the numbers, but obviously with the big bump in torque the R34 has over the R33, there would be additional Hp as well. Soon as I find something definitive, I'll post it. There is a video I found of an R34 V-spec-II dynoing 360 kw with only filter mods, but I'm sure you guys wouldn't treat that as stock....


----------



## ReVerm (Jan 13, 2003)

[email protected] said:


> You should have seen the outrageous dynos for R34s, then. 330-350 from the Vspec II and upwards around 400 for the Nur. This is, granted, recalculated to engine (IE flywheel) Hp, but with over 330 at the wheels. Maybe in range for fudging the numbers, but obviously with the big bump in torque the R34 has over the R33, there would be additional Hp as well. Soon as I find something definitive, I'll post it.


There are a number of videos and dyno plots out there which seem to be showing something insane at first, but are actually the result of the AWD dyno not being set properly (AWD dynos do not like cars which can do a 100/0 or 0/100 center torque split). When the Vspec and Vspec-II came out, a number of smaller Japanese car magazines jumped the gun and published articles claiming that Nissan was blatantly violating the 280ps restriction. It turned out later that these magazines were either using the results of an inconsistent run or were using a dyno which was not calibrated. Best MOTORing and Engine had a field day with that one.

The torque increase with the R34 doesn't affect peak power much. Transpose a R33 dyno chart over a R34 dyno chart and you'll see that the extra torque doesn't do too much around 6800 rpms, where the R34 GTR makes peak power.



[email protected] said:


> There is a video I found of an R34 V-spec-II dynoing 360 kw with only filter mods, but I'm sure you guys wouldn't treat that as stock....


I think I know which one you're talking about. Let me see if I can find the one I'm thinking of.


----------



## Zen31ZR (Mar 24, 2004)

ReVerm said:


> There are a number of videos and dyno plots out there which seem to be showing something insane at first, but are actually the result of the AWD dyno not being set properly (AWD dynos do not like cars which can do a 100/0 or 0/100 center torque split). When the Vspec and Vspec-II came out, a number of smaller Japanese car magazines jumped the gun and published articles claiming that Nissan was blatantly violating the 280ps restriction. It turned out later that these magazines were either using the results of an inconsistent run or were using a dyno which was not calibrated. Best MOTORing and Engine had a field day with that one.
> 
> The torque increase with the R34 doesn't affect peak power much. Transpose a R33 dyno chart over a R34 dyno chart and you'll see that the extra torque doesn't do too much around 6800 rpms, where the R34 GTR makes peak power.
> 
> ...


 HERE Unfortunately the links no longer seem to be working. claims 360 bhp with just "breathers", whatever that means, but I'm assuming just filter mods.

If dynos are such inconsistent beasts, how can we expect to get accurate information from them...... Seems to me then it's probably just as good to plug your car stats into a G-tech or the equivalent, you have a better chance of getting accurate results. Kinda makes you wonder about these GNX guys claiming 1000+ Hp, maybe the dyno was helping a little.


----------



## ReVerm (Jan 13, 2003)

[email protected] said:


> If dynos are such inconsistent beasts, how can we expect to get accurate information from them...... Seems to me then it's probably just as good to plug your car stats into a G-tech or the equivalent, you have a better chance of getting accurate results. Kinda makes you wonder about these GNX guys claiming 1000+ Hp, maybe the dyno was helping a little.


Dynos are inconsistent when the operators don't know what they're doing. The point I'm making is that getting proper measurements out of the ATTESA E-TS system is tricky because of the way it reacts to certain things (like % throttle open at a certain speed. Yep. It checks this with the latest gen ATTESA systems).

Although AWD dynos are finicky things to begin with. If you've ever seen one in action, you'll know.


----------



## Zen31ZR (Mar 24, 2004)

ReVerm said:


> Dynos are inconsistent when the operators don't know what they're doing. The point I'm making is that getting proper measurements out of the ATTESA E-TS system is tricky because of the way it reacts to certain things (like % throttle open at a certain speed. Yep. It checks this with the latest gen ATTESA systems).
> 
> Although AWD dynos are finicky things to begin with. If you've ever seen one in action, you'll know.


Never seemed to be anything odd going on with the only one we have in Colorado, so I have no idea.


----------



## Joel (Jun 11, 2003)

Common dyno practice on the R32GTR's is to pull the ATTESA fuse and run RWD.


----------

