Hi All.

Can anyone tell me why the auto tt makes 280 bhp and the manual makes

300. what is the technical reason for this? does it make any difference

when tuning?

Auto has slightly smaller turbos to spool up quicker IIRC - I'm sure someone else will verify this ......

 

The difference is mainly with J-spec and USA spec cars. I believe all UK/EEC models were all 280bhp.

 

Richard

The auto produces less power but more has more under curve area on the torque chart which better matches the four gears on the automatic rather than the five on the manual.

read an article in mag about steer from the rear the display team they also said manuals have larger tubs and also different cam profiles, and a larger final drive in fifth gear for a better top end speed dont know myself if this is true so any info would be gratefull just to set the story straight :duffer:

I heard only USA manuals had the 300bhp, the rest are 280.

at first i heard that all USA were 300 and everyone else was 280, but then i heard that all were 300 but the series 4 onward had to be toned down to 280 to meet some emission requirements. the debate goes on... and on... and on... :p

Hi All.

Thanks for the response guys but we still dont know, there must be a way to find out

So what has an auto converted to manual???

 

ie manual box and smaller auto turbos??

So what has an auto converted to manual???

 

ie manual box and smaller auto turbos??

 

The same BHP as a regular auto ;)

 

After all, the engine is the same, it's just the 'box that has been swapped

 

Richard :cool:

difference between the Auto & manual is in the turbo & cam profiles.

 

differences between US/JDM/UK is down to differences in HP measurement & marketing IMO!!

iv yet to see any consistant documentation on the differences in each market!

So what has an auto converted to manual???

 

ie manual box and smaller auto turbos??

 

interesting question. when it was an automatic, after a few relatively minor mods i had mine dyno'd to 275 RWHP which equated to about 350 at the fly. ive recently had it converted to a manual so although the engine would still produce 350ish, more power would be going down to the tarmac as less is lost in transmission so i should be getting about 300 RWHP.

Japanese Lgislation specifies that all volume cars made for Japanese market are limited to 280bhp at the crank. Only left hand drive models of the 300ZX (ie manly to America) were 300bhp. All right hand drive models where built to same specs in Japan ie limited to 280bhp as are all Skylines, Evos, later scooby's and all Jap import supras.

 

Manuals have very slightly bigger turbos and different cams to produce the best power curve to suit the box, like wise the turbo cam combination on the auto is designed to produce the best power curve for that box. As the man already said.

 

And before anyone says UK cars are different spec. Let me assure you the spec changes where made in UK by official importers.

Japanese Lgislation specifies that all volume cars made for Japanese market are limited to 280bhp at the crank. Only left hand drive models of the 300ZX (ie manly to America) were 300bhp. All right hand drive models where built to same specs in Japan ie limited to 280bhp as are all Skylines, Evos, later scooby's and all Jap import supras.

 

 

That was only really adhered to when the law 1st came out (Zed kinda time) since then stock Evos and Scoobys put on rollers produced a hell of a lot more than 280 out of the box.

 

BHP dont mean Jack we all know that (or at least i hope we do) so dont worry about it.

Japanese Lgislation specifies that all volume cars made for Japanese market are limited to 280bhp at the crank. Only left hand drive models of the 300ZX (ie manly to America) were 300bhp. All right hand drive models where built to same specs in Japan ie limited to 280bhp as are all Skylines, Evos, later scooby's and all Jap import supras.

 

Manuals have very slightly bigger turbos and different cams to produce the best power curve to suit the box, like wise the turbo cam combination on the auto is designed to produce the best power curve for that box. As the man already said.

 

And before anyone says UK cars are different spec. Let me assure you the spec changes where made in UK by official importers.

 

But we all know that Manfucturers never adhered to the 280 agreement, see the Skyline GTR, that claimed 280bhp..but actually is more like 320bhp standard.

 

Its likely that if the American Market got 300bhp.....then the RH Drive market also got 300bhp, and it was just Nissan claiming 280bhp for Legal reasons.

 

Plus as mentioend earlier, they officially lowered the output to 280bhp for the series 4 when they dropped VVT. Lowered from what?, if it was already 280.

That was only really adhered to when the law 1st came out (Zed kinda time) since then stock Evos and Scoobys put on rollers produced a hell of a lot more than 280 out of the box.

 

BHP dont mean Jack we all know that (or at least i hope we do) so dont worry about it.

 

Show me where you get this info from Chris. This is just herban myth however The later scoobys Evo's made for Export are higher and present WRX 2.5 ltr is 300bhp ,but not sold in Japan at more than 280bhp.

 

 

But we all know that Manfucturers never adhered to the 280 agreement, see the Skyline GTR, that claimed 280bhp..but actually is more like 320bhp standard.

 

Its likely that if the American Market got 300bhp.....then the RH Drive market also got 300bhp, and it was just Nissan claiming 280bhp for Legal reasons.

 

 

The Skyline was and is 280bhp and were governed down by the air box design and scrapping the standard GTR airbox released an extra 40bhp with no other mods. Remember we are talking Japanese here and if they are told 280bhp that is what they will produce. Japan is the land where the honour code is still so strict that people still comitt Hari Kari if found to have not told the truth or been disonerable.

 

There too much bullsh1t talked about BHP and what this car and that car can do, or how much bhp it really is. The truth is, if it was or is made for the Japanese market and is a volume prodution car like the above and not a Nismo ltd addition. Then it will be 280bhp and the volume of 300ZX's sold to anywhere with right hand drive was not high enough for them to alter production for specific export. Where as you cannot move for Evo's and more so Scooby's so Export models are worth while however the basic Scooby 2.0ltr twin turbo isn't even 280bhp.

 

More BHP does not mean its faster its power to weight ratio that wins everytime + a good chasis.

Show me where you get this info from Chris. This is just herban myth however The later scoobys Evo's made for Export are higher and present WRX 2.5 ltr is 300bhp ,but not sold in Japan at more than 280bhp.

 

 

.

 

 

No mate the 280bhp rule is the myth

No mate the 280bhp rule is the myth

 

Tommorrow I'll show you that it is Fact. :shock: ;)

How does the US Spec zed differ from the rest (engine/turbo wise) to give it the extra 20bhp ?

Also, looking at Supra Forum - Stock Jap (claimed 280) and stock UK (claimed 320)...were putting out about the same RW dyno figure...... with a flywheel calculation of 320 'ish

I once read a Spec sheet on TT net which had all the technical guff on it and the compared the Us spec the the Jap spec and in brackets it said UK and Aus were the same as Jap.

 

I would imagine the ECU mapping is different or Cat design because US emitions arn't as strict as Japanese. :confused:

....... because US emitions arn't as strict as Japanese. :confused:

 

I'd have thought it was the other way round - aren't US regs the strictest in the world?

 

Richard :)

I'd have thought it was the other way round - aren't US regs the strictest in the world?

 

Richard :)

 

yes....although dependent on state

Also, looking at Supra Forum - Stock Jap (claimed 280) and stock UK (claimed 320)...were putting out about the same RW dyno figure...... with a flywheel calculation of 320 'ish

 

UK spec Supras are 320 BHP - this is achieved with bigger turbos. That is also why the UK car has bigger and better front brakes to cope with the extra power.

 

As Mark has said, the J-spec Supras were indeed 280bhp

 

I'm sure Big Roy will confirm this.......

 

Richard :)

SKYLINE DAVE.

What were the few relitively minor mods ?

UK spec Supras are 320 BHP - this is achieved with bigger turbos. That is also why the UK car has bigger and better front brakes to cope with the extra power.

 

As Mark has said, the J-spec Supras were indeed 280bhp

 

I'm sure Big Roy will confirm this.......

 

Richard :)

 

yes...but proof shows that J-spec supra's are indeed NOT 280bhp

 

.....according to the Supra forum, on a rolling road test..stock Jap's were given out between 310 and 330 bhp - stock.

read an article in mag about steer from the rear the display team they also said manuals have larger tubs and also different cam profiles, and a larger final drive in fifth gear for a better top end speed dont know myself if this is true so any info would be gratefull just to set the story straight :duffer:

 

Apparently the auto has a higher top gear and hence a higher "theoretical" top end.....

 

http://www.300zx.org.uk/gear_ratios.htm

 

I know I've had my pretty much stock auto up to stupid speeds measured with GPS without too much hasstle (needed a long run up and of course a private test track)