And may I say first off, sorry if this has been covered but, if it has I haven't seen it and if it hasen't then, Why?

What performance difference does each JDM/USDM final drive gear give?

And for the love of God Why is it different? Don't say Just because... I see and have seen several differences between the JDM and ours related to performance parts and not just cosmetic stuff. Is it because of value for dollar? Or "and I hope it's not this" Do they think that we won't miss or deserve these extra goodies?

While we're on this topic why don't we all list the performance part differences between the 2 different market R's.

I know of the final drive gear, Oem header JDM= SS 4-1, USDM= cast 4-2-1, some upper control arms, and what about the rear strut tower bar? Is that stock there? Seats if they are performance oriented and I feel they are.

And what else?

Just some random thoughts to provoke intelligent posting amongst educated owners or knowledgeable enthusiests...

A.

 

Rear strut tower bar is stock. So are Recaros there. We get shafted.

 

front seats are those nicey Recaros.
they also get the many-spoked 16" rims.
no clock, different radio.
no table between the rear seats.
center console has no armrest.
front end obviously.

I dunno what else.

As to why we get fewer performance goodies...if we got them all, the price would be a little bit higher. And, Americans are perceived as not caring about performance as much as we actually do.

 

Maybe it is to save money on manufacturing costs, so the importing freight over here to the U.S. will not raise the price too much.
In Japan, I am pretty sure, all cars have an electronic speed limiter set for 112mph. And maybe they have slower speed limits, so a shorter final-drive ratio will not sacrifice fuel milage due to the lower speeds. Like I said, just theories.

 

The Final drive is because they get the 16" wheels.

 

Only the 98 and up JDM ITRs had the higher final drive.
It was done by Honda to freshen up the ITR, they added more power, final drive, improved the suspension, bigger brakes, bigger wheels, HIDs, etc.... Oh cant forget the plaque on the center console that look like ours but said "98SpecR"

 

I agree with Chris--they did it to compensate for the increased diameter of the 215/45-16 tires and wheels. In Best Motoring's comparison, there is almost no difference in acceleration between 96 and 98 spec. Exactly the same in the 400m dash, and only slightly different in the 1000m dash.

 

The difference is diameter between the 15" wheels with 195/55/15 tires and the 16" wheels with 215/45/16 tires is effectively zero (~1/10th of an inch). The diameter difference is not the reason for the change in final drive ratio.

The larger wheels and slightly wider (and thus heavier) tires may be some jusfitication though.

 

They probably send us wimper versions of everything so domestic auto makers can compete.


[Modified by jond, 7:46 PM 7/26/2001]

 

okay, the 16 has more rotating mass. the final drive will help accelerate the wheels rotating mass. also, the FD helps keep a high hp low torque motor stay in the high hp rev band. as you are in the power more, you accelerate faster. accelerating from lower rpms = slower acceleration

also for the US spec crap, the 4.4 is more streetable. the US itr is just a tamed version of the real ITR.

 

IMO it is the size difference of the two countries. Bigger land means more highways. I am sure not very many ppl will like to stay in the higher rev doing 70mph.

 

Thanks again guys.

This ends todays endless quest for further knowledge with all things related to differences and variations between JDM and USDM ITR's...

A.

 

I thought the final drive on the JDM ITR is different to compensate for the bigger wheels. 45/215/16.

 

And yet it still seems the original question stands!!

 

Didn't the 98Spec JDMs get different 4th and 5th gear ratios as well??? (slighty higher) Or am I thinking of something completley different!!!

If yes, then that could be a factor....

Sam

 

Yeah, what about the control arm or something that they show in the Best MOTORing video? Spoon guy says that it improves the handling.. and I'm assuming we don't have this on our 98+ ITRs. Does anyone know???

 

then how do you explain the fact that we (euro) have 15" wheels and JDM final drive?!

 

The rear upper control arms are beefier on the JDM....I think IPS racing has pics of them.

 

98SpecR got bigger brakes obviously. The 96spec's brakes are like the same with the Integra SiR-G or those u can find on EK4 SiR etc.

Yes rear upper control arms are beefier and lighter too. I think they're forged?? I know the chinese term on that but not sure if i should call it forged. Someone with better english pls help me, tks...

 

no no no...you losers are all wrong!! (j/K) ...the question isn't why are the JDM final drives different...its why are the USDM final drives different?? (Remember...JDMs came first!!)

The reason why is because the JDM final drives are very impractical for use in the States. Japan has no freeways, only very expensive expressways, so many folks use inter-city routes to get from city to city...these inter-city routes have on average, traffic lights every 100 meters...and they are all out out sync, and on timers.

JDM final drives are excellent for quick acceleration but are really annoying on freeways and long drives because the engine can be at a constant 5500 rpms drive you crazy. THATS the reason why the US doesn't get the JDM final drive!!


[Modified by MiraiZ, 11:33 PM 7/27/2001]

 

http://www.montrealracing.com/...03372

A very informative post on a Canadian forum that states many differences between USDM and JDM Type-R's.


Modified by Fink2iCe at 11:50 PM 12/11/2004

 

I remember on the BMI video; Gan-san said the JDM 98 spec final drive also gives you enough revs for corners in circuits.

 

i love her and she's all mine

JDM 98 Spec R !!

 

The United States has a very stringent clean air policy and the Final drive would HURT gas milegae. I think its all emissions related. Look at it, lower compression, a less efficient header, lower final drive to keep the revolutions down at higher speeds and ultimately the horsepower down (due to the lower compression.)

So I think its all emission related as that is super difficult to maintain! There was a reason back in 1980 that Porsche stopped importing Turbo's for sale. It didnt mean they stopped production, they just couldn't meet the emission requirements at the time and they did not want to sacrifice sales b/c of lost performance. Trust me, there are many greymarket 1980-1985 Turbo 911's running around that were at one point illegal!

Anyway, I don't have any proof on the subject, but it all makes sense to me!

 

Back from the dead....man somebody was sure gravediggin