I wonder how does the USDM 2.5L STI compares with the JDM 2.0 Twin-scroll Turbo STI on the straight, track, and handling.

I read on a Japanese mag, the JDM STI pulls a .94g on the skidpad and every US magazine so far rates the STI only .91g at best. Even though the JDM STI comes only with the older wheels and Potenza RE040 and the USDM STI comes with R rated RE070 on lighter BBS wheels.

I also read that the JDM STI pulls 0-100km/s in 4.8 secs, isn't this comparable to the USDM STI that does 0-60mph in about 4.6 secs also?

Another thing to remember is weight. USDM cars have a lot of extra beefy/heavy additions in the name of safety to meet US requirements. JDM cars can get by with a lot that won't fly in the US market. They also tend to have better/lower/stiffer suspension components to name but a few differences. They also have access to higher octane gas which results in being able to squeeze more hp out of the motors which will skew the performance numbers slightly.

Well you forget that the surface of the test facility, and the radius of the circle can make a HUGE difference. So the results are not comparible in anyway to any other results at a different facility.

Originally posted by WReXinEfX
I wonder how does the USDM 2.5L STI compares with the JDM 2.0 Twin-scroll Turbo STI on the straight, track, and handling.?


Twin scroll has nothing to do with it.

JDM makes and estimated 300 hp on higher octane gas and with lower emission requirements of Japan. You wanna know how much hp it would make in the US (?)....just look at the US Evo 2 liter twin scroll..... 271 hp. Lusting after the JDM 2 liter is a misguided waste of time - imho.

As for handling skidpad numbers, it depends on the skidpad.
US STI recorded a skidpad average of .96g at Tireracks sticky skidpad, but only .88g via Road and Track.

Road and Track managed to test the same exact Evo in back to back months and recorded .97g in the 1st month and .88g (same as STI) in the 2nd. So what does that tell you?

100 = 62 mph

I read Road and Track and they claim the JDM STI handles better than the USDM one. They claim the handling was much sharper and crisper.

Could the suspension be the only one at play here?

I wonder what would happen if someone swap the twin-scroll turbo to the USDM STI
That should be interesting:cool:

Originally posted by WReXinEfX
I read Road and Track and they claim the JDM STI handles better than the USDM one. They claim the handling was much sharper and crisper.

Could the suspension be the only one at play here?

lol. Here's the comment you are referring to:

"The U.S.-spec WRX STi starts life quite differently from its Japanese counterpart. The Japanese version continues on with a 2.0-liter turbocharged flat-4 that produces 280 bhp and 291 lb.-ft. of torque. Although the US STi is faster than the Japan car, the handling of theirs felt a bit more crisp. I suspect that the Japan car had fresher tires, and the car's suspension, which is identical to the U.S.-spec WRX STi's, is suited more for the 2.0-liter powerplant than our 2. I give the nod to the US STi over the US Evo. Between the two Japanese versions, I would opt for the Evo over the STI . — SM"

Well, as far as handling goes, I think the base JDM STi doesn't get DCCD so that may complicate matters.

JDM makes and estimated 300 hp

I am told that this is a bit of mythology --- the gentleman's agreement does exist on the power quoted, but I am told the JDM twin scroll does actually make 280-285. Take that for what it is worth.

Glenn

Now having watched the Best Motoring Video..

The JDM EVO 8 is almost untouchable by the JDM STI 8, however the JDM STI 8 Spec C which makes something like 335HP with a different Twin Scroll Turbo with DCCD had the fastest lap also it is lighter. It was faster than the EVO 8 and EVO 8 RS.

JDM EVO8 6-speed was also beating the EVO8 with 5 speed...

Having read a bunch of reviews from everywhere the USDM EVO 8 5 Speed seemed to be beating the USDM STI 8 on the track by every magazine so far... which is very confusing as far as STI's real performance compared to JDM ones..

I wish they could import the USDM STI to Japan so Best Motoring can lap it against the other STIs and EVOs.

Originally posted by WReXinEfX
Now having watched the Best Motoring Video..

Having read a bunch of reviews from everywhere the USDM EVO 8 5 Speed seemed to be beating the USDM STI 8 on the track by every magazine so far...


I know of 3 magazine comparisons that have done track tests betweetn the US Evo and the US STI.

Road and Track, and Car and Driver.....which both found the Evo to be faster, and Sports Compact Car, which found the STI to be faster. The only other track test I know of was done here: http://www.vwvortex.com/features/06_03/index.shtml with the STI again edging the Evo.

It's been suggested that the results vary because the Evo is usually the more agile handling car with the STI being more powerful......a track with more straights favors the STI, a curvier track favors the Evo. That's the theory anyway.

well i just went to a subaru dealership in japan to look at their suspension set up on the sti and the sti spec c... i want to compare it with the usdm version but they couldnt fine the specs for ours (and mabey buy some parts while im at it)..... anyway according to them all jdm sti's now get dccd's and have strut bars which could have something to do with it also.... does anyone have a diagram of the usdm suspension they can post so i can compare it with the jdm and spec c?

edit:: never mind... i found my answer in another thread.....

Originally posted by WReXinEfX
Now having watched the Best Motoring Video..

The JDM EVO 8 is almost untouchable by the JDM STI 8, however the JDM STI 8 Spec C which makes something like 335HP with a different Twin Scroll Turbo with DCCD had the fastest lap also it is lighter. It was faster than the EVO 8 and EVO 8 RS.

JDM EVO8 6-speed was also beating the EVO8 with 5 speed...

Having read a bunch of reviews from everywhere the USDM EVO 8 5 Speed seemed to be beating the USDM STI 8 on the track by every magazine so far... which is very confusing as far as STI's real performance compared to JDM ones..

I wish they could import the USDM STI to Japan so Best Motoring can lap it against the other STIs and EVOs.

I know this is gonna draw some flames but I am gonna say it anyway.

The JDM STi has a handicap by being .5l smaller than the USDM version but do not kid yourself the twin scroll has more to do with it than you think.

Faster, smoother spoolup along with a better exhaust manifold helping to reduce back pressure as well as the 520 or 550cc?? injectors that they run. As for the crap they can get away with well they still are running 3 cats on this car!!

The higher Octane gas has alot to do with it also.
Also I did see a video with the JDM STi running a 12.6 stock not that drag racing this car is what it is all about.

Japanese STi's run on 100 RON and our 94 octane is about 99RON, so it's not that far off. My car feels extremely fast on 94.

Originally posted by DuoMaxwell


I know this is gonna draw some flames but I am gonna say it anyway.

The JDM STi has a handicap by being .5l smaller than the USDM version but do not kid yourself the twin scroll has more to do with it than you think.

Faster, smoother spoolup along with a better exhaust manifold helping to reduce back pressure as well as the 520 or 550cc?? injectors that they run. As for the crap they can get away with well they still are running 3 cats on this car!!

The higher Octane gas has alot to do with it also.
Also I did see a video with the JDM STi running a 12.6 stock not that drag racing this car is what it is all about.

I didn't think ANY STI had 3 cats, but rather 2. Injector size doesn't matter when talking about stock cars (Which aren't maxing them out).

If the EJ207 makes 291 ft lbs of tq, reving to 8K, then it for sure makes over 291hp. The 207 is a peaky motor.

The only true numbers I've seen is 320PS for the S202.

didn't see this mentioned, but the spec c has a different steering rack than the USDM sti.

I would take the ej207 over the ej257. I like high reving motors... Thats about all it comes down to, what you like best.

DCCD is an option for JDM ver8 STis but standard for ver8 STi Spec Cs.

we are working on a ver8 Sti swap into a 93 Impreza. Should be even more fun with a lighter body. :)

What's the minimal gas octane required for JDM STis?

Is it the same for all versions?

2003......2009.....
http://www.clublexus.com/forums/attachments/es300-and-es330/113727d1194053211-es300-a-c-or-cabin-filter-change-97-01-holy-thread-revival-batman.jpg