shaggadelic

iTrader: (26)

those 3 have JDM goodness

iNfEk

iTrader: (33)

2.0L semi-closed deck, forged internals with big port heads + AVCS + 8k redline stock + all the extra goodies I've thrown at mine

simontempler

iTrader: (2)

That is JDM goodness! Woohoo!

Is the 2.0 as torquey as the US spec 2.5?

iNfEk

iTrader: (33)

not really. It's a different kind of pull... smooth linear pull all the way to redline as if you're getting sucked into a drain or a vortex of death... LOL The RPMs climb very quickly and there is no dead spot in the RPM range. 1k-3k is just a blip away really.

stets

iTrader: (4)

i wanna feel that....

simontempler

iTrader: (2)

You should get a ride on one of them super duper rare JDM engines after your PDX tune with the new HTA Green in your car so you can can have a seat-on-your-pants comparison between your car and a JDM one.

Feel the goodness of both!

dub81

iTrader: (39)

Hey Simon, Yup just as equal or even better than the US version. Trust me, I know... My pants came off a couple of times. LOL.. Sorry simon, I just got on board but Ill WIIIILLLLL GIIIVVVVEEE you a call tommorrow definetly!! Schedule is busy tomorrow!!

simontempler

iTrader: (2)

No worries, Walt. Just let me know what you need.

It's funny you said the JDM is as torquey or more than a 2.5. Was chatting with Jarrad and he had a JDM Spec C that redlined at 9k. When he drove and felt the torque of the 2.5, he sold the Spec C.

I, of course, have never sat or driven a JDM spec car but I would love to soon just to experience the magic of this EJ207.

Anyone with one wanna give me a ride? I'll trade you a ride in my car.

dimsumboi

iTrader: (1)

Double 20g turbos, gave my Rx-7 520whp on conservative tune with 91 fuel.

Krang

iTrader: (14)

so.. 49lb/min x2 = 98lb/min turbo!

Neat.

Krang

iTrader: (14)

It's really not magic, just a different feeling. Also, I'm beginning to believe that it really shines with a similarly geared, short ratio, 6MT. While with the 5MT I have very versatile gearing and essentially stay in 2nd and 3rd when trying to go fast, a short ratio gearbox would allow much more precision and also put a lot less stress on the motor itself. I can feel the longer gearing loading the motor a lot, when its purpose was intended for shorter, faster gearing.

Deraj_53

iTrader: (5)

Not really if you compare both motors stock or even with mild mods the 2.5L is definitely more torquey in the lower rpms according to the butt dyno. I don't have a comparison graph.

Maybe someone could ask RADs to poke around in their dyno computer for baseline graphs of My ej207 and a similarly modded USDM ej257.

@Krang Yea the JDM 6-speed is seriously short, its like 3k rpm at 60mph in 6th
According to the list below the WRX gearing is taller thru all the gears.

JDM Impreza WRX STi MY04 + V-Limited MY04 s/n:TY856WB4KA
1st:3.636
2nd:2.375
3rd:1.761
4th:1.346
5th:1.062
6th:0.842
Final Drive:3.900

US Impreza WRX STi MY05 s/n:TY856WW6MA
1st:3.636
2nd:2.375
3rd:1.761
4th:1.346
5th:0.971
6th:0.756
Final Drive:3.900

US Impreza WRX MY02 s/n:TY754VN2AA
1st:3.454
2nd:1.947
3rd:1.366
4th:0.972
5th:0.738
Final Drive:3.900

If your thinking of keeping your WRX trans then get RA gear ratio's Just ask shaggy on how quick the gears in the RA set were

JDM Impreza WRX STi RA Ver.II MY96 s/n:TY752VB4CA
1st:3.454
2nd:2.333
3rd:1.750
4th:1.354
5th:0.972
Final Drive:3.900

Although different years had different ratio's because of the different final drive ratio.

JDM Impreza WRX STi R & RA Ver. V/VI MY99-00 s/n:TY754VB1CA
1st:3.083
2nd:2.062
3rd:1.545
4th:1.151
5th:0.825
Final Drive:4.444

reido

iTrader: (1)

It's good that you focus on torque, as HP is the crappier of the 2 to look at. The torque curve will show you the bottlenecks in your exhaust and intake and will give you a feel for the car.

The calculation for HP is Horsepower = torque X rpm / 5252
If torque is high, HP will be high depending on the speed of the motor. If you're able to produce a higher torque figure, like tuning in a lower gear, you'll raise the torque figure, and you can see how the math will be affected. It all goes down to how the torque is calculated on the dyno. Some dynos look at the gear ratios to calculate torque, while others do not. If gearing is not accounted for in the torque calculation, then you can manipulate final HP by messing with gearing.
The HP figure is simply how fast the engine is spinning relative to that particular torque figure. If you can increase the torque applied to the drum--a final drive ratio will change this slightly--HP goes up. The percent increase will depend of course on the amount of torque difference at a particular RPM


When people say HP wins races, they really are referring to how long the torque can be sustained over time as the speed of the engine increases, so they're really saying time under curve with the least amount of torque decrease. So a Spec C motor can win the race if it can produce a high enough torque figure for a longer figure of time with gearing that allows it to stay there. The peak torque figure is just that. That's the grunt you feel.

Look at any dyno chart and you'll see that HP and Torque cross at 5200rpm; that's jsut the math at work. Also, look at any torque curve of an engine with an EWG, and you see this really sharp ledge or shelf. The above car obviously has one. It's a steep curve. The peak number may not be there, but you can feel it in your *** when the torque suddenly climbs in this really sharp way, and that's why EWG really make cars feel fast by the way they're able to get up to boost and then bleed off exhaust very quickly.

I posted here about how the STI gearing is really crappy for the smaller turbos in drag racing because when taken to redline, the rpms drop to a point on the torque curve where torque has already fallen off, meaning the RPM doesnt drop low enough between gears. But with a SPEC C motor that revs to 8.5k or more, the STI gearing (04-05) makes a LOT of sense. The next gear change drops the motor still in a relatively high part of the torque curve.

Judging from people I've met and talked with though, what they seem to want is a curve as posted above. But then they talk HP, and I don't know why. You can see how torque just ramps up very sharply. That car must have a quick rush, and the fall off on torque is not THAT bad. It probably feels like it pulls to redline, but the falloff is gradual as you can see in the curve, but your *** probably can' feel it. But I'll bet big money that if you rode the car, and the owner told you it made 550whp, you'd believe. Your *** and heart can feel the sharp increases. There are ways to raise the peak by trying to get torque to sustain itself a hundred more RPM or so. Or you could just tune in a lower gear to raise the torque and then the calculated HP will be higher, and that should make the owner feel better. Also, any tuner will tell you that they tune for torque and NOT hp. Their job is primarily to make the most torque at full boost and try to keep timing such that it doesnt fall off that bad.

As an STI owner, I envy the 2.0l guys, especially the high revving JDM guys, because they have engines with torque curves that match their gearing IMO. I still like the grunt of my car, but sometimes I wish had a WRX tranny with RA gears.

stets

iTrader: (4)

Wow this is like subaru school. Anyway, I GOT MY HTA GREEN! Arrived 2 days ago.

Krang

iTrader: (14)

RA Gearset is probably my best/only option since it is cheap!