ummmm...why do 3sgte's have different HP ratings Options

[Swifty]

Ive been researching the topic and have yet to come across a reason for the difference in the ST185 ratings, the USDM engine only pulls 200 HP and 200 lb/ft of torque, while the JDM versions of the same engine make between 221 and 231, im almost positive that the engines themselves are identical, same bore, stroke, CR...etc, so where does this mysterious power lie hidden. Could it just be the difference in the stock boost setting, are the turbos the same, what gives?
I'd like to get myself one of these babies, and im wondering if i get the USDM version if it would be an easy matter of freeing up the 21-31 HP in there,
this is only regarding the ST185 3SGTE, and not any other generation of the engine
Also if anybody knows any place that would sell the USDM engines here in Ontario (maybe even Quebec), cuz id much rather not end up having to buy the whole car (im on a freakin' buget, university starts in the fall)

[Uppitycracker]

Well Ive been reading to, the reason for this is 1. They are from different generations in the engines development so obviously there are improvments along the way. The reason for the difference between USDM and JDM is the in North America the polution laws are more strict and require things like egr valves that constrict precious power. Basically the engines are toned down to be more fuel efficient and have less emmissions. Which makes no sense to me sine I think the Japanese are the most intelligent people on this planet, so why they dont protect them selves from pollution is beyond me. THough Im sure they make up in other areas.

[Swifty]

but the engines are from the same generation (2nd gen 3SGTE) so it should be the same engine.......DAMN north american polution laws, JDM cars run cleaner than USDM cars, the only problem up here is visible emissions (north america is way too strict with that), the US version of a JDM car would never pass japanese emissions testing (this is a fact), and i refuse to believe that emission controls rob the engine of 20/30 horses. ARGH, haha this is frustrating
thanks for the reply

This post has been edited by Swifty: Jul 21, 2003 - 1:26 PM

[Uppitycracker]

I find that hard to believe considering when you import a jspec car or engine most people have a very difficult time getting them e-tested, since they almost will never pass.

[Swifty]

The emission rules in japan are different than the ones here, but the cars over there have less actual emissions and run cleaner, people who import cars to North America cant pass "visual emissions" which is part of e-testing, so thats what the big deal is...even if USDM engines had insanely draconian (haha, i feel smart) emissions controls, that still wouldnt drop the power of an enigine by That much, the only thing that i could see being emission control related would be if it had something to do with the ECU cuz i have no idea what OBD system JDM cars use vs. USDM ones (either OBD I or OBD II)
haha, thanks for the help though, got me thinking some more about it.
So if anybody knows why the engines are rated differently please post, my best guess is something to do with the turbo/turbo settings.

[Supersprynt]

The JDM ECU is programmed more aggressively than the USDM ECU which makes up for most of the power loss. Also, cars in the U.S. are sometimes, and often rated lower than they really are.

[GT4SUM]

Yeah its just the ECU, thats the only difference. Oh and your guys ones have an extra cat(JDM only have one in the downpipe)

[Andason]

So if i imported an ECU from Japan my HP would go up?

[Uppitycracker]

QUOTE (GT4SUM @ Jul 21, 2003 - 3:33 PM)

Yeah its just the ECU, thats the only difference. Oh and your guys ones have an extra cat(JDM only have one in the downpipe)

sayyyyyyy what? I think we need some verification on that. Ya the ecu is modified to ease emissions and efficiencey. Also remember Jspec cars run higher octane fuel so theres a few hp there. Im almost positive jspec cares are missing a few sensors that effect power, such as egr valve. I could be wrong but I really doubt the ecu is the only difference. Some internals could be different to increase performance.

[GT4SUM]

Sorry but as far as i know thats it. Your right about the fuel thing though. Over here we mostly get the JDM versions. However we have pretty crappy fuel(our best is 98 octane), so sometimes the cars run a bit weird. Like they seem to have good days and bad days. But yeah, its basically just the ecu which affects the power ratings. Ill try and find some evidence and post it though

[Uppitycracker]

haha cool man, its not that i dont believe you, just from experience there is usually alot more different then simply the ecu. But Im more informed about mazda engines then toyota since I just got on the scene.

[abatardi]

QUOTE (Uppitycracker @ Jul 21, 2003 - 5:46 PM)

sayyyyyyy what? I think we need some verification on that. Ya the ecu is modified to ease emissions and efficiencey. Also remember Jspec cars run higher octane fuel so theres a few hp there. Im almost positive jspec cares are missing a few sensors that effect power, such as egr valve. I could be wrong but I really doubt the ecu is the only difference. Some internals could be different to increase performance.

Internals are identical. The ECU tuning is all that is different. Different fuel, different conditions, and optimized for all of it. Also the US version has an EGR valve... I'm sure that's a part of it..

- aba

[Four]

the easiest answer for most people is the ECU, the main part being the stock boost levels. jdms low stock is 10psi while usdm low is 7psi.

[Supersprynt]

Ok - the ECU accounts for most of the powerloss, the EGR kind of recylcles exhaust and burns more of the vapors so that the exhaust is "cleaner." JDM engines actually run cleaner tho.

Is everyone satisfied now?

[Swifty]

just so i know, its the ECU that robs the USDM version of 31 HP?? Thats nuts, you can only optimize a car so much for 103 octane (thats regular in japan) and it wouldnt have that great of an affect, EGR valve does some of that by creating more back pressure than the JDM version sans EGR, but its only by a couple of psi, which shouldnt have a big effect, no more than 3-4 top end HP, but 31 no way, again the best thing i can think of would be increase the boost to stock JDM levels (10 psi, is it?) and that should have it back to proper 231 HP spec, if anybody has anymore info please post
thanks for the posts, i just wanted your opinions on the subject, cuz the 2nd gen 3SGTE is fairly cheap if bought domestically and i wanted to clear up the issue of the missing HP, 30 is alot when u think about it people, and if it can be had with stock boost levels then all the better, plus by not having to import the engine i save a ****e load of money, money that will one day (a year or two from now) be used for an AWD conversion, Muahahahahahahahaa

[GT4SUM]

you keep mentioning 231hp. No regular GT4 came out with that much. The JDM version came out with around 225hp, as i understand, the USDM came out with around 205hp(or something around that). Now they both run the same boost pressures-9 to 10psi. The 7 psi you talk of is the low boost setting. When the computer feels conditions are right, the VSV lets you flow the extra 2-3psi.

Now back to the 231hp figure. As i said, no regular GT4 came out with that much. However, the JDM version of the RC GT4 did(well actually more like 235hp). But this had additional things to make the extra power(water to air intercooler etc).

So really the loss between JDM and USDM is really more like 20hp

[stelica85]

just curoius when did they start putting on egr valves and if you don't have to pass emisions can't you just take it off.

[Swifty]

QUOTE (GT4SUM @ Jul 22, 2003 - 3:27 PM)

you keep mentioning 231hp. No regular GT4 came out with that much. The JDM version came out with around 225hp, as i understand, the USDM came out with around 205hp(or something around that). Now they both run the same boost pressures-9 to 10psi. The 7 psi you talk of is the low boost setting. When the computer feels conditions are right, the VSV lets you flow the extra 2-3psi. Now back to the 231hp figure. As i said, no regular GT4 came out with that much. However, the JDM version of the RC GT4 did(well actually more like 235hp). But this had additional things to make the extra power(water to air intercooler etc). So really the loss between JDM and USDM is really more like 20hp

take a look at the feasible engine swaps page here
go under 3SGTE and look at the specs of the engines

Even a 20 HP difference with identical engines is too high to be caused by an ECU, when ppl get new ECUs, no matter how aggresively modified they dont produce 20 HP on a bone stock car, so i doubt that the JDM version does this, if it does however i would suggest the first mod made to any car running the 3s would a modified ECU that should net about 20-30 HP, lol
Emissions controls shouldnt drop it that much either, all they do is create extra back pressure, not allowing the exhaust to flow as freely.
but ive come to the conclusion that the its the stock boost that the engines run at, ive read that 1 psi = about 10 HP, so 2-3 psi should put the car in at around 225 instead of 200.
Anybody with a USDM 2nd gen 3SGTE know anything about this, its starting to bug me.....where the hell have all the horsies gone

[GT4SUM]

231/235hp-it doesnt matter. What i was trying to get at is that the RC version those power ratings come from has extra stuff to make the higher power rating.

I still think its just the ECU thats making the difference. Its generally considered amongst GT4 owners thats the reason. But I will keep looking for more proof, so we can lay this to rest

[abatardi]

QUOTE (GT4SUM @ Jul 22, 2003 - 3:27 PM)

So really the loss between JDM and USDM is really more like 20hp

And getting 20 extra horsepower from not having an EGR system and with aggressive tuning maps is VERY possible.

- aba