jdm 7mgte more power than usdm gte?????????
 

i have a jdm spec gte in my 89. are their any differences in the two, besides the missing egr?

I'm afraid I'm not sure what the differences are (aside from reading somewhere that JDM's were a bit more agressively tuned than US or Euro markets, possibly due to tighter emissions law in America) but please could you possibly post a couple of biggish pictures of your engine bay, and more specifically ones of where your vacuum lines are running from/to? I'm working on an '89 JDM model myself at the moment & someone's been "playing" :frown: so any reassurance that I've got stuff back where it belongs would be brilliant.

Thanks in anticipation, Dan. :help:

Aside from the lack of the EGR system and the tuning to make up for it there is reportedly no difference. Toyota's published numbers are the same for all models of 7M-GTE engines of the same year. There is a guy over at SM who is reverse engineering the ECU though and has found that both the JDM and USDM maps are present in the N/A's ECU... no word yet on the Turbo's ECU. But, this does mean we may have the chance to test them out ourselves with the addition of one resistor. Even if the GTE's ECU doesn't contain both, I'm sure he'll publish the fuel and timing tables of each for comparison... should be pretty cool.

Okay, I'm now somewhere where I can add a little bit of info to this.

The JDM 7M's use a Lamda sensor (also called an O2 sensor) the same as the USDM. The ECU uses this sensor to monitor and maintain an air to fuel ratio of 14.7. Given that the JDM ECU would actually have to pull timing any time that the EGR system is active the JDM 7M would make less power. Now, at WOT the ECU does not refer to the Lamda sensor and returns to the base fuel maps. If the maps are the same then the JDM would now make the same amount of power as the USDM engine. The JDM engine may be tuned differently across the board, but there's not really any more power to be made without a boost controller. There may be significant differences in responsiveness and that combined with the timing differences may result in very slightly different power curves, but the peak power will remain roughly the same.

i thinks pics of my engine bay wont help, all of my emissions components have been removed so any open vacume has been pluggd

cre-: Given that the JDM ECU would actually have to pull timing any time that the EGR system is active the JDM 7M would make less power.

Shouldn't that be the USDM? JDM has no egr does it? Or do you mean that on the JDM it would have to pull the timing back in situations where the EGR would have been active if it were present?

Interesting note on the GE ECU's containing both J & US maps though, especially if it turns out to be the same for the GTE lump's brain. If there was any specific advantage to one map we'd be able to swap without spending 100's on a new ECU.
I suppose, as you say there isn't any real power discrepancies between markets, the benefits would be limited to USDM owners just being able to remove the EGR both physically & "mentally" from their car...

Though I wonder if the different maps are stored on seperate chips? That could be a significant breakthrough for people suffering an ECU software failure of some sort if they were able to simply add a link or extra resistor to make the ECU revert to another chip & hence start it working again, albeit in the other country mode.

P.S. milhouse, any pics of any JDM engine bay would be better than nothing. If you don't have the time or something then no worries, I don't wanna impose, but if your car's running OK as it is & all else fails I could try plumbing it as per yours... (That said, I had a play yesterday & I think it's just a fuelling problem now anyway. Think the injectors are gummed up & sticking/leaking, and the cold start wasn't even plugged in!)

EDIT-: no worries milhouse, cre came through with some cool diagrams of a JDM setup here http://www.toyota-supra.info/forums/...html#post74926 so I'm set.

Cheers, Dan.

If the JDM had EGR it could run more aggressive timing such as the USDM does when the EGR system is active.

As I said, it may be worth it just for the properly tuned timing maps.

Nope, same chip IIRC.

Whats the EGR system?

It's a system which is used to reduce combustion temperatures (good for emissions reduction but also good for engine longevity). It just routes a small amount of spent gasses back into the engine to pull down engine temps. Most cars have it (despite popular belief) whether it's accomplished using variable valve timing or an external valve system... The use of an extremely aggressive EGR system is how Honda gets such outrageous mileage and is able to run an engine WAY leaner than what's considered a safe and practical level.

What I don't know
 

When ever I start to think I know something about cars, all I have to do is come here and read your posts and I quickly realize I don't know shite about cars....lol

Ah i see, i think ill keep mine in my car then haha, i do seek to remove my ac compresser and all that mumbo jumbo, i love the heat. Would that affect anything?

And hahaha i agree batman, with my friends im the genius, come on the forums these guys are the Yodas

Removing EGR is pointless. I'm not even sure if it's even open when at WOT... I'll have to look it back up.

I've learned what I know from people MUCH better educated than I; engineers, mechanics and such.... they own cars too. ;)

There are bigger things to nipick though, like the popular PCV delete which is also a greatly ignorant move... then there's the charcoal canister.... oh, don't get me started... :frown:

At any rate, the point of it is that all of these systems have their benefits and unless you're working to a VERY specific end you really should work to ensure they're operating properly. If they're operating properly they'll actually help, if not, well THEN you might see gains from their removal, but it's the same gain you'd generally see from just fixing it (on top of the positive side effects).

Reminds me of Love
 

All these systems remind me of a relationship

When you first get that Hot babe to say yes and it's all new and working for you, then as time goes by certain systems aren't working or you're wondering about everything and pretty soon, you're wondering if all the extra decoration is now simply baggage and you look for the first available way to lighten the load, get that fresh octane back or finally the nearest exit...lol

you think this is bad batman.. head over to supra mania.. bunch of lab geeks over there.. blow your mind with technical garble .

it's like a bootcamp for supra owners... I think we should require all new members to spend 3 months over there before they're allowed to post here. love that place, if you're wrong about something they let you know it fast AND they tell you why.

hahaha sounds like a fun site! This is my fav but ill check that out, good to have a refresher i suppose haha

I started here.. went there.. came back here. Am on the Alberta Supra owner clubs forum as well : )

I like cross referencing. Helps when you think you understand, then hear a different point of view to get the old neurons firing...

Haha yea this is my first, and now i got a mania account. And i concur, its also fun to be bombarded with tons of information i sometimes know not about but it all helps in the end:gotnos:

jdm
 

im in the process of swapn a jdm na 7mge i found sum diffrences in vacume hose routing and lack of egr i mhope to have it running in a few days

hey love the colour of ur supra can u send me colour code?

Is the color code info in the door panel? I didn't paint this and this is not original. My grey on this has a heavy metallic flake in it and I dont believe the stock Supra color has the metallic. It is very close to the stock color, but if you look closely at the inner door or engine bay you can tell the difference. The old grey is flat. Not sure where I find the color code for it though.