6G Celicas Forums

My thougths....

IF you use the 4age ecu, how hard is it to wire in and get everything to work? The only reason I would personally modify the 7a ecu is becuase it would be plug and play.

plug and play on the ecu side, still wont be plug and play in the engine bay.

I'd imagine the reason he wants to use the 7A ecu is so he won't have to mess with wiring... however, that's unavoidable, considering the different sensor set-ups between the 2 engines, different mechanical operations, etc... (depending on which 4ag you use). You will need to do either a full wire changover, directly swapping the 4AG wiring harness (from an ae92 or ae82... not ae86 or aw11 cause those harnesses will need to be modified) or splicing. I would much rather swap over the entire harness than splice into the exsisting harness. If I were to go as far as taking apart the main harness in order to correctly wire in the 4AG signals...might as well drop in a 3sgte or JDM 4AGZE or something of the sort (there would be no difference)...

Problems will also arise depending on which car (make, model, year) this set-up goes into, cause that matters also. All OBD2 cars will have problems with splicing harnesses because OBD2 and OBD1 don't mix (assuming the donor 4AG car is a USDM)...

actually we're about to do a swap in my ae92 SR5 to a 16V smallport..... the wiring is about 90% the same and what isn't the same can be spliced at the sensor..... a lot of the sensors & whatnot even have the same plug style

also, this gives me the advantage of not having the AFM and running off a MAP sensor

Well... if you swap out the 4afe/7afe then save for a MAP 4AGE conversion... I guess that could work... I'll have to check this out some more... My biggest problem with building a 7AGE hybrid was the afm v.s MAP problem... I don't want to splice harnesses, cause that would just justify me to go all out and swap in a 20V or 3SGTE or something... however, if you go from Map 4afe/7afe then swap in a 4AG then convert to MAP 4AG...it may work. hmmm... *could save me from having to source out an entire parts car...*

I'll still stand by my ECU statements though... ;]

actually the latemodel ae92 in japan was map sensored.... there are also map sensored 4a-gze's and the blacktop 20V's were map sensored

what i'm saying.... the engine itself doesn't care what sensor it has... since i'll be using the tuned 4a-fe ecu, it'll be expecting the 4a-fe map sensor, but it'll be running through the 4a-ge.....

i'll let you know what happens when we attempt the swap... it's going down on superbowl weekend.... but since we're using the 4a-fe ecu we also went with a few other choices in the matter including a sard adjustble fpr for a higher fuel pressure and a full msd ignition (either way, i would have to get a 4a-ge ignition and coil, since the 4a-fe is all internal)......

my thought was to fit the 4age with the 7a wiring parts. If I had to, I would just make the 7a intake manifold fit the 4a block.

too restrictive..... the only diff on the intake manifold itself may be the throttle cable and the TPS wiring..... (not 100% sure on that one).....

then there would surely be a way to swap over the sensors and wiring from the 7a manifold to the 4a manifold. Then all you would have to do is call jet and have them swap in the performance settings they use for a 4age and put those settings in place of the 7a configuration.

yes, that is what i'm getting at, and in fact in essence will be doing...

i won't be sending the ecu out anywhere, luckily i have a friend down south who can help me tune the 4a-fe ecu...... we'll be using the 4a-fe wiring as well, and splicing into the sensors that fit into the 4a-ge.....

where down south???

"down south" from where i live.... i'm in northern washington state, he's in mid state....... roughly 50 miles or so from me......

I repeat it ; I will use e manage with the ecu (stock 7afe or 4age ecu ?? still don't know) and this allow to remake all the fuel and air curves. My head is a big port from ae86 and the tvis will be dismanteled (no need with turbo).The bigest problem in this hybrid is the wiring. My friends repeat me to use the ecu wich come from the head but if you say that it can work with the 7afe.... I'll ready to make the wiring in april so I'll wait to see all the options (except the stand alone too expensive for me)

thank you

frotou

My suposition about using the 7afe ecu with the 4age head is that the ecu will not be able to run or reconize the distributor, all the others sensors will work perfectly.
The difference between the two distributor are countless .... Make this two motor with the same distributor and I sure the 7afe ecu can run it (not perfectly but ok with a piggyback)

Ha! Found it.

Sorry to bump such an old post, but it's got alot of good info, and Kwanza, I was wondering what your updated thought here are? As far as I know, the emanage should actually work for a MAP conversion. I could be wrong. And as far as the 7A ecu needing alot of tuning, that's actually what I WANT to do. I really want to get my hands dirty (er... digitally) and tune my own efi. My only issue is the rev limiter on the 7a ecu. I'd feel stupid paying 300 bucks just to get the rev limit moved.

Hehe... toyotaspeed_90 has actually had great success with his set-up running the old 4AFE ECU. His ECU is modified to redline at 7800 rpms, but he hasn't had any problems with it, infact, he dynoed his engine at something like 110whp. You can e-mail him and ask a bit for more ECU detail, cause he would probably know a bit more than me. He's not active around here anymore, but he's very active elsewhere and is a good source for information regarding 4AGs. Electricals isn't my strongest. As for Greddy eManage, like I said previous, they merely interpret MAP/AFM voltage, TPS, and a few other signals then replace them according to user fuel adjustments. It should work with most models of cars, but will not work with some oddballs and won't work with a lot of older cars. Possibly modifying a 7AFE ECU to run a 7AGE 16V will work, since it's not very different from what toyotaspeed_90 did with his rolla, but it's a different story for a 7AGE 20V if that's the route you choose. I reccomend a smallport 4AG head for any n/a application as will toyotaspeed_90 (most likely).

Yes, I was planning on a smallport head for this app.

The reason is that although I was intrigued by the 20v, I've seen some pretty outragous prices for cam and valvetrain upgrades compared to the 16v. Is this normal or am I shopping in the wrong places. Another thing that really burst my bubble about the 20v was seeing a dyno of a silvertop falling well short of Toyota's claimed hp. =( Still tempted to try just for the sound, tho.

My experience after one year , go with the 4age ecu. But the f****ing usdm 4age ecu afm isn't compatible with the e manage. This spring I restarted the project with an jdm 4agze map dli ecu and wiring , wich will be a LOT better . I think It can run with 11-12 lbs with little correction with the e manage, I can't wait to see !
For the 20 valves head ; I highly recommend the ecu wich come with the head.

Claude

Finally I go stand alone this spring (autronic). The e manage is not compatible with the dli system in the 4agze wiring/ecu .

I've see many toyota hybrid in magazines (4agze turbo , 3sge with sc14 , 7agze , 3sge beams turbo etc.) and EACH times the featured ride run with stand alone.....
Looks like toyota hybrid are hard to tune ....

Claude

Here is the rule of thumb with any hybrid. You must (or should) use the ecu that matches the head. So if you going with a 7age, you should use the ecu from the 4age. Frotou, with your setup perhaps standalone is a better option because it appears as if you did not get the complete loom with accessories and ecu to match the 4age head. For all others reading and want to do the swap as well, be sure to get the head, wireloom, and accessories from the 4ag or 4agze. I am a big fan of piggyback until you must use standalone. Standalone is not something Novices like ourselves should try to get, and shame on all forum members who talk about standalones when they are using the stock ecu and have no experience with them. If you do have a standalone on your application and you mentioned standalone then I am not talking about you. I do not want to debate the standalone situation but If have not configured one, been to the dyno to trust someone you do not know to tune the parameters on your car and you have no idea what the hell he is doing but you are just trusting him, then lets not mention standalone.

Best way to get to a 7agte would be a 4agze head, loom, ecu and accessories. With this you can use a safc for fuel tuning. If you are big on the greddy emanage then I would suggest you use the 4agze head and efi from the US model. If you choose to use the Jdm 4agze with Dli then you will need to wire in a special resistor so that you can subrtract timing. The only issue with the greddy emanage and the dli 4agze is you get a check engine light when you subtract timing. Everything else works fine ie.. add and subtract fuel and add timing.

So sorry to catch the post so late as I would have loved to chime in earlier but I frequent the Mr2 message boards and sometimes catch topics that I can chime on in a bit late. One thing that is a must when doing a 7ag project is to change the stock rods into full floating with a bronze bushing and balance the ENTIRE bottom end. This is the ONLY way to have longevety out of this hybrid as I see so many make the mistake in not modifing the stock rods when they use them, or not balance the entire bottom end as these 2 things are critical with the 7ag hybrid.


Ron (951) 283-3778
Motors Unlimited