4AFE to 7AFE AE92 hatch

[mattysshop]

i know it's not a breathtaking conversion..

but a very daily driveable torquey economicle (read sensible) conversion..

the plan in my head..

basically swap out my old, tired 4afe, bolt in the 7afe (AE102)

and throw on all the 4afe sensors electronics injectors etc etc..

the ecu is map sensored, and i would try and use all the 4afe gear..

now my experience so far with toyota ecu's had led me to belive they are more than capable of compensating with fuel.. 4AGE bigport aussie ecu/injectors etc etc, on a high comp, cammed up quad throttle smallport.. it just wanted to dump fuel in.. i had to tune fuel OUT of it actually..

just wondering on peoples thoughts? ofcourse i could always throw in the 7afe injectors just incase?

are they the same impedance as the 4a ones?

[Harreh]

Any reason why you wouldnt just go 4AGE? Probably going to be easier in terms of installing it, fairly econimical, faster engine and they arent exactly piggish to drive for what they are

[mattysshop]

i've built and had many many 4ag's.. GZE's, 20v's etc etc

i want torque and economy..

[Harreh]

Fair enough, I'd try it with the stock injectors and see what the AFR's are, to my understanding the heads of the two motors are very similar

[mattysshop]

yeh the 7a's are a bit better, especially with regards to cam profiles from what i have read..

there isn't much wrong with the 4afe in it at the moment.. other than when i did plugs on it recently it pulled a massive 110psi across the board... with a wet test showing 160-165... so that explains why she feels like i'm towing 4 people in the car all the time..

spose i could just use the bottom end of the 7a? the 7afe i have sorta held aside for me only has 120km's on it, very good condition..

[Harreh]

The 7A bottom end would be an idea, but then nobody I know of has run a 4AFE head on a 7AFE only the 4AGE head, having said that I really cant see it to be a big problem.

It does sound like a fair wack of effort, I personally would just get my hands on a 7AFE loom and ECU from a wrecker, I cant imagine it will be expensive nor rare, this way its all setup correctly from the get go

[Hiro]

Find a late-model AE9x RV or Ultima Seca and swap over all the 7AFE gear

[mattysshop]

i've already sorta hooked myself up with this 102 7AFE

[briney]

i would use the 7A's injectors and the 4A's everything else. i did a similar thing with a vitara once. i replaced its 2L V6 with a 2.5. just used the bigger injectors. runs like a charm.

[Hiro]

You'll most likely need the 7AFE computer, as the 7A has a knock sensor and pretty sure the 4AFE doesn't. Injectors would be best to carry over from the 7A, as the intake design is different between the AE9x 4AFE and the AE102 7AFE (injectors in head in the 4A, in the manifold for the 7A), same goes for all the 7A sensors - just in case. The long motor should have all of them anyway.

[mattysshop]

that doesn't make sense hiro.. lol..

i would need the 7a ecu if i wanted to run a knock sensor..

but i don't want to run a knock sensor.. cos i'm using the 4a ecu..

[Hiro]

that doesn't make sense hiro.. lol..

i would need the 7a ecu if i wanted to run a knock sensor..

but i don't want to run a knock sensor.. cos i'm using the 4a ecu..

So you'll have a useless sensor sitting in the block then?

[mattysshop]

yep.. or take it out and have a useless threaded boss in the block.. along with prolly 10 others