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View Full Version : 4AFE with 7A bottom end?


mattysshop
2nd January 2007, 01:31 PM
long story short, 7A-FE bottom end (fresh and cheap) replaceing a 230km worn out 4afe bottom end, not for the purpose of racing or a quick car etc etc, just a little bit more mid range for daily driving (my mum and dad),

but the head has been done recently, so my idea.. pull motor out, fit new h/g to 4afe head ontop of 7AFE bottem end, leave ecu injectors etc etc everything stock as a rock 4afe stuff.. minor mod to the exhaust (as the 7a block a little taller).. will the injectors/ecu be ok with running an extra 50cc each cylinder? sureley it won't run lean or anything right?? there is enough sensors on it to register a slight difference and adjust slightly??

your thoughts..

thanks
roadsailing
2nd January 2007, 02:23 PM
i wouldn't do it, at WOT the engine would assume a set VE, and put in fuel that is appropriate for that at whatever RPM

if it was an AFM engine it wouldn;t be such a bit deal, and at light loads it might not matter anyway.

what you could do is put in a set amount more fuel over the whole range, but i think it would be more hassle than it is worth.

if you want to try it, put it on a dyno to make sure you arent going to melt those crappy pistons http://www.ae86drivingclub.com.au/forums/emoticons/tongue.gif
rthy
2nd January 2007, 02:33 PM
isnt 4afe's/7afes afm?
Hen is a total nutcase
2nd January 2007, 02:34 PM
I reckon it'd work. From the factory it'd probably run on the rich side anyway, so a little leaner wouldn't hurt. Or you could just up the rail pressure (adjustable or find a suitable regulator that is set slightly higher) to compensate.

Though I really doubt it'd be worth the hassle. Though it depends how much your folks want their daily to be a project car and off the road. I think there'd be little problems fitting it all together and getting it running nicely.

Hen
mattysshop
2nd January 2007, 02:43 PM
smack the end of the fuel reg in a wee bit with a pin punch http://www.ae86drivingclub.com.au/forums/emoticons/smile.gif ups it a few psi http://www.ae86drivingclub.com.au/forums/emoticons/smile.gif

this 4afe is map.. http://www.ae86drivingclub.com.au/forums/emoticons/smile.gif
mattysshop
2nd January 2007, 02:44 PM
once running i can throw a wide band o2 sensor in the back and see what it displays.. as long as it's no higher than 13.5 i reackon she will be fine!