Lexus AFM and 550's

[supradjza80]

lexus and 440's is not a bad idea if done properly. Just throwing the lexus on a car with 440's is a very bad idea and will cause the motor to run lean. But with an AFPR and SAFC a lex with 440 setup will work just fine but needs to be tuned. If do not want to tune, change fuel pressure etc. then go lex with 550's and call it a day. This is close enough that the stock ecu should be able to compensate for any differences (lex is 25% bigger in area, 550s 25% bigger in fuel flow) so same ECU signals are generated just with the ability for more power. To get the most out the 550/lex combo you will need an AFPR and some fuel tuning device though along with the all important wideband.

My car running stock afm/440s/fuel pump/pressure reg. also runs pig rich above 3k rpm's, AF's about 10.5 to redline @ 12 lbs of boost.

 

[Hmong_1G]

Thank you for putting some substance behind your post. Yet with out asking a few simple questions you make inaccurate assumptions.

To clarify.

When I cross reference the part numbers Toyota and the Lexus number they are identical. From part to part, year to year. Even comparing several electronics side by side, they appear to be identical. I would speculate this is pretty solid evidence that the part numbers are the same.

My car has always run very rich when I am in boost. I did not say all the time, did I? I will have to check the A/F ratios that were provided when I had it dyno’d about 3 years ago. The only change in the last 2 years was a ported and polished the head with some valve work. The car ran fine at idle and was fine in boost.

After I installed the FPR and the Walbro fuel pump my car my car still ran fine with out issues, except for the rich issue. After installing the Lexus AFM, the car was stumbling more and dumping fuel into the cylinders. During higher RPM and boost, the car would stumble (due to spark blow out) and there would be fuel dumped into the exhaust. There was a substantial amount of backfiring. Other drivers, and supra drivers behind me were able to verify that I was having more fuel into due to clouds of burning rich and the stench of unburned fuel stinging their eyes as they drive behind me.

After I backed out the Lexus AFM screw all my issues went away. I do have a wideband, it is just not wired up 100% in my car.
Anything else you want to add?

Take a look at this thread. Not linked to the subject at hand but a good idea to go off from.
http://www.supramania.com/forums/showthread.php?t=103265&highlight=injector