MAF to MAP +20hp? - Toyota Nation Forum : Toyota Car and Truck Forums

Gerkn · 02-11-2009, 10:47 AM

I have an '89 GTS and I read somewhere that the JDM 4AGE had a MAP sensor instead of a MAF sensor and it made a 20hp difference because of airflow restrictions. Is this true? Is there a way to just install a MAP sensor and take out the MAF? Would I need a JDM ECU to do that? How hard would that be? I'm a n00b, but thanks in advance.
Also - could I just fix the problem by installing a cheap air filter?

eage8 · 02-11-2009, 11:28 AM

Is this true? No

Is there a way to just install a MAP sensor and take out the MAF? yes, but it's more trouble than it's worth
Would I need a JDM ECU to do that? yes, + the wiring harness and maybe a few other things
How hard would that be? pretty hard
could I just fix the problem by installing a cheap air filter? there's not a problem to begin with, but yeah, air filters help performance, but I wouldn't get a cheapo one.

toyotaspeed90 · 02-11-2009, 03:19 PM

there's about an 8-10 crank HP difference.... only way to tell is that the JDM smallports having identical engiens have about a 10 hp difference.

it's not simple. You would need the entire harness and ecu, or go full standalone and tune it.

Gerkn · 02-11-2009, 03:34 PM

So the USDM 4AGE and JDM 4AGE are the same except that the JDM has a MAP sensor and USDM has a MAF sensor and because of the different sensors, the JDM version gets +8-10hp at the crank? The engines are about the same otherwise?
I'm trying to restore the car to JDM-spec with maybe a few bolt-ons but I want to know if the JDM engine (which from what I read has 130hp as opposed to 112hp) is a lot better?

Quote:

The use of an air flow meter (MAF) sensor, which restricted air flow slightly but produced cleaner emissions that conformed to the U.S. regulations, limited the power to 112 hp (84 kW) whereas the Japanese model — which used a manifold absolute pressure (MAP) sensor — produced 130 hp (97 kW). - Wikipedia on "Toyota A Engine"

eage8 · 02-11-2009, 04:21 PM

if you really want to be "JDM" I wouldn't bother with that engine and just get a japanese 4A-GZE, it came in the japanese trueno GTZs and has a lot more power. (it's supercharged)

toyotaspeed90 · 02-11-2009, 06:11 PM

well you have to keep in mind that in 1989 your car came with a bigport. I am referencing a smallport 4age.... US/afm electronics it was rated at 130hp and the JDM/map electronics it was rated at 140hp. The motors themselves are identical.

the bigports also did come map and I am unsure on the power variances between them, as it's never really mentioned.

4agze's came in many car's.... aw11's in the US, AW11's in japan (same setup as in the US), and in ae92's and ae101's.

freakinbox · 02-11-2009, 07:17 PM

I thought the Japanese motors were also missing alot of the emissions equipment.. I don't remember seeing much of that stuff on Recardo's imported Levin when he popped the hood

Rookie_One · 02-11-2009, 07:36 PM

X2, i they were late in adopting catalytic converter if i remember well

freakinbox · 02-11-2009, 11:58 PM

not just the cat, things like the egr valve are missing too from what I remember

That was why our sr5's didn't have the 1.5 liter. Ours have 1.6 liter for the lower end models since the emissions equipment takes power from the engine.

toyotaspeed90 · 02-12-2009, 10:18 AM

there is no EGR valve and the other sensors don't affect performance....

the EGR is closed at WOT, so the power figures wouldn't change with or without the EGR.

jmaz87 · 02-12-2009, 11:18 AM

and lots of corollas came with and without EGR. i have three ae92's and only the older 4af had EGR. heck i don't even run pcv but thats' unrelated...