What MAP sensor can I run? - Toyota Nation Forum : Toyota Car and Truck Forums

dsm-drvr · 12-29-2008, 10:38 PM

Hi, I own a 92 corolla with the retardedly small, yet torquey 4afe. I recently turbo'd it. The set up is more or less that of a first gen Talon, with the 14b turbo. I put in a 12:1 FMU, 255lph pump and 7mge 315cc injectors. It also has an MSD 6a box and 8.5mm wires. It has a bit of an exhaust leak before the turbo so it spools a little slow and doesn't hit the full 12-14lbs that the wastegate is set to. It pulls decent with 75% throttle at 7lbs with no fuel cut. As soon as I give it WOT it hits 10lbs and the MAP cuts fuel and throws the engine light. I would LOVE the help if anybody could give me any pointers on what MAP sensor i could use from another Toyota that can read boost and be compatible with my ecu. I was thinking one off of a 3sgte or 7mgte, but dont know if my ecu will read a different one. Thanks

RED91SR5 · 12-30-2008, 12:35 PM

Well I haven't ventured into the land of turbos yet but from what I've read and how far you've gone already wouldn't it be better to go with an aftermarket ECU like Mega squirt or something that can be tuned to your application? Chasing around for a MAP that will work with your specific setup will be a challenge, just my thoughts.

jmaz87 · 12-31-2008, 12:25 PM

synapse engineering (i think thats the name) makes a synchronic map bypass basically a bleeder valve so your map-sensor only sees atmosphere at wot and gets proper vac readings the rest of the time...

i'm setting up a t3 with a 36a/r : i have the 255 walbro and 12:1 vortech fmu. also have integra-gsr fpr and forged fuel-rail i stumbled upon... all of this is NA as i was a little worried about stock ignition...

can you shed any light on the msd 6a? was it hard to setup? i looked into it a while ago but people kept saying stock ignition would be fine...

jmaz87 · 12-31-2008, 12:27 PM

if you still are stuck on using a map sensor you can try one off an early gen 3sgte or map 4agze (jdm)

i also hear dsm map sensors work too but i don't really think the ecu will know what to do with a boost signal... i don't really know how that works

toyotaspeed90 · 12-31-2008, 02:28 PM

I was going to say that the 4agze (late JDM), 3sgte, or the 2jz all use map systems, but I think all of those ecu's are far superior to the 4afe ecu.... the 4afe ecu may not recognize the signals correctly -- even if it does, there's a very good chance that there's nothing loaded in the computer for those values (or what's loaded is way wrong).

to do this properly you'll need a bandaid computer (piggyback) or standalone.

6a is useless in a Toyota, IMHO. I've been shocked by both a 6al/blaster 2 (with properly setup tach adapter) and the stock Toyota stuff (which was in good shape)..... the 6al melted coil wires making it difficult to maintain -- on top of that on a 4afe you will have to use a tower adapter -- something I don't think the stock cap will take very well, and you'll end up replacing quite a bit. Toyota stuff hurts worse to be shocked by, by the way.... also my ae92 idled smoother on the stock stuff. Needless to say, I sold the MSD stuff off.

Again, if you want to do this properly use a standalone with coilpacks/individual coilpacks.

jmaz87 · 12-31-2008, 03:04 PM

i might have to get those tables off your megasquirt setup...

do you recommend going full standalone?
i was thinking more along the lines of using stock ignition for starting but then let MS take over

or just use MS as fuel-adder under boost, something like that.. ( i don't feel comfortable just using FMU and retard the timing)

dsm-drvr · 12-31-2008, 06:41 PM

you probably will be alright with stock and a set of colder plugs. I just set up the MSD (before I turbo'd it) just to see if I would notice any differences. It was a little tricky to install, only because you have to cut and splice the LITTLE wires under the dis. cap. but other than that not to bad. and yes I did see a little difference in power but not much. Btw, I am only doing this whole turbo thing because I cant stand driving a stock car. This is just my daily driver, I race DSM's and right now I have a 2nd gen with 498hp and 11.8 in the quarter. I run AEM standalone on it and let me tell ya its much easier making things work on that than just trying to change map sensors and what ever else it takes to make a motor that never intended on seeing boost work. thanks for the advise on that synapse place I will look in to that for sure.

jmaz87 · 01-03-2009, 01:06 PM

ill put some pics of my setup up tonight if i have time so you can see the direction i'm going in...

what will be the first things to start limiting/failing EX: will my ignition start breaking up or advance to the point of detonation???

how much will i have to retard timing on 93 gas with under 10psi? i have the 12:1 FMU but i was thinking about using some 270cc rb20 injectors if that won't fuck up my idle too much...

i have walbro and integra gsr fpr (higher idle psi) so far... plz any advice would be great

toyotaspeed90 · 01-03-2009, 07:01 PM

Quote:

Originally Posted by jmaz87

i might have to get those tables off your megasquirt setup...

do you recommend going full standalone?

I always recommend MS for those who are going turbo..... if you are mechanically and electronically inclined you will learn a lot about your setup.

my maps probably won't work as it's from an old MS1 pcb 2.2 with a very early firmware setup.

eage8 · 01-03-2009, 08:01 PM

Quote:

Originally Posted by toyotaspeed90

I always recommend MS for those who are going turbo..... if you are mechanically and electronically inclined you will learn a lot about your setup.

my maps probably won't work as it's from an old MS1 pcb 2.2 with a very early firmware setup.

the maps should be fine for a rough starting point which is all he should be using them for... just recently in V2 of ms2/extra they added support for 16x16 fuel maps, but you can still set it for 12x12 maps.

and jmaz: setting it up to use both ecus is going to be way more trouble than it's worth, and megasquirts start engines fine, way better than the stock ecu would with upgraded injectors... and way better than my 4A-F starts

PS: when am I getting my suspension links

dsm-drvr · 01-03-2009, 09:50 PM

Well as long as you run under ten psi you will be alright with those 270cc injectors. you shouldnt have any problems with detonating with your stock ignition, just at least upgrade the wires to a little bigger (8mm would be fine) and try to find a liitle colder plug so it burns hotter than normal.

NGK should make one. they do for my Talon, but Im not sure on the toyota, I havent done it yet because I know my MSD is doing its job.

And on the retarding of timing- I retarded mine to 8 degrees, it idles fine and I havent detonated from it either.

Update on my car: I got the exaust leak fixed, I had come to find out that the 315cc injectors I had in there were running a little too rich with just having the FMU and no engine management to tune them (It was fouling my plugs bad). So I put 220's in it and it helped out tremendously. It does run a little lean though so I would suggest 250cc to 270cc for that close to perfect air/fuel ratio with just the FMU. I hit 7 psi now with no problems except for the little leaness thats going on. I still dont detonate though.

I hope that helps some. If I could post pics I would, but I have no way of doing it

eage8 · 01-03-2009, 10:04 PM

Quote:

Originally Posted by dsm-drvr

Well as long as you run under ten psi you will be alright with those 270cc injectors. you shouldnt have any problems with detonating with your stock ignition, just at least upgrade the wires to a little bigger (8mm would be fine) and try to find a liitle colder plug so it burns hotter than normal.

NGK should make one. they do for my Talon, but Im not sure on the toyota, I havent done it yet because I know my MSD is doing its job.

And on the retarding of timing- I retarded mine to 8 degrees, it idles fine and I havent detonated from it either.

Update on my car: I got the exaust leak fixed, I had come to find out that the 315cc injectors I had in there were running a little too rich with just having the FMU and no engine management to tune them (It was fouling my plugs bad). So I put 220's in it and it helped out tremendously. It does run a little lean though so I would suggest 250cc to 270cc for that close to perfect air/fuel ratio with just the FMU. I hit 7 psi now with no problems except for the little leaness thats going on. I still dont detonate though.

I hope that helps some. If I could post pics I would, but I have no way of doing it

small fuel injectors make me lol

it's all about the 1680cc injectors

dsm-drvr · 01-03-2009, 10:30 PM

Yeah, I know. I have 1000cc in my talon so when I talk about the ones in my corolla it feels that Im talking about a little toy car or something. But whatever ones make the rolla run good (with LOW boost) works for me.

jmaz87 · 01-04-2009, 10:42 PM

this is great input thanks

Now, when you say "liitle colder plug so it burns hotter than normal" i got a bit confused...
i thought the lower the number the hotter the spark...

i have 5's or 6's NGK that was the hottest i could get without ordering and for NA it works great with the extra fuel (pig rich)

my subaru buddies get "colder plug's" i think in the 8 range when they run higher boost

EAGE8 im going there this WED I PROMISE!!!(got lazy with holidays)

dsm-drvr · 01-05-2009, 05:37 PM

Yea I run the NGK 8's in my talon with 24 psi. They are the bpr8es', however they won't work in toyota's because they have the 13/16" head and ours are the 5/8" heads. NGK 7 range are definately something I am going to look into for the toyota's.

BTW, I am going to try to figure out how to post pics soon!