marshm4ll0w

I was wondering if anyone knew of any fuel managing computers or chips to change fuel/air mixture. looking into turboing one of my my 2 4runners. Would do a 3.4 swap but i wanna do somehting less common, something that will be unique and an interesting project. Iv only read 2articles on turbos 3vze. one on toyota nation i believe and i think one on here. been reading a book on how to turbo a vehicle, and was wondering if anyone has used any or knows of any good fuel computers or chips for these things. iv also read that someone else used a 7th njector, and had aninjector controller.

sundog kid

Go megasquirt and never look back.

PLUS, then you can start an entire new hobby, with car computers from mp3car.com!

Erik Beeman

MegaSquirt is a pain in the ass! I'm ran it on my 88 22RE, and I have it on order for my 92 22RE. You have to make a adaptor harness, or I can make one for you and ship it to you. You will also have to run a wideband O2 sensor, such as the AEM UEGO. I am currently running that, it's a decent install. Then you have to tap and run a vacuum line from the intake manifold to the MegaSquirt so it can read manifold pressure. It's a real project, let me tell you.

Btw, the 7th (or 5th) injectors are the cold start injectors. They take them and mod them into the fuel rail to gain an extra injector.

abecedarian

sdsefi.com has an alternative as well.

marshm4ll0w

i think i read somewhere else that someone used a jet computer, and i read sopmewhere else that people used an apexi one or something. has any of you guys ever heard of any of these?

abecedarian

jet is mostly a stock ecu mod that tricks the ecu into running rich.
apexi had a piggyback controller that modified the signals to and from the ecu in order to trick it into doing things it wasn't designed for.

As far as I now, the Apexi unit is no longer in production.
What Jet did could be accomplished by a backyard mechanic with access to Radio Shack and a soldering gun.

If you're serious, you'll need a fully self-contained stand-alone unit, not some over-rated, under-performing promise.

annoyingrob

A megasquirt unit will be cheaper than an Apexi piggyback, plus 22R adapter harnesses are so rediculously easy to build. I built mine in like 10 minutes.

marshm4ll0w

ok thanks abe. got the rights answers, or the ones i was hoping for. from reading those websites theres a lot more to know about fuel management that you wouldnt think. the other thing i was wondering was, that if you change all these sensors etc, emissions testing probally wouldnt like it? its no longer stock or doing what the vehicle is rated for

marshm4ll0w

oh and seeing as your good with answering questions abe, i was reaing on here i think that a guy was running a turbo with no fuel mods, he let the stock ecu do it or something, he said they can handle like 15 pounds boost. wasnt on running stupid amounts of boost througha 3vze anyway the head gaskets are a wimp. I dont know if this would be true or not. once the turbo spools up and adds more air wouldnt the ecu see it as lean form o2 sensor and try and richen it? but then it can only richen so much

abecedarian

Well, yeah. The ECU can only add so much fuel. What I've heard is that the stock ECU can compensate for about 5 PSI boost max. If you trigger the cold start injector under boost, that may increase to the 8-10 PSI range but significantly affects the ECU's ability to read the O2 sensor to compensate... since triggering the CSI would likely mean you're at wide-open-throttle and if that is true (TPS reads WOT) the ECU ignores the O2 sensor / acts as if in open loop mode.

Unfortunately, the ECU cannot retard timing based on boost- it can only use the knock sensor (on vehicles so equipped) to compensate for detonation, in which case the timing drops all the way to the base timing setting of 5 BTDC for the 22re and 10 BTDC for the 3VZE (or whatever base timing was set at the last tune-up) when detonation is encountered. Not exactly a good thing to do, with regards to maximizing power output.

It is possible to adjust the VAFM to add some fuel with increased air flow and let the O2 sensor correct the mixture but then again you run into a situation where at or near WOT, the O2 is ignored.

The personal cost involved with tweaking this and adjusting that would be far better spent installing an engine management system capable of dealing with all the variables and utilizing sensors far more accurate than a vane air flow meter et al... like MAF or even 2 or 3 Bar MAP sensors and such as well as being able to control timing curves based on throttle position, boost and the like.

abecedarian

I should also say that with the appropriate engine management system, it's entirely possible to pass tail-pipe emissions 'requirements' while still being able to deliver power. Unfortunately, most emissions requirements also require some amount of reliability and longevity, i.e. the system and engine will operate properly and pass emissions requirements for 50,000 miles or so. So getting these systems 'legal' means that they can't stress the engine too much and cause the engine to fail too soon.

marshm4ll0w

oh thats not so bad then. i was only intending on running like 5-7lbs boost. i gues i could try running it and see weather or not the ecu could handle it. i figure if i use a small turbo, it wont spool up to bad, and then it will accel better, and the plan is for basically towing small trailers, but once you hit a hill with the trailer its like driving a tank up the hill. so i figure by adding a few pounds of boost, i should be able to compensate for what i need. i was reading that for every pound of boost its like another 10hp, so i figured 5-7lbs would give roughly the same power as the 5vzfe, and my parents runner and tacoma pull a boat not bad. so i figure this should work out.

basically my biggest concern was the fuel management, once i get this hurdle covered i should be alright. so you figure if i run a small turbo from like a 2-2.5ltr engine and go for 5-7 boost id be okay for fuel management or id have to run a fuel managing system. whats your imput.