Well, Gadget has done extensive testing to figure out how to make a S/C'd 3.4 as reliable as the N/A's 3.4, he's done his homework, found the problem (which is NOT being contested, the S/C alone is a lean engine...) and fixed it with a kit that not only makes your rig better overall, it's cheaper than a new engine.

Same with the VB upgrade, some preventative measures make sure you can have fun without any catastrophic meltdowns...

As generally quoted from Gadget's website:

 

But, you're talking about being higher up in elevation... 6-7,000'? The air is thinner which means that the fuel that the stock system will try to dump will end up creating a richer mixture, which will tend to reduce ping, and more importantly, keep you safe from the highend lean-out issue.

Down here in the lowlands, that's not the case. We add the piggybacks and/or the 7th injector to get more fuel into the system and retard the timing.

 

LOL well I'll be adding underdrive pulleys and a URD kit to make it as though I was at sea level

Every single person up here at 7500 ft will be jealous of me because I have awesome power still, but their N/A engines will be wheezing (my little 3.0 does that right now, it sucks).

 

BTW, you're not helping

 

Mr. Brian sir, THAT is my role on this forum... to NOT help in very fun ways!

I get a monthly kickback from Visa and Mastercard for just those kinds of posts!

HAHAHAHAHAHHA!!!!!!!!!

 

LOL you're going to end up being that little devil on my shoulder

Fortunately, I will be happy with the horsepower my new runner will be putting out... it's the suspension I'll get annoyed with I think

 

Midiwall, I can't address the altitude issue you raised, however what you are saying seems plausible to me because the S/C 4Runner I've owned has always been at high altitude (lowest I've drivin at is about 4500 ft).

Is it relavant that I don't go faster than 80mph? I thought the high-end lean-out issue arose at higher speeds. From what I remember, Gadget was drag racing his 3.4L and wanted to push it to its limits. If I remember correctly, he even removed his stock speed limiter so he could drag race. Anyway, Gadget was attempting to push the 4Runner to its limits, and at or over 100 mph, maybe the pump is insufficient as he found. Maybe I'm being pessimistic in asking this, but isnt Gadget also the person selling the 7th injector kit? It just seemed like overkill for everyday use.

I can't imagine the stock pump would not deliver sufficient fuel pressure at 80 mph - but I'm not a mechanical engineer with verifying calcs. If I spent more time at 90-100 mph, I could see this being more of an issue.

As is evident in my post, I didn't research and learn a heck of alot in making the decision to buy and install the S/C. It was, however, the best money I spent on this truck. I'm cheap, so given the 4Runner's limited value and mostly utilitarian purposes in my circumstances, I wasn't willing to put much more $ into it. Heck, I'm beginning to wonder if I'll even get the $8900 I'm asking for my '96. I'd really be kicking myself if I had spent the extra $3000 for the additional mods. Ouch!

All I know is that I've owned 1991, 1994, and the 1996 4Runners (and now a 2005). The first three were all dogs that I had to whip (i.e. put in 3rd gear and floor it) to drive through the Rockies and maintain 60 mph - God forbid I had a trailer attached - not to mention the crappy mpg. The stock 3.4L was marginally better than the 3.0L. The S/C added power and mpg for me.

With the S/C, I only rarely see 3rd gear on the drive to Utah. I easily maintain a constant 70 mph while occasionally using 4th - sometimes to slow myself down or to pass. I've got power to spare - even w/ the trialer in tow.

Again, I can't address the altitude issue and its affect on the HG ping. I guess in my ignorance, until I see or hear of blown 3.4L's as a result of the S/C w/out the 7th injector, or the other mods, I'd rather not toss more money into the pile I've got going on.

 

Not really... The issue is WOT (wide open throttle) not speed. It's more tied to RPM and the amount of air you're sucking through the intake.

When the ECU sees the extended air flow, it will try to prempt a lean condition by adding more fuel, the net effect of which is increased power. This happens by the ECU extending the length of time that the injectors are open. But, the actual amount of fuel that's shot into a cylinder is limited by the size of the orifice of the injector, and the pressure on the fuel rail.

An injector can't be open for more than 100% of the alloted time slice in the 4-stroke engine cycle; and inadequate pressure on the fuel rail will not let the injector deliver it's rated amount of fuel.

A stock fuel pump is 45psi, a stock injector is 235cc. There are a dozen calculators on the 'net that will tell you what kind of horsepower you can make with that combination in a 6 cylinder engine. Here's one:

http://www.rceng.com/technical.htm

If you take the "normal" values for the other variables that we haven't talked about here, you'll see that the HP ends up being 218. The HP rating of a STOCK 3.4L engine is 183bhp.

(fwiw, the other variables are: # of injectors: 6, Brake specific: .5, Duty cycle: .8, Fuel pressure: 45psi)


side note: The ECU is also watching the front O2 sensor, and when it shows lean, it will go into react mode by again trying to dump more fuel. The exception here is when the ECU is in Open Loop, which results in the ECU ignoring the O2 sensor.


No, URD (Gadget) doesn't resell the TRD 7th injector, he _does_ sell a piggyback to the TRD piggyback which give you more control over the 7th.

He _does_ sell the "Fuel Upgrade Kits" which are a set of:

• A high output fuel pump
• larger injectors
• An injector/timing controller (piggyback)
• "Colder" spark plugs
• Software for programming the piggyback

This kit is infinitely more configurable than the 7th injector, but at the cost of being more complex to install and of course, configure.


Again, we're talking about the ECU reacting to air flow, which is generally an RPM issue, not speed.


That's a position that many people take. But you're rolling the dice in a game of physics. Ping is a telltale sign of problems that will break a connecting rod. The high RPM leanout is a sign of a condition that will burn a hole through a piston.

There's a guy here locally that S/C'd his 3.0... No fuel mods. There are pics around showing the results after about 2 months.

btw, this isn't a 3.4 problem, this is a simple physics issue. It shows up and is talked about on the 3.4 because a) this is a Toyota 4Runner/Tacoma forum where the 3.4L engine is commonplace; b) Toyota makes a user-installable S/C for the 3.4L engine; c) people have documented the effects of an unmodified install in a lot of detail (ping and extreme exhaust temps); and d) people have documented the effects of a _modified_ install.


And again again... Because you're at a higher altitude, the effects of running on an unmodified S/C install will be reduced - but the underlying issue is still there.

 

 

Before you dump money into modifying any vehicle, think about your goal with the vehicle to see if it makes sense.

If I got a dime for every person I've met in Texas (or east coast) that had lift kits and big tires, but never wheeled in their lifetime, I'd be rich enough to buy everyone on this board a couple pints. If you don't go offroad or trailing that often (like never), then don't buy the big tires and suspension/body lift kits, lockers, snorkels, etc because it's just a waste of money for you. It doesn't necessarily "add" value to the truck.

Same thing applies for the supercharger. If you are concerned about gas mileage and speed limits, then don't get any major performance bolt-on or modification.

The truck in its stock form already requires maintenance and if it's already too much to handle, then you should definitely stay away from supercharging the truck.

For those who have a hard time with soldering, you can use other things like Posi-Taps or butt connectors. FTC only has about 7 signals or so to connect. Just do one at a time and mark them before cutting. If you plan it out, it's very straight forward and easy to install.
For example, I used a silver sharpie to make sure I had the polarities right on the fuel injector wiring (even though it shouldn't matter since the only thing injectors need is the current to flow through the coil to "open" the injector). However, the point I'm illustrating is that you can mark things to make sure you're connecting the right signal after a cut/splice.

J

 

Midiwall.... hanks. Your post has simply confirmed my concerns and my understanding of this....exactly the same as with my 3S-GTE. I just wasn't sure if the 97 Toyota ECUs were any better as far as accomodating the piggybacks or reflashing. Is there a company that adds 'daughterboards' to them?

I'm not up in altitude so I was concerned about the denser air and leanout. Even worse, I'm in the southeast and it gots quite "hawt" here in the summer (no intercooler sucks) and also gets cold in the winter (even DENSER air for leanout). I saw that the URD kit was a more flexible and better value option, although more complex than the 7th, but since I'm not looking to race or tow a house, I was hoping I could get away with Ram's philosphy about only needing all these mods for extended WOT pulls and heavy towing..guess not.

My thought was that water injection wouldn't necessarily involve tuning, especially if only used for added safety...inject only above a given boost pressure via solenoid? I'd be giving up torque based on the decreased flame propagation in the cylinder, but that's what I'm trying to accomplish and yet still much better than no SC at all. Definitely a band-aid vs really fixing the root issue. I could probably do that cheaper than a 7th (I'm assuming it would be hard to find a used 7th kit). I'm very disappointed with Toyota on this issue.

I see my SC as a freebee that came with the truck, so right now my perspective is a little different than it would be if I was paying for an SC as a performance upgrade.

I've got much more info to search on the board. Is an adjustable Fuel pressure regulator a viable option for a small bump in fuel pressure?

Kevin

 

Not that anyone has found... The closest thing is JET, which produces a chip (actually a daughter board of sorts) which replaces a ROM in the ECU. The purpose is to change the fuel and timing tables to setup for more fuel and add some timing advance. The net effect varies, their website will give you the normal marketing lies, but the bottom line is that it's WAY overpriced. For almost $500 you get to pull your ECU, send it off, and wait a couple of days to get it back. For $375 you can buy an SMT-6, attach 6 wires and have a _programmable_ set of fuel and timing tables.


yeah, that's not a bad thought but again there's a potentially high cost involved here. An Aquamist system will run you close to $1000, Snow Performance will set you around $400. Both companies offer boost activated or MAF following controllers.

The downside is a) you're running methanol, not just water - so there's an additional runtime cost there. b) for the same money (or, 1/3 the money in the case of the Aquamist) you can run an SMT-6 and "fix" this more properly.


A lot of us are, but I think most folks have stopped complaining to Toyota since it hasn't gotten us anywhere expect to see their own bandaid.


As you wander, you'll find people talking about the "Free FPR mod". This is where we basically take the input to the FPR (Fuel Pressure Regulator) and hijinx it into thinking that it's cranked open all the time. The timeline of when the mod showed up points to Gadget as the one to propagate it around - and without any credits, Toyota now walks people through the mod in the S/C install instructions as if it were their own.

The mod helps, but you'll still be lacking up top with an S/C.

 

Did Toyota offer models with the S/C installed from the factory? If so ,how would that be designated, and did they have the appropriate mods? I test drove a used S/C'ed Tacoma a year ago at a local dealership and it was incredable!!! Wanted another 4Runner though. The salesman told me that it would be a two thousand dollar add on from them, labor and all, and the original Toyota warranty would still be good. Now these posts make me wonder if they knew what they were talking about? (That Taco with an auto trany went through the gears so fast , I couldn't have shifted fast enough with a 5spd.)

 

I'm fairly sure that you couldn't order the SC preinstalled from _the factory_. The SC has always been a TRD part, which to a dealer is an add-on.

I'm sure that the dealer would be happy to charge you $2k for an SC and labor. And actually, if you figure labor at $100/hour, that's about right. Then like we said above, the warranty is certainly still valid - even if the consumer does the install.

Any mods that we're talking about here are purely aftermarket, even the "7th injector" which is a TRD part. Though again, I'm sure that a dealer would be happy to come up with a price to quote you including an install.

Now, when we're talking about a high capacity fuel pump, or larger injectors, a fuel/timing controller, smaller pulleys, etc. then those are NON TRD parts and I wouldn't expect a dealer to install them, or even know about them, or even "admit" that anything other than something pure TRD is needed.