descendents

aye aye aye 35" and no regearing... i know im going 5.29 soon when i gte myself some 35" mt/r.... 35" and 5.29 is pretty close to stock, it'll bring your gas mileage back up.. i know people go 5.29 for manual.. it hink its a bit different for auto

kelly

Dr. Zhivago

Until you do this mod yourself and experience the difference, I don't really see the point in discussing any of this wth you. It seems to me that you've already made up your mind that I (along with everyone else who's done the mod) is full of ˟˟˟˟˟. I've learned from years of being involved wth forums and BBS's that people like you aren't much better than trolls and most of the time end up being just that.

However, with that said, I will answer your questions...

Nope. But my butt dyno is pretty accurate (based on my own experience) and I've spent a lot of time dyno'ing previous cars that I've owned. I do have a performance measuring device, but since it isn't an "officially" recognized piece of equipment, I don't see the point in publishing the results. A lot of people have poo-pooed this mod already. Dyno runs would only add fuel to the fire. People dyno'd the Deckplate mod and people STILL say that it's BS.

Yep.


I did. They're in the article. It involved measuring the length and diameter of the Intake Silencer, the Throttle Body Bore Size and the ID of the Intake Tubing. Replacing the Intake Silencer, which by the way, is what TOYOTA calls it, with a tube of a slightly larger, less restrictive pipe allows more air to enter the engine at a higher velocity. I don't think I need to explain why that benefits performance...

Peace.
Dr. Z

CMUpike

Dr Z - 1
4RUNR - 0


boo ya!



oh, and just to reiterate what everyone said earlier:

1. Heavy foot = MPG loss (duh, if you floor it every time, you're gonna burn a lot of gas... quickly)

2. ECU generally needs at least a tank to readjust

3. Since a lot of these mods are done "DIY", there's a chance that someone messed up the install (even the slightest mistakes can lead to serious problems)

4. If you don't like the idea of it, don't do the mod! There's no reason to whine about it. (probably the most obvious statement)

oly884

Come on guys, give the guy a break. He's new to this stuff just like we were at one point.

I had the same thing happen to me when I got the K&N FIPK kit. It was the heavy foot that lost the gas milage. The ECU does need to learn the new intake and driving habits so it will seem crappy for a little while. Just try to go easy on the throttle and go through a few gas tanks and I'm sure it will rise.

Tacoma Dude

Just thought I'd add my little experience.

I did the ISR first before the deckplate on my 02 Tacoma. I did notice that I had poor mileage first few tanks after the ISR but then again the gears on my auto switched at higher RPMs. Once the engine settled and became accustomed to the mod I had no problems getting back the same MPG as before. I don't remember noticing any increas in the MPG though.

After running the deckplate and getting rid of my leadfoot-itis I can tell you that my MPG has actually increased. My first 1/4 tank I used to get 75-80 consistently. Last few tanks I've been noticing 85 at that same mark.

Yeah, I know it's a subjective call but I know at least I'm not hurting on the mileage.

Like Dr. Z said - chances are you guys have already made your mind about the mod - hopefully, you've actually done it and had the patience to allow the engine to settle with the it.

4RUNR

Now that was uncalled for! You can’t stand ever be questioned in your reasoning or what is it? Or were you presented with more solid logic and the only way out was personal attacks? Sure sounds like it, and your opinions without any hard data like dynos is only as valid as the next.

Not exactly, but I do need to find logic behind the mod instead, even if more than one personally attests to the “improvement”.

The two reasons as you confirmed were responsible for the improvement (I) No entrapped hot air (II) Air resonance.

(I) I can’t swallow because my common sense suggests that the air volume entrapped in the resonator is negligible relative to the whole intake, which starts before the air filter and ending behind the throttle body. Even if we assume that that half cubic foot of air inside the piece that we replaced would be cooler by many many degrees, the air would be exchanged instantaneously when getting on the gas anyway. I don’t refute that this entrapped air in theory is detrimental to the response of the engine, but the improvement is nothing short of superfluous in our context, an SUV.

(II) Air resonance should not come into play here anyway as I’ve realized that “piece of tubing of the appropriate diameter” means “piece of tube that fits”. I’m sure Toyota had many very talented air dynamics engineers crunch the numbers to get most torque at the most usable RPM range. Again, I won’t refute that you might gain a few hp in high RPM where the pulsation doesn’t matter, but then again those few hp do not matter if those RPMs are not seen in 99.9999% of all cases. I personally would not trade even 1 unit of torque down low for 20 units up high, as I rarely see anything above 3k RPM, or 2k when following normal traffic. The cases where fuel efficiency went down probably can be partially attributed to detuning of the intake.

The real problem I see with this mod is the reported pinging, and the aforementioned fuel efficiency, neither of which logically are related to (I) and (II) points above, which only support my theory that neither of those are the real reasons behind the power increase. If you ask me, if there is an urge for more power what’s wrong with advancing timing slightly and filing up with a higher grade of gas? Same power increase, and will gain a few MPG actually with that, guaranteed!

You are free to pick apart my logic here, I just ask of Shivago to keep it civil and not resort to childish personal attacks or falling back on false sense of seniority.

Yoter

?:pat: ?

Jay

How would you do this on a DIS (Direct Ignition system)?

4RUNR

Well, ok, bad example but THE point was(is) that the perceived power improvement is not for the reasons listed, and not in the RPM band where it matters.

midiwall

I'm curious... At what point in the RPM band doesn't a power increase matter?


The net result of doing the ISR mod is an improvement in throttle response. Coupled with the deckplate mod, there is also a power improvement.

The physics behind why this happens (not the "logic") has to do with the volume of air that sits in front of the intake manifold. The ISR mod reduces that volume, thus when you jump on the skinny pedal on the right, there is less air "to get moving" before it finally reaches the throttle body and starts making a difference.

Given that this mod is totally reversible and inexpensive to do, I think it's "odd" and "interesting" that you're arguing about it instead of trying it yourself.

2001Millrunner

i love it when ppl start gettin mad on the forums lol, adds a little spice to the dullness

4RUNR

Shivago is the one who got his panties in a bunch really quick I'm still trying to understand how this mod really works (will probably try one time or another anyway when really bored).

midiwall

Dr. Z has a lot of this covered, and it's been covered on the forum before.

Have you seen the writeup?

https://www.yotatech.com/~corey/tech...ntake/dr_z.htm

There's a link in the writeup that points to another site which covers more of the fluid dynamics of what's happening:

http://www.users.bigpond.com/pgscott...resonator.html

denverbikeguy

With the ISR, deckplate, minor tuneup, and cleaning of the throttle body and my K&N filter, I noticed just under 5mpg improvement! I'm at 24mpg highway now, 20 city (up from 18 for both). I fail to see how you're seeing such a huge loss unless A) it's driver input or B) you really, really ˟˟˟˟ up the mod somehow.

Try doing the deckplate. Seriously. Too many people have done it and liked it for it to be a bad thing!

2001Millrunner

i just wanna say that im on my quarter tank mark and on regular unleaded gas and my milege is reading at just a little over 109 on freeway mile, i used to get around 85-89.

rwmorrisonjr

Have found that on mid-grade (87 out here) that I get about 18-20 mpg in the city and ~22 highway, 19-20 average, both with & without the mod. Am going to replace the silencer due to the noise (g.f. commented) and the lack of any noticeable gain in power. Have given it a good try and don't feel and difference on a non-supercharged engine (see link mentioned above). No flaming/trashing here, just honest opinion from my personal experience.

RidgeRunner

I'm happy with the ISR & Deck Plate Mod. I did those at the same time and put on 265/75/16 too. My mileage went down slightly but barely noticeable.

Over the 4th, I got 19.8 mpg and that included 6 hours of wheelin'. Probably 2 hours in 4lo. (you guys that don't have a locker won't believe it) I've consistently gotten 17 to 18 around town and 19 to 20 on the road, depending on speed.

Sometimes I'm on the throttle when I want to show a passenger how "kewl" the 4Runner can be but usually I'm pretty easy on the gas.

Let's go out and have some fun!!

Mick

bamachem

First a little background...

99 limited (3.4L Auto) with deckplate mod and amsoil filter.

I did the ISR mod a couple of weeks ago, and the first two tanks (actually 1.5 tanks) after the mod I got 14.5 MPG! Before the mod, I constantly got around 18-18.5 in mixed driving and sometimes 19.5-20.0 on the highway. I admit that I "got on it" a few times after I first did the mod to check the change in sound, but after playing around for about 10 minutes, I went back to my regular routine. You guys are saying that I never got decent milage with it since the computer had not "learned" the new intake conditions after 300+ miles...

Anyway, I could barely deal with the roaring of the intake, but I could not toleerate the loss in MPG's, so I took it off last Thursday. I drove THAT NIGHT for 250 miles to the beach, and I got 19.85 MPG!!!! This is immediately after taking the thing off! Explain that... Did the computer "learn" faster with the stock intake - not a chance. Did it "revert" back to the original configuration - no way after 300 miles!

Simply, the mod gave me more power and quicker spooling, but ATE my MPG's and made for quite a noisy ride in the process!

The next thing on my list is electric fans to get a few HP back...

midiwall

Well, that's why its a good mod to try. It's cheap and reversible if it doesn't work out for you.

The arguing above started with someone complaining about it without trying it for himself. Kudos to you for giving it a shot. Sorry to heard that it didn't work out for you though.

It's interesting that there seems to be a 90/10 split between people here that got good results with it and those that didn't.

Hard to say what the issue is, though from looking at the geography of the posters, it could be tied to humidity. Much like someone else pointed out asking about climates where you live with the air conditioning on.

Tencast

That is kinda what I was thinking. I'm now on my 4th tank of gas and this last tank averaged 17.3 mpg. That was a combination of town and freeway driving. I'm going on a trip on Friday and it will be almost all freeway. I will watch the mileage very closely and make a final decision when I return.

Tencast--