Well I got the isr mod done yesterday, big thanks to Christian <96 Runner> who helped me with it at our little az meet. Took him only 5 minutes with all the parts already. First drive out, punched it, WHOA!!!!! Now that is loud!!! But it isn't annoying loud, it's more of a beefy loud. I don't really see how people can get annoyed by the sound, I think it sounds great, with an aftermarket exhaust it'll probably sound even better too.

The only draw-back is running premium, it's sorta pricey out here at $1.71 / gallon, but I feel it's worth it. However I am gonna put the intake silencer back on in a week and run regular again because I have a huge road trip I have to make. But once I reach my destination, it's coming right off again.

Big props to both Christian, for knowing about this mod a looooong time ago, and Dr. Z for making it known and also creating it.

A definite must to at least try it out.

 

Umm, you have to run Premium gas with this mod? I must have overlooked this when researching it. Ive yet to do the mod but have been planning on it for the early summer. What will happen if I keep running regular or mid-grade?

 

i want to do this mod too, but also failed to know about the premium gas thing. also, anyone from the Atlanta area want to help me out with it???

 

Prolax,
From what I've read, it will make the engine ping. Apparently this thing makes a huge difference in the amount of air going into the engine. I want to do it, I'm just concerned about the sound. Seems to me like it will be loud as hell.

Matt

 

Yea from what I heard, regular unleaded does make it ping, however I think there is a member with this mod on a taco that's running 87 octane and isn't pinging. Don't remember who though.

Matt the sound isn't THAT loud. I think it sounds awesome. It only cost me 7 bucks and 5 minutes. I think it's AT LEAST worth a try. Real easy to reverse.

 

Im running 87 on my 99 with ISR and Deckplate. No pinging.

 

I did the ISR mod yesterday. It si more of a more prominent growl from the engine than it is noisy. On my 88' it just sounds like I have a better motor than I do .

I have only had it a day, but I am not running premium, and it is running just fine. When my tank is empty, I will try premium and see if there is any difference.

What is the logic behind needing premium with this mod anyway? Dr.Z?

 

I'm guessing since you're removing the intake silencer, also other empty compartments that trap air on the intake, it lets the air go straight from the airbox to the motor without getting trapped anywhere. So with the extra air coming in, the octane of the fuel should be higher for a more powerful combustion? Maybe....

Just a guess

Hmm...I might try and run regular 87 and see how that goes.

 

I did this mod last Oct. and have been running nothing but 87 in my runner with no pinging problems.

Just got back from a trip today which included steep climbs to 6,000 ft and still no pinging. I've never run premium in mine.

Mick

 

I saw Christian install the mod. The runner is quite a bit louder now. I would say no louder than when I installed the deckplate, however.

Not as loud as a supercharger, that is for sure.

I'm going to try this next week. I have tested my EGT with and without the deckplate and I get 1525 as the hottest temp under both conditions. (so I'm just slightly lean I think)

I'll post my ISR results next week when I get some time.

Dan

 

sorry if I sound like a newbie when I ask this.
I've researched all kinds of stuff about toyota
trucks, so I do know a fair amount about them.
not to mention Ive done clutch changes and timing
chains in 22re's, but what is the ISR mod, and
can it be done in a 2nd gen runner with a 3vz

 

See Here:
Click it! You know you want to!

 

First the premium fuel issue:

Many of us have experienced a lean condition at some RPM's with the ISR mod. You have to REALLY listen for it due to the enhanced growl of the ISR mod with the deckplate open. Because we are messing with the FPR (Fuel Pressure Regulator) and removing all baffles on the intake (streamlining the airflow), some engines are leaning out. Running premium fuel (burns longer) allows for more complete combustion during the compression stroke, thus reducing the chance for a "flame-out" (pinging).

I truly believe some are not experiencing pinging. However, this may be directly attributed to the knock sensor doing its job. When pinging (well knocking, which is worse) is detected, the engine retards the timing to prevent damage. I feel this is happening on some engines where premium is not being utilized. Therefore, performance potential is not being realized completely.

Run premium. My .02.

 

I second 96_Runner.

Dr. Z

 

Very well put!! Looks like I might stay with premium instead.

 

FWIW, if you're at altitude like I am in Denver, you will not need premium. The air is thinned out here enough that even with all the ISR and deckplate mods in the world, you will never be at sea level air pressure where the engine is designed to run, so it's no big deal to run 85 octane gas like I do (no pinging, I listen real close).

Maybe at low elevations you need it. But it does not give you more powerful combustion as one person suggested it might, higher octane = slower burn like 96_runner pointed out. If you are pinging and the knock sensor is retarding the engine, it will help, but in a truly non-knocking (i.e. not modified by the computer) engine the premium gas will actually hurt performance.

Not sure what the elevation is in AZ where you are, but it might be low enough that you need higher octane gas with these mods. Though in AZ I would think 87 octane would be fine...

 

Denverbikeguy, we are generally Sea Level to 1000 in the PHX area. So, altitude is not a factor. However, heat just might be.

I agree, at higher elev such as denver, normal fuel will suffice. In fact, when I go up north for camping, I plan accordingly by running lower octane. Saves money and makes sense.

Good points.

 

Can someone post an audio clip so those of us who aren't ISR'd can see how loud it really is inside the cab?

Matt

 

Before

After

Above links courtesy of (College Boy) RTDawgs.

Dr. Z

PS Matt, just get off your ass and do the mod already! :bounce2:

 

Dr Z,
I am going to. Just wanted to hear it first. I've got a monster hill to climb coming from work and another monster mountain before I get home. I've got a feeling the engine will ROAR after doing this mod when climbing these hills. Have I touched a nerve with you Doc? Just kidding. Later.

Matt