So I did the ISR mod on my '97 runner tonight. Wouldn't say it's the "4-barrel carb on a V8" sound like the tech page mentioned, but the intake is definitely noisier. (Yes I do have a 4" deckplate mod too.) The power increase is nice however! I'm sure it'll improve even more once I clean the K&N off.

The instructions were a bit off however... Unless I managed to screw something up. I will take a pic later, it was dark when I finished up. Anyway, when connecting up the FPR and PSP to the intake plenum, the two tees were overkill. In reality I should have connected the FPR to the intake with a tee, then the other end of the tee straight to the PSP with a longer hose. I'll take pics later like I said so this makes more sense. I think the hoses are a little different on some years perhaps.

My plan is to exchange the hoses with the 99 and up models so I can clean it up. For now I just capped off the existing hose. 2 of the caps I got were not the right size, but I found on the large hole that the lid to a spray paint can was the perfect size and could be trimmed to the right size. The other one I plugged with a rubber furniture foot. When I exchange the hoses I will remove the throttle body as well and deal with the metal gasket which blocks part of the flow.

 

Yes this is true. I have both intake mods done too on my 2001 and for me all I had to do was move the FPR hose from the silencer to the thing on the intake manifold, no "T" involved and no hose connected to the intake manifold plug previously. Used original FPR hose and just snipped off the last warped 1" of it so it would fit snugly on the plug. Easy as pie.

Zach

 

The hoses are different, but it was impossible to account for all the variables. The article is meant mostly as a guide for doing the mod, with as much detail as possible so I'm not swamped with emails asking questions about it. :eek:

Oh, and the 4 Barrel reference is just that. A reference to that type of sound. I wanted people to be sure to understand that it is loud without the ISR in place and the deckplate open.

Anyway, I'm glad you like it.

Peace!
Dr. Z

 

I cant tell from your post if you capped off the FPR line or not...anyway, if you did, you may want to reverse it. Click my sig under "ISR Mod" for some threads regarding why.

 

It's not capped. He went with the recommendations in the article...

My .02
Dr. Z

 

Fine!

 

Well, here is one question I came up with maybe you guys can help with-

On the power steering pump, there are two air lines. One of them looked to go to the intake manifold already, and the other one went into the silencer box. Now they are both going directly to the intake manifold. Is there a specific reason they didn't just both go to the manifold to begin with? I'm just wondering if there was supposed to be some kind of pressure differential between them or something crazy... ??

I'm going to redo how my air lines all hook up and clean it up a bit, and do a little writeup on it to add to the tech forums. It's probably as simple as identifying the difference on how the intake looks to determine which way you need to go...

Dr. Z I see what you're saying now. Yeah there definitely is a noise difference! My next trick will be the ECT mod. Gotta love cheap HP gains. I also ran some injector cleaner and mid grade gas (I usually run low grade, being in Denver the chance of pinging from octane levels is almost nonexistant). I think the engine is a lot happier now!

 

Yeah, I know what you mean. I believe Toyota routed that line there due to cost. Its cheaper to run a nipple from the silencer box than to make one come out of the intake tube. Its all about lean production! (Toyota rules at this, if you havent noticed).

Dont worry about it, no adverse effects will occur to the steering.

 

I hear ya. Just seemed silly ... why not just run one line to the PSP, if they both do the exact same thing?:pat: Seems like that would be the cheapest way of all. That's why I had to think there was some other purpose for that extra hose.

 

Because that's what GM does, and we all know about them.

(j/k, I have no idea)