BigBen

My friend recently did the irs mod to his gen 2 4runner and i was thinking about doing it...is it a good or bad idea and why?

Thanks

midiwall

"IRS" - is this a mod to avoid paying taxes? I figure you mean "ISR", as in "Intake Silencer Removal".

There's a lot of information here on the forum, "Good vs. Bad" is up to you. There are people that say you have a higher risk of sucking water after doing it, there are folks that say the added risk isn't that great.

The Good side is undeniable... It smooths out the intake path between the air box and the throttle body, and reduces the volume of the path. That translates to increased throttle response.


Is this a 3.0? Check here:
https://www.yotatech.com/forums/f130/intake-silencer-removal-mod-2nd-gen-4runner-75167/

tc

Independent Rear Suspension? That's a helluva involved mod! LOL

chimmike

After reading that How-To thread.....don't go to a muffler shop and have them crush-bend piping.

Go to any exhaust supply shop or website, I prefer www.vrsexhaust.com and buy a 3" mandrel bent 90* bend. That way you can cut the piece exactly how you need the bend, and then have pieces welded together.

Also, the 3" ID rubber hose, BAD IDEA!! Rubber like that will dry out, crack, and rot......which will leak and cause the MAF to freak out when metered air is being lost. 3" ID silicone couplers can be had cheaply from most turbo supply shops, and worm gear clamps are more than sufficient.

The beauty of this is that mandrel bent tubing doesn't decrease the inner diameter like crush bent tubing does.

Also, if you get threaded fittings, you can tap the metal pipe, simply run some grey rtv around them to lock 'em in, and not worry about fittings dropping through or not.

I think I actually have a 3" mandrel U bend at home. I might try this in a couple weeks with parts I have left over from old turbo cars and see how it goes.

BigBen

QUOTE:["IRS" - is this a mod to avoid paying taxes? I figure you mean "ISR", as in "Intake Silencer Removal".]


Yes i mean ISR sorry i was in my computer class trying to look like i was paying attention to the lesson when i posted this

YotaPower

Are the tubes on VR Exhuast Mandrel bent? doesn't seem to say . . .

I don't understand the welding back together part. So I would order a 90 deg. bend, cut off as much as I don't need (like you said), but then why would I need to weld anything? (I don't have access to any kind of welding equipment) Why not just order a 45 deg.? Because it's not a perfect 45deg?

chimmike

exactly, I don't think it's a perfect 45* bend. Plus I just like cutting/welding

Tofer

talk to cootees on this forum. he sells them last time i checked.

mochester

hah thats what i was thinking when i read it too

thook

Hey, just a thought...
I bought a 45deg piece of schedule 80 pvc electrical conduit from Lowe's, cut off the tapered end, and mated it up to the TB and air box with 2.5" rad hose from NAPA. This set up fit perfect with no fuss and very cheap. The brass fittings for the two hoses threaded right into holes drilled into the pipe at the appropriate spots with (edit)...NO.. backing nut required. I didn't even need to use sealant, although it wouldn't hurt. The PVC will not break down, will not rust, at the perfect angle, and saves having to buy a pipe and then pay to have it bent. This is, of course, on my 3.0 4rnr. Plus, you can paint it any pretty color you want...like blue to match NGK plug wires.

Oh! I might add, for the sake of the original question, it definitely increase throttle response. But, it also increase air flow, which is good for the motor breathing. Top it off with the crossover exhaust pipe mod, larger exhaust diameter, and the holes in the air box and you're set.

Morphine

Any chance of some pics????

Thanks
-=Morphine=-

traben27

he did it....i helped.

thook

Sorry, I missed this. Actually, I had thought of posting it with pics. The pics just happen to be on my wife's computer...where all the camera softs are, too. I will transfer the pics over to mine and post it.

thook

My ISR mod...





This is before I rebuilt the top end. After the rebuild, the mod really shined through performance wise. Until then, it still helped with mileage and all even with a progressive burning exhaust valve. It's still gray because my wife (her runner) likes it that way. I wanted it blue...like the wiring. So, I may compromise with her and paint the rad hose connectors blue.

And don't laugh at my dirty motor. I live in the country. You give up after a while...maybe cleaning only once in great while.

Morphine

Thanks for the pics. I'm a visual learning so this helped a lot.
-=Morphine=-

thook

You're welcome!

chimmike

I would definitely not use PVC like that due to the possibility of breakdown, etc.

Mandrel steel bends can be had so cheaply it's almost ridiculous

enoc

mmmm interesting, im still concerned about the water, i added a high performance filter and idont know how to protect it form water entering, never had a problem but the rains are coming.

midiwall

Rain is rarely an issue. When you hear us giving the head's up on keeping water out, it's based around those folks who like to dunk the truck and/or run through mud puddles.

In those situations, the K&N cones just don't cut it.

Elvota

Hey Thook... that mod looks familiar... except your engine is cleaner.



I had some left over header wrap and figured why not. That PVC is easily 1/4" thick. I've run it for close to a year now with no issues.

Seems to me the PVC would outlast the original thinner factory ISR setup, even if the factory plastic is a different composition. The rubber couplers I used were 3" to 2.5" reducers found in the local HD plumbing aisle. They are very thick as well.

It may all be expereimental (with emphasis on "mental") but it has been working so far.