Hey guys i have a 3.0 in my 4 runner and i am doing oversized valves a port and polish and downey headers and full exhaust. What kind of power inccrease will i see? Thanks pat.

 

Honestly, I highly doubt that you'll be able to break 200 horsepower with 2K invested. I hate to be the first to generalize it, but you are polishing a turd.

The head work and the headers may net a 15-25 horsepower gain with a free flowing exhaust, and you're pretty far in the hole just after headers.

There are better alternatives, like just dealing with it (or doing a swap).

 

Yeah i figured it wouldn't be much and anything is better than stock. I just didn't want to mess with a swap, and i think i can live with a 150 wheel horsepower, if i even get that. I just hope that the motor lasts another 150k. All around it cost me 500 for heads to be done at machine shop, 300 bucks for valves and full gasket kit form engnbdlr , and 379 for the headers, and 130.00 for dyno max exhaust. I figure add another 200-300 for odds and ends like oil, filter new o2 sensor, knock sensor and wire and some other stuff.

My total between 1600.00 and 1700.00 for 15 horsepower that sucks.

 

Basically. You could swap to a 3.4 for somewhere near 2K and get 20 horses, but better economy and overall design, plus alot better power base.

 

I doubt you'll see 15-20hp from a full exhaust.

Maybe 5-10hp.

 

You could search and find out from people who have done it instead of relying on people's conjecture...

From what I've read, I'm not spending money on modding my 3.0 - for what it will cost I can put in a 3.4L and have A LOT more options.

 

Yeah i know about swaping but i am just scared of cutting up the wiring harness. Do they make a harness for the swap yet?

 

I have but one acronym for you:

ORS

 

ummmmm i dont think a 3.4 swap can be done for 2k, unless you get a free engine/tranny/tcase setup. then you have to buy or fab up everything else which could cost over 2k, just for the misc. bull ☺☺☺☺

 

A 3.4 swap can be done for as little as $1K if you get lucky and can fab. I have a friend who is into his for about that - got the entire 3.4 drivetrain for $500, though. :laughing: :laughing:

I had done DOA polished/ported heads (never again - go w/ Engnbldr.com instead), intake, exhaust, ignition, etc. Was fun to drive, but definitely not a 3.4. The most you'll likely see is 175 hp.

That said, the 3.0 in my 88 out pulls the 3.4 in my 96... Don't ask me why; I don't know.

 

I am only relying on what I've read and heard from other people and threads.

Typically, if you have the means to drop so much money into the 3.0, you're better off just swapping up or dealing with it.

 

IF you do heads, cams, oversize valves, headers and full exhaust you might see 10-15hp at the rear wheels, That'll be just barely noticeable on the seat of the pants dyno thought it will give you a wider powerband, particularly in the 4500-5500 rpm range.

Having done this to mine (and a whole lot more) the cost of this work far exceeds the return on investment.

IMHO Don't polish the turd. Save your pennies and do the swap.

 

I like to try and look at it from a dollars per horsepower standpoint.

$1700 / 15 hp = 113.33 $/hp

Ouch, that's a pretty painful wad of cash for not a whole lot oomph.

Just for reference, supercharging a 3.4l with a URD kit, with all of the diagnostic equipment required works out to about 25 $/hp. Of course you have to get the engine first, but still it seems like a good rule to try and stay under 50 $/hp.

 

Nitrous? Sounds relatively cheap. Lot's o' HP. But everybody knows a guy that blew his engine with that junk.
On a serious note, I'm pleased with the hp on my 3.0, just enough for me. If you wanna do yours up right you better get that over-bored throttle body Downey's got. It will compliment everything else.
Heard a guy mention porting his plenum chamber for more volume, too. The only thing I've done is remove my muffler, and on an occasion or 2 unbolted my cat. It's loud as hell, but that sound be equatin' to some easily felt extra power. I'll be installing cut-outs soon.

 

Lower gearing is the best mod for a 3.0 IMHO.

 

I can deal with the 3.0 as long as it gets me another 150k. I'm not looking to drag race the thing, so long as it will do a little better than stock. Why don't they make a supercharger kit for the 3.0? i bet you could get one off a mustang a paxton or vortech and make custom brackets and what not. Just a thought. I just don't know if the hg will last, you would probably have to get a boost a pump fuel pump like paxton makes so you can get more fuel. Does anyone know what the compression is on a stock 3.0?

 

Ummm - have you looked in a 3.0 engine bay? Where the hell you gonna put a supercharger if someone DID make one?

 

Compression stock on the 3vze is 9.0:1. The hg issue is solvable. I read about this same topic on here not to long back. Somebody chimes in with "yeah such an such has a 3.0 that dynos over 400hp" also something to the effect of "solid metal head gasket" I don't recall exactly.

 

I saw a turbo rigged up on a 3.0 once but it wasn't pretty.

 

No one out there makes a supercharger or turbo for the 3.0 specifically because you can't just bolt one on to a stock engine, you have to do all of this work to the intake, exhaust, heads, and fuel system. No company wants to make a product that a bunch of people are going to bolt on to their 3.0 and then blow it up, which is definitely what would happen. And you can't really make a full kit that costs $7000 because no one would buy that either.

Sure, you can make a fully custom system but at what price? I guarantee you get more bang for your buck with a 3.4 swap, after market alone is ten times as big as for the 3.slow. So many people have brought up the "why hasn't anyone come out with a 3.0l supercharger" and the answer should always be the same: SEARCH and ye shall find.