Improving Toyota Highlander engine performance?

Eric P · 12-12-2006, 04:44 AM

Alright, I have a 2003 Toyota Highlander (V6). Not exactly sexy or choice for hot rodding but I'm going to be towing a lot this Summer with it. I'd like to squeeze out a little more HP. Even 10 more would be nice. I'd rather not do serious engine mods like cams or supercharger but intake, exhaust, and computer/brain changes would be fine. I'm not having any luck searching the web though.

Anyone do this. Suggestions?

What other Toyotas share the same motor?

Thanks

sammyg2 · 12-12-2006, 05:48 AM

Supercharging is the only thing you can do that will make any real performance increase.
You can put on a catback exhaust, a K&N cold air intake, and you will make more noise but no real power increase IMO.

I have a tundra with a v8.
My best friend bought a 2004 tacoma. We compared acceleration a couple of times, then he did the bolt-on routine.
More comparisons, if there was a difference it was too small to see. Non scientific but more accurate than marketting claims.
His truck was more noisy and obnoxious though.

Eric P · 12-12-2006, 05:57 AM

That is kinda my concern. I've always been skeptical of some of these flow systems.

BUT, did your friend do any ECM (ECU?) mods. I wonder if the brain has to be reconfigured to maximize increased flow. Otherwise, it may just operate the same. I don't know much about how the computer senses and adjusts though.

Eric P · 12-12-2006, 06:08 AM

Something like this:
www.***********************/performance/brand.php?makeid=25&modelid=513&year=2003&partid=12378

Don't know if they just take your $, dust it off, up the RPM, and send it back though.

sammyg2 · 12-12-2006, 06:29 AM

I didn't comment on any computerchip or other tuning modification because I don't have any first hand experience with them.
As far as tuning to compensate for the bolt on parts, the computer does that automatically to a point. I guess it would be possible to richen up the mixture a tiny bit on top end and you might get an extra hp or two.

I can say that I would be skeptical, toyota usually doesn't leave much on the table as far as tuning. That's why I bought the v8.

Your engine is tuned for a truck, designed for torque and not high rpm power.
If you changed the FI, cams, heads, and computer you could get more HP but that's an awful lot of work.

Eric P · 12-12-2006, 07:08 AM

Yeah, I might just let it go. It actually pulls fine. I was just hoping I could get it to stretch out a tiny bit more on uphill pulls.

It probably isn't even a HP issue. Basically, on long, slight uphill pulls it just barelly drops out of overdrive. It would FEEL better to me (less RPM, noise, etc.) if it stayed in OD. It may be more of an issue for me than my engine.

They didn't put the V8 in the Highlander and I didn't want a larger vehicle (this is my daily driver, only tow about 10% of the time).

Racerbvd · Racerbvd's Garage

Quote:

Originally posted by sammyg2
Supercharging is the only thing you can do that will make any real performance increase.
You can put on a catback exhaust, a K&N cold air intake, and you will make more noise but no real power increase IMO.

I have a tundra with a v8.
My best friend bought a 2004 tacoma. We compared acceleration a couple of times, then he did the bolt-on routine.
More comparisons, if there was a difference it was too small to see. Non scientific but more accurate than marketting claims.
His truck was more noisy and obnoxious though.

I have a Lexus 4.2 V8 engine with an extra 4.7 crank, TRD oil sump, TRD cams the racing oil plate, ect. Stock headers and no intake (TRD sells one to work with a Holley). It was taken down at 42K as it was going to be built to a Ivan Steward type engine.
Here are some of the goodies I have to start with.

Lexs 4.2 & TRD parts

81 911 SC · 12-12-2006, 12:27 PM

I have a feeling you are going to have a hard time finding anyone that does ECU upgrades for a Highlander. The majority of the people that buy a Highlander could care less about having their ECU reflashed or what not. They are not into modding.

sammyg2 · 12-12-2006, 01:10 PM

I've seen used TRD supercharger kits for the toyota V6 in the recycler www.recycler.com for as little as $1700.
I don't know your location so that may be of little use to you. but $1700 for close to 90 extra hp is a pretty sweet deal, especially when it is CARB certified smog legal and does not affect the factory warranty.

I love forced induction. One of these days my tundra will be sportin a huffer.