So the 2003 V6 X's get 10 more horsepower. Has anyone heard how this was accomplished? Is it an electronic modification to the timing or mechanical change to the engine? If it's a change to the timing I'd LOVE to be able to pick up 10 HP if this mod were backward compatible! Probably just wishful thinking though.

Thanks group!

Probably the same way they found 10 more HP on the Sentra, and then had to pull the claim because it just wasn't there.

Nissan probably found a couple good ones coming off the line, and based the statement on that.

K&N INtake, high flow exhaust, MSD ignition and Maganacore wires. That should be good for 10hp

Could buy an 03?

As I understand it it was done through some changes to the ECM programming. In other words, you can't really duplicate it yourself.

Brent

But is it something we could get if we go to the dealer? Like a reprogramming?

Nope. All the dealer has access to, if anything, are generic code flashes, or updates to fix problems like some early SC models had. They won't be able to custom-tweak your current code, nor would they be able to dump an '03 flash into your 2000 system.

Sorry,
Brent

That's interesting, same engine just ECM programming? If the dealers could flash the '03 code into older models could be a way for Nissan to make some extra $$ instead of giving it to the aftermarket guys or some looney on E-Bay.

Oh well, it's frustrating that this is the same engine except for a few lines of code...so close yet so far!

Thanks

No Shit! I'd take the extra ten ponies! No questions asked!

On the Nissan Plant Tour in June, I asked if the 2000-2002 Xterra could be tweaked for the extra 10 horses. The Xterra dude(engineer,tech, whatever)told me that if the dealer or anyone else tried to tweak the older Xterras, it wouldn't run the same, he recommended against trying it. I then asked how they got the extra horses, he said they tweaked the ECM, the fuel mixture, the EGR, and some other stuff.

Well seeing how the VG33 hasn't had an EGR system since early 2000, that's interesting...

Brent

They must have 'tweaked it' right outta there! LOL

Y'know, I'm trying really hard not to just suggest slapping on a "Powered by Nissan" windshield decal and some Kanji lettering on the back.

Oops, too late.

I know I've seen a yellow X with some kanji on the hump, but tell me you're kidding about the windshield decal...

Brent - still wanting "powered by hydrocarbons"

You're not implying that >I< would do that, are you? Only thing on my windshield is a small "star" crack and the first aid hump has a couple decals on magnets (NCCX and obligatory Puckett). If I want to feel like I have an extra 10hp, I just remove the rock sliders.

Then I guess they wouldn't have tweaked that, I must have heard EGR in there somewhere, maybe some kind of code, can you break it Brent?

I stand corrected, I was just looking under the hood of an 03 and by damn if there wasn't an EGR system in place. Go figure...

Brent

I believe my 02 SC has EGR as well. I thought it was only the variable valve pathfinder engine that lost EGR, because they used some overlap to do the EGR function across the top of the exhaust/intake stroke? (ie hold the exhaust valve open for a split second longer at the beginning of the intake stroke to pull exhaust back in?)

Also - I noticed the haynes manual has an entire section devoted to EGR (pg 6-24 to 6-27) on the 4 and 6 cylinder models.

With regards to the extra 10HP... I wonder if they put the SC model exhaust and injectors on it? Would help gain some HP, plus they would reduce parts count across the 6 cylinder models as a possible costs savings..

I Flash the PROM in my Corvette; takes a special electronic unit & software, plus a spare PROM is helpful.

I've only had my Xterra 5 days, but it could very well have a replaceable PROM that can be ordered from the dealer.

New BINs are developed & released throughout the life of the platform; it's how the factory updates the ECU to address problems. GM is very good at this.

I don't have a repair manual (yet), so I don't even know where to look for the ECU to see if it has a replaceable PROM or if the entire ECU requires re-programming, but if you know what you're doing, it only takes a few minutes to Flash a PROM (or ECU). If you have a manual, look for something like "memory calibration unit"...

And no, I'm not an expert; I just know a little about *my* cars...

ecu in my 2000 X is on the tranny hump, near the fire wall, behind the change pocket at the lower portion of the center dash console.

On reflection I'm pretty sure the bulk of the extra power came from the new exhaust manifolds. The originals forced the rear cylinders to make a 180 degree turn before they left the manifold, while the new ones all flow directly downstream.