I just finished installing the 2 items. The truck sounds mean now!! It actually may be too loud for my liking. If there is enough of a HP benefit, I won't mind though.
I already did the stock HP and 0-60 numbers using a g-tech meter. They may not be totally accurate, but I will make sure that I stick w/the same perameters so it is a fair comparison. Some variables that will affect the numbers using a g-tech are:
1. Incline in road (I will go to the same section of road)
2. Fuel level (I am using the same amount)
3. Items in veh. ( I will have the same amount of stuff)
4. The weight I input for the vehicle. (I looked on my registration and it said 4008 lbs., I input 4000 into the g-tech meter (needs it for HP rating) That number will show a false low HP rating because the weight of the fuel, myself, equipment etc. the truck is probably closer to 4375lbs.
There are a few other variables, but if I keep everything under my control the same, I think I will get a pretty fair percentage of improvement.

OK, here are the stock numbers for my 3.3l auto 4x4:
0-60: 11.44 sec
HP: 106 at the rear wheels

Like I said, these may appear low, but the g-tech itself is very accurate, all of the other variables may not be.
I am going to try and do another run asap to give the new numbers with the mods.

Cool - make sure you post the results. I've got the exact same intake/exhaust so I'm curious.

The results are in!!! I am a little confused at the result though.
the 0-60 improved a good amount. It went down to 10.39, so it took at least 1 second off.
The HP actually DROPPED by 1 to 105!!!
I don't know what the hell is going on, or if it is even possible. I think I know what the problem may be. On the 0-60 times, I made sure the unit was mounted perfectly level, but when I did the HP setting on the g-tech, I can't remember if I leveled it perfectly yesterday, when I did the stock runs. If it wasn't perfectly level, that would explain the difference.
Going by the seat of the pants, and the reduced 0-60 times, I would have to guess that I picked up about 12HP or so. Does anyone else have one of these meters, that did the same thing i did, so we can compare numbers?

Is it possible that you increased the torque, rather than the HP?

That would explain the faster acelleration and essentialy equal HP.



The less restricted exhaust typically robs low rpm torque, but improves higher rpm figures...if you were winding it out between gears, as is typical for this type of run, you would spend more time proportionally at higher rpm than if shifting at traffic intervals/low rpm.

its about time someone tried this.. thank you for helping us all with the decision!

update! update! i want an update!

I think with the 2 upgrades that the torque would go up. The engine is only breathing better now, to up the HP you'll need to push more gas down its throat.Try a fuelpressure riser.

up4speed,
have you let the ecu reconfigure? unplug the battery over night and then do another test run. the computer might give you a little more fuel with the increased air flow.
good luck

Its not necessary to leave your battery unplugged overnight. All you need to do is disconnect the battery and turn on your lights. This should discharge the entire system in a couple minutes.

Reconnect everything and start it up. Let it idle in the driveway for a couple minutes to let the engine relearn all the new airflow parameters.

I'm very interested in your numbers. Try another test run to get a couple runs and average the new numbers. Faster in the 0-60 is faster....period. Can't argue with that.

By the numbers, highflow intakes and exhausts reduce torque but increase horsepower. Most people don't notice more tire-spinning power, but they get better acceleration for passing on the highway and the engine can hold gears longer in the auto tranny cause there is enough power to hold speed.

Exiled,
I didn't leave the battery unhooked over night, but I did disconnect it while I was doing the work, so it was disconnected for a few hours. That should probably be enough. I can't imagine it making a huge difference.

106 hp at the rear wheels. I find that hard to beleive. Thats almost a 40% loss in power from crank to wheels. No vehicle puts a loss that hgh. I would more tend to beleive 150 hp at the wheels.

I had a G-tech meter and used it on my '89 Jetta.

It said that it had 133 horsepower although it only had 102 Hp stock. G-tech meters are not very reliable in my book as you've found out. It really all depends on how hard you gun it and try to throw yourself back in the seat. I had the Jetta at about 6,000 RPM's in first to get that reading.

Chia,
As I wrote earlier, I used the numbers for comparison purposes, not accurate HP readings. I knew they would be way off b/c I used 4,000 lbs as the weight. I know that I am way more than that. The truck moved a certain weight (according to the g-tech) at a certain acceleration, then the unit does the math. If I put in that the vehicle weight was 50,000 lbs and it accelerated the same speed, the computer would have told me that the Xterra had 1,000 hp. In other words the computer is only as accurate as the operator, and I already admitted that I punched in the #'s way off. The important thing is that I kept my error consistent, so I can see the approximate improvement. As you said, I would probably expect almost about 150 HP at the rear wheels.......maybe 140 or so?

I think the non-SC Xterra is 160 at the rear wheels...haven't researched it in a while, but back when I was looking for exhausts I ran into a few articles that stated 160 hp at the rear.

I dont believe any results coming from a $100 piece of fast&furious doo-hicky. My store used to carry these and they are complete garbage...

Find a local place that has a dyno if you're really interested in finding accurate improvements by adding exhaust, intake, etc. Then you'll really see if the stuff you bought actually improved anything....

i know in the tacoma world, fipks will acutally reduce hp.