Since there were multiple threads containing intake, chip, and exhaust threads, I decided to create a new one that concerns what I like to call Stage 1. Stage 1, in my mind, is putting the basic performance mods on a car like intake, chip and exhaust.

To track my progress throughout, I am going to have dyno support and post the results of each mod. Yesterday, I went to MAC Autosport in Parker, CO and talked to them about what I was doing with the 4Runner and they were very excited to help me out. One of the guys who works there is even an old high school friend of mine who I haven't seen in a long time. The shop mostly does work on Supras, STi's and other high performance cars. But they said they have had a fair amount of trucks in there, but I was the first V8 4Runner. I did three basline pulls and printed out the best two, this is wheel horsepower corrected for elevation. The baseline is stock+catback exhaust. Enjoy!

Here is my first dyno pull in 2nd gear, where I had the best results: Max power = 213 HP, Max Torque = 249 ft-lbs. Notice the stock ECU keeping the A/F at almost exactly 12:1:

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Here is another dyno pull that was completed in 3rd gear. The power is a little less but he was able to pull from 2500 rpm without downshifting. Max Power = 211 HP, Max Torque = 255 ft-lbs:

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Notice the obvious dip in power and torque around the 4250 rpm mark. This dip showed up in every run, and had us fooled. He thinks the engine is cutting back timing here for some reason. If you look at the chunk of incremental area under the curve I am losing, you can see that this is a significant drop in power. The guy at the shop told me that we should be able to smooth that out once we tune the chip.

One other thing I should mention: I cancelled my Unichip order because in the past few days from shop owners I've heard nothing but bad reviews about them, and about tuning them. Shop owners have told me that they really have a hard time functioning up here in CO and rarely get the A/F right. So for a couple hundred bucks less, Nick at MAC autosport is going to throw on a AFC (air-fuel controller) on top of my ECU and custom tune it to altitude and optimum power/air-fuel. Sorry for bailing out here because I know you all are curious about the Unichip results, but I can accomplish basically the same thing with a custom tuneable setup and have shop support.

Conner...jesus man, its only april and its already 80 in Colorado? Cripes!

Congrats on the numbers, being corrected those are right where they should be.

As for the dip in power, what octane are you running again? 87? This could be why. Due to the high Density altitude and octane rating the engine is bringing back the timing.

If you are running 93, well then we certainly know its a timing issue.

As for the unichip, interesting that the guys had that to say. I really havent heard anything about those guys. AS for the AFC, sounds good, and it should be better for you at the higher altitudes as you can lean it out even more than unichip has done. I think i might still go ahead with it, but I need to talk with unichip again, especially now.

casper,
let me know what you hear. I am still interested because unlike out I live in georgia and dont have the same thin air problems he will have....

Lee

The dip may be a VVTi or acoustic intake transistion.



I love the tq down low.

Yeah, it was actually more like 75 yesterday, but the temp was taken inside the shop and the higher one was the second run, my car heated the shop up that much. They had 3 huge fans too.

Good call on the octane. Yes, I was running 87 at the time, and that could be why we see the dip in power. Maybe the computer has some kind of rpm checkpoint where depending on the octane it runs different maps and 4250 rpm is where that map kicked in. Next time I will run 93 before being tuned and see if that has any effect. Question: Does the engine know exactly what octane is being run and run a preset map for this fuel (open loop fuel sensing)? Or does it correct for bad or lower octane gas by sensing knock and pulling back timing variably and continuously (closed loop fuel sensing)? Just curious.

I think you might be right though. Next time I talk to the guys at the shop I'll bring up the octane issue.

I believe it uses a knock sensor. As far as I know, there is no way for the engine to know what octane fuel you are running. It just listens for the pings and adjusts accordingly.

wow good numbers and I guess I hit the nail on the head with the 213? but mine was @ almost sea level...in third gear and I dont have that dip maybe the knock sensor picked up something and pulled the timeing back for a milisecond?????? are you stock? and was that with the diff locked?...mike

Conner,

I have a dumb question. If you are trying to get as much power as possible for your 4Runner why are you using 87 octane?

If it is because of the current price of gas I might understand but the amount of mods you spent on your truck the couple of cents difference in price from 87 to 93 should be a drop in the bucket.

Mike, my 213 HP pull was done with the dif locked in second gear. The only performance mods I have are K&N drop-in, Magnaflow Catback exhaust, and NGK spark plugs.

The reason I'm running 87 is, yes because its cheaper, but from what I've read on the forums and researched, our compression ratio just isn't high enough to warrant the use of premium fuel. The manual recommends 87 so that's what I'll use. Plus, I really didn't think it would make any difference in performance on the stock ECU, but maybe it does. Once I tune my air/fuel I will switch to premium.

That being said, if the dip in power that I noticed on my dyno runs is because of too low octane (computer sensing knock and pulling back timing) then obviously I need to switch to premium. For now however, it is just a daily driver and if I can get by paying $2.80/gal vs. $3+/gal then I'll stick with the 87. I'll make sure my next dyno pull is using premium fuel and report if there is any difference.

actually are CR is high enough to run it, it wont make a huge difference but its one of the reasons why the GX/LR have higher output out of the 2uz than we do. They are mandated to run premium fuel. While i know that their ECU is tuned to run it, and ours isnt, knock sensors should adjust timing accordingly if it has been programmed in there at all.

How much were the dyno runs? Always cool to see dyno runs..