Squeezing out more horsepower

My wife and I are getting ready to go camping for the first time in our new 2720SL. We picked up our TM in Tucson and while our V6 Tacoma pulled the trailer very well across the desert to our home in Goodyear -- I had some concern about how it will pull at altitude. So I installed a K & N Air Intake System (about $250) and a Redline Power Chip that attaches to the mass air flow sensor. I found the chip on Ebay for $29.95 and saw that virtually all the reviews were very positive. I installed both in about 2 hours. I believe I'm still in compliance with emission standards in all 50 states and I have a sticker afixed under the hood that is supposed to satisfy inspection station personnel. The bottom line is that I've noticed a significant increase in power and acceleration (I would guess about 15HP). I think my Tacoma will do just fine now in Arizona but Colorado may still be a challenge (I may do a "cat-back" muffler switch). If your TV is a bit under-powered maybe one or both of these modifications can help. Oh, my "check engine" lite has not come on has a result of the modifications. And -- I also installed an Equal-i-zer hitch to my swing tongue. This also required a few modifications not covered in the installation instructions. I'll share them as a thread if anyone is interested. TM folks have expanable RV's and expanable minds and hearts. Maybe the leaders of the world could find more concensus if we could put them all in TM's and place them beside a mountain lake ? I know -- "dream on".

[Denny_A]

......has a K&N Air Intake System also. The claim is that the peak HP is boosted from 245 to 255. I can't confirm that since it was already installed when I bought the truck....but, that truck can giddy-up and go!

http://www.dragtimes.com/Toyota-Tund...art-12502.html


Denny_A

[RockyMtnRay]

Originally Posted by Denny_A

......has a K&N Air Intake System also. The claim is that the peak HP is boosted from 245 to 255. I can't confirm that since it was already installed when I bought the truck....but, that truck can giddy-up and go!

Those K&N intakes have a really, really bad reputation amongst those of us who know what does and does not really improve Tundra engine performance...especially towing performance. K&N engineers have publically admitted there really wasn't anything they could improve on the Tundra intake system so they just tweaked the torque curve toward more top end horsepower at the expense of less mid range torque. That's great for the street racers but bad news for those who haul or tow with these trucks.

First, they do not "flow" any better than the stock intake filter/air box. The very slight horsepower gains come only because there is a tiny lip inside the tube that distorts airflow enough at high intake velocity to fool the Mass Airflow Sensor (aka MAF) into thinking a bit less air is coming in than is. The engine control unit (ECU) therefore runs a slightly leaner mixture, which at full throttle produces a tiny bit more power than the stock, richer mixture will.

Second, at low to mid range RPM (around 2500 to 3500 RPM) where the engine is at peak torque, the K&N reduces torque by about 10% because it very adversely affects the tuning of the intake tract.

Third, if you are not exceedingly careful when oiling the filter after cleaning it, you will get too much oil on the gauze and that extra oil will be sucked down onto the heated sensor wire inside the MAF. Once on the sensor wire, it bakes on and makes the sensor less sensitive...the net result is the ECU thinks less air is coming in than actually is and tries to lean out the mixture. Eventually, you'll get a Malfunction Indicator Light (MIL...aka check engine light) and the underlying trouble code will be excessive leaning (which in turns leads to excessive pre-ignition and a bunch of other nasty outcomes). It's sometimes possible to restore the MAF sensor wires by removing the MAF and dousing the wires with electrical contact cleaner. More often than not, the cure is a brand new MAF at around $250 to $300. This is such an endemic problem with K&Ns that the first step that virtually all dealer service departments do with an ailing Tundra is rip the the K&N off the engine and clean or replace the MAF. If there's still a problem (a rare situation), then they do further investigation.

Fourth, a Tundra K&N is NOT, repeat NOT a cold air intake (to bring cool, dense air into the engine). The stock system is a true CAI because it pulls air out of the inner fender. Despite the appearance of having an air dam, the K&N mostly just sucks in hot, low density engine compartment air, especially at low speed.

Finally, K&Ns make a huge amount of gratuitous noise...noise that becomes extremely tiring when towing because of the much larger throttle openings.

I personally wouldn't install a K&N on my Tundra if you paid me $10000 to do so and I strongly recommend you get that thing off your engine ASAP.

[Denny_A]

Originally Posted by RockyMtnRay

......snip the engg stuff 'n cut to the chase.....
I personally wouldn't install a K&N on my Tundra if you paid me $10000 to do so and I strongly recommend you get that thing off your engine ASAP.

Thanks RMR! Seems it were a lucky thing for me that I responded to the original post. Otherwise I'd be toolin' along FD&H until a costly failure occurred.

Fortunately the previous owner included the OEM intake system with the truck. It's safely in my wheel barrow as I type. Think I'll see my local dealer for a reverse surgical operation. Hopeing that's possible w/out having to undo ($$$) extensive plumbing changes made to accommodate the K&N.

If it ain't sumpin', then it'll be sumpin' else! Sigh.


Denny

[RockyMtnRay]

Originally Posted by Denny_A

Thanks RMR! Seems it were a lucky thing for me that I responded to the original post. Otherwise I'd be toolin' along FD&H until a costly failure occurred.

Fortunately the previous owner included the OEM intake system with the truck. It's safely in my wheel barrow as I type. Think I'll see my local dealer for a reverse surgical operation. Hopeing that's possible w/out having to undo ($$$) extensive plumbing changes made to accommodate the K&N.

If it ain't sumpin', then it'll be sumpin' else! Sigh.


Denny

Welcome Denny. If all the OEM parts are there, it shouldn't be a big job to replace the K&N. I'd recommend a MAF sensor cleaning while the dealer is replacing the parts. After the ECU adjusts to the change, you'll find you have noticeably more mid range (~3000 RPM) torque though perhaps a tiny bit less at the top end (~5000 RPM) and the truck will be a heckuva lot quieter and more civil.

And there's undoubtedly there's some believes-everything-he-reads sucker out there who will pay you a pretty good price (at least $100) if you auction the K&N on eBay. List on the K&N is somewhere around $300 so you should be able to get at least $100 for yours. Oughta cover the dealer charge or a goodly chunk of it.

And if you want to get some really serious towing torque out of your truck's drivetrain, just do the same mods I did to mine. The JBA headers (7% mid range torque gain), Gibson muffler (3% mid range torque gain), and regeared axles (10% across the board rear wheel torque gain) have collectively given me a solid 20% increase in rear wheel torque over stock. My truck literally pulls like a diesel...I can tow my TM west from Denver (climbing from ~5200 feet to over 11,000 feet) with only 2 stretches where it has to shift down out of 3rd (Drive). And even at 6000 feet, I have to be real careful to avoid rear tire spin...even when the trailer is hooked up and weighing down the truck I can readily spin the rear tires if the road surface has the slightest bit of sand or gravel on it. I've got so much torque available that mountain towing is a positively enjoyable experience.

Ray,

Thank you for explaining your rather strong bias re. K&N's.
I did call a factory tech today and I felt that he probably was not as well informed about his own product line as you seem to be. He, of course, denied most of your assertions which I read to him over the phone.

So, I tried on my own to compare the dyno study done by K&N for the V8 Tundra and the V6 Tacoma. It appeared to my uneducated eyes that the HP increase for the Tacoma (about 9.45) is more or less consistant throughout its mid to upper range (3k -5k rpm). This increase (I would think) would tend to be more noticeable in a lighter weight vehicle like the Tacoma. Unlike the Tacoma, the HP increase for the Tundra is not consistant throughout it's range & it doesn't come on strong until the engine is almost screaming. So, I guess I can understand why Tundra owners are so disappointed with minimal performance gains.

I very much appreciate your warning about over-oiling. I intend to be Spartan with the oil. But I'm just so atuned to my little truck that I can't help but appreciate it's increased mid-range performance. It only gets noisy when I "get on it" -- which is almost never. I just need to get up an occasional hill or two when I am towing and the consistant increase across the power band suggests to me that I haven't lost torque. I'll be running the Tacoma and the TM up to about 5k ft in a few weeks as a test run.

I'm doing my best to learn about coxing more power out of my Tacoma. I guess that sometimes you have to decide to whether to trust your personal experience -- or whether to trust the experience of better informed sources. Ray, I can hear my dear, departed Dad's voice saying, "Son, ya better listen or you're gonna get yourself in a mess".

But I'm glad that folks like you are still willing to share their knowledge with folks like me. One way or another -- it all works for our growth.

Thanks for yout time, eric

[Denny_A]

Originally Posted by RockyMtnRay

Welcome Denny. If all the OEM parts are there, it shouldn't be a big job to replace the K&N. I'd recommend a MAF sensor cleaning while the dealer is replacing the parts. After the ECU adjusts to the change, you'll find you have noticeably more mid range (~3000 RPM) torque though perhaps a tiny bit less at the top end (~5000 RPM) and the truck will be a heckuva lot quieter and more civil.

Thanks a bunch for your help Ray. My 'yota dealer did the reverse operation and the patient has recovered! The MAF unit was cleaned and tested. Good to go. All the OEM parts were there. Labor and new filter just busted the $100 threshold.

Re., the roar. Since the Tundra was new to me, I assumed that roaring sound was normal. Now I know what normal sounds like; a great improvement for sure. Also, when the K&N was in use, and I did a hard acceleration, the truck would lurch forward (large increase of accel) at around 45-50 mph, w/o a change of pedal input. More like an afterburner. Now the time-rate-of-change of velocity is predictable, and a welcome change!

And if you want to get some really serious towing torque out of your truck's drivetrain, just do the same mods I did to mine. The JBA headers (7% mid range torque gain), Gibson muffler (3% mid range torque gain), and regeared axles (10% across the board rear wheel torque gain) have collectively given me a solid 20% increase in rear wheel torque over stock. ........snip......

Since I will be more a flat land camper, I think I'll wait to see how the truck works out with my next (still waiting to purchase) trailer. I do not plan to tow a trailer in excess of 5500 lbs.

Again, thanks for the heads up.

Denny

Eric,

Did you buy from Ed Hannon's Freedom RV in Tucson. If so, how was the delivery process? I have a 2007 2720 standard on order (9/9) that I should pick up in three to 5 weeks. I'm over in East Mesa. Did you use any sway/WDH system?

You have to be very care with these devices. I have tried various filters and MAF's on my race car and it will alter the way your car runs, shifts, and pulls. Most times for the worse.

For example if you have a K&N filter on a vehicle with a 4L60E transmission it will change the shift point so that your car may be "running better" but your transmission life just got killed. As a matter of fact GM will not warranty your transmission if you have one on certain models. It also leans out you car and the oil from the filter can mess up you MAF sensor.

Unless your drag racing and need every drop of HP and you are not worried about engine life. Run a paper filter.

Originally Posted by Debian Dog

You have to be very care with these devices....... As a matter of fact GM will not warranty your transmission if you have one on certain models. It also leans out you car and the oil from the filter can mess up you MAF sensor.

I have a 2004 Chevy Avalanche. Put a K&N filter in it. Haven't noticed a difference in anything (maybe 1 mpg better). Should I remove it?