As promised, I took my '99 4Runner Ltd, 4WD, 3.4 to be Dyno tested today.

Thanks to Brad Brand at Atlanta Chassis Dyno for making my visit a painless experience.

The first two runs yielded almost identical results:

143 Peak HP
185.1 Ft/Lbs Peak Torque

In fact, the results were so close that Brad was not even going to make a third run, so I suggested we try something......

We opened the Air Filter door on the top of the airbox and made a third run......the results???

149 Peak HP!
191.2 Ft/Lbs Peak Torque!

Brad said he'd rip that door thing off right away! hehe

(I have a jpg photo of the printout but it was too big. I need some help with getting photos into my posts.)

I will install my Injen IS2055P this weekend, wait two weeks, and then head back to the Dyno shop to record the difference. I hope I get a bigger increase than what I got by just opening the door on the airbox.

This is going to be fun!

 

You should try the deckplate mod and see what it does for you. Do a search for it...you will find a ton of info.

 

I think you lose HP with deckplate mod, because there is no cold air blowing into the airfilter.

 

I think I've read every post on the Deck Plate Mod, as well as the K&N FIPK. The results seem pretty consistent with gains in HP and MPG. There are exceptions, of course.

Nevertheless, I decided to go with the Injen "Cold Air" Intake. Purely a subjective decision on my part. As I have already indicated, however, I will be taking by 4Runner back to the Dyno to test actual results and not rely on my own subjectivity.

I may still do the Deck Plate Mod while I have the stock stuff off, but I'm now committed (money spent) to the Injen system.

Doesn't anybody think it's odd that there was such a significant increase in HP from simply opening the Air filter door? Talk about low cost!

I'm just hoping the Injen will make more of an impact than simply opening the door!

I still need some help getting my photos in my posts. I tried twice and each time got an error message saying the file was too big and had to start all over again with my post.

Thanks in advance for your help.
mdvga

 

Opening the lid, opening the front of the airbox (deck plate or just cutting a hole in it), or removing the elbow always gives a consistant 6 HP whether you are supercharged or not.

Feel free to stop by my site and check out the dyno runs I did years ago.

It is always good when others confirm the results I came up with previously.

Gadget

www.GadgetOnline.com

 

I need to second what Gadget said.
I have done the deckplate to mine and several others vehicles.
Always a consistent gain in HP and mileage in the + direction.
...and boy is it ever cheap too.

 

I put dry ice in my airbox to counter this.

 

Ok, the Injen IS2055P is now installed. It took me about an hour. I videotaped the whole thing and took lots of digital photos. The instructions say the ECU only needs 15 to 20 minutes to adjust to the new airflow conditions. I will drive it for a couple of weeks and go back to the Atlanta Chassis Dyno for another couple of runs.

I could not perceive any noticeable change in power as the result of the Injen install. It is definitely noisier. I'm not sure I like the growl every time I step on the gas, but I'll just adapt.

The only problem I had was a head of a phillips screw holding the MAF stripped out. I bought some "easy outs" and the screw came out easily enough. Just a minor annoyance.

 

16.1 MPG, down from 17.8 average.:cry:

 

Thats probably because of the lead foot sindrome. The injen intake is just basicly a prettier (more expensive) way of doing the ISR and Deckplate mod together. My roomate as a true cold air on his 03 accord and it seems like a great product. The only problem with it so far is that we can't figure out a way to clean the filter without taking off the whole bumper grrr. Your gains won't be that much more than the door removal but should get a few extra ponies. If you s/c though you will loose power from the airbox.

 

 

Baseline Dyno Printout - Blue Line is with Air Filter door open

 

so this is before you installed the Injen?

 

mdvga-

THat Injen intake sure looks nice in there. Its good that you are taking the initiative to document and dyno everything. Good job.

I would like to mention one thing however, to anyone thinking that removing the stock airbox dox is a easy or cheap alternative to the deckplate or elbow mod. BE CAREFUL! There are a couple of little metal tabs on the door that help keep the filter seated/sealed against the back of the air box. No door could result in a loose filter...

/soapbox.

 

ok i could be way off here seeing as how i dont have the 3.4...
but where the heck is the MAF sensor? shouldnt it be right after the filter?

-Casey

 

On the 99+ trucks, the MAF sensor is different than the earlier trucks. It's just a small piece that fits into a hole on the intake tube. In that picture, you can't see it because it's on the side facing away from the camera.

In this pic, it's part #3:



See how small it is?

Hope this helps.
G

 

Hey, keisur, yes the Dyno Printout is from before the Injen was installed. I'll go back to the Dyno after a few more tanks of gas.
My second tank MPG is looking more normal, I'll know tomorrow.
mdv

 

Tank number 2 MPG: 17.8

 

How do you guys measure mpg? '99 4runners got a 15 gal. tank, right? I guess you have to measure by using up the entire tank? ex. 250mi divided by 15???

 

ok this might be a stupid question but would you get more power if you did the deckplate mod and opened up the lid to the air box?