Does anybody know what the coefficient of drag and frontal area is for a 4th Generation 4Runner (2005 4x4 V8 Sport to be specific). I did a couple runs with mine today and I want to calculate the power output based on that and the other standard correction factors (weather, weight, etc). I found a posting on www.toyota-4runner.org <http://www.toyota-4runner.org/> forum saying the Cd is .39, but I think that was just the SR5 (not that there would be that much of a difference). Thanks Chad

Hi Chad, Glad you brought this subject up. It was only last month when I, myself was again attempting to recalculate the drag coefficient of a similar frontal lobe. I was indeed able to deduce that labatomization would be absolutely necessary on not only the 4th, but definitely the 5th and possibly the 6th generation as well. Weather we weight for the standard correction factors to attain max synchronization or forge ahead from here is the Real nomenclature. I did a couple of runs myself..as you may have guessed... and have decided to proceed with the appropriate calculizations. Standard courtesies dictate that I will keep you and the group informed. MexicoMike Chad Jones

Mike: Whithout going into why you call yourself Sherry, I was going to answer this query from our friend Chad but you said everything I planned to say. I may have to take you to task on the reccommendation for labatomization. It seems you could achieve the same result with some good liquor. After all, I would rather have a bottle in front of me, than a frontal labotomy. But I digress. The only thing I would add is, when computing drag Co/E be sure to account for non-standard pressure and tempurature, humidity, and then factor in wind speed and direction. After factoring in all those variables I just did a quick calculation of my 3rd generation 4Runner and find that the drag coefficient is exactly equal to pushing a 4 x 8 foot sheet of plywood through the air broadside, as it is with most SUV's. When I turn off my radio, and the antenna goes down, I easily gain another 15% so YMMM. If you think this type of discussion is bad, you should check out some of the airplane newsgroups I visit. David

Ok, since you guys brought it up again, I?ll post my test results. I determined that the drag coefficient is .39 and the frontal area is 26 sq ft. (not quite a 4x8 sheet of plywood, but pretty darn close). After adjusting for weather factors according to the SAE J1349 spec (yes this includes pressure, temperature, humidity, etc), we came up with a ? mile of 15.36 @ 90.2 mph (raw numbers were 15.56@89). Given the drag and weight of the vehicle (a whopping 4720 lbs), this calculates out to 264bhp@5000 and 311lb-ft@4100 at the crank (RPMs may be a little off because we couldn?t get a good reading off of the filtered power ports). Pretty close to Toyota?s rating of 270bhp@5400 and 320lb-ft@3400. We also recorded a 0-60 time of 7.6 seconds. Erick, what were your times before and after that K&N filter again? If you?re curious, acceleration doesn?t improve if you brake-torque so you?re fine to just stomp on the gas. I didn?t try a neutral drop; this thing hooks up too well to bother trying to break the tires loose. However, we did find that keeping the transmission in 4 instead of D improved the time by .2 seconds and 1mph (quite a bit of a difference for something this minor). It also makes the shift points a little bit later and a little faster. So if anything, this is a good reason to stay in 4 when doing any sort of towing (besides the obvious benefit of not shifting all the time and heating up the tranny). So mock me as you will; it?s cool. Chad -testing nerd ;-) Granted my cars are more fun to test, but this one was interesting.

Wow, I bet you are a lot of fun at parties. So OK, what does this mean, "we did find that keeping the transmission in 4 instead of D improved the time by .2 seconds and 1mph (quite a bit of a difference for something this minor). It also makes the shift points a little bit later and a little faster."? Do you mean to keep it out of overdrive? That would be 3rd gear, wouldn't it, or does it have 5 gears? The ECT switch will give you better times too, I would think in that it holds the shift changes out a little longer to higher rpm. For sure you need to keep it out of OD when towing. The only time I re-engage OD when towing is on straight and level ground above 70 MPH or going downhill at any speed. So anyway, what now? Test the K&N system and see that it makes things worse, not better? Attach wings and hope to fly? Take it to the drag strip?

Parties? Oh yeah, I usually bring some pretty graphs to how the vehicle ran on the way over; the ladies love it. The 4th gen V8 4Runners have 5-speed autos, so that would mean put it in 4. The best thing this shows in a practical sense is that there is another reason to have it in 4 when you?re towing. We all know you should do it so it doesn?t constantly shift from 4-5 and heat up the tranny, but this shows that there actually is a slight power advantage. ECT switch? Are you thinking of the ECU? Either way, you?re right, it does delay the shift slightly: 5550 vs. 5500 for 1-2 and 5450 vs. 5500 for 2-3. I don?t have any plans to get a K&N system or any other mods at this point. Drag strip would be fun, but only if you do bracket racing. You?d be able to win as long as your reaction time is good. This thing was very consistent on the multiple runs that we did. Especially since there wasn?t any wheelspin to worry about; just floor it and go straight. However, I?ll stick to drag racing my car; that?s a lot faster. Chad

On my old '93 Camry and my '99 4Runner, the switch is labeled ECT which only stands for Electronically Controlled Transmission. I like that little switch, especially in the hills.

That makes sense. Sorry, I didn't realize there was such a thing on the 3rd gen. Looks like the functionality still exists, it's just tied to 4th gear instead of a separate switch.

Ummm, no, it effects all the gears. The ECT switch just changes the shift patterns so the lower gears are hled out longer and shift at higher RPM, also downshift earlier. IT also has an O/D switch, as they all do, to hold it out of overdrive for towing or long uphill driving.

Right, I just meant that in the 4th gens they took that switch away, but the functionality exists when you have the shifter in 4th gear (not necessarily the transmission in 4th gear)