TOPIC: 2010 Toyota Sienna DYNO REPORT

I have the honor to report Craig Gunnefson of Prescott Valley AZ drove down yesterday (amid our frantic quest for transportation) to have his mod done.

Craig flew to the <strong> Untitled Document </strong> (updates are at the link) where we met. He was so impressed and felt the excitement of those who had received the mod that he HAD to get one for himself.

So, we met at Chuck's Speed and we did a before and after series.

Would you like to see what it looked like after only a VERY short conditioning run?



Chalk up yet another HAPPY CUSTOMER!

BTW, the Dyno Tech, Errick, remembered me. When I told him you didn't believe me then, did you?" (following a 54% increase on a 91 S-10) he said "No." After, I can't tell you how many times he said "It WORKS!" then proceeded to tell everyone in the shop about it!

Oh, and (in his words) "It cut the CO2 under load in HALF!"

Kicks butt, Ron!

TracyG Gadgetman Reno

Hello. I am new to this sight and have had a few customers ask me about this procedure as I own my own private repair and custom shop (with a dynomometer), and the internet has quite a bit of info on it about the "groove". My question for this particular thread, as it was one that a customer showed me because of the dyno chart, is how it is possible for the HP and torque numbers to not cross at 5252 rpm? ALL internal combustion engines MUST have HP and torque equal at 5252...this is not conjecture and cannot be changed. HP is a mathematical result of torque readings. The simple equation is HP = torque x rpm/5252. Therefore, below 5252 ANY engine will make MORE torque than HP. Above 5252 ANY engine will make HP than torque. Therefore, can some explain how the dyno chart on this thread go against this known given? This fact cannot change, and there is no other way to measure HP to where this is not true. Could someone please explain this engine defying the laws of physics and math for me and the other skeptics please? Oh, and the two charts don't even cross HP and torque at the same RPM on the two runs, so please do not tell us that the numbers are moved right or left, or the scale is off. Both runs should cross at the same point regardless-even if for some reason the dyno "doesn't know what it's doing" on this day and read the rpm wrong instead of the 5252 it must be. Thank you.

JIMMY

Nobody? Almost 100 views since I posed my question and NOBODY can explain why these dyno charts are completely inaccurate? Not trying to stir the pot or anything, BUT.....There HAS to be an explanation.......

Jimmy, I just checked this out and you would be correct on the cross, I have no explanation for this as I wasnt there.

I am trying to figure this out Ill let you know if I figure it out.

Very observative,lets see if we can figure out why.


dan gadgetman mo.

Any new info on this? My customer is asking me questions but hard for me to recommend the procedure to him with questionable info on this, and no other real dyno charts to be found....

In the process of doing a web search to understand the purpose of the 5252 I found that there have been other instances where things just didn't line up. No explanation on them either.

I kind of grasp the concept of the calculation and where it comes from, there are a number of things about the groove yet to be understood.

One thing that has become obvious with the smaller engines, ie: lawnmowers, is that there is a noticable increase in torque and rpm. Granted an increase in rpm doesn't always mean an increase in torque.

Another thing that has been noted by several is that at 60 mph the tachometer is showing 1,700rpm instead of the typical 2,000rpm for the same speed for vehicles with an auto trans. There are those that say this too is not possible... but there it is none the less.

I know this doesn't explain the dyno but I wanted to post this because the dyno creates the HP graph through calculation not through measurement directly and the above traits of the groove may be a small part of the ultimate explanation.

Food for thought

Karl Fortner
Tacoma, Washington

Sir, I understand that there are other dyno charts where they do not cross at 5252 rpm...The FACT of the matter is that they are completely inaccurate as well. It HAS to cross at this RPM. It CANNOT cross at any other RPM as I stated before, because HP is not measurable without first knowing torque, and then HP is determined through the mathematical equation HP = torque x rpm / 5252. The only way for it to cross somewhere else is for someone to invent a different number to punch into the equation, and then they are reporting FALSE findings, for what purpose, we can't say. If someone ever says that there is an engine where they do not cross at 5252, they are terribly mistaken, don't know any better, or are , dare I say it, lying. I hope that this is a case of being mistaken, but I'd like an explanation from the original poster or someone else involved on this one. It is IMPOSSIBLE for anything else to have happened to where these will not cross at 5252, from a lowly lawn mower, to a nytro burning, supercharged, 15,000 hp drag engine...all engines must play by the rules of this simple math equation. It's a math equation, sirs, where the determining number is 5252, therefore all must cross at 5252. Enough said without a true explanation.

Chuck's Speed and Dyno , 2923 West Weldon Avenue, Phoenix, AZ 85017 • Office: (602) 266-5101. The tech's name is Errick.

I just called there and spoke to Lance, the owner. In his own words (don't get mad!) "Anyone that tells you the curves have to cross at 5252 is an idiot."

This (according to Lance) "is a mathematical number used to calculate hp from torque and the chart will NOT cross at that point unless the engine is designed that way."

One phone call.

Maybe you should try doing some more research by TALKING to the experts instead of risking misinterpretation of data and presenting your inaccurate assumptions as fact.

This ends this discussion until you verify your statements.

I have asked for Errick to call me in the hope he will be able to make an appearance here and straighten you all out.

I wish you had done so. Then, my forums would not have had all this animosity on it.

PS: Your comment about the charts being altered for (implied) nefarious reasons was not lost on me.

I hate to inform you of this, but I do own a dynomometer. And, your so called expert friend, is misinforming you. I want you to go to Google, and type in the search "hp and torque must cross at 5252" and hit enter. You will get to read thousands and thousands of websites and literature that will explain this to you and your friend. To quote one site "if you see any dyno chart where the numbers do not cross at 5252 rpm, you know you are looking at a bogus chart." If your friend has some magical dynomometer that can mystically report numbers that don't work in a math equation where 5252 is a constant (a constant means just that-the numbers constantly have to cross at 5252 rpm) then his dyno is inaccurate to begin with and I suggest you find a new dyno man. HP is not measured by a dyno, torque is. Then horsepower is MATHEMATICALLY determined from the torque reading...therefore using the math equation to determine HP from the actual torque reading that the dyno is ACTUALLY measuring will always have a crossing at the 5252 rpm. Google it and read my friend, and you will find that your "expert" is wrong. I am sorry about this, but I have dyno'd many many many engines, and all are this way, because it has to be this way. I will take actual math, facts, and the basic knowledge that a math equation cannot be changed over what your friend states.

You are talking apples to oranges, Jimmy.

Your reference to the 5252 is valid, but ONLY on an engine dyno. With the parasitic losses between the flywheel and the tires, further research indicates there is no true way to measure torque at the tires.

I have checked with other authorities, and they concur with these statements. So I can suggest you re-think your approach. Attacking the data does not change the data. Attacking those responsible for presenting the data only creates animosity.

Thank you for your efforts and for giving me a reason to dig further into the science of engine testing.

Sir, I e-mailed the tech department at Dynojet (you know Dynojet, right?-the company that builds more chassis dynamometers than any other company, and which all the big name magazines and aftermarket companies use). Anyway, I got the Technical Support Manager for Dynamometer and Performance Products, whose name is Keith Lockliear, to e-mail me back. He stated, and I quote "the formula for HP, as I believe you know, is: Horsepower = Torque x RPM / 5252. As such, if you do the math, horsepower and torque must always match or meet at 5252 rpm." I then replied and asked the question "And this is true whether it be a chassis or engine dyno, correct? That is this individual's argument to me-that a chassis dyno does not need to cross at 5252 rpm like an engine dyno." To which he replied, and I quote again "That is correct. Regardless of where the engine is running (engine dyno or in a vehicle), the RPM is still being sampled from the engine."

So, sir, how much more of an "expert" would you like me to get a hold of next? Are we to believe the head tech guy at the largest manufacturer of chassis dynos, or your friend, the guy that dynos your stuff for you? As I have been trying to show you, a constant is a constant, and to get HP ratings, chassis dyno, engine dyno, or otherwise, that constant is 5252 rpm. Period. End of story.....

Furthermore, your friend just called the Technical Support Manager at Dynojet, as well as myself, an "idiot" as you stated, because we said all must cross at 5252 rpm. I would suggest otherwise, and as I stated before, you may want to get a different dyno guy, as he apparently is HUGELY misinformed about how his own equipment works....

Thanks for playing , and I look forward to your and your friend's rebuttal of the chassis dyno manufacturer's statements.

Jimmy