To cut a long story short, I have been on the dyno for the first time in my life last Friday and it would like to share the results with all of you. Can anyone help me posting the results? I can e-mail it to anyone.
Since I live in Dubai, it was kind of hard to find a shop with a dyno and someone who knows how to do it. We were fine-tuning the VAFC2 after it was already tuned @ the street with a lambda sensor.
Since I have no idea about different types of dyno-machines, all I can say is it was a 4WD dyno, directly to the wheels (did NOT take of the wheels) and the brand is DASTEK-Dynamometers. The tuner was holding the engine @ every 500RPM, fine-tuned the VAFC to see if there is power to be made with a safe A/F ratio. Since he reads in lambda, he was tuning for 0.88 and we were realy doing more power with this number.
While recording the numbers, again he had to hold the car at every 500RPM for a few seconds and wait for the computer to save the numbers. A big display on the side showed the numbers as well.
What is funny to me, when we have done a clean run in 4th gear on a cooled out engine (he had a HUGE fan spraying water as well) I saw the number 241 at the display. But when he went 500rpm after 500rpm and had to hold it there, the best I saw (same as on print out to be posted) was 224.9WHP till he worked his way up to redline.
Now thats not a bad number for a NA car since its like 270HP @ the crank, but why is there a difference of over 15WHP between these two numbers???
The temperature in the room was never less than 35C with a high humidity, the A/F corrections have been done only from 6000rpm to redline (runnig @ 0.88 lambda from 3000-6000rpm anyway), the VTEC point was lowered to 5500rpm I think (need to check), no correction on temperature like I see on the forum.

Here the corrections and lambda readings after A/F correction:

6000 0
6500 +2
7000 +2
7500 -2
8000 -3
8500 -5
9000 -1

here some numbers:

I have a 2003 with 15000km on it, 98RON octane gas, did NOT dyno when stock.
Peak 224.9WHP on paper, saw 241WHP
best gain @ 7000RPM 180.6>>>189.6WHP and @ 8000RPM 204.8>>>215.7WHP

Please help to post and let me know what u think.

Thanks

 

I'm not sure if I am understanding you correctly. When you say you say 241whp on the screen but the highest it showed on the printout was 224.9 that is probably due to the fact that it needed to be SAE corrected. So in reality your car is making 224.9 not 241. The machine has to take in the correction factors, it's a standard.

 

No, what I am trying to say is that if you go from 1000rpm all the way to 9000rpm in 4th, the mashine will also record 241WHP (and show a graph on the sreeen that goes all the way to that number),but in order to get a print out from another computer attached to it (that will later on print out a different type of graph) you need to go 500rpm after 500rpm untill you reach 9000rpm. By that time the engine is too hot to push that numbers. He had 2 softwares recording the numbers, one can show the full run from 1000-9000rpm but he can not print it out, the other can do prints but need to stay at every 500rpm to save the numbers (the software will than conect the points and create a graph). As I wrote before, after we let the car run at 2000rpm for 10 minutes and it cooled down, it was able to push 241whp...keep in mind that it was 35-37C in the dyno room all the time.
So my question is:

Do you dyno your cars in the U.S. by making ONE pull from 1000rpm all the way to redline in 4th gear or do you hold it at every 500rpm and then create a graph???

 

It's a WOT run, we don't stop at every 500rpms. I've never heard of a dyno run like that, to be honest with you. You'd only stop to tune, not on a peak hp run.

 

If you look back over time, dyno procedures have changed as needs and understanding of engines and the relavance of dyno testing to the real world have changed.

For example, traditional engine dyno testing has usually been done in a step test mode, whereby the engine is held for a set period at a number of discrete rpm points. This allows tuning for absolute maximum load, and will also tend to record higher readings than a ramp test (more in a minute) provided that engine temperatures are kept within spec. Of course, if there are engine dynos that can do this, there are chassis dynos that can as well (Dynapack, for example).

The tuneup delivered with static or step testing usually works pretty well for part throttle conditions where the engine may be at a constant speed, or lightly accelerating. However, for full throttle use, the tuneup can be off for most conditions (except, perhaps WOT near top speed, where engine speed changes very slowly. This is why both engine dyno and chassis dyno makers began testing engines is a more dynamic mode, whereby the engine was accelerated through an rpm range. Ideally, you'd want to test it over a variety of acceleration rates, but that isn't always cost effective for most people, so you choose one or two rates (if you can, a Dynojet, for example, is a fixed load, so it is more difficult to vary rates) that represent the conditions you'll spend the most time in.

That's why older chassis dynos like the Dynojet are increasingly being passed over in favor of more modern, variable load dynos like the Dyno Dynamics, Dynamic Test Systems, Dynapack and Mustang (among others). While more expensive and complicated, they allow more flexibility in tuning. Its also why modern engine dynos (the really good ones) are now incorporating advanced loading features (either hydraulic, electrohydraulic, eddy current or new AC dynos) so as to be able to not only load the engines, but also _drive_ them under deceleration conditions. Would that I could afford a Froude F1 style dynamometer!!!

That said, the short answer to your question is that we test both ways, but peak power numbers are usually delivered when testing in dynamic mode (ramping from one rpm point to another). Static testing often delivers higher numbers in my experience, but I'm not familiar with the dyno that was used on your car.

UL

 

UL I am glad you have replied .

The funny thing is, the static numbers are showing 15whp less than a dynamic run.
The tuner was sitting with me in the car and had a controler in his hand. He was able to be f.e. in 4th gear at WOT at any rpm he wanted the car to be for as long he wanted it to be. This way we have tuned the VAFC2 at WOT only and I was happy with this. But when I wanted to record the peak number (ego booster ), we have done a clean run from 1000 all to way to redline and the computer showed a graph that peaked out at 241whp. Again, this software did not provide a print out. To give me a print out, he went 500 after 500rpm all the way up and we recorded 15whp less than a clean run on a cooled out engine.

1. So can I sleep well thinking my car pulls 241whp as per computer and as per display ( i have a picture btw. that shows 239whp on the display) and be able to justify the $$$ I have spended on all the NA mods or am I still missing something?

2. Do you know a piggyback called UNICHIP? The guy is a dealer of it and it will run me 750USD to have it installed and tuned (including the unit). He says it can control timing as well.

thanks again for your help

 

Your engine was probably way too hot on the static testing. On a hot day, and depending upon load times at each rpm point, I would suspect you'd have to stop every 30-40 seconds for some cool down unless your dyno operator had some mega fans. If he didn't stop, coolant temps would be through the roof and the ECU would be pulling power.

I'm familiar with the unichip, but never seen it used on an S2000.

UL

 

not to be a buzz kill, but I don't see anything in your sig that would take an 03 to 240+rwhp.... I have several of the same mods, along with much more (including a blueprinted and balanced Spoon crate motor), and the last I dynoed was about 222rwhp... Granted this was with a dual RS*R exhaust and an ARC intake (everyone has their own ideas as to the powergains (or lack) on these items, but I'm not looking to have a debate) so I know I could make more power if I wanted to stay NA by getting another intake and a single amuse... again, not saying you didn't see it on the computer, but I've also been the victim of a malfunctioning dyno (it said I had about 255rwhp)

 

The ARC intake is all show no go first of all and your RS*R exhaust is dual...for what? To make peaple think you have a V12?
I am running a T1R with a test pipe and 98octane (RON) fuel...just gimme your @mail and I will send u the dyno and the picture showing 239WHP..it went up to 241...and I still have 224.9WHP on the paper so in my account thats 20WHP gain in NA mods What is the highest NA number we have seen on the forum so far?

To UL:

The fan he has was the biggest and strongest fan I have ever seen, he even put a water hose on my radiator, but he was running the car pretty long. Thats why the peak number was reached only after a 10 min. cool down run.
Today I will know if the latest UNICHIP can control timing on the S already, because the previous models dod not (multiple coil?????)

Anyway, thank you guys for your comments.

 

interesting setting

6000 0
6500 +2
7000 +2
7500 -2
8000 -3
8500 -5
9000 -1



most s2k's run... rich.. so it should be - numbers..

have u had chance to race other s2k?

if ur 240 whp... u should pull other s2k's easy...