jerryd87

iTrader: (4)

Yah and its pretty obvious that the operator messed with the dyno since somehow you seem to get significantly higher power numbers then every other z out there for the mods done, your thread mentions 50 degree temps but if the dyno is setup correctly it accounts for that and calculates power based on the temp set in the computer not the actual air temp. On the same dyno in the same conditions my 600 hp tune was probably close to 670 =/ in reality your on a dyno that wasn't messed with your gona be in the 260-270 range just like everyone else.

mattman87

Can you be more specific than, "messed with the dyno somehow" haha. I hear ya, and I bet that 670 would make you feel as good as I do; you wouldn't tear yourself down. I mentioned in my thread the dyno is the piece I know the least about. What if the temp in the computer was set to the outside temp? I thought those temp corrections were mostly used when dynoing on hotter, more humid days (than average for an area). Besides I did dyno originally at 237whp; how come no one thinks that's outrageous? Hill's Garage is also extremely reputable in their work - they are the best on my portion of the east coast hands-down.


I'm not thread-jacking so here's my point....

It looks like this car (in the article) got tuned, and then had bolt-ons added and was not retuned after each bolt-on (impression I got). Seemed like reasonable gains in that light. Because again, I got zero gains from the intake and exhaust and art pipes and spacer. 0hp/0tq. But I didn't go into my dyno with a pre-tuned engine.

jerryd87

iTrader: (4)

most dynos allow you to edit things like air density ratios and temps, something as simple as the ignition calibration being screwed up would skew it. perfect example the sg motoresports 372 dyno, if you look right at the dyno it is set at 1.2 air density ratio, about equal to running 4 or 5 lbs of boost after figuring in heat raise from compression its likely something similar.

not really because i would know the number is bs, i would look at it and simply figure it was high and judge it as an actual number that most people encounter. why would i be excited about a fabricated dyno result? the car isnt any faster just because they messed with the dyno to make it rear higher.


but like i said air temp could do it but not 50 degrees considering sae is standard is 72 degrees and std is 65 degrees it would have to be closer to 45 ish sae or around 40 std. humidity has a very minor effect, sure some but not as much as people think, at my 600 hp i would say mayby 10 hp difference at a lower humidty area but the dyno is supposed to correct for that, thats the whole point of the correction standards.

237 is a bit high but not much, my bet is they dynoed it, then adjusted the numbers in the dyno to read higher so there tuning looked better then it was, wouldnt be the first time ever.

bmyles

Putting down more than 270whp with your mods should throw a red flag. It's not magic. That's the problem with arguing about dynos, though. Dynos vary widely from shop to shop, so it's difficult to compare numbers...although a majority of the time, if you dyno on a DynoJet and use SAE correction, your numbers will be very comparable to others.

Usually you want to look at the DELTA (baseline vs. tuned) and that will tell the story. So you put down 237 the same day that you put down 287? Sorry to burst your bubble, but plenum spacer/test pipes/exhaust is NOT making 50whp.

binder

iTrader: (8)

There can be as much as 5% variance in hp readings in back to back pulls on a dyno. That can be as much as 12hp. The 6hp increase in the last 500rpm means nothing. They didn't even do a number of pulls and present an average. It shows just 1 pull on the dyno per upgrade.

Intake is a waste of 200$. Test pipes and better exhaust with a tune will show nice gains however.

trunks

iTrader: (1)

would be nice if we can separate the variables that are taken into account and narrow down what can make a difference, i.e. all the variables in the dyno process, given the same dyno of course, and the ones that fall under SAE computation. then we can identify likely variables outside the process that can be introduced into it that may change the dyno numbers and by how much in variation, i.e. the article says spark plugs were changed, but give me a break are they implying that they got 250 whp or ~ 10 extra whp due to spark plugs alone? would be nice to have a list, plus the list would def be finite that we can reference to future dyno "processes" under the same conditions.

trunks

iTrader: (1)

i agree there should have been multiple pulls, present the average, and figure if the numbers were at least consistent. it would seem to me that they did but just presented the highest that they recorded.

jerryd87

iTrader: (4)

most dynos can display the calibrations but most dont put it on the dyno readouts

trunks

iTrader: (1)

i am aware of that, there is very little info out there so i hope that we are aware and make better comparisons for future reference.

Resmarted

iTrader: (2)

There are a million ways they could fudge those numbers.
Magazines can get away with fudging numbers because to many people what they say is law. And any decent writer worth his weight in salt knows some very very despicable ways to edit "facts" and or quotes.
I'd bet they cranked the numbers up on the dyno and retuned after every mod.
And also, don't take what stupid street, import pooner, modified ***, etc says for anything more than entertainment value. The only magazine I've seen to know what they're talking about is d sport, but even they publish bs from time to time that's just product placement.