[TXCSSU]

Originally Posted by EDFHOBBIES

Okay... so what would a 141mph be in hp?

http://www.wallaceracing.com/Calcula...or%20Speed.php


And granted, there's most likely more to consider but essentially a Dyno is just making the calculations for you. The key is consistent numbers.

[ZL1Atlanta]

Originally Posted by TXCSSU

http://www.wallaceracing.com/Calcula...or%20Speed.php


And granted, there's most likely more to consider but essentially a Dyno is just making the calculations for you. The key is consistent numbers.

The Wallace calculators have been almost spot on for my car’s, and others, weight and trap to what it made on the dyno once fully dialed in.

That said, we gained several MPH and shaved several tenths from my car from the first time it hit the track (same weight). Put it back on the dyno after a few months and it still made the same in a single 6th gear pull… So there are other variables to even just using trap speed. Best bet is to just use it as a tuning tool to compare changes against a base run. :-)

[BlaqWhole]

Originally Posted by clg82

Isn't 7th gear our 1:1?

Originally Posted by arpad_m

This may have been done to limit the max speed, many dynos do not like 200 mph or more.

Well 7th gear isn't exactly 1:1...it's just the gear that is closest to 1:1. As arpad said, 7th gear on a dyno puts you over 200 MPH. These dynos are rated up to 200 MPH. So there could be some questioning of the accuracy of the readings when going over that speed. On top of that a lot of shops just don't feel comfortable spinning the dyno that fast in case something breaks. Many of them won't go that high. So they stay in 6th. Typically 6th reads about 20 RWHP lower than 7th.

[synolimit]

Here I can officially join…

585hp, 581tq
MBRP race CBE
Rotofab CAI
6th gear
SAE Dynojet

[synolimit]

Originally Posted by BlaqWhole

Well 7th gear isn't exactly 1:1...it's just the gear that is closest to 1:1. As arpad said, 7th gear on a dyno puts you over 200 MPH. These dynos are rated up to 200 MPH. So there could be some questioning of the accuracy of the readings when going over that speed. On top of that a lot of shops just don't feel comfortable spinning the dyno that fast in case something breaks. Many of them won't go that high. So they stay in 6th. Typically 6th reads about 20 RWHP lower than 7th.

Seems high, 605hp no tune and just a intake and CBE?

[s346k]

Originally Posted by BlaqWhole

Track times, ET, and 60-130 will paint a much better picture than a dyno can.

this is blasphemy. real world results? but how would we argue over 10-20 hp if we weren't comparing a million different cars on different dynos? but the dyno said it made an extra 12 hp, its definitely a worthwhile mod, idk why it runs the same. must be the weather.

[clg82]

Originally Posted by BlaqWhole

My 93 octane tune on a Dynojet in 6th gear made 745 RWHP.

I then had it on a Mustang Dyno at a different shop and it made 688 RWHP in 6th gear with 93 octane.

So yea that is roughly 6-7 percent difference.

Although the shop that had the Mustang Dyno did retune it before they got those numbers. But their tune was more for driveability so they didn't really touch anything to impact the power.

The problem with dyno shops is a lot of them simply plug in numbers here and there and factor in this and that and before you know it they're handing out inflated numbers like candy on Halloween. And they do that because if shop A builds 5 cars and they're all making "900+ RWHP" and shop B is building similar cars but they're making only "820 RWHP" then people are all gonna want shop A doing their work because they're getting inflated numbers. And now there is some new type of dyno that spits out even higher numbers than a Dynojet does. So I wouldn't put too much stock into what the numbers are. Track times, ET, and 60-130 will paint a much better picture than a dyno can.

Serious question, but why those mph specifically?^

[BlaqWhole]

Originally Posted by s346k

this is blasphemy. real world results? but how would we argue over 10-20 hp if we weren't comparing a million different cars on different dynos? but the dyno said it made an extra 12 hp, its definitely a worthwhile mod, idk why it runs the same. must be the weather.

I do believe that a dyno has it's purpose. But these days that purpose is limited to seeing what difference a specific mod makes after it is installed. So if I swap a pulley and am now making an extra 25 RWHP then it served it's purpose. But when there are hundreds of dynos and some of them allow for factors to be typed in to get a higher reading or some of them can be altered and some read higher than others and yada yada, then those results all become diluted.

I think a good rule of thumb would be to factor in a +/- range to account for errors and variances and other BS. So if you're making, as an example, 750, then it should be a range instead of a hard set number. So 750 should be more like approx 735-765 given the same type of dyno and similar conditions. And really, it is just splitting hairs when you're comparing a 760 RWHP dyno run to a 740 RWHP dyno run. When factoring in a range, any given day a 740 RWHP car can beat a 760 RWHP car.

Originally Posted by clg82

Serious question, but why those mph specifically?^

It seems to be a good starting and stopping range. I also think at those speeds, once you get to 120-130, you're pretty much not gonna stay in it. And if you're ahead of the person at 120 chances are they won't catch up given you didn't just get a lucky jump. In some cases there have been GTs and GT guys with mods who have been able to keep up with or even get the edge on stock ZL1s to about 120-ish...at which point the ZL1 just barrels past them. But I would think that 60 to 130 is the best range to determine which car is faster. And with Dragy boxes it is becoming the standard test.

[cjperformance]

Testing 60-130 you are much less traction limited too, so measurements can be more accurate on higher hp builds w/o factoring tire slip.