Dyno'd the Z06 today...

[overst33r]

Very happy with the results. Runs really strong. FWIW they are rated at 405hp. I'm going to be taking it to a local road course in a couple of weeks and try to actually use the power. :biggrin:

 

[punjabiplaya]

is that uncorrected? good numbers either way.

 

[thescreensavers]

^ Dyno's Read Wheel HP. What the manufacture puts down is at the crank.

You cant really get a 100% accurate if you correct for transmission loss.

 

[punjabiplaya]

i meant correction for altitude/humidity/temperature/etc... either way those aren't going to be that large. 405hp and 358whp puts him ~12% loss.

 

[vshah]

what? i thought z06s were rated at 505hp

or is yours an older one?

 

[exdeath]

12%-13% is the industry wide accepted loss figure for RWD, so its spot on.

It is my goal in life to send a dyno into emergency shutdown... some day D:

 

[overst33r]

i meant correction for altitude/humidity/temperature/etc... either way those aren't going to be that large. 405hp and 358whp puts him ~12% loss.

Yeah, it was 379whp before correction. Humidity was 25% and temp was 70deg.

what? i thought z06s were rated at 505hp

or is yours an older one?

Yeah I have a C5.

12%-13% is the industry wide accepted loss figure for RWD, so its spot on.

It is my goal in life to send a dyno into emergency shutdown... some day D:

I thought it was closer to 15% for FR and 12-13% for FFWD and RRWD cars...

Compound boost!

 

[exdeath]

I thought it was closer to 15% for FR and 12-13% for FFWD and RRWD cars...

Compound boost!

Well you have a T-56, one of the most bad assed transmissions know to man :awe:

Sorry, you're just going to have to deal with 12-13%.

 

[thescreensavers]

12%-13% is the industry wide accepted loss figure for RWD, so its spot on.

It is my goal in life to send a dyno into emergency shutdown... some day D:

A Dyno'er got pissed at me when I started talking about % lol

He was saying if you start adding power you don't loose 13% out of 700. Its only 50 or what not.

 

[PricklyPete]

Nice numbers...awesome car.

 

[EightySix Four]

A Dyno'er got pissed at me when I started talking about % lol

He was saying if you start adding power you don't loose 13% out of 700. Its only 50 or what not.

Not true, drivetrain loss is a percent. I got into an argument with an engineer over this because I honestly don't understand why it's a percent instead of a fixed number. I can't remember his evidence, but after he presented it I couldn't argue with him. I'll see if I can dig up the thread on the forum I used to frequent.

This percent is not fixed though, depending on the level of power the percent goes down, but not enough to be considered fixed.

12%-13% is the industry wide accepted loss figure for RWD, so its spot on.

It is my goal in life to send a dyno into emergency shutdown... some day D:

Hehe, I watched that happen to a Z06. IIRC it was one with a 403 iron block and twin charge set-up, a nice fat blower with a pair of twins. 1493 whp and the Dyno cut out.

 

[exdeath]

Some easy power to be had there with a tune for sure. Crank that baby up to 13.x:1 for n/a. You're dipping 12 and under, that's what a tuned boosted car runs 😛

Needs to be richer down low on the hit when load is highest and leaner on the top end, basically the opposite of what yours does 😀 Probably looking at picking up 20 RWHP from afr tweaking alone.

 

[EightySix Four]

I apologize for this being OT: but would AT:G have any interest in me doing a mini-guide about how some of the newer PCM's work and go through the basic tuning of a car? I'm pretty comfortable with LSx motors now as well as my LNF (the guide would be over the LNF but it would have information for everything in general).

 

[exdeath]

Hehe, I watched that happen to a Z06. IIRC it was one with a 403 iron block and twin charge set-up, a nice fat blower with a pair of twins. 1493 whp and the Dyno cut out.

D: D: D:

:awe:

*fap* *fap *fap*

 

[JCH13]

Not true, drivetrain loss is a percent. I got into an argument with an engineer over this because I honestly don't understand why it's a percent instead of a fixed number. I can't remember his evidence, but after he presented it I couldn't argue with him. I'll see if I can dig up the thread on the forum I used to frequent.

It's close to a constant percentage (probably) because of dry kinetic friction in the gears and bearings.

This type of friction is proportional to contact force in the gear set, as torque goes up, contact force goes up the same amount (i.e. you double your torque, the contact force doubles) this also doubles the kinetic friction loss of the gear set. Each gear set in your power train adds only a few percent of loss, but it eventually adds up, and their losses scale directly with torque, and therefore directly with power. Similarly, as PT torque goes up the side-load, and therefore friction, on any bearings goes up proportionally with torque and power. Make sense?

 

[Arkaign]

Ah, nice. I notice the CF:SAE at the top right. Can someone explain to our beloved DBZ in the TG:USA thread that Corrected wheel hp is not the same thing as crank/flywheel hp?

😀

 

[JCH13]

Derp?

SAE corrected hp the same as crank? :hmm: As in SAE correction factor accounting for variations in temp, humidity, barometric pressure to estimate what each engine would produce under the same atmospheric test conditions? That is far different from having the engine move the entire drive-line vs just a crank and flywheel. That's not even apples and oranges... that's like apples and whatever the hell he's smoking...

 

[Arkaign]

Derp?

SAE corrected hp the same as crank? :hmm: As in SAE correction factor accounting for variations in temp, humidity, barometric pressure to estimate what each engine would produce under the same atmospheric test conditions? That is far different from having the engine move the entire drive-line vs just a crank and flywheel. That's not even apples and oranges... that's like apples and whatever the hell he's smoking...

rofl exactly. I actually have my suspicions that he's trying to troll gullible Americans into a fun internet flamefest, but I'm not sure. I've been beating my head against the wall re-reading that thread and trying my best to put the truth in plain sentences.

 

[EightySix Four]

It's close to a constant percentage (probably) because of dry kinetic friction in the gears and bearings.

This type of friction is proportional to contact force in the gear set, as torque goes up, contact force goes up the same amount (i.e. you double your torque, the contact force doubles) this also doubles the kinetic friction loss of the gear set. Each gear set in your power train adds only a few percent of loss, but it eventually adds up, and their losses scale directly with torque, and therefore directly with power. Similarly, as PT torque goes up the side-load, and therefore friction, on any bearings goes up proportionally with torque and power. Make sense?

Yes it does, academically, logically it still feels like to me that the friction of turning the gears should be the same no matter the power output. Eh, as long as I know I'm wrong right? 😛

 

[Elfear]

Nice OP. I'll bet your car is a blast to drive.

I'd throw my car on the dyno but I think it would stall out trying to turn the drum. 🙁

 

[Arkaign]

Nice OP. I'll bet your car is a blast to drive.

I'd throw my car on the dyno but I think it would stall out trying to turn the drum. 🙁

^^ 🙂 Well have no fear! Even Ford Aspire 1.3L 63hp can gain 50HP with just a chip!

http://www.horsepowerchips.com/aspire.html

😀

Hah, seriously though, I know what you mean. I drive a non-turbo i4 2.0L, I would die of embarassment taking it to a dyno. Now if I had a gem like a SC Mustang, Vette, 911T, etc, it'd be a different story!

 

[natto fire]

rofl exactly. I actually have my suspicions that he's trying to troll gullible Americans into a fun internet flamefest, but I'm not sure. I've been beating my head against the wall re-reading that thread and trying my best to put the truth in plain sentences.

Maybe. I just don't understand it though. I have neglected to post in that thread because I have no room to talk as I have really not been into any TV shows for a while. That said, I have been watching that Top Gear while down here on vacation and it is very painful to watch. The scripting, the chemistry, it is all just terrible.

OP: I'm assuming no mods, and what tires are you running? I have a friend who did road course HDPE and he just slapped some tires on and it was night and day.

 

[JCH13]

One common use of the dyno correction factor is to standardize the horsepower and torque readings, so that the effects of the ambient temperature and pressure are removed from the readings. By using the dyno correction factor, power and torque readings can be directly compared to the readings taken on some other day, or even taken at some other altitude.

That is, the corrected readings are the same as the result that you would get by taking the car (or engine) to a certain temperature controlled, humidity controlled, pressure controlled dyno shop where they measure "standard" power, based on the carefully controlled temperature, humidity and pressure.

From here. A very straight-forward explanation. Basically it lets one directly compare dyno readings from 10,000ft in Colorado, where there is less air, to a dyno reading near sea level, where there is a higher air density. It also lets you compare dyno results from days with different ambient temperatures. Say you go to AZ and run on a dyno when it's 120F out, your engine will have piss-poor power because the air is so hot. Drive the same car to AK, dyno when it's 0F out and suddenly you've got a bunch more power. A rule of thumb is 1%hp for every 10F or so intake temperature. That is to say dropping your intake temperature 10F will add about 1% more HP because the air is denser. The SAE correction factor takes these variables out of the measurement so that every engine, regardless of where it was tested, can be compared on equal footing.

 

[LTC8K6]

10,000ft in Colorado

There's a dyno at that altitude?

 

[JCH13]

There's a dyno at that altitude?

I was posing it as a hypothetical situation, though there are several cities world-wide that are above 10k feet. There are certainly dynos at a wide variety of elevations, and the SAE HP correction equation is generalized enough to handle all of them.