What should a stock Zzz be putting down for HP?

[Heavy Duty]

I saw the sheet on an '02 Z06 - it was at 356 rwhp

Hope that helps

Thanks 89x2. I am starting to get the idea that each car/engine is different and no two will have the same performance results. Given that, one can expect the RWHP in a stock Z-06 to be somewhere between 345-365 HP. FWIW, I still say that the Z-06 is suffering some serious parasite HP loss if there is truly that much of a HP loss between the flywheel and the wheels. Think of it, in a manual tranny the only weak link is the clutch and pressure plate right? Dose flywheel HP rating include or exclude assessories such as powersteering, A/C, alt, and such? If it excludes assessories then that could be part of the reason for the huge loss.

I know that several years ago Ford had a class action lawsuit filed against them for false advertisement on the Cobra Mustang. It seems that Ford really over stated the HP rating so they could sell lots of cars. Ford had to pay back lots of moneys to the poor saps who got suckered in on the deal.

H.D.

 

[DRTH VTR]

This is my understanding, but I am no expert.

When the engine is dynoed on an engine stand with no accessories attached (the way it used to be done) the output is gross horsepower. When the accessories are attached, it is net horsepower. Engines are rated in net horsepower today. The old ratings of the 1960's are in gross horsepower. Gross HP readings are in the neighborhood of 20% higher than a net HP rating. Horsepower is a unit of work, so accelerating the wheels and driveline components is a loss of work that is not planted to the ground. The losses are not just due to friction, slippage, etc. A loss of about 15% seems to be typical.

 

[Heavy Duty]

Thanks DRTH VTR for defining the difference between the two HP ratings. So the advertised HP rating for the Z-06 is 405 net HP? If so, a difference of 40-60 horses between the flywheel and rear wheels is still a huge loss. How much of a loss can you expect in torque?


Thanks
H.D.

 

[Robert YellowVette]

Thanks DRTH VTR for defining the difference between the two HP ratings. So the advertised HP rating for the Z-06 is 405 net HP? If so, a difference of 40-60 horses between the flywheel and rear wheels is still a huge loss. How much of a loss can you expect in torque?

The 15% drive train AND tire to roller interface power loss on the most common chassis dynos is not unreasonable and has been generally accepted in the hot rod community ever since chassis dynos were first used.

Just be glad you are not using V-belts and pulleys, they have a 60% power loss...

Since torque is what the dyno actually measures and hp is always calculated from torque the 15% loss still holds, ie, 400 ft lbs X 85% = 340 ft lbs...

 

[ScatRat]

In 1971, the SAE net horsepower rating was implemented (yes, I'm from that era, but don't hold it against me) using the numbers reflecting any and all accessories that could be installed on a car. So, the flywheel rating is the SAE net that we see today. On average, again I say ON AVERAGE, you can multiply the SAE net horsepower rating by 1.3889 to give you the horsepower ratings of pre-1971 cars.

We ran the numbers on over a hundred vehicles rated horsepower between gross hp in 1970 and SAE net in 1971. That average is what is shown above. It doesn't necessarily apply to all vehicles, but it's darn close. Thus, the 405 rating of the ZO6 equates to a pre-1971 rating of about 560 hp.

If you look at the numbers for cars back in that era and what the ZO6 can do today, it's not unrealistic. The quoted horsepower ratings by Chevrolet are always caveated with SAE net. Read the fine print in their advertisements/brochures. They have never quoted RWHP. As already stated, the parasitic losses one encounters through the drivetrain and transferring that to a dyno roller to give you your RWHP is not unreasonable.

My two cents worth.

Scat Rat

 

[TODD L GRIFFITH]

If your friend is in Natick with you, 350rwhp seems fine, because your PCM is set up for optimum performance based on 29.92"Hg barometric pressure (sea level) and 50%RH (65degrees dry bulb /55degrees wet bulb) Depending on when and where the dyno was done, it could have an affect on the dyno results. If it was done recently in the Natick area, 350 is good. We are talking rwhp correct? lol! A quicker calculation to save you a couple of steps is 405hp (.85) = 344.25hp assuming a 15% driveline loss.

 

[Heavy Duty]

In 1971, the SAE net horsepower rating was implemented (yes, I'm from that era, but don't hold it against me) using the numbers reflecting any and all accessories that could be installed on a car. So, the flywheel rating is the SAE net that we see today. On average, again I say ON AVERAGE, you can multiply the SAE net horsepower rating by 1.3889 to give you the horsepower ratings of pre-1971 cars.

We ran the numbers on over a hundred vehicles rated horsepower between gross hp in 1970 and SAE net in 1971. That average is what is shown above. It doesn't necessarily apply to all vehicles, but it's darn close. Thus, the 405 rating of the ZO6 equates to a pre-1971 rating of about 560 hp.

If you look at the numbers for cars back in that era and what the ZO6 can do today, it's not unrealistic. The quoted horsepower ratings by Chevrolet are always caveated with SAE net. Read the fine print in their advertisements/brochures. They have never quoted RWHP. As already stated, the parasitic losses one encounters through the drivetrain and transferring that to a dyno roller to give you your RWHP is not unreasonable.

My two cents worth.

Scat Rat

560 HP. holly cow batman. A guy over on the C-6 z-06 thread just did some figures like that for the new z-06. The new Z-06 HP ratings (gross) is unbelieveable. I guess that I'll have to accept the huge parasitic loss this car has.

H.D.

 

[Heavy Duty]

If your friend is in Natick with you, 350rwhp seems fine, because your PCM is set up for optimum performance based on 29.92"Hg barometric pressure (sea level) and 50%RH (65degrees dry bulb /55degrees wet bulb) Depending on when and where the dyno was done, it could have an affect on the dyno results. If it was done recently in the Natick area, 350 is good. We are talking rwhp correct? lol! A quicker calculation to save you a couple of steps is 405hp (.85) = 344.25hp assuming a 15% driveline loss.

Todd,
my friend had the dyno done in Raleigh, NC. I've yet to dyno mine. I had thought about doing it when I go to Carlisle this year. right now, both of my vettes are in N.C. until the spring. I am thinking that I may bring either the Z-06 or the C-4 up here so i'll have something to tinker with during the summer.

The 344 RWHP I guess would be right for the 15% rule. If a Zzz is dynoing at 350 at the wheels that means that there is a 13.6 % loss between the flywheel and Rearwheels. So the Rule is that Net HP is less than Gross HP, RWHP is less than Net HP. So if Net HP is say between 76-83% of Gross Hp that means that the Z-06 should be pumping between 530-486 gross HP.

h.d.

 

[TODD L GRIFFITH]

I have to get a base line dyno done for mine before I install my new cam package. I have a guy down the cape that does the dynoing. I believe TByrne may have a dyno, or can hook us up with someone closer. I'll let you know what I find out. When are you going to Carlisle? I've been thinking about the May trip.

 

[Heavy Duty]

I have to get a base line dyno done for mine before I install my new cam package. I have a guy down the cape that does the dynoing. I believe TByrne may have a dyno, or can hook us up with someone closer. I'll let you know what I find out. When are you going to Carlisle? I've been thinking about the May trip.

Todd, i'll be bring mine up once the weather is back to NICE. I am going today to look at one of those car storage places to check out their prices and such. There is no way I would bring mine up and park it here at the apartments outside unattended. I live just west Leicester off of Rt-9. We can get togather one Sat and run over to that guys dyno. Do you know what he charges to dyno and do a little tuning?

I am planning on going down to Carlisle that Friday. I have a couple of friends who live around Thurmont, MD which is about 45 miles from Carlisle. The rooms are cheaper than at Carlisle and we have a blast running up togather. Last year we cought a rustang on Rt 15 going up . After 5 vettes got through tormenting him for about 10 miles he decided it was time to pull over on the shoulder. It should be an interesting cruse down to Carlisle this year. If I don't dyno the Z-06 here then I'll do it at Carlisle. Also I am in the market for a car lift. Last year they had some great deals on them but I didn't have my building up. Now that it is under construction and should be finished by then, I want to get a lift so i can do most of the work myself.

Do you know anything about the Corvettes United of Central Mass? Seems like a good bunch and I had thought about joining.

H.D.

 

[TODD L GRIFFITH]

Todd, i'll be bring mine up once the weather is back to NICE. I am going today to look at one of those car storage places to check out their prices and such. There is no way I would bring mine up and park it here at the apartments outside unattended. I live just west Leicester off of Rt-9. We can get togather one Sat and run over to that guys dyno. Do you know what he charges to dyno and do a little tuning?

I am planning on going down to Carlisle that Friday. I have a couple of friends who live around Thurmont, MD which is about 45 miles from Carlisle. The rooms are cheaper than at Carlisle and we have a blast running up togather. Last year we cought a rustang on Rt 15 going up . After 5 vettes got through tormenting him for about 10 miles he decided it was time to pull over on the shoulder. It should be an interesting cruse down to Carlisle this year. If I don't dyno the Z-06 here then I'll do it at Carlisle. Also I am in the market for a car lift. Last year they had some great deals on them but I didn't have my building up. Now that it is under construction and should be finished by then, I want to get a lift so i can do most of the work myself.

Do you know anything about the Corvettes United of Central Mass? Seems like a good bunch and I had thought about joining.

H.D.

I imagine dyno time will be about $100.00/Hr., seems to be about the going rate, so it is a good idea to be prepared for tuning to make the best of that time. You can get 3 pulls in an hours time. I'm not familiar with the central mass corvette clubs, but have a few friends that are in the south shore club here in my area. I'm sure you can find a storage place for $150.00/mo. Some are also heated and air conditioned. I would love a lift too. I've seen some lifts around $1200.00 that are portable...............cool! Worth having if you enjoy doing the work yourself like me. After a stressful week at the office, I enjoy a stressful weekend of doing mods. on the vette. I'm due for a semi- baseline dyno before I install my new cam. I already have intake, fuel and exhaust mods., so that is the baseline I'll have to start with. I'll grab some prices this week on dyno time and contact you where, and how much. My first pull will probably be in March when the snow melts.

 

[ScatRat]

Preliminary RWHP Results

The preliminary results are in. My `03 started at 341 rear wheel horsepower. It dynoed today at 494 (uncorrected) rear wheel horsepower. That's about 520-530 corrected rear wheel horsepower with today's conditions. This gave us a minimum of 52% increase over stock. The horsepower could have been increased, but the driveability of the car would have suffered. This was through the STOCK mufflers. Aftermarket mufflers might have gained us another 5-6 horsepower. Not worth the cost.

As I said before, it takes serious money to make serious HP for a ZO6. The car now has an ATI Procharger system, long tube headers, bullet catcons and an X-pipe. These are the only performance mods on the car.

It will be ready for pick up tomorrow. Can't wait to drive this thing.

Cheers,
SR

 

[Heavy Duty]

The preliminary results are in. My `03 started at 341 rear wheel horsepower. It dynoed today at 494 (uncorrected) rear wheel horsepower. That's about 520-530 corrected rear wheel horsepower with today's conditions. This gave us a minimum of 52% increase over stock. The horsepower could have been increased, but the driveability of the car would have suffered. This was through the STOCK mufflers. Aftermarket mufflers might have gained us another 5-6 horsepower. Not worth the cost.

As I said before, it takes serious money to make serious HP for a ZO6. The car now has an ATI Procharger system, long tube headers, bullet catcons and an X-pipe. These are the only performance mods on the c

It will be ready for pick up tomorrow. Can't wait to drive this thing.

Cheers,
SR

Holy crap batman, that is some serious horse power. So what kind of $$ do you have in the engine to get those kind of ponies? Are you going to Carlisle this year? I'd like to see what you've done (externally) and maybe get some ideas. Cheers to you and don't forget to as you go by us slow pokes .

H.D.

 

[ScatRat]

Holy crap batman, that is some serious horse power. So what kind of $$ do you have in the engine to get those kind of ponies? Are you going to Carlisle this year? I'd like to see what you've done (externally) and maybe get some ideas. Cheers to you and don't forget to as you go by us slow pokes .

H.D.

Just to repeat, everything is external. They didn't even go into the block. I did forget to mention that 42 lb injectors replaced the stock injectors. I haven't seen the final bill yet, but the total cost is probably going to be in the $12K to $15K price range. What the heck, you only go 'round once in life...

Oh, and I won't forget to . You just might not see me as fast as this thing will be able to go now...

SR

 

[Edmond]

494 at the wheels is more than 580 at the flywheel!

 

[TODD L GRIFFITH]

An LS1 is capable of putting out +520hp. The mods. were a cam, ported LQ9 heads, valvetrain swap, long tube headers, FAST Intake and 78mm TB. Without the TB and FAST intake the output is 506hp. Pretty impressive given the starting point hp. I found this particular build in Chevy High Performance magazine. The article is called "Patriot Games." The dyno results was 522hp 466 ft.lbs. of torque. The cost was $2539.00 for everything. A good deal if you ask me. When my new cam goes in the cost to me will be around $1500.00 for everything including injectors, replacement coolant, lubes and any special tools bought for the project. With an 03' +405hp LS6 as the starting point with bolt-on mods. headers, intake, exhaust etc. I should see atleast 400rwhp with the new cam. The corvette ZO6 guys I know with similar mods. and cam put out over 500hp at the flywheel. That is where I want to be to keep my mind off the new C6/ZO6.

 

[ScatRat]

The final numbers are in: 494.3 RWHP to the ground. Corrected horsepower to the ground according to http://wahiduddin.net/calc/calc_hp_abs.htm, is 518 RWHP. The SAE Power/Corrected Power at the flywheel is 584.2 BHP. Final cost - $12,500.

I guess you can make or form your own opinions from here...big gains, big cost - about $70 per horsepower. All of this is verifiable. I have the dyno sheets and specs. Can be scanned and posted if anyone's interested.

All I can say is at this point, now that I've driven the car and gotten into it a few times, is that the car is frigging SCARY. I LOVE IT!

Rat out.