Mopar Jimmy

What am I missing? You're not calculating based on 15% of 500 hp are you?[/QUOTE]

AGAIN, there are diffence in opinions here as to what the parastic loss is on a Z06 and i am not going to debate that as i am no expert on this topic (nor claim to be). That being said, as a rule of thumb, many tuners, etc. and other schooled hot rod people will state, that the average loss for manuel tranny C5 is 15% and 20% for an A4.

Assuming for my hypothetical that this is accurate the way you would caluculate the crank HP (or so i have been told on many occassions) is to take the rwhp 425 and divide that by .85 which give you (500 crank ponies) and for an A4 tranny (assumig 20% drivetrain loss) you would take 425rwhp and divide that by .80 which would give you 531crank HP) !!

J-Rod

AGAIN, there are diffence in opinions here as to what the parastic loss is on a Z06 and i am not going to debate that as i am no expert on this topic (nor claim to be). That being said, as a rule of thumb, many tuners, etc. and other schooled hot rod people will state, that the average loss for manuel tranny C5 is 15% and 20% for an A4.

Assuming for my hypothetical that this is accurate the way you would caluculate the crank HP (or so i have been told on many occassions) is to take the rwhp 425 and divide that by .85 which give you (500 crank ponies) and for an A4 tranny (assumig 20% drivetrain loss) you would take 425rwhp and divide that by .80 which would give you 531crank HP) !! [/QUOTE]

We used to do that math when we were calculating the markup from WD to list price as we had to add a certain percentage.

Do the math of adding 15% to the RWHP.

425 * 1.15 = 488.75
425 /.85 = 500

That all being said, you'll need 450-460 RWHP to keep up with a new Z06 if that is your goal. Look at a standard 2002-2004 Z06.

350-360 RWHP in most cases

350 * 1.15 = 402.5
360 * 1.15 = 414
350 / .85 = 411.76
360 / .85 = 423.52

The problem is I don't think you have a solid multiplier that you can use across the board in all cases. IMHO (and I'm not a mechanical engineer) you have a certain ammount of loss through the driveline (say 50HP). But I don't think it continues to grow as HP grows, it may to some extent grow, but I don't think its a linear relationship.

Anyhow, I think 425 RWHP would be a lot of fun, but, you're only looking at peak HP. You're going to need to fatten up that area under the curve if you want to compete with more displacement.

Mopar Jimmy

Anyhow, I think 425 RWHP would be a lot of fun, but, you're only looking at peak HP. You're going to need to fatten up that area under the curve if you want to compete with more displacement.[/QUOTE]

J-ROD,

As you know i have owned a big cubed 427 C5R Motor and realize that i could not even come close to keeping up with the new Z (and its big cubed torque curve) with 425 rwhp, even though the new LS7 motor is a detuned version of what i used to own!!! Now with the ECS or A&A Procharger kit giving me around 550rwhp, that would be a completely different scenerio all together!!!

THat being said, i sent you a IM regarding your opinon on a cam for my Z but need you to clear out your message box so i can get it to you!!

zo6vetteman2003

Yes, this cam I believe has been superceded, upgraded with a different model similar to this. The lift has no clearence issues at all with the valves and pistons. This cam makes all its power in the high rpm range from 5000-7000 rpm. It sounds real nice at idle and with some AC compressor load at idle it just amplifies the lope (sweet!) I was reading in Chevy High Performance magazine that cams with a duration greater than 230 and a lift more than .600" are alot harder to pass emissions with. I just passed my inspection no sweat all codes deleted with my tune.
Like I said AFR heads and FAST intake are my last two mods. and I will be done for the time being. I expect SAE 450rwhp/420lb./ft. if I am lucky. The new heads most likely have 62cc or close to it, combustion chambers to raise my compression to 11:1 or so.

zo6vetteman2003

I figure it as 425rwhp (1.15) = 488.75hp at the crank.

My STD hp numbers were 436rwhp/414 lb./ft. 502 crank hp / 476 lb./ft.
Looks good like this lol! I always post the SAE corrected because I want people to know that with these mods. and a good tune the numbers are realistic on the dyno.

ZO6Les

AS J-Rod said, and also avoiding the whole debate on parasitic driveline loss .. the majority of folks use the 15% manual and 18-20% automatic levels.

What is not under dispute is the correct way to derive the number - i.e. you divide the RWHP number by .85 to get FWHP. So to get 505 FWHP you need 430 RWHP.

Even with the slight weight advantage of our Z06's - the new model will/should kill one of ours who get to the number with a peaky cam, unless you can get him to race you only between 5000 and 7000 RPM's

Les

ZO6Les

As J-Rod said, and also avoiding the whole debate on parasitic driveline loss .. the majority of folks use the 15% manual and 18-20% automatic levels.

What is not under dispute is the correct way to derive the number - i.e. you divide the RWHP number by .85 to get FWHP. So to get 505 FWHP you need 430 RWHP.

Even with the slight weight advantage of our Z06's - the new model will/should kill one of ours who get to the number with a peaky cam, unless you can get him to race you only between 5000 and 7000 RPM's

Les

zo6vetteman2003

If that is how it is derived, then I'm happy with that. I believe the new C6 Z would be 505hp @ +/-6800rpm. It's the torque from a larger displacement alot earlier that is hard for us to reproduce. In a drag race, or coming out of a corner on the track, that is where it's torque would show up. The C6 ZO6 is running 11's on street tires lol! I surely need M/T's lol! When I end up with 450rwhp on my next two mods., I'll be satisfied with saying I'm done. (ya right)

zo6vetteman2003

We used to do that math when we were calculating the markup from WD to list price as we had to add a certain percentage.

Do the math of adding 15% to the RWHP.

425 * 1.15 = 488.75
425 /.85 = 500

That all being said, you'll need 450-460 RWHP to keep up with a new Z06 if that is your goal. Look at a standard 2002-2004 Z06.

350-360 RWHP in most cases

350 * 1.15 = 402.5
360 * 1.15 = 414
350 / .85 = 411.76
360 / .85 = 423.52

The problem is I don't think you have a solid multiplier that you can use across the board in all cases. IMHO (and I'm not a mechanical engineer) you have a certain ammount of loss through the driveline (say 50HP). But I don't think it continues to grow as HP grows, it may to some extent grow, but I don't think its a linear relationship.

Anyhow, I think 425 RWHP would be a lot of fun, but, you're only looking at peak HP. You're going to need to fatten up that area under the curve if you want to compete with more displacement.[/QUOTE]

I don't think it is a linear relationship either. There are factors involved such as rpm, wheel mass and the force of gravity pushing down on the car, not to mention the heat that is generated and how it reacts with the engine in terms of intake air temperature and combustion. The tuning program really throws another wrench in the works. I do accept the losses 15% for manuals and 20% for A4's. Sounds just like Mercedes came up with those lol!, but is what I've always seen too.

J-Rod

All cleared out

davidp

Here is another twist. I have the LPE 500 HP heads and cam package in my 03 Z. I chose the GT1 cam lift is .631/.631. Before and after dynos are always provided by LPE my RW HP #'s are 431. I included in the set up heavy duty pushrods, corsa x pipe. The install comes with kooks lg tube headers, coyles heavy duty timing chain, heavy duty oil pump, ported throttle body, port matched intake and hurricane air intake plus a 160 thermostat. Also included is a two year warranty. The car passed emissions in Milwaukee County. I have put 8k on since mods were done, no issues. I can drive it in traffic with the AC on and oil temps are about 208 and coolant temps are 178 - 182 on a 95 degree day. I can run in the low to mid 11's all day. The best run was with my brother driving 11.02.
I have gotten as good as 28 mpg and as poor as 15 mpg. The average since the mods we done is 19.8 according to the DIC.
Naturally aspirated is my preference and the idle is great, everyone notices at any traffic signal, I have the stock exhaust.
You have to slip the clutch a bit when leaving but that is very minimal considering how the car visible shakes when it is idiling. My wife has gotton used to it. LPE considers 18% a fair average for drive train loss. So 431X1.18=508 or 431/.82= 525. Take your pick. To me what is important is the overall drivability of the car along with reliability. One last note, this is done with a very conservative tune or emissions would not have been met and I have 0 timing issues.

C5 CU

430rwhp from cam only is not an easy task, especially if you want to keep "true" street manners....I know a few ZO6s with 228/114* cam they tune relatively easily, gives power in the 410-420 range (no cats) and decent TQ. They have not given up much streetability at all. Once cams get much above 230s and 112* some sacrifice of street manners.

Ebbsnflows

Regardless of how the 15% is calculated (.85 vs 1.15), my point of contention is why everyone feels that the amount of parasitic loss INCREASES in direct relation to subsequent HP increases. How does a head and cam swap (or adding headers or a Throttlebody, or an Intake or catback or whatever) result in an increased Parasitic loss?? You're simply allowing the engine (a giant vacuum) to flow and displace more air, resulting in the production of more HP/TQ. With those basic mods, how have you introduced more parastic loss? Your driveshaft doesn't become heavier and more difficult to turn, you're not adding additional accessories/belts, your crank pulley doesn't have higher resistance, your wheels/tires didn't grow and require effort to turn, your A/C compressor doesn't kick on more often, and you made no changes to your transmission (such as a less efficient converter in an Auto car)...so how does a 50 hp loss in stock form suddenly become a 75 hp loss in mildly modified form? Just as an Underdrive pulley or an electric H20 pump doesn't produce HP (it frees up existing hp) adding headers and an air intake doesn't increase parasitic loss.

...and this isn't directed at anyone specifically in this thread It's just that this "across the board" type calculation is something that I read A LOT...and it's something that confuses me. Is there some physics anomaly that exists, that I don't understand (that very well may be the case ) and that a mechanical engineer can explain to me (in simple terms)....Is it a pride/ego thing? Do we just like adding 15% to our 450 rwhp #'s?

robz

Nice set up! Give us some details on the 11.02 run!

AZ99FRC

That is a nice package! What did that run ya?

Mopar Jimmy

Thanks for the input guys but no cam for me as I have decided to get my 02 Z Blown by ECS with an ATI Procharger and alky injectin putting down an easy 560 to the wheels with my stock untouch LS6 motor with bolt ons (and that's detuned as i could get up to 600rwhp if i pushed it a bit but want this setup to last)!!!!!! I AM PUMPED UP!!!!!!!!!!!!

davidp

I was looking for the time slip so I could scan it. My brother has it somewhere. I had nitto D.R. with 21lbs of air. My older brother was driving, warmed the tires dry, not a huge burn out. Launched at 3000rpm. 60' 1.51 1000' 9.16 1/4 11.04(sorry I thought it was 11.02)trap speed was 121. Shift point was 7000.

davidp

Just about $8000.00 I purchased some xtras, LPE coil covers=$399.00
A hand held tuner in case the memory gets flashed. $299.00
I have had 0 problems, fans are reprogrammed to come on at #1@172 #2@180. I am about to change the plugs, LPE recommends 10,000 miles but I think I am going to change them early.
Take Care

Twil1ght

I'm still a little confused about the desire to compete with a new Z. #1, there's no prize money or trophy for getting to work, the store, the mall, etc., faster than someone else. #2 The new Z is about as ugly a car as has ever been made. I for one wouldn't care if it weighed 1900 lbs and had 2000 HP. It's ugly, I won't drive it... period. I'd rather look good in a fast car than look bad in a faster one.

zo6vetteman2003

The new Z will be pretty fast, 3.8sec to 60 in first gear and 11's in the quarter, but can be real bad a$$ with a larger cam. I've gone over the parts list and it's a jewel in quality and go fast parts. I heard from a GM source that did the road testing for the 2001 ZO6, a larger cam will make huge power over stock. For $6000, you could have a Blue Devil by adding a procharger and installing it yourself.
I don't think it is the best looking Vette ever, but with that performance I'm interested. Anyway, any Vette owner will stare long enough at it that it will become attractive. That's the way it works usually lol!