offshore241

Are the factory horspower claims rated from the crank or RWHP ?

LS2 400

LS3 430

LS7 505

Anyone ever test a bone stock car to see what numbers they produce ?

How much extra should a Pro Charger really add with a moderate tune? I've heard some numbers but there all over the place.

FastestBusaAround

These are crank HP ratings, not RW. I'm not sure where your numbers come from other than the LS7, as the LS3 is rated @436 for the 2008+, not 403...

The BreeZe

The factory number is rated at the flywheel. The RWHP is about 85% of the rated crank horsepower.

A stock Z06 should be about 430 HP at the RW.

They call me the BreeZe

RichieRichZ06

I have seen many stock LS7's put down 460+RWHP (SAE Corrected) which is roughly 520 HP or so. Our Z06 did 464 bone stock. I would not be suprised if they were slightly under rated just so they did not disappoint, like the early Mustang Cobras.

offshore241

I am looking at a Pro charged vette. Dyno sheet said 485 RWHP. So a stock LS 2 should be around 340 RWHP based on the 15% ?? Thought the car should have been faster then it felt

HP ADDICT

In my experiance supercharged cars feel slower then a similar rwhp NA car. Usually reflected in 1/4 mile times also. A 500rwhp NA car will generally be faster then a 500rwhp FI car. There are always exceptions but I find this to generally be the case.

2k Cobra

Tell me about the Cobras!

camarodoctor

If you use a properly calibrated engine dyno and randomly test 100 LS7 engines, I bet 99 of them would be between 502 and 508 hp and one would be 509 hp. There are no "strong" engines or factory freaks. Stock tuning with 93 octane gas will produce 505 hp. If your 100% stock car makes 460-470 rwhp on a chassis dyno, then you should be more suspicious of the dyno before making claims that you have a factory freak.

Chassis dynos introduce too many factors into the equation. It's like using 1/4 mile MPH to calculate engine HP. Too many factors from 100's of tracks and cars. I've heard of people run 126-127 mph stock and I've seen people run 120-121 mph on the same day, same track.

Until someone shows me several stock LS7 engine dyno pulls making less than 500 hp or making more than 510 hp, I will still be a true believer in the factory rating of 505 hp SAE.

...but I defer to Katech and other tuners with lots of engine dyno time.

Lucifer13

I put my '09 Z on a "dynojet" dyno just for fun. Only mod is Borla Stingers. 448 rwhp and 412 ft/lb torque. This is pretty consistent with other stock engines I've seen on here.

haljensen

New SAE terms for "Factory" Advertized Flywheel HP allows for either a plus or minus 1% or 2% variation (Depends on which source you believe).

Z06 = Advertized 505HP
505 + 1% = 510
505 - 1% = 500

505 + 2% = 515
505 - 2% = 495

So; Factory advertized could be legal from 495 to 515 Flywheel.

Any more variation and I'm sure that Ford and/or another manufacturer would be screaming fraud.

Since most honest (not by a Vendor trying to sell you something) Dynojet 248 SAE corrected, smoothing 3 numbers are around 450 RWHP I'd say the 1% variation is close to correct.

stabori

Katech has answered this a few times already. Every engine they have tested on an engine dyno was within factory spec.... no freaks.

50 4Ever

The standard LS3 is rated at 430, add the optional NPP exhaust and it goes up to 436.

glass slipper

The 1% and 2% numbers are both correct, however they each refer to different parts of the SAE J2723 procedure. SAE J2723 is the certification procedure while SAE J1349 and SAE J1995 are the engine testing procedures where SAE J1349 is used for net HP/torque ratings and SAE J1995 is used for gross HP/torque ratings. Obviously, SAE J1349 is used today for all cars sold in the US and sets the standards of testing in reference to engine coolant temps, intake air temps, absolute pressure, humidity, etc. SAE J1349 was changed in '04 to provide more strict testing ranges because a lot of car companies were "playing loose" with the rules to inflate their HP numbers. SAE J2723 requires witnesses to certify the HP/torque readings were done within strict adherence to SAE J1349 procedures and all engines submitted for testing have to be within 1% of rated HP/torque. All production engines can be within 2% of rated HP/torque and that is where the confusion usually comes from.

http://www.sae.org/certifiedpower/brochure.pdf

If you want to read more details, you can buy any of the SAE procedures above here:
http://www.sae.org/certifiedpower/details.htm
It takes a very sophisticated engine dyno and facility to perform these tests which is why it always amuses me when people try to equate a chassis dyno number done in Joe's garage to a flywheel HP number in an attempt to compare it to the factory HP rating. I wish I could post all of the procedures above online so others would see what an exercise in futility that is. Even though the chassis dyno number can be corrected back to SAE, the test conditions (ambient and engine parameters) on the chassis dyno are all over the place.


The LS7 was the first engine to go through the new certification procedure in '05 and GM was going to rate the engine at 500 HP before it was put through SAE J2723...that should tell you a little about which way the numbers are skewed even though they can be between 495 and 515 HP in production as you pointed out above. Simple math tells you there were a lot of engines submitted for testing that were in excess of 505 HP but less than 510 HP which goes along with what Katech says...the engines they test are in the 506-508 HP range.

All engines GM put through SAE J2723 had small increases in their HP ratings while a lot of Japanese engines saw decreases of 10% or more...I wonder who was "playing loose" with the rules.

'06 Quicksilver Z06

Well put.

spdmn75

Most LS motors pick up a little power after a couple thousand miles also

haljensen

Makes me wonder about some of the other Forum Vendors that always Dyno higher than anyone else and always have the only Factory Freak motors.

4+ years of seeing Dynojet 248 postings here and most are;

Stock LS2, M6 = 340-345, A4/A6 = 330-335

Stock LS3 w/NPP, M6 = 380-385, A6 = 370-375

Stock Z06, 450-455

My '05 M6 was in this range on 3 different Dynojets, my '08 A6/NPP was in this range on a different Dynojet.

NORTY

Here's my 100% stock LS7, with a modified dyno!



Question: If I used a "special" fuel, would it still be considered "stock?"

Another question: If I used special lubricants in the engine,trans & diff, would that be considered a modification?

'06 Quicksilver Z06

These are STD numbers, as opposed to SAE, right?

andy82

Min '07 was tested ~470 RWHP before with just a high flow filter before I did any bolt ons. Of course that also depends on the dyno used

1.8t

My 08 dyno'ed @ 478whp/446wtq with a Killer Bee CAI and a 160t-stat. On this same dyno, my old LS3 Coupe dyno'ed at 385whp/378wtq(it was a 6spd).