GM LS3 LS376/525 Crate Motor - Page 3 - LS1TECH - Camaro and Firebird Forum Discussion

Notices
Dynamometer Results & Comparisons Dyno Records | Dyno Discussion | Dyno Wars

GM LS3 LS376/525 Crate Motor

 
Old 08-09-2018, 07:41 PM
  #41  
10 Second Club
iTrader: (7)
 
HioSSilver's Avatar
 
Join Date: Aug 2002
Location: Winchester, VA
Posts: 4,917
Default

That's a cool set up. I love irs
HioSSilver is offline  
Old 08-09-2018, 09:25 PM
  #42  
TECH Enthusiast
 
eb110americana's Avatar
 
Join Date: Jun 2008
Location: South Pasadena, CA
Posts: 693
Default

Originally Posted by lees02WS6 View Post
Wouldn't a 15% loss equated to around 460? I was figuring on 18%.
At 18%, 416 WHP would equate to 507 HP at the crank. Do you have a dyno graph of the 416 run?
eb110americana is offline  
Old 08-09-2018, 10:15 PM
  #43  
TECH Fanatic
iTrader: (5)
 
lees02WS6's Avatar
 
Join Date: Mar 2004
Location: Lansdale, PA
Posts: 1,344
Default




Last edited by lees02WS6; 09-08-2018 at 10:31 PM.
lees02WS6 is offline  
Old 10-07-2018, 11:31 PM
  #44  
Teching In
 
rdymond's Avatar
 
Join Date: Jun 2017
Location: Calgary AB
Posts: 16
Default

Having installed the LS376 525 in a 996 and dyno'd it on two separate occasions, I can confirm that the 525 hp number is GM fiction. The GM LS376 525 hp output number is crank hp with no water pump, alternator, power steering pump, or AC pump. It is with a straight pipe exhaust little to no back pressure, and of course there is no transmission losses.

First dyno run: 92F in the shop, intake air temp hitting 160-170F. 280 hp max with very late timing due to air temps.
- Added a big fan to the rear deck lid that had been deleted during the swap. intake air temps dropped to +10-15F above ambient.
- Deleted the CATs

Second Dyno run, with a big fan pointed at the intake to better simulate a moving vehicle. 75F in shop and air intakes +10-15F. Max output was 346 wrhp. The car has a twin turbo 6 speed manual transaxle. Front cardan shaft (drive shaft) for the AWD was removed for the tests so all power was RWD.

Same motor, different car: A SLC Superlite coupe on the same dyno with $3k+ custom titanium exhaust, a TT transmission and much better air intake design than in the 996 produced 350 wrhp. The reality is GM performance is selling BS numbers on their crate engines.

Dyno shop: http://tecmotion.ca/


Show lessREPLY
rdymond is offline  
Old 10-07-2018, 11:44 PM
  #45  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 8,993
Default

The cam in that engine only has .525" lift. Any cam nowadays with the duration of that cam would have at least .600" lift. The ONLY difference between the 525, 480, and OEM 430HP LS3 is the cam. THAT'S IT. I've always thought you would be better to get the 430HP LS3 and put an up-to-date cam in it for way better results.
G Atsma is offline  
Old 10-08-2018, 12:09 AM
  #46  
Teching In
 
rdymond's Avatar
 
Join Date: Jun 2017
Location: Calgary AB
Posts: 16
Default

I seriously wonder if the LS376 525 engine is the same as the LS3 in the 2014-2015 Camaro SS. Here is a dyno pull of a 2014 Camaro SS pulling 380 rwhp.

Below is the dyno chart from a 2015 Camaro SS seen here on the dyno producing 367 rwhp at the wheels. The pull is here:
If dynos vary by up to 10% then that might explain some of the differences. My 996 dyno discussed above was done at 75-80F and 3000 ft. elevation.

rdymond is offline  
Old 10-08-2018, 12:50 AM
  #47  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 8,993
Default

The 525 is NOT the engine that came in the 2014-15 Camaro SS. This engine idles with a VERY pronounced lope that would never pass emissions in any modern country. If you heard it you would never think it was original in the Camaro.
The above dyno tests were of the standard 430 FWHP LS3 with possible mods.
G Atsma is offline  
Old 10-08-2018, 02:15 AM
  #48  
Teching In
 
rdymond's Avatar
 
Join Date: Jun 2017
Location: Calgary AB
Posts: 16
Default

Originally Posted by G Atsma View Post
The 525 is NOT the engine that came in the 2014-15 Camaro SS. This engine idles with a VERY pronounced lope that would never pass emissions in any modern country. If you heard it you would never think it was original in the Camaro.
The above dyno tests were of the standard 430 FWHP LS3 with possible mods.
So you have demonstrable proof that an LS525 would not pass emissions?

You also have proof that the SS Camaro is running the standard 430 LS3?
rdymond is offline  
Old 10-08-2018, 03:02 AM
  #49  
Teching In
 
rdymond's Avatar
 
Join Date: Jun 2017
Location: Calgary AB
Posts: 16
Default

Originally Posted by G Atsma View Post
The cam in that engine only has .525" lift. Any cam nowadays with the duration of that cam would have at least .600" lift. The ONLY difference between the 525, 480, and OEM 430HP LS3 is the cam. THAT'S IT. I've always thought you would be better to get the 430HP LS3 and put an up-to-date cam in it for way better results.
So the cam doesn't have enough lift, or it has too much lift? Seems you make one point in one message and the opposite in another.

Also you may be unaware of GM's warranty policy. If you buy a new crate a change ANY part of the internals, your warranty on the engine is void.
Here are the LS3 525 CAM specs:
  • Camshaft Type (P/N 88958770): Hydraulic roller
  • Valve Lift (in.): 0.525 intake / 0.525 exhaust
  • Camshaft Duration (@0.050 in.): 226 intake / 236 exhaust
and according to the web site: "The ASA camshaft is a hydraulic roller with .525-inch lift on both sides, along with 226 degrees duration on the intake side and 236 degrees on the exhaust side. And for durability, we complement the cam with higher-rate valve springs." https://www.chevrolet.com/performanc...ines/ls376-525

So after reading the great LS3 camshaft comparison http://www.superchevy.com/how-to/eng...ft-comparison/
and reviewing many articles on camshafts and other performance build topics, I did the math:
Cost for the stock LS3 430
Cost for Lingenfelter, lunati or comp cams replacement cam, springs, and possibly valve work if ingress is too high.
Cost to install and test
Cost of void warranty.
Adding up the additional costs to the stock motor, I would spend a little less than 525 cost around $500, but not have a 2 year warranty on an expensive swap that already has had an LS3 430 that failed and had to be replaced. So after doing my homework the decision was clear, get the LS376 525 with GM's performance CAM and the 2 year warranty and reduce the risk of screw ups while leaving some top and performance on the table.

Having driven the LS376 525 a small amount, I think sucked before the tune and was perfectly fine after getting it tuned. I will report more later once the last bits are completed and can get the first 500 mi on it.

GM has priced the LS376 525 very well compared to buying the LS3 430 and upgrading it. Buyers are paying a premium for the upgraded performance while still getting to keep the warranty.
rdymond is offline  
Old 10-08-2018, 07:58 AM
  #50  
12 Second Club
 
Utinator's Avatar
 
Join Date: Dec 2017
Location: San Antonio
Posts: 259
Default

Originally Posted by rdymond View Post

You also have proof that the SS Camaro is running the standard 430 LS3?
The Gen. 5 SS Camaro actually came with the L99, which is mostly the same as the LS3. I'm not sure what they call the 6.2L engine that they are putting in the Gen. 6, but it has a little more hp.

Utinator is offline  
Old 10-08-2018, 09:39 AM
  #51  
TECH Fanatic
iTrader: (5)
 
lees02WS6's Avatar
 
Join Date: Mar 2004
Location: Lansdale, PA
Posts: 1,344
Default

I'm going to add long tubes and rework the exhaust, starting the work in November. We'll see how much that changes the power output. I'm adding a pair of 22" resonators, and moving the magnaflow mufflers to the rear just ahead of the tips, keeping the cats.

lees02WS6 is offline  
Old 10-08-2018, 11:48 AM
  #52  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 8,993
Default

Originally Posted by rdymond View Post
So you have demonstrable proof that an LS525 would not pass emissions?

You also have proof that the SS Camaro is running the standard 430 LS3?
The Camaro SS with manual transmission came with the LS3. Those with automatics came with the L99. That is a matter of record, which is demonstrable proof.
The difference is the LS3 does not have DOD or VSS, and the L99 has both, along with 400 HP instead of 430.
Anything that idles as roughly as the 525 does would not pass a sniff test. Too many unburned HC's. Rough idle indicates intermittent misfire. Comes with the territory of a radical cam.
The lift on that cam is much lower than most cams of that duration. Most cams in that area have close to or over .600" lift.
G Atsma is offline  
Old 10-08-2018, 11:56 AM
  #53  
TECH Fanatic
iTrader: (5)
 
lees02WS6's Avatar
 
Join Date: Mar 2004
Location: Lansdale, PA
Posts: 1,344
Default

Originally Posted by G Atsma View Post
Anything that idles as roughly as the 525 does would not pass a sniff test. Too many unburned HC's. Rough idle indicates intermittent misfire. Comes with the territory of a radical cam.
I can vouch for this. The CARB ****'s could probably smell, and see the soot, from the exhaust from 3000 miles away. It must be hell for drivers behind me. It can certainly be heard from far away. No gen V or VI stock camaro of any stripe (z/28, SS, ZL1) sounds any where near this in your face, and I say that with envy of a more subtle exhaust note.
lees02WS6 is offline  
Old 10-08-2018, 12:01 PM
  #54  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 8,993
Default

I actually do NOT consider the ASA cam a street-worthy cam. Way too rough.
G Atsma is offline  
Old 10-08-2018, 12:41 PM
  #55  
TECH Fanatic
iTrader: (8)
 
Join Date: Sep 2005
Location: MD
Posts: 1,389
Default

Originally Posted by rdymond View Post
Having installed the LS376 525 in a 996 and dyno'd it on two separate occasions, I can confirm that the 525 hp number is GM fiction. The GM LS376 525 hp output number is crank hp with no water pump, alternator, power steering pump, or AC pump. It is with a straight pipe exhaust little to no back pressure, and of course there is no transmission losses.
Wrong.

Originally Posted by rdymond View Post
I seriously wonder if the LS376 525 engine is the same as the LS3 in the 2014-2015 Camaro SS.
No.

Originally Posted by rdymond
Below is the dyno chart from a 2015 Camaro SS seen here on the dyno producing 367 rwhp at the wheels. The pull is here: https://www.youtube.com/watch?v=OtuX9Gf3mB0
That's not an LS3, it's an L99.

Originally Posted by rdymond View Post
So you have demonstrable proof that an LS525 would not pass emissions?

You also have proof that the SS Camaro is running the standard 430 LS3?
He doesn't need to prove a thing. If you're capable of buying a GM crate engine, those answers have already been provided to you.

Either your dyno reads really low, your swaps are garbage, or you have tuner problems. The fault isn't in the engine.

Last edited by Marc 85Z28; 10-08-2018 at 12:58 PM.
Marc 85Z28 is offline  
Old 10-08-2018, 08:08 PM
  #56  
TECH Fanatic
iTrader: (7)
 
Join Date: Apr 2013
Location: S.A., TX
Posts: 1,760
Default

Originally Posted by rdymond View Post
…...You also have proof that the SS Camaro is running the standard 430 LS3?
Seriously dude?

All F-bodies from the factory that had a LS3 came with a 430HP LS3......to include the Camaro SS.

KW

Last edited by KW Baraka; 10-09-2018 at 09:56 AM.
KW Baraka is offline  
Old 10-08-2018, 08:41 PM
  #57  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 8,993
Default

OP is starting to sound WAY too much like a lawyer... lol
G Atsma is offline  
Old 10-10-2018, 12:27 AM
  #58  
10 Second Club
 
big hammer's Avatar
 
Join Date: May 2009
Location: over dere
Posts: 3,090
Default

The difference between the regular ls3 and the 525 is really only around 35-40 hp. The 430 rating of the regular ls3 is net hp and the 525 hp rating for the crate engine is gross.

run the regular ls3 in the same gross conditions and it’ll be in the 470-485 range
big hammer is offline  
Old 10-10-2018, 10:03 AM
  #59  
TECH Fanatic
iTrader: (8)
 
Join Date: Sep 2005
Location: MD
Posts: 1,389
Default

Originally Posted by big hammer View Post
The difference between the regular ls3 and the 525 is really only around 35-40 hp. The 430 rating of the regular ls3 is net hp and the 525 hp rating for the crate engine is gross.

run the regular ls3 in the same gross conditions and it’ll be in the 470-485 range
Incorrect.

https://ls1tech.com/forums/dynamomet...l#post19510295
Marc 85Z28 is offline  
Old 10-11-2018, 09:27 PM
  #60  
10 Second Club
 
big hammer's Avatar
 
Join Date: May 2009
Location: over dere
Posts: 3,090
Default

Originally Posted by Marc 85Z28 View Post


no im correct. The 525 is not an SAE net rating.
big hammer is offline  

Thread Tools
Search this Thread
Quick Reply: GM LS3 LS376/525 Crate Motor


About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: