Why such a cam in the GMPP LS376?

[Samckitt]

Got the catalog from Pace Performance Parts today & noticed in there a GMPP LS376, it is GM's hyper aggressive LS3. The cam in it is the "HOT" cam & has lifts of .525" & 219 duration intake & 228 exhaust with 112 lobe centerline. Seems like a VERY mild cam for that, mine in the LT1 is bigger. Now I am not knocking it because I am not making anywhere near the 480 hp that this is advertised at. Why not go with something a little bigger? Maybe a little bigger cam & you can make more HP than that of the LS7, at less than half the price. Maybe that is why, don't want to cut into the sales of the LS7.

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=229270

https://static1.pt-content.com/images/noimg.gif

Me wants one for the Monte. :bananna2:

[subtlez28]

I know a couple guys on here who put stock LS7 cams and car intakes in/on otherwise stock L92 engines. They made 418 hp to the wheels. Assuming the 85% rule that is right in line with GMPP. This route was even cheaper!

I'm sure the mild cam is so you can have reliable, flat power curves. Certainly more power is on tap w a bigger cam (but you always have to give up something).

As far as competing with LS7s... They are also compromised for reliability and low rpm power. 427 vs 376, you are giving up 51 cubic inches. Can you make more power with 376, yes. Can the 427 make much more power w a cam change also... yes. Kind of an apples to oranges comparison.

That said, I agree that the L92/LS3/SS376 is a huge bargain for power! I have an L92 waiting on a stand for that very reason.:cheers:

[Samckitt]

Man I need a second job so I can get on the LSx bandwagon.

The LS3 is the motor in the new Camaro, right?

What is the L92? Is that the HO 6.0L engine in the Cadillac SUVs?

[alowerlevel]

Man I need a second job so I can get on the LSx bandwagon.

The LS3 is the motor in the new Camaro, right?

What is the L92? Is that the HO 6.0L engine in the Cadillac SUVs?

http://en.wikipedia.org/wiki/GM_LS_engine#6.2_L (http://en.wikipedia.org/wiki/GM_LS_engine#6.2_L)

[WS6]

I'm sure the mild cam is so you can have reliable, flat power curves.



This is why right here. Numbers aren't everything. The power/torque curves are what matter. If you think that cam is small, look at the power of any of the factory LS engines and how small their cams are. The power is in the heads.

LS3 is in the manual camaros. autos get the L99.

[Rhino]

Furthering a little bit of info, the difference between the LS3 and the L99 is simply that the L99 has VVT. With a simple cam/lifter change the motors are identical.

[CarlC]

Agreed. The power is in the heads. With a small cam and great airflow management you end up with a nice idle and great power production.

Today's intake port designs may not end up making more quality power than what the factory has spent $millions developing. It's not just mass airflow, but qualiity airflow management.

Another thing to consider. GM performs 300 WOT durability testing for crate engines. How many aftermarket companies do that? There is a lot of power, and peace of mind, in that picture.

[79-TA]

A lot of LS builds like to make power with a lot of lift and not much duration. This seems to follow the same convention.

[ProdigyCustoms]

the cam can be easily bumped up in the low 230s duration and 600 lift in automatics and high 230s / low 240s in manual cars and make 520 and 540 respectively, and still be very streetable

[Samckitt]

Dyno chart from the above LS373 480 engine:

https://static1.pt-content.com/images/noimg.gif

[novaderrik]

Furthering a little bit of info, the difference between the LS3 and the L99 is simply that the L99 has VVT. With a simple cam/lifter change the motors are identical.


i bet that's why the automatic Camaros have a higher mpg rating than the manual Camaros. it has nothing to do with the more efficient shifting of the computer controlled auto and everything to do with the VVT.
i wonder what kind of mileage a stick shift Camaro would get with the addition of the VVT setup? and i wonder why they did it like this...

[Samckitt]

Why not put the VVT engine with the manual trans?

[subtlez28]

Good question! I intend to keep the VVT and go manual TRANS (T56). I won't be the 1st, aftermarket controllers/warnesses (or even GMPP ones) make it possible.

My guess is that the engine management is easier with the auto (both computer controlled). Or maybe a cost saving measure, or protection from the missed shift crowd (warranty issues).

I'd like to hear the answer from a GM insider!

[79-TA]

i bet that's why the automatic Camaros have a higher mpg rating than the manual Camaros. it has nothing to do with the more efficient shifting of the computer controlled auto and everything to do with the VVT.
i wonder what kind of mileage a stick shift Camaro would get with the addition of the VVT setup? and i wonder why they did it like this...

Automatic Camaros come with "active fuel management" which is GM's name for cylinder deactivation. That is, automatic Camaros can cruise on 4 cylinders. This feature is not offered in the manual version as there is no torque converter to soak up the harsh bumps and sudden jerks from the wheels.

[novaderrik]

Automatic Camaros come with "active fuel management" which is GM's name for cylinder deactivation. That is, automatic Camaros can cruise on 4 cylinders. This feature is not offered in the manual version as there is no torque converter to soak up the harsh bumps and sudden jerks from the wheels.

but at steady cruise- where the cylinder deactivation is going to kick in- the torque converter is going to be locked up, which would transmit the shocks thru the driveline just like the clutch of a manual trans. if anything, any driveline shocks would be more noticable in an automatic trans car than a manual trans car because the clutch in a manual trans car has springs to absorb those kinds of shocks that a lockup torque converter doesn't have.
personally, i think it is a part of the drive to get rid of manual transmissions in cars altogether. many high end cars don't have a true manual transmission any more- unless you count the silly buttons or flippers mounted to the steering wheel or automatic transmission shifters that move sideways to give the driver the illusion of manual transmission control- and there is no such thing as a manual transmission in a hybrid or electric car.
put the automatic transmission in the model with the higher fuel economy rating, and people will start to connect automatic transmissions with better fuel economy.
or maybe GM just figured that the people that buy a 420hp car with a manual transmission don't really care about fuel economy anyways.