ls3 vs ls7

[thumper877]

I'm torn between ls3 and ls7. What's the advantages and disadvantages between the two. I know the ls7 is more money but is the return if u sell the car better. This is a high dollar build will all the name brand stuff. Detroit speed subframe,art Morrison 4 link. I have drove lots of ls7 but not to many ls3. I would build the ls3 with comparable hp. The car is mainly street drivin. Mabye a autocross or track day here and there.Thanks

[Schwartz Performance]

Cost is the main con of LS7's.
It's likely the return will not be the same as the cost difference since others will just see it as an LS engine either way.
The other con is packaging.. Since you need a dry sump tank mounted in the engine bay it can take up some space plus you'll need to plumb it.
LS7's are much more capable of power out of the box. We've actually made 730hp out of a stock displacement naturally aspirated LS7.. You can't do that with an LS3.
LS7's have more torque because of the displacement.
They also come with an LS9 oil cooler from GM now, you can remove it if there's not enough room in the subframe or for headers.

If you get an LS7 crate I can help a bit with price if you get it through us.
I would highly recommend putting ARP rod bolts in, as the stock LS (3 or 7) ones are weak.

Peterson makes nice dry sump tanks.. Were a dealer for them too.
If you get more into autocrossing and racing, it may be beneficial to put an Aviaid baffle inside the stock pan if you can use the stock pan in the AM frame.

-Dale

[parsonsj]

What Dale said.

I'd emphasize the dry sump angle: the factory dry sump is barely good enough for the track if you stay with street tires and keep track speeds at "beginner" levels. Once you go to R-comp tires, high end brakes, and driving skills to match, the factory dry sump won't be able to keep up. Of course, the LS3 doesn't even have that.

My point is that if you will spend serious time and money on a road course, you need to upgrade the factory dry sump on the LS7. If, as you say, you're just building a cruiser, then the LS3 makes the most sense. You can skip all the dry sump complexity of the LS7.

[thumper877]

thanks dale and john dale if u can u can pm me some prices thanks

[Schwartz Performance]

If you wouldn't mind emailing me [email protected] that'd help me remember

Also, we've run an Ls7 dry sump on our 65 Tempest shop car for 6 years and have not had any issues.. And that car gets abused! We use a 2 gallon tank and the baffle I mentioned.

[Revmax]

I'll just quickly throw in my 2 cents. I'd go with the LS7. If you're doing a high dollar build I think an LS7 sells the price of the vehicle more than an LS3 powertrain. If people are spending high dollars generally they are a little in the know of what's what. All I'm saying is open the hood and show me a dry sump LS7 in the bay instead of an LS3 and I'd be more willing to give you you're asking price for the vehicle.

[Decline]

LS7 is certainly more exoctic if its a no holds barred build
I read somewhere the opinion that LS7s will be collectors items because according to where ever i read it that GM can't built a large displacement car engine anymore because of emissions.. Not sure I buy that angle
The new Z06 LT4 has overheating problems at the track and LS7 is discontinued so the last gen C6 z06 may go up in value as well as LS7 engines.
*EDIT:apparently the new ATS-V+ will pack an LS7 under the hood..This car has now just shot to the top of my want list if it turns out to be true
http://wot.motortrend.com/1505_cadil...ls7_power.html

[Revmax]

*EDIT:apparently the new ATS-V+ will pack an LS7 under the hood..This car has now just shot to the top of my want list if it turns out to be true
http://wot.motortrend.com/1505_cadil...ls7_power.html

This would be news to me. Cause it's almost time for the ATS-V to start showing up at showrooms and as far as I've been told it's suppose to be powered by twin turbo v6 producing around 430hp.

[Blevinator]

Supercharged LS3 is a great option.
You can get more power and much better driveability with this set up vs a built LS7.
Better fuel economy as well.
Car will drive like stock but have the power when you need it. Cost will be the same or less than a built LS7.
You will also have much more hp capability than a built non boosted LS7 setup.
With a centrifugal SC setup you can be well over the 800 mark with stock driveability.
We all know LS3's are better suited for boost as well. You an boost an LS7 but gets to be cost prohibitive.
I have seen stock bottom end LS3 setups pushing 650 RWHP with no issues.

I am installing a supercharged flex fuel setup in my 68 Camaro.

E85 will make for cooler Intake air temps which will reduce heat soak.
Also will make for a much safer tune.

I will also add a meth injection set up if needed
to bring the intake air temps down when using 93 octane fuel.

That being said you don't see as many LS7 high end builds

I just think that a high hp car with stock driveability and reliability makes the most sense
to future buyers spending that much coin

[parsonsj]

The new Z06 LT4 has overheating problems at the track and LS7 is discontinued so the last gen C6 z06 may go up in value as well as LS7 engines.

Factory LS7s overheat at the track too. It takes a significant investment to get a C6 Z06 to have manageable temps. I know several folks (myself included) who have custom hoods, aftermarket radiators, aftermarket oil coolers, and custom transmission and diff coolers just to get a 30 minute HPDE session in.

I was out at Daytona last fall, and got a kick out of the C7 guys coming in after 15 minutes with oil temps north of 300*. Talk about some pissed off guys!

[sheck44]

How about a 'Supercharged' LS7 ... (8

[70camaro406]

This would be news to me. Cause it's almost time for the ATS-V to start showing up at showrooms and as far as I've been told it's suppose to be powered by twin turbo v6 producing around 430hp.

The ATS-V is going to have 464 hp, and the newly announced "ATS-V Plus" is the one getting the LS7....so I've heard.

[Blevinator]

How about a 'Supercharged' LS7 ... (8

Awesome!!!!
What did that set you back?
Built the motor?

[sheck44]

Thanks !!
Dasilva Motorsports in Kitchener Ontario built and installed the motor
As far as $$ ... Too much, but that said I got a great deal from Dasilva on the 'built' forged LS7, and got lucky on finding the E Force supercharger from a guy on the Vette forums for half price. If you had to pay full pop for everything it would be waaaaay too expensive, and the LS3 route would definitely be the way to go.

Cheers
Steve

[parsonsj]

How about a 'Supercharged' LS7?

Nice. How did you do your oil tank?

[CarlC]

What jp said.

That is part of a build equation that many do not take into account when building a dual purpose car. For a car making big horsepower be ready to spend $4-5k+ on heat exchangers and a similar amount on a fuel system that will support those needs on a very warm 20+ minute track session day.

[sheck44]

John
Dasilva converted the dry sump to a wet sump system using a Holley oil pan system ... exactly how I'm not sure and yes also running a separate oil cooler and of course the supercharger heat exchanger
Also this is a show/street car so no tracking for this car....

Cheers
Steve

[killer69]

Factory LS7s overheat at the track too. It takes a significant investment to get a C6 Z06 to have manageable temps. I know several folks (myself included) who have custom hoods, aftermarket radiators, aftermarket oil coolers, and custom transmission and diff coolers just to get a 30 minute HPDE session in.

I was out at Daytona last fall, and got a kick out of the C7 guys coming in after 15 minutes with oil temps north of 300*. Talk about some pissed off guys!

Damn!! what do you want for 95K. ??? it's supposed to ba a super car at 1/2 the price I guess they left some room for upgrades.