LS7 or LSA?

Tech discussions on the L77 6.0L V8.
Post Reply
User avatar
eagle-co94
Posts: 306
Joined: Fri Oct 04, 2013 4:47 pm
Location: Bloomington, Indiana

LS7 or LSA?

Post by eagle-co94 »

I'm on the fence about which way I'd like to go with my 9C3's locked up motor. My wife may be driving the car initially as her '05 V has developed a nasty diff whine and the car has a rebuilt title already (Hurricane Sandy). Her car is the LS6 with Volant intake, Stainless works longtubes and a Magnaflow cat-back on a stock tune. She's not happy about it being an automatic but wants it to have "GTFO of my way" power if she's losing the V. :lol:

I'm curious what everyone else's thoughts are on this. In the Camaro it looks like both motors get within 1mpg of the other at 14 city, 18 highway on an automatic. The CTS-V gets the same mileage with the LSA. I'm more concerned about smiles per gallon than miles per gallon though.
-James . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Life without knowledge is death in disguise."
Navy Lifer
Administration Staff
Posts: 1724
Joined: Tue Mar 19, 2013 6:30 pm
Location: Canton GA

Re: LS7 or LSA?

Post by Navy Lifer »

James, in conversation with "Kiwi", the guy at Hendrick Motorsports who has been driving their Caprice LS7 conversion, the car gets terrible fuel economy. You can re-tune the engine, but it's not a given that you can get results that are acceptable in the process. Of course, his driving of the car is mostly limited to back & forth from home to work, a very short distance--but he did say "it's bad".

I think, from a performance-to-cost standpoint, unless you're totally hooked on the adrenaline-rush power of 500+ HP, the investment in that on a salvage-title car is risky. Find a good low-mile LS3, freshen it, use a good cam & tune, maybe put in a 3.45 axle, and enjoy the results. Less total invested, less complicated change, good reliability, and big smiles when you want them--there is no guarantee that the greater effort & investment with LSA or LS7 will do any better.

Another thing you've got to consider, if you haven't already, is that the higher HP options will demand brake, suspension and wheel/tire upgrades to take advantage of the expanded performance envelope as well as a matter of safety, so that needs to be figured into the mix. Not that a warmed-up LS3 would not, but not so much an absolute necessity from the front end of the project.

Link to more/pictures: http://www.ssforums.com/forum/393002-post6.html" onclick="window.open(this.href);return false;
User avatar
eagle-co94
Posts: 306
Joined: Fri Oct 04, 2013 4:47 pm
Location: Bloomington, Indiana

Re: LS7 or LSA?

Post by eagle-co94 »

Thanks for the advice. I've got a set of V2 wheels here already and will be lowering the car as well. I've got the set of V1 brakes from my wife's car that will eventually go onto the 9C3 unless I use the brakes from whichever car I end up going with, be it a GXP, SS or Camaro. My first plan was to just get an LS3 Camaro SS and use the motor, diff and possibly brakes and seats but since I sold my DeLorean it gave me the budget to dream. I keep watching the auctions and have seen several ZL1's and CTS-V's go by that are in the range of acceptable pricing. An LS7 sounds nice but I'll end up with the rest of the car that I can't use. I like the idea of a 427 but I'm more inclined to go LSA if I can't get an LS3 car for a nice price. With my 70 mile commute that's mostly highway I've already decided that an L77 or L99 will have little benefit as DoD won't kick in much down here.

I'm not hooked on the rush of 500+ hp yet...but the 400+ of the V1 has left my wife and I wanting more. ;)
-James . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Life without knowledge is death in disguise."
User avatar
eagle-co94
Posts: 306
Joined: Fri Oct 04, 2013 4:47 pm
Location: Bloomington, Indiana

Re: LS7 or LSA?

Post by eagle-co94 »

I'm going to venture that he's probably getting around 10mpg in that car then. The weights listed for the CTS-V and PPV are almost identical so those numbers should be more accurate. I checked and saw that the Z06 weighs about 1000lbs less than the V or ZL1 while getting around the same mileage so an LSA is probably a more economical route between the two while putting down more power. Looks like I need to do a test drive. I'm going to yank my motor this week so I'll get a chance to see what's going on inside and why it won't turn over.
-James . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Life without knowledge is death in disguise."
Navy Lifer
Administration Staff
Posts: 1724
Joined: Tue Mar 19, 2013 6:30 pm
Location: Canton GA

Re: LS7 or LSA?

Post by Navy Lifer »

speaking of DeLorean's, got a kick out of the new "Lost in Transmission" show with Rutledge Wood, which featured the DeLorean--lots of less-than-serious banter, and a huge gloss-over of the actual work done to make a running car out of a rust bucket (replaced the ratted out car with another)....the problem is Rutledge may be a "car guy" but he's not a mechanic/fabricator, so the best he can do is the attempt to be funny/stupid (and hope that it's entertaining).

Back on topic....
9C1fanatic
Posts: 430
Joined: Tue Dec 30, 2014 8:58 pm
Location: Texas Hill Country

Re: LS7 or LSA?

Post by 9C1fanatic »

I can verify LS3 potential based on working on a close friends 13 Camaro 1LE, is that his car was rated at 436 HP (I believe) with the optional NPP exhaust. After installing American Racing headers, American racing x pipe, K&N cold air intake, and keeping the stock axle backs, the car delivered a surprising,

430 HP to the rear wheels, 501 at the crank all with a stock LS3 and some bolt ones.

That number includes the tune installed by Henderson Performance. Really amazing potential there, of course I would argue that although the L77 is not as powerful in factory form, the untapped potential may be higher since its detuned and choked down so bad from the get go in this application.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
User avatar
eagle-co94
Posts: 306
Joined: Fri Oct 04, 2013 4:47 pm
Location: Bloomington, Indiana

Re: LS7 or LSA?

Post by eagle-co94 »

I've heard pretty good things about the LS3 as well but I figured if I have the chance to go big I might as well take it. We'll see what ends up happening. I'm watching multiple vehicles right now. I finally pulled the LS7 cars from my list so that helps narrow the search a tiny bit.
-James . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Life without knowledge is death in disguise."
Post Reply