Mod the LSA or Sell It And Replace with Supercharged LS7 ???

[BiggFoot]

Ladies and Gents,

Here is where I am struggling and I will need to make a decision fairly soon. I am currently considering two choices and I would like your opinions please along with any supporting information to back your stance:

Turn the LSA into a 417 Stroker with GT-9 or GT-11 cam, forged pistons, 2300 maggie, 10/14 rib pulley upgrade cranking about 750 hp.

OR

Sell the stock 580 HP LSA engine for about $12K and replace with an LS7 block, LS9 heads, forged pistons, GT-9 cam, 10/14 rib pulley upgrade, headers, cranking about 775 HP.

So what do you guys say???

[91Z28350]

LS7 is a great motor, but if you are going to go with a 427, I have heard the RHS block has thicker cylinder walls and holds up to boost better. There is a reason why GM went with the 6.2 in the ZR1!

One more point, myself, I like the whipple, great whine and from what I have read and seen, the 2.9L Whipple seems to make = or more HP at lower boost and lower IAT, for about the same cost.

[Mr. Wyndham]

LS7 block doesn't like boost...very thin cylinder walls to manage that 427ci volume...

[IOMZL1]

Originally Posted by Dragoneye

LS7 block doesn't like boost...very thin cylinder walls to manage that 427ci volume...

This. And the first post too.

[Mr. Wyndham]

Wouldn't the first option be a little less expensive, too?

[radz28]

LS7 block is relatively expensive. Stroke LSA and call it a day, after your cam ans SC. How much power anyways? Maybe you could get by with rods and pistons on LSA. Same heads as LS9...

[91Z28350]

My understanding also is the LSA block has additional reinforcement in the block over the LS3/LS9 block, though I do not know that for fact, I seem to remember reading it in the description of the LSA motor. If you are going for increased boost, forge the LSA, get a larger twin screw blower or TT and have at it!

[GM4lyfe]

All Al 6.2's should be the same. After the LS9 came out the LS3 got updated to the new casting.

[GM4lyfe]

Originally Posted by BiggFoot

Ladies and Gents,

Here is where I am struggling and I will need to make a decision fairly soon. I am currently considering two choices and I would like your opinions please along with any supporting information to back your stance:

Turn the LSA into a 417 Stroker with GT-9 or GT-11 cam, forged pistons, 2300 maggie, 10/14 rib pulley upgrade cranking about 750 hp.

OR

Sell the stock 580 HP LSA engine for about $12K and replace with an LS7 block, LS9 heads, forged pistons, GT-9 cam, 10/14 rib pulley upgrade, headers, cranking about 775 HP.

So what do you guys say???

A cheaper option:
Pulley down the stock s/c
Forge pistons, rods
Cam
Tune
Headers
See where that will put ya.

Stock s/c not good enough go with the LS9 s/c. They do it for the CTS-V.

So far what has been offered to the LSA/LS9 is s/c aftermarket inlets and larger heat exchangers net great results.

[Milk 1027]

You can get that much horsepower out of the LSA without spending as much money.

[GEEo]

Originally Posted by Milk 1027

You can get that much horsepower out of the LSA without spending as much money.

+1

[payne.jeremy82]

Lingenfelter is where im going 700+hp at the crank Lingenfelter is the choice for me

[DGthe3]

There are better options than the LS7 if you want to swap in a supercharged engine.

Originally Posted by payne.jeremy82

http://www.lingenfelter.com/engine-p...charged-engine-
This is where im going 700+hp at the crank Lingenfelter is the choice for me

I just lost a little respect for Lingenfelter after looking at that URL (link is broken by the way). Someone over there needs to be told that the LS3/L99/LSA/LS9 engines are not 378 cubic inches, because they're not exactly 6.2L ... they're 6.162L, which works out to 376 cubes. I thought they'd be better than that.

[a_Username]

Originally Posted by DGthe3

There are better options than the LS7 if you want to swap in a supercharged engine.
I just lost a little respect for Lingenfelter after looking at that URL (link is broken by the way). Someone over there needs to be told that the LS3/L99/LSA/LS9 engines are not 378 cubic inches, because they're not exactly 6.2L ... they're 6.162L, which works out to 376 cubes. I thought they'd be better than that.

Apparently they listened to ya... I just got "page not found."

[DietCoke]

Stroking a boosted motor is an exercise in futility. You're limited by what the boost device pushes into the motor, not by the motor itself.

[91Z28350]

2.9L doesn't limit it! Just saying And for that matter, I think you would be good with the 2.3 up to 750-800, at least ADM, SLP, Lingenfelter, Hennessey (and other tuners I missed) seem to think so.

[BiggFoot]

All great comments gentlemen, and taken under advisement. In my gut I felt like keeping the LSA would probably be the best route to take as I understand that it is basically a detuned LS9 which upgrading the supercharger and forging the bottom end can easily fix. As one of you pointed out, modding the LSA would be cheaper in the long run VS relpacing with the LS7, but you must admit there is something a bit sexy with saying you have a 427 sitting under the hood

I really dont know much about all of this engine detail stuff, that is why I am asking. The little bit I have picked up just by asking questions is just enough to be dangerous, but I have never owned a muscle car and I would rather shell out the bucks to get it right the first time instead of continually going back to add this or that later on.

One of you stated that stroking doesnt necessarily add HP and that could be true. But since I am having the bottom end forged I may as well, right? I understand it does improve torque, but someone (possibly Ted Jannety) stated that you gain about 1 hp for each cui added so going from 376 to 416/417 would add about 40 hp and a bunch of torque so I am told.

[djsnoflake]

Why not Sell the LSA and buy an LS9?

Pretty good starter motor. You could mod after if you still felt the need.

Although if you have never owned a muscle car, you should try renting an SS and see what you think. That might be more than enough car for you.

[radz28]

Originally Posted by 91Z28350

My understanding also is the LSA block has additional reinforcement in the block over the LS3/LS9 block, though I do not know that for fact, I seem to remember reading it in the description of the LSA motor. If you are going for increased boost, forge the LSA, get a larger twin screw blower or TT and have at it!

As pointed out in later posts, I believe the blocks are now the same, since LS9/LSA came out. The only differences now, are steel caps in LS9, while LS9/LSA share the honing proceedure. I believe the cylinder walls in LS7 are also a different metal casting, and the way they're anchored into the block itself doesn't really lend as well to boost as opposed to most of the rest of the aluminum LS-blocks. I was thinking the heat treating on LS9/LSA were of higher standards (T-319 or something...), but I can't verify LS3 blocks are any different...

Originally Posted by 91Z28350

2.9L doesn't limit it! Just saying And for that matter, I think you would be good with the 2.3 up to 750-800, at least ADM, SLP, Lingenfelter, Hennessey (and other tuners I missed) seem to think so.

I believe the R2300 rotors are good to 800 horsepower (R1900s are like 100 less), just like you were saying. I know I have the compressor maps, but there are too many colors and numbers I think the 2300 runs out of breathe after 850. Lingenfelter's LS9-car is running +1200 RWHP, but it also has a 500-shot, lol. Either entry-level twin screw (2.8/2.9) for these cars will easily support near 1000-horse.

Originally Posted by DietCoke

Stroking a boosted motor is an exercise in futility. You're limited by what the boost device pushes into the motor, not by the motor itself.

I was only saying stroke because I was expecting the later comment by the OP about getting 427 CI

Originally Posted by BiggFoot

All great comments gentlemen, and taken under advisement. In my gut I felt like keeping the LSA would probably be the best route to take as I understand that it is basically a detuned LS9 which upgrading the supercharger and forging the bottom end can easily fix. As one of you pointed out, modding the LSA would be cheaper in the long run VS relpacing with the LS7, but you must admit there is something a bit sexy with saying you have a 427 sitting under the hood

I really dont know much about all of this engine detail stuff, that is why I am asking. The little bit I have picked up just by asking questions is just enough to be dangerous, but I have never owned a muscle car and I would rather shell out the bucks to get it right the first time instead of continually going back to add this or that later on.

One of you stated that stroking doesnt necessarily add HP and that could be true. But since I am having the bottom end forged I may as well, right? I understand it does improve torque, but someone (possibly Ted Jannety) stated that you gain about 1 hp for each cui added so going from 376 to 416/417 would add about 40 hp and a bunch of torque so I am told.

I also suggesting stroking because boring will put you back into a similar wall-thickness situation like LS7s sort of have. Adding CI will add power if everything else is matched, but it costs more $$$. If you have it though, why not get it to where you want it the first time?

The best suggestion I can offer (because I'm certainly no expert on anything) is to figure out where you want to be. If you're only looking for 700 horsepower, you don't need to do a fraction of what you were thinking. If you want 800 horsepower, you'll definately want to get into that shortblock and get at the valvetrain and heads, and probably upgrade the SC and intercooling system. If you're looking for more, you're certainly looking at probably going down the road of a completely re-worked long block and SC. There are many Sponsors here that can help you with a plan once you know where you want to go. I'd urge you to establish the goal, and seek out a Sponsor to help you get there

Good luck and please keep us posted

[Z4me]

Mod LSA if I was to choose. They have just placed so much research into this project, plus the caddie has been using the LSA for awhile now. So
I would stay with the LSA and do whatever you can afford up to the capabilites that the LZ1 can handle.

[radz28]

Originally Posted by Z4me

Mod LSA if I was to choose. They have just placed so much research into this project, plus the caddie has been using the LSA for awhile now. So
I would still with the LSA and do whatever you can afford up to the capabilites that the LZ1 can handle.

I can't post the companies link because they're not a Sponsor, but I'll definately be looking into similar mods' for mine. They're all pretty simple and push that "little" 1900 to it's limit. I think they can pulley to 19 psi with their H/C package... They don't really have anything too much more special than our Sponsors, but I see they just make LSA one of their top focuses.

[GM4lyfe]

To be on the safe side while you have the bottom end apart go with good ARP bolts. I would also do ARP head bolts with MLS gaskets. Boosted motors put more stress on parts than a equal powed NA motor. Do it right the first time and save yourself the trouble later down the road. You notice the LS9 have larger head bolts with only 80hp more than the LSA.

[Milk 1027]

Originally Posted by djsnoflake

Why not Sell the LSA and buy an LS9?

Pretty good starter motor. You could mod after if you still felt the need.

Although if you have never owned a muscle car, you should try renting an SS and see what you think. That might be more than enough car for you.

That's still more expensive than just modding the LSA to have the same power.

[DGthe3]

Originally Posted by a_Username

Apparently they listened to ya... I just got "page not found."

I couldn't find the exact page either, at first I had the same thought you did ... that they have since fixed the page. But I went looking through their site (to try and find the page he tried to link to) and every engine package they have for the 6.2L V8s (LS3, L99, LSA, LS9) describes them as '378 CID'. Whoopsie.

[Go Fast Kid]

Biggfoot

Stick with the LSA and do your mods. I transplanted an LS7, race cam, 305cc intake chamber Mast heads, FAST intake, ZR1 injectors and all forged internals, mahle pistons 11.4:1 compression. The motor makes almost 600 lbs of torque @ 630 hp.

The trouble with all that power is you start breaking, drive train parts, suspension parts and the like. My car runs great however foot to the floor shifting through four gears, lots of stuff breaks.

GM did good job of upgrading the drive line in the ZL 1 however that might require more upgrades still.

The LS 7 block and forged internals are bulletproof and the cylinder walls are more than strong enough for a street car.

Save some money in the budget to replace broken drivetrain components.