monzaaddict

is there any physical difference between the these manifolds?

v1 casting numbers 12578029 12578030

lsa casting numbers 12611322 12611324

monzaaddict

Anyone?

Is the exhaust port different?

I found a few vague references to the lsa manifolds being tighter to block but really do not want to buy another set just to find out they are the same as the ones I have.

They look the same to me.

aurora40

iTrader: (1)

I'd be interested in anything you find out. I have a friend with an LS2 C6, he put LS7 manifolds and exhaust on it and it really woke things up. Since then I have wondered if LSA manifolds were internally larger and would bolt up to the stock V1 cat-back for a similar improvement without the downsides of headers.

punishmentcycle

iTrader: (6)

i would think that the ports would be larger due to the bigger cubes. but i dont know..

aurora: what downsides are there to headers? out side of removing them they are the best bolt on you can get

aurora40

iTrader: (1)

Plenty of people have clearance issues, with wires burning on them, or the steering shaft clunking. Plus in many states you are unlikely to pass a visual inspection with them. And they are pricey with cats, and louder.

Headers are a good mod, but I don't want them on my Caddy. I'm sure I'm not the only one.

jmilz28

iTrader: (13)

Thread revive -
anyone offer anything on this?

SE-R Spec

iTrader: (2)

This has my attention

Doble

I bought some LSA's and the intent of running them and comparing them. They look similar never got the chance to see the v1's side by side with the LSA's. Long story. Went kooks. Wish me luck with visuals.

jmilz28

iTrader: (13)

Some good pics:
https://houston.craigslist.org/pts/d...409237788.html

versus the ones reckless has in the classifieds now...hard to see a difference.

AAIIIC

iTrader: (19)

Do you still have the LSA ones, Doble? Maybe you could coordinate with someone that's got some V1 manifolds to compare? Or maybe post up some measurements (port diameter at the heads, collector outlet diameter)?

I agree with jmilz28, though - looking at a few Ebay ads, it's hard to see any difference.

Doble

No, they got stolen or lost. I might have to get another set in case I need them for smog.

ls1247

iTrader: (2)

why limit this conversation to manifolds. How about the cats and the entire exhaust system.

jmilz28

iTrader: (13)

Good question: because the manifolds and the cats are the biggest restrictions, by a lot. The dual 2.5" system with an X inside the resonator, smooth bends, and dual mufflers doesn't cost power until you hit BIG numbers. High flow cats alone will free up 10-15 at the tire and headers another 20-25, all on a stock re-tuned 243 headed LS engine. A 3" system will not give anything more than single digit gains over stock, if that, until well over 500 at the wheels. Don't get me wrong, I love big exhaust, but on ANY LS motor, headers and tune are your best first mod, and supporting mod for a long time. That said, it's still a fair question, and buying a whole V2 setup and testing it vs. stock would be cool, after you modified the V2 system to work. There's an awesome thread on V2 headers, bet it holds up through the whole system. Still don't think it's as worthwhile as the headers, that's the biggest restriction on our cars from the factory. Only way manifolds may matter is if the internal diameters are bigger, as the tube shapes look identical to my eyeballs. LS7 manifold have intrigued me for a while but after all the labor, I think headers would be better net worth. If they were a bolt on affair like vettes, that would change things.

ls1247

iTrader: (2)

I wouldn't be looking towards V2 stuff for horsepower gains as much as I would for serviceability.

jmilz28

iTrader: (13)

That's a great point.