In reply to Pete. (l33t FS) :
Well aware of those but a 5.0 at the 350hp level is super reliable. Now when you start trying to get them past 450-500 not so much.
LS motors are popular for a reason.....so can't go wrong there either.
Ironically I don't like the exhaust note of American V8s but they sure make sense as a powerplant.
Just came here to say I don't see EVs replacing ICEs anytime soon.
V8 for sure. Under stressed and you can have that 350hp however youd like it, low rpm, mid range or high rpm.
Im not even a huge fan of LS swaps but there is a reason everyone does them.
Id be willing to bet resale is better on an LS powered answer
I don't know... there's a few people around here that seem to like the LFX swaps...
It would be a downgrade, I want more power not less
In reply to AngryCorvair (Forum Supporter) :
Don't you mean you don't see turbo 4s replacing LSs.
So to give you some numbers, My 2009 LS3 was the heaviest factory miata (GT PRHT) and with the heavier rear end (8.8) came in just under 2800 LBS with 0 efforts for weight loss (full interior, all the creature comforts, Etc). When dynoed, It did 409 WHP with just the bolt ons for needed for the swap. The torque curve was a plateau. It wasn't a curve.
Oh and it was a kitten to drive when you wanted it to be and would boogie when you asked it to. Very easy to DD and would run all day long.
V8/End thread
I have seen this in another swapped NC, LS3 and he has no weight reduction and he was somewhere in the 2700 lb area. My car has weight reduction, and my end goal would be to keep it around 2650-2700 lbs to keep my car in XA. (I am a bigger boy and weigh in at about 275lbs)
In reply to Classy :
I would imagine a lighter flywheel, crank and other bits would take about 40-50lbs off the motor.
Tom1200 said:In reply to Classy :
I would imagine a lighter flywheel, crank and other bits would take about 40-50lbs off the motor.
That seems pretty optimistic to me. A stock LS flywheel is usually around 24lbs. I'm seeing lightweight ones around 16lbs. GM isn't leaving tons of unnecessary weight in the bottom end of a modern V8 (assuming we're starting with an aluminum block).
At some point changing out all of the stock parts for lighter ones just erodes the benefits of reliability, driveability, and (relatively) low entry cost that motivated the swap in the first place and what you end up with is a high strung, unreliable and expensive race engine.
you'll never regret going with a v8
In reply to Classy :
The min weight is without driver for XA/XB. You would probably be under the min for XA as it's 2750 LB. You would probably be in the high 2600s range looking at your car at a maximum. You would be in XB and no way to get to that min weight with a NC. (2150 LB) I would have been at the min weight for XA with my full weight LS3 swap.
So really it's how much do you want to change and how much do you want to worry about your transmission.
In reply to STM317 :
I actually went and looked as I'm not familiar with LS motors. From actual parts that were weighed; flywheel saved 15lbs, fancy crank was 10lbs lighter (as well as stronger), headers saved 15-18lbs. There were some other misc bits hence my 40-50lb estimate.
"Fancy crank" is asking for trouble and is going to mean cracking into the motor. Keep the engine a black box - instead of spending money on a fancy crank, get a factory crate motor and enjoy the two year warranty. Flywheel is easy enough, headers are more likely the place to save weight as stock is a big cast iron chunk. But the goal is a reliable track day hammer, so just leave the engine internals alone and concentrate on other things like the chassis instead.
In reply to Keith Tanner :
I'd trust a junkyard engine over a crate engine. At the machine shop, we treated "crate engines" as a complete engine kit of parts, not a finished product.
It is amazing how many had the timing chain installed wrong, or had torn valve seals, or iffy ring or bearing clearances.
Warranty is nice, as long as you don't void it, but I think the crate engines are/were factory seconds that they didn't trust to put in a production car.
Tom1200 said:In reply to STM317 :
I actually went and looked as I'm not familiar with LS motors. From actual parts that were weighed; flywheel saved 15lbs, fancy crank was 10lbs lighter (as well as stronger), headers saved 15-18lbs. There were some other misc bits hence my 40-50lb estimate.
Headers/manifolds have tons of stock and aftermarket combinations, and will probably have to be vehicle specific if we're doing swaps. That's not something that should be counted on to lose a given amount of weight. They may or may not depending on the chassis they're going into.
My larger point was that in this case, the motivation for a potential v8 swap over the existing boosted 4 cyl is to gain reliability and reduce expensive, specialized parts. Swapping out stock LS parts for more tailored, race specific parts seems to work against those goals to me.
Pete. (l33t FS) said:In reply to Keith Tanner :
I'd trust a junkyard engine over a crate engine. At the machine shop, we treated "crate engines" as a complete engine kit of parts, not a finished product.
It is amazing how many had the timing chain installed wrong, or had torn valve seals, or iffy ring or bearing clearances.
Warranty is nice, as long as you don't void it, but I think the crate engines are/were factory seconds that they didn't trust to put in a production car.
The LS3 crates we received were all rock solid*. There's no way they were tested and identified as seconds, I think they were just plucked off the production line as the LS3 was still an active production engine at the time. I don't know how they're built now, probably in batches. And hey, two year warranty. I know from experience that GM will even pay the labor to replace the part.
I wouldn't feel the same way about a rebuilt crate from a random rebuilder. I would view that with suspicion unless I knew the builder.
* we had one that was identified as bad because of a squeak. The dealership thought maybe the cam bearings had been nicked when the ASA cam was installed at the factory - obviously that was a post-production modification. It turns out the squeak was the rear seal housing (aluminum) rubbing against the crank (steel). It would have self-clearanced in short order, and I'll bet that you'd have never heard the noise buried deep in an Camero tunnel and automatic bellhousing. That engine has been doing heavy duty for years since.
I'd do something like v8 swap a 350Z but some of the motorsport I do penalizes you for not staying in make between car and engine. This is something i'd only do on a dedicated track car.
If I owned a RX8 or any "jdm" type car part of the appeal to me is sticking Japanese. Also to me owning a RX8 without a rotary seems to be kind of losing the point of buying a RX8.
STM317 said:Swapping out stock LS parts for more tailored, race specific parts seems to work against those goals to me.
I should clarify: I only made the comments because the weight discussions came up.
Other then the flywheel and header I'd also be inclined to leave it alone. My personal preference is to give up some horsepower and weight savings for reliability.
I don't think 40-50lbs of weight is going to be night and day in a 2700lb car.
In reply to bmw88rider :
That is 2022 rules, 2023 is 2920 lbs with driver. My car is between 2650-2700 lbs now, supercharger, my fat ass, huge wheels and tires, it all adds up
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