[Cpanthers85]

Okay, okay, here me out on this one before you grab your pitch forks and torches and send me to a mustang forum.

I too, as many of you, have been trying to speculate what the mysterious motor is going to be for the upcoming Z models for the 2017/2018 Camaros. I too, am chomping at the bit to trade in my 2011 SS for one of the beautifully crafted new 6th gens. My daily driver is a Cadillac ATS 2.0 AWD and just the very thought of that car with the pure brute force of a supercharged V8 makes me giddy (knowing that the ATS and the Camaro are on the same frame).

Most of us know by now that they are clearly working on a Z model, whether it be a Z28 or ZL1, no one knows for sure. We also don't know which motor is going into it. Most of us are assuming it is going to be the LT4, which makes sense based on the hood scoop and similarities to the CTS-V and the Z06.Which is all very possible.

We also know there might be two models floating around, leading to further speculation that maybe its a 1LE, Z28 and/or a ZL1 (Some of you 80's diehards are hoping for an IROC, I know).

We've also seen the spy shot where the numbers are on the side of the car, and we've all taken a crack at decoding it, but the one number we all are getting hung up on is the power to weight ratio number. The math doesn't add up. 4200lbs in a Camaro with a LT4, sounds like they stuffed it in a 5th gen hog. And some have speculated that maybe GM is working on a naturally aspirated LT1 variant that puts out 550hp or dream of a 383 or 427 'LT7', but I am here to propose another idea...

What if GM is indeed working on an LT4 Z**, but what if they are also working on a variant that has the LF4. For those of you that don't know, the LF4 is the twin turbo 465hp Cadillac ATS-V motor. https://en.wikipedia.org/wiki/GM_High_Feature_engine

Could this possibly be the Z28 motor we've all been wondering about? I know, most of the purists would scream, as would I, that they put a V6 in a Z28, but GM currently doesn't have another production motor that could possible see the 500hp output numbers we saw in the 5th Gen Z28 unless they drastically de-tune the LT4.

So my idea is this: They turn the boost up on the LF4, giving us a 500hp, an even lighter Z28 and make the ZL1, the big HP motor, similar to the 5th Gen.

Or

You could flip it. The luxury ZL1 gets the LF4 at 500hp, similar to the luxury ATS-V and the Z28 gets the LT4 and the higher price tag.

Just my ideas. Of course, this could all be for naught, if they decide to kill the ZL1, in similar fashion to how Corvette killed the ZR1, and just offer one model, a Z28 with the LT4. But the rumors suggest two models are coming, and theres only one motor we keep looking at, so could the LF4 be the other? I think so...

[TLSTWIN]

Well, anything s possible, BUT, the sound from the video are not 6 cylinder cars.

[WHAMMO]

Originally Posted by Cpanthers85

We've also seen the spy shot where the numbers are on the side of the car, and we've all taken a crack at decoding it, but the one number we all are getting hung up on is the power to weight ratio number. The math doesn't add up. 4200lbs in a Camaro with a LT4, sounds like they stuffed it in a 5th gen hog. And some have speculated that maybe GM is working on a naturally aspirated LT1 variant that puts out 550hp or dream of a 383 or 427 'LT7', but I am here to propose another idea...

Where the 4200lbs is coming from? Did I miss something!!?? Impossible that the 6th gen ZL1 is going to be heavier than the 5th gen ZL1.

[drivingagain]

plus you mentioned three engines. The LT1 in a 550hp version, LT4 and LF4. I think the LT1 in na 550hp is very doable in 427 cu in and would be a great fit for the z/28. Then just build a FI engine lower compression supercharged LT4.

[Bhobbs]

The power to weight on the side of the car was less than 6.XX. They could have it down to 1.0 if they make enough power. The LT4 making 650 with the ZL1 weighing around 3900 lbs would give a p/w of 6.0, which is less than whats on the side of the car.


There's no reason to have the LF4 in the Camaro. The ATS got it because Caddy is trying to be BMW, so they went TTV6. Besides, the LF4 only makes 464 hp. I doubt they can hit 500 while meeting fuel goals and emissions regulations. I would much rather have a LS6 like version of the LT1 making a little over 500 hp.

[Cpanthers85]

Originally Posted by TLSTWIN

Well, anything s possible, BUT, the sound from the video are not 6 cylinder cars.

GREAT Point. Pretty much debunks that idea.

Originally Posted by WHAMMO

Where the 4200lbs is coming from? Did I miss something!!?? Impossible that the 6th gen ZL1 is going to be heavier than the 5th gen ZL1.

The side of the mystery Z had a bunch of markings on it and one said something similar to PWRWGHT: <6.46. Most have interpreted that to mean Power to Weight less than 6.46.

You take the 650hp from the LT4 and multiply that by 6.46 and you get 4,199lbs.

[Jeffro19]

Yeah the sounds of the cars on the videos we have seen they are both V8's. I see a 1LE model coming with the LT1 and some better brakes, tires and suspension upgrades. The other car I think will be the Z28 with the LT4.

[Cpanthers85]

Originally Posted by Bhobbs

The power to weight on the side of the car was less than 6.XX. They could have it down to 1.0 if they make enough power. The LT4 making 650 with the ZL1 weighing around 3900 lbs would give a p/w of 6.0, which is less than whats on the side of the car.


There's no reason to have the LF4 in the Camaro. The ATS got it because Caddy is trying to be BMW, so they went TTV6. Besides, the LF4 only makes 464 hp. I doubt they can hit 500 while meeting fuel goals and emissions regulations. I would much rather have a LS6 like version of the LT1 making a little over 500 hp.

Great point, too. I am watching the ATS-V Head to Head video right now, and that seemed like the primary reason why they went V6 was to compete with BMW.

[mcsoul]

Life is like a box of chocolates...

[Trans damm]

Is there a mystery motor? I think people are over thinking this. GM is not known to pull off big surprises. The motor is an LT4. If they add another NA motor to the Vette that will be your NA Camaro motor. Not before. IMO.

[BradfordCamaro]

Originally Posted by Cpanthers85

The side of the mystery Z had a bunch of markings on it and one said something similar to PWRWGHT: <6.46. Most have interpreted that to mean Power to Weight less than 6.46.

You take the 650hp from the LT4 and multiply that by 6.46 and you get 4,199lbs.

You are doing it wrong. You are taking a power number that doesn't exsist to figure out the weight of the car.

You are supposed to use the weight to figure out the power.

It means 1HP for each 6.46 pounds or less.

If an SS is 3700lbs and has a 6.46 Pwr/wght it would put it at 570HP.

If there is a new ZL1 it should weigh less than 4000lbs. You would get about 620hp with that power to weight ratio.

[V6CamaroRS]

There's one of two questions that is going to need to be answered before we can speculate on a "mystery" engine. That question is:

Will there be a ZL1 or will the Z/28 be a supercharged vehicle?

Keep in mind that the ZL1 was supposed to be the Z/28. The Chevy engineers didn't think the result was worthy of the Z/28 badge, though, and ended up calling it the ZL1. With the Z06 consuming the Corvette ZR-1, it's quite possible there will be no 6Gen ZL1.

So quick answer is: If there is no ZL1, the engine will be the supercharged LT4 used in the Vette Z06 and CTS-V.

But what if Chevy does plan on a separate ZL1 and Z28? What then?

Simple answer for the ZL1. The ZL1 will use the supercharged LT4 engine used in the Vette Z06 and CTS-V. This shouldn't even be a question. Here's the question:

Where is Chevy going to find a 500+ horsepower, Naturally Aspirated, Gen V engine to use in the Z/28?

The answer is that it will have to be either the LT5 or the LTX.

It's extremely unclear what the LT5 is. The LTX is presumably a variant on the LSX racing engine using Gen V design and technology. The current LSX is unsuited to road or production use. However, Gen V technology (Direct Injection, AFM/Cylinder Deactivation, CVVT, all aluminum block & heads, etc.) may make even the LTX a street-viable engine.

The current LSX is a big block 454 (7.4 liter) engine with a 13.1:1 compression ratio generating 770hp at 7000 (!) RPM on 110 octane fuel. This gives us a few clues to work from:

• Linearly scaling the 6.2L LT1 engine to 7.4L would give us ~550hp
• Improving the LT1 design from 6600 RPM to 7100 RPM would probably get the engine up over 600hp
• Reinforcing the block for a 13:1 compression ratio would probably bring it up to around 800hp

(Disclaimer: All of the statements above are my amateur estimates. Take them for what they're worth!)

It doesn't make any sense that the LTX would be less powerful than the outgoing LSX. Which means that a Z/28 using the LSX would be a massively overpowered brute of a machine that would almost certainly shred a lot of tire. Considering that the Z/28 needs to be composed enough for street-driving, the LTX is probably an overkill.

If we assume the LT5 is a slightly scaled back version of what will become the LTX, then we're probably looking at a 600hp, naturally-aspirated LT5 engine as the powerplant for the upcoming Z/28. No question that the engine will be a torque-monster that will laugh at the GT350R and its Voodoo flat-plane engine. We'll have to see if there is a GT500 that would pick up the slack. (I suspect it's unlikely at this point, though time will tell.)

The only monkey-wrench in this speculation is that the modern Camaro has not been used as a platform for new engines. All the V8 engines used have first been proven through high-end areas like Cadillac or Corvette. Even the 4 & 6 engines are modifications to generally available GM engines. If the Z/28 uses the LT5 or LTX, this will be the first time the Camaro has led in a new engine deployment.

That being said... I think it might be a mistake to dismiss the idea of the Z/28 being the first consumer of an engine. My read on how GM has been deploying parts and architectures is that they are taking an opportunistic approach to deployment. The Camaro has simply not been positioned to lead in the deployment of a new engine. The timing on the new Z/28 may change that situation and cause the Camaro to be the vanguard for the first time.

In summary:

Possibility 1: Z/28 will use the LT4. No ZL1.
Possibility 2: ZL1 will use the LT4. Z/28 will use the LT5.

[detltu]

Originally Posted by V6CamaroRS

In summary:

Possibility 1: Z/28 will use the LT4. No ZL1.
Possibility 2: ZL1 will use the LT4. Z/28 will use the LT5.

This is correct. I would not rule out the LT5 popping up in a ZR1 Corvette at some point. I think we get a LT4 equipped Camaro next year. What they call it will tell us a lot.

[Bhobbs]

The LSX 454 is not a street legal engine. It does not need to meet fuel and emissions regulations, and it doesn't have the same durability requirements as production engines.

If GM doesn't go with an LT4 Z28, the most reasonable option would be to improve the LT1 along the lines of the LS1 to LS6. The LS6 ended up being a 15% improvement over the LS1. The LT1 improved by 15% would make 525 hp and tq. That would be a very good Z/28 engine.

The odds of that happening without another Corvette coming along are 0. If the ZR1/Zora does come out, it will likely be a forced induction engine.