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4.5 V8TT engine

16K views 73 replies 19 participants last post by  Guy.Seminerio 
#1 ·
Today on leftlanenews.com there is an article on a new Cad concept with a 4.5 V8TT engine producing 500/500 hp/torque. Here is a perfect motor for the ATS-V. :cool2:
 
#42 ·
definitely have to chime in and strongly disagree with someone stating BMW hasn't made a good sounding engine.

the only M engine i'm not the biggest fan of is the S14. i love all the others, even the bastardized s50/s52 sounded great.

it must be me, but i can't believe someone doesn't like the v10! sure at idle it's a bit mechanical sounding, but any throttle on load and it is like the old v10 f1 cars.
 
#49 ·
I could definitely see this mystery engine being that "ultra v8" coming to fruition. GM could easily take a DOHC 4.5l engine and pull 600hp from it with forced induction. There are plenty of pros for a small block; size, weight, simplicity, reliability. But the DOHC adds refinement. Something you want in a Cadillac and I think GM agrees. I doubt you'd ever find a small block in a car like the Elmiraj. And while modern technology allows us to make the small block feel refined when necessary, it can make the DOHC engine feel that much better. There's also the perception of a small block vs DOHC. I don't like it either but face it, it matters. It would be great to see something like this in the ats-v and then a supercharged or turbocharged version in the new cts-v. Either way, Cadillac has to build this engine. GM can't have it's flagship sedan due in a couple of years, the LTS (the name makes my ears bleed) go up against the s550 and 750 with an LT1. That's the bottom line.

About the ats-v, I believe v series engines should be EXCLUSIVE to the most performance oriented cars in GM. Top line vette, camaro, v series caddy. I think using the 2nd best engine in the cts as the engine in the ats-v is unacceptable. I can see the base engine in the cts (2.0 turbo) being the one up from base engine in the ats. That's fine. But when it comes to the v series, exclusivity is important. Bad move on GM if they decide to put cts vsport engine in ats-v.

Also, I've read in recent pubs that the next m3 will in fact have a twin turbo v6, not the rumored tri turbo. Either way, GM does not need to follow in anyone's footsteps. I doubt BMW is saying "lets build our engines to line up with cadillac's engines." The pubs also say that they predict around 450hp with 0-60 in about 4.5 secs. Doubtful. 335 is about that fast. M3 will be much faster. CLEARLY, the 3.6 v6 cannot compete with BMW's 3.0 i6 with "300" HP so what cadillac needs to do is put the ttv6 in the ats but NOT as the ATS-v. As the ats vsport. Yes I know that messes with the cts vsport, but that can be addressed afterwards. The ttv6 in the ats-v would line It up with the 335i. Bottom line. No good. I predict the next m3 will hit 60 in under 4 seconds.
 
#50 ·
The term "refinement" is subjective, and I'm not sure what you mean other than a DOHC, four-valve motor typically has lower valvetrain mass allowing it to rev higher and can have a volumetric efficiency advantage. This comes at the cost of complexity, higher repair costs, and requiring more head room. Cam-in-block vs DOHC is a tough choice for GM and may come down to, as you point out, the need to address public perception now and in the future.

I like your idea about the V6TT not being in the ATS-V not that I'm alone in this opinion. In fact, to apply that concept more generally, let's have GM relegate the V6TT to Vsport-only status (XTS, CTS, & ATS) and to follow your proposal by putting "that ultra V8" with FI in the ATS-V. This would be done even though the heavier CTS Vsport seems to have exemplary performance numbers implying an LF3-equipped ATS (i.e. ATS-V) would be expected to be even faster.

Assuming the ATS-V will be targeting the new M3 (and not an existing M3 or especially an older M3) and using only one metric of comparison for simplicity, low 4-second 0-60 would seem to be absolutely mandatory, 4.0 if possible. Could the new M3 indeed go under 4 sec? If that's the case, then that also has to be met or preferably exceeded in the ATS-V, IMHO. One can argue whether or not a new M3 will go 3.9 or faster (unless its AWD or BMW's engineers really have gone mental), but the point is the new ATS-V simply has to put the new M3 in second place in this regard even if all or most other metrics are in favor of the ATS-V. Anyway, that's my humble opinion.
 
#56 ·

That article also mentions a new 3 liter turbo V6 in the lineup - an engine that by all accounts makes even less sense than a 4.5L TT...

GM phased out the 3.0L displacement - it is obsolete and served no purpose other than increasing GM Powertrain's design budget and capital overhead costs.

A few years ago, the rumor was GM was going to put out a 3.0L TT. The belief was they would use the smaller displacement in order to (1) get better emissions, (2) better fuel economy, and (3) the thicker cylinder walls would increase the longevity of the engine - all to slot between the 3.6 and the 6.2. GM wanted to bring Opel's TTV6 straight over here, but it had a hard time hitting our emissions and the engine was too thirsty and had questionable reliability on our fuel and driving habits - but GM brought over Opel engineers to North America - and the thought was they would develop a new TTV6 with Opel's knowledge and experience.

Before TTV6 development even really began, GM had the 3.6L DI and 3.0L DI (normally aspirated) engines side by side in mules - and the smaller displacement offered no major advantages on paper (fuel ecomomy, emissions, reliability, power, NVH) compared to its bigger counterpart, and the 3.0L was shelved from GM's product offerings... Now many still expected to see the 3.0 live on as a TTV6 thanks to its thicker cylinder walls - but the introduction of the 3.6L TT proves GM was able to make their reliability targets with the larger displacements - nailing the coffin on the 3.0L.

Moving forward from what we know today (3.6L N/A@320hp and 3.6L TT@420hp)...

We know GM is developing a new V6 architecture, rumored to also be a 3.6L, to upgrade the LFX with the latest combustion tech. GM isn't going to keep multiple displacements unless it absolutely has to (and if they do, I think they're idiots), and a 3.0L N/A would be sitting at just about 300hp - which puts it at overlap with the LTG making no sense - and a 3.0L TT V6 would put the engine at 350-375hp, and the next gen 3.6L N/A is expected to push 350hp anyway, putting it as a SERIOUSLY expensive alternate engine for only a few hp more.

The theory used to be that smaller displacements got better emissions and fuel economy, but with the advent of 6 and 8 speed automatics and direct injection, those advantages are largely diminished - if they exist anymore at all.

Also, using some armchair maths. Take this with a grain of salt. I do, and I just wrote it:

2.0L TT - 270hp - 135hp/liter
3.6L TT - 420hp - 116hp/liter
6.2L SC - 550hp - 89hp/liter (LSA)
6.2L SC - 640hp - 103hp/liter (LS9)

6.2L NA - 420hp - 68hp/liter (LS3)
6.2L NA - 450hp - 73hp/liter (LT1)

Typically, increasing displacement on a boosted engine (meeting reliability targets) mean a decreasing curve on your horsepower per liter - but if GM was able to match that of their current OHC offerings, a 4.5L OHC TT would put out between 520 and 610hp - which makes a LOT of sense as the LT1 spits out 450hp and it'd slot above it.

But when a boosted variant of the LT1 could spin anywhere between 550hp to 670hp, the 4.5L TT ONLY makes sense as a "one off" engine on super expensive halo cars... You'd need all unique castings for a pretty darn high strung engine that you likely wouldn't even want to do in high volume - exotic car engines aren't known for lasting hundreds of thousands of miles without a LOT of maintenance.

And then riddle me this - the Z06 guys love the raw power (and sound) of the LS7. It fits the Corvette, so a "ferrari" sounding engine would get away from the "American muscle" sound that the Vette is known for. I think a 600hp OHV TT in a Vette makes more sense than a 4.5L OHC TT, and it'd likely be a cheaper engine.

What about a high-end Cadillac flagship? If GM is serious about high end "money nearly no object" then keep an engine unique to Cadillac's flagships and be done with it - keep it out of Corvette. But will GM's bean counters let it happen? Will the still living "old GM" faces within the new company keep such things from happening?

Hard to say. But if I were Reuss and the 3rd gen CTS launches well alongside a "still strong" ATS and XTS lineup - if Cadillac keeps growing and gaining ground - I'd go for the throat in one shot - put all of Cadillac's progress on one shot - and release a large sedan along side a mid engine hypercar at the same time. That's what I'd use the 4.5L TT V8 for. Good luck trying to get that through the board though.
 
#57 ·
That article also mentions a new 3 liter turbo V6 in the lineup - an engine that by all accounts makes even less sense than a 4.5L TT...

GM phased out the 3.0L displacement - it is obsolete and served no purpose other than increasing GM Powertrain's design budget and capital overhead costs.

A few years ago, the rumor was GM was going to put out a 3.0L TT. The belief was they would use the smaller displacement in order to (1) get better emissions, (2) better fuel economy, and (3) the thicker cylinder walls would increase the longevity of the engine - all to slot between the 3.6 and the 6.2. GM wanted to bring Opel's TTV6 straight over here, but it had a hard time hitting our emissions and the engine was too thirsty and had questionable reliability on our fuel and driving habits - but GM brought over Opel engineers to North America - and the thought was they would develop a new TTV6 with Opel's knowledge and experience.

Before TTV6 development even really began, GM had the 3.6L DI and 3.0L DI (normally aspirated) engines side by side in mules - and the smaller displacement offered no major advantages on paper (fuel ecomomy, emissions, reliability, power, NVH) compared to its bigger counterpart, and the 3.0L was shelved from GM's product offerings... Now many still expected to see the 3.0 live on as a TTV6 thanks to its thicker cylinder walls - but the introduction of the 3.6L TT proves GM was able to make their reliability targets with the larger displacements - nailing the coffin on the 3.0L.

Moving forward from what we know today (3.6L N/A@320hp and 3.6L TT@420hp)...

We know GM is developing a new V6 architecture, rumored to also be a 3.6L, to upgrade the LFX with the latest combustion tech. GM isn't going to keep multiple displacements unless it absolutely has to (and if they do, I think they're idiots), and a 3.0L N/A would be sitting at just about 300hp - which puts it at overlap with the LTG making no sense - and a 3.0L TT V6 would put the engine at 350-375hp, and the next gen 3.6L N/A is expected to push 350hp anyway, putting it as a SERIOUSLY expensive alternate engine for only a few hp more.

The theory used to be that smaller displacements got better emissions and fuel economy, but with the advent of 6 and 8 speed automatics and direct injection, those advantages are largely diminished - if they exist anymore at all.

Also, using some armchair maths. Take this with a grain of salt. I do, and I just wrote it:

2.0L TT - 270hp - 135hp/liter
3.6L TT - 420hp - 116hp/liter
6.2L SC - 550hp - 89hp/liter (LSA)
6.2L SC - 640hp - 103hp/liter (LS9)

6.2L NA - 420hp - 68hp/liter (LS3)
6.2L NA - 450hp - 73hp/liter (LT1)

Typically, increasing displacement on a boosted engine (meeting reliability targets) mean a decreasing curve on your horsepower per liter - but if GM was able to match that of their current OHC offerings, a 4.5L OHC TT would put out between 520 and 610hp - which makes a LOT of sense as the LT1 spits out 450hp and it'd slot above it.

But when a boosted variant of the LT1 could spin anywhere between 550hp to 670hp, the 4.5L TT ONLY makes sense as a "one off" engine on super expensive halo cars... You'd need all unique castings for a pretty darn high strung engine that you likely wouldn't even want to do in high volume - exotic car engines aren't known for lasting hundreds of thousands of miles without a LOT of maintenance.

And then riddle me this - the Z06 guys love the raw power (and sound) of the LS7. It fits the Corvette, so a "ferrari" sounding engine would get away from the "American muscle" sound that the Vette is known for. I think a 600hp OHV TT in a Vette makes more sense than a 4.5L OHC TT, and it'd likely be a cheaper engine.

What about a high-end Cadillac flagship? If GM is serious about high end "money nearly no object" then keep an engine unique to Cadillac's flagships and be done with it - keep it out of Corvette. But will GM's bean counters let it happen? Will the still living "old GM" faces within the new company keep such things from happening?

Hard to say. But if I were Reuss and the 3rd gen CTS launches well alongside a "still strong" ATS and XTS lineup - if Cadillac keeps growing and gaining ground - I'd go for the throat in one shot - put all of Cadillac's progress on one shot - and release a large sedan along side a mid engine hypercar at the same time. That's what I'd use the 4.5L TT V8 for. Good luck trying to get that through the board though.
I believe the 3.0L motor is a new motor ... at least that's what I read on gminsidenews. You're right about the older 3.0 being disliked by consumers because it just didn't have enough fuel economy advantage and lacked the power people liked (at least in the SRX application anyway).

Just one or two comments on your armchair math. Remember that those smaller motors are four valves per cyl and DOHC while those 6.2L motors aren't thus the 2.0 and 3.6 have a slight volumetric efficiency advantage and lower valvetrain mass theoretically allowing them to rev higher (though I didn't check to see if their hp ratings came at a higher RPM).

I think GM knows that they can't be doing any risky moves now or in the foreseeable future. I think they've got a plan -- a darned good plan -- and they're following it quite well while revising it to fit what they've learned while implementing it. Unfortunately, I'm afraid that plan has the ATS-V being equipped with the LF3 motor and not a 4.5 V8TT, and it's not going to be enough to slamdunk the competition. I hope I'm wrong.
 
#53 · (Edited)
JimmyH said:
In some tests, the V-sports acceleration looks great. In others it looks disappointing. Need more tests to be sure about that turbo 6.
I hope that the TTV6 as a Vsport option is a success, acceleration tests notwithstanding. It's not for me but will make the country-club-type set happy and they're a lot more plentiful than real car guys. As others have said before, that gives Cadillac more money for development of the true V's for the car guys, too. And now car guys are an important part of the mix for Cadillac's future success. I hope that they build the Elmiraj and a V version, too (16 cyl. ala "16"), as long as they stay profitable.

Jud
 
#54 ·
Chris, I agree that the ats-v should be able to walk away from the m3 in a straight line, especially after the ats 2.0 and 3.6 are embarrassed by the 328 and 335i respectively. But I definitely also agree that it needs to trump m3 in many other areas, namely handling. But with the "lesser" ats cars are embarrassing the 3 series in the handling department, I have no doubt the ats-v will trump the m3 in that respect.
 
#68 ·
I'm reading elsewhere that though the 4.5 V8TT was suppose to be under the hood of a GM concept vehicle (the Elmiraj), no one actually saw it.

Other writings said it was somewhere in development within GM.

Could be that this thing, if it exists, is a few years away which, if true, would make it unlikely to power to the new ATS-V which is expected to be available for the 2015 model year.
 
#70 ·
Why would they put a better motor in the ATS-V and not CTS-V?

Honestly, I'd be more than happy with that 420hp TT V6 that they put into the CTS-V....but then you have 3 different Cadi models with the same motor.

Why they put that motor into the XTS or w/e I'll never understand...
 
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