C7 Corvette Z07 to get 4.5L TTV8 from Cadillac Elmiraj.

[Jag530G]

Looks like the 4.5L twin turbo V8 previewed in the Cadillac Elmiraj concept coupe is set to be the engine for the 2016 (so late 2015 release) Corvette Z07. The new TTV8 is based on the HFV6 so quad cams, 4 valves per cyl, direct injection etc. GM quoted 500hp for the Elmiraj but the article speculates that the for the Z07 the power will be bumped a bit more, possibly 600hp. Makes you wonder what a future ZR1 (if there is one) will put out?

http://www.carscoops.com/2013/09/we-...turbo-for.html

I take from this that the classic small block V8 will continue as it is mostly used in GM's Pick-ups and there will always be a need for a cheap-to-produce pushrod small block V8 and GM can use this engine for the base model Corvette and Camaro as well since the cost has beem amortised over millions of Pick-ups. But I think it is fair to say that in more powerful versions of the Corvette the small block is dead. GM can then amortise the cost of a TTV8 over various Cadillacs, Hi-Po Corvette and possibly a Hi-Po Camaro.

Since the TTV8 isn't due out until late 2015 I'd say there won't be much chance of seeing it in a future HSV GTS. This news seems to also indicate there won't be a supercharged version of the LT1 to replace the LSA/LS9 so the GTS will continue as is and maybe the Clubsport will get the LT1.

Cheers, Matthew

[mjrandom]

There are rumours about a force fed LT1 on various forums so it will be intersting but it looks like the plan for a forced LT1 to power the Corvette are dead and maybe so is that version of the engine.

[Marco]

Based on HFV6 - does that mean a 60 degree V8? I thought one of the main advantages of the pushrod V8 is that it could fit under the low bonnet line of the Corvette, so I'm interested to see how they will get what is presumably a taller engine in there.

[Jag530G]

Based on HFV6 - does that mean a 60 degree V8? I thought one of the main advantages of the pushrod V8 is that it could fit under the low bonnet line of the Corvette, so I'm interested to see how they will get what is presumably a taller engine in there.

Doubt it will be 60 degree but I'd suspect it will share things like bore spacings, combustion chamber design, valve train design etc. THe engine height issue will probably mean a big bonnet bulge, although the original ZR1 with the LT5 quad cam engine seemed to fit in the C4 reasonably well.

I think a big driver behind this move is CAFE, smaller turbo engines seem to do pretty well on Gov fuel economy tests. Also, as we have seen in the various GTS vs E63 comparisons, the huge area under the torque curve and the better fuel economy of the AMG TTV8 versus the LSA shows the way of the future.

Cheers, Matthew

[Marco]

I'm curious as to why they wouldn't do a smaller capacity blown small block instead.

[Jag530G]

I'm curious as to why they wouldn't do a smaller capacity blown small block instead.

I'd say 1) Cadillac needs a DOHC V8 engine to be market competitive with their new large car, especially as it will compete with the BMW 7 series, MB S-Class, Jag XJ and Audi A8, an OHV engine won't do. By using the same engine in the Corvette will get defray costs. I admit I don't think there is anything wrong with the pushrod small block but many potential buyers will. I suspect GM will look to push the Corvette further up market and charge more for it, historically that has been a problem for GM because the Corvette has been perceived as being made on the cheap, with a DOHC TTV8 that will quell some of the criticism.

2) the HFV6 puts out 238Kw and 373Nm in the Cadillac ATS/CTS and the LT1 puts out 339Kw and 624Nm in the C7 Corvette, that's 66.1 Kw/L vs 54.7Kw/L and 103.6Nm/L vs 100.6Nm/L, so using the HFV6 as a design base means better specific power and torque. Plus the HFV6 now comes in a Twin Turbo version so a lot of the design work is already done.

Cheers, Matthew

[surfwagon]

Isn't the base HFV6 similar to our Alloytec?

[Jag530G]

Yes, the Alloytec is a Holden marketing name for the HFV6, basically the Holden 210kW is a detuned version of the LFX HFV6 used in number of US cars. The Camaro V6 has a 241kW version. The Holden 185kW 3.0L is the LF1 version of the HFV6 and is missing the cam phasers on the exhaust cams IIRC.

Cheers, Matthew

[itsme4g63]

Well see if any of this pans out was the last non-pushrod corvette was the 90-95 zr1 which didn't do so well, maybe due to pricing and lack of aftermarket for the toyota/lotus engine, but it did make 400hp while the standard model was making 150 less at the time. It would just seem out of place to put such a technologically advanced motor in the upper scale vette whilst history shows that previous models had just better versions of a similar design.