The Dodge Viper's V10 might sound like a garbage truck at idle, but who cares when it delivers 600 horsepower with emissions certification and a warranty? Still, for some, that's just not enough power, and so the Mopar guys have come through with some parts to take the new McLaren-engineered 8.4L up to 650 HP.



Extracting more power from a 2-valve pushrod engine that already makes nearly 75 HP/L is no easy feat. So how did the Mopar boys pull off this daunting task?



The five individual equal-length primary tubes meet at a set of intermediate collectors, with air flow from the front three and rear two cylinders combining into larger-diameter secondaries before joining into the huge collectors. This is commonly refered to a a "tri-Y" design, and generally favors broad powerband instead of maximum peak horsepower.

A pair of electronically-controlled throttle bodies, each with its own actuator, control airflow into the intake plenum. They look just about big enough to swallow a Cornish game hen. To achieve the hp increase over the stock engine, the incoming airflow is routed through a Mopar cold-air induction tract.


A pair of electronically-controlled throttle bodies, each with its own actuator, control airflow into the intake plenum. They look just about big enough to swallow a Cornish game hen. To achieve the hp increase over the stock engine, the incoming airflow is routed through a Mopar cold-air induction tract.


The intake manifold is said to be a "prototype" version of the production item, with a highly-polished upper half, and black powdercoat applied to the lower. From the outside, we can't see any obvious differences compared to the production item, but we wouldn't be surprised if the internal surfaces were massaged somewhat.



Note that the indirect (port) injector is now located in the cylinder head (unlike the older versions of the Viper V10 that placed the injector in the intake manifold). The exact reasons for doing this are unknown, but the change was obviously aimed at improving charge distribution across the rev range.

Still, 650 hp from a 8.4L V10 isn't much

From a old school pushrod engine? It's quite enough.

I always notice that it's the Europeans saying this... but then again, it's the ones that don't look at the torque numbers that very closely match the horsepower, or the ones who realize that 75/hp per liter is amazing for a naturally aspirated engine.

Yes, Honda did 125/hp per liter in the original S2000, but where was the torque? And then look at where all the torque in this engine is located. I get it probably gets peak torque a couple ticks off idle.

I'm sure they could extract more, but if this engine will enter production, you have to balance it for emissions, fuel economy and of course durability. An engine with over 100-hp / liter will generally not last as long as an engine with less than 100-hp / liter. Wear and tear, engine RPM etc. all are factors here.

Jelous cause AMG can't do it ?!

Yep you Merc./Chrysler boys enjoy the torque, but it's how it's controled and used with a fancy clutch that matters.

Because we have taxes on displacement, and we watch Formula 1 not NASCAR.
... and F1 rules, and our tax sucking politicians rule even more ...




In the 1970s, yes.




Honda forgot the fancy superfast clutch.
How low can you rev that engine ?!
And how much fun is to strugle with the gearbox against the torque ?!
Why do I need all that torque, it's not like I'm towing a 747 ?!

And why a pushroad ?!
There were only absolete about 100 years ago.

I'll take F1 "with greater RPM comes greater performance" aproach against the "there's no replacement for displacement" aproach.

... it's called engineering.

First of all, CHILL OUT! I didn't mean to insult any AmericanI know that you Americans live with the motto "There is no replacement for displacement" and I respect that. It's just that, everytime I see a big American V8 engine with not more than 300-400 hp, I can't stop of thinking that Europeans get the same hp from engines that are 1.5L-3.0L smaller.
Second of all, "cawimmer430", I don't think that Americans care much about fuel economy. Almost everyone there drives a 4.0L or 5.0L PicK Up truck or SUV. For a second time, I don't mean to insult any American, but I'm afraid that's the truth.
PEACE!

lol, just gotta love the heading of this topic...

yeah, well i dont mean to flame anyone but they could definitely push out more power with such high displacement, btw wat are tht torque figures?

The push-rod engine, no matter how ancient it is, is a proven engine that has become the "trademark" of American cars. They are cheap to manufacture and build, which is one big plus point: there's gonna be power for more people, and not just the high-end buyers like high-powered European cars aim for.

OK so maybe the hp/L figures aren't that fantastic, but those engines sure are torquey: I had a go around in the 300C SRT-8 and oh boy, for the price of an E200, I'll get the SRT-8 anyday.