Pull my dyno - Automobile puts the IS-F on the rollers
Lexus is billing the IS-F as "Everything you thought we weren't," and the potential is certainly there. The engine bay is filled with 5 liters of 4-valve V8 putting out 416 horsepower and 371 pound-feet of torque. The Minilite-esque wheels hide a Brembo braking system with six piston front calipers and cross-drilled rotors 14.2 inches in diameter. The sill extensions wrap up the front fenders to form a styling detail reminiscent of extractor vents, and the rest of the body has been tweaked in the wind tunnel to improve high speed aerodynamics. It all sounds good when you read the spec sheet, and the car does at least look aggressive . What everyone's dying to know, though, is "has Lexus done it this time?" Automobile magazine had the same burning curiosity, and they just also happened to have an IS-F sitting in their lot.
In no time, they headed over to their local Dynojet. The result? Well, they're a little disappointed, and they're calling the torque delivery peaky. Looking at the dyno graph, we're not sure we'd agree entirely with that assessment. There's at least 225 lb-feet at the wheels from 1,800 rpm, topping out at 318 lb-ft. First, let's point out that 15 percent torque loss through a drivetrain including an eight speed automatic is pretty phenomenal. Secondly, the torque curve is pretty fat below the peak. What is surprising to everyone, though, is the way the power drops off precipitously on the other side of the 5,200 rpm peak. You'd think an engine with 4-cams and Yamaha-designed cylinder heads would be a revver. Of course, there are lies, damn lies, and statistics and these dyno results are sure to kick up some debate. What still remains to be seen is how the entire package works when pitted against its bogeyed competition. For that, we must still wait.
[Source: Automobile, photo: Automobile]
Reader Comments (Page 1 of 2)
hoeun kim 11:37AM (10/25/2007)
you guys ever proof read?
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Joe K. 11:40AM (10/25/2007)
You see their interview on Autoline? Get it out quickly, as fast as possible, make corrections later...
Dan Roth 11:46AM (10/25/2007)
Specific gripe?
James 11:56AM (10/25/2007)
Dan:
Perhaps hoeun was referring to the "4-valve V8" - while you probably meant 4-valve per cylinder, it sounds a little weird.
nissanfreak87 11:46AM (10/25/2007)
"We're still not allowing you to have fun with this"-Lexus
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David 12:48PM (10/25/2007)
This is an unusual lexus with weirdness all over. The biggest offender: the quad exhaust on the back are completely fake and not connected to anything. At all!!! WTF lexus!?! The actual exhaust ends about four inches before these exhaust rings.
500 8:36PM (10/25/2007)
@David:
Really? The world is full of Japanese poser cars with fake dual/quad exhaust tips, but I would have expected on a car with this level of performance they'd be real.
I always thought that huge fake exhaust tips, particularly on tuner Civics etc., are kind of like stuffing a sock in your pants to impress the ladies. They may fool someone at first, but when it comes right down to it, you're going to be humiliated.
Johnny Rotten 11:47AM (10/25/2007)
I've said it before and I'll say it again, Lexus cannot and will never build a true or respectable sports car. They build luxobarges and show ponies. The fact that this so-called hi-po, DOHC engine dies at 6500 rpm is pathetic. Maybe if it were a OHV torque monster, it would be different, but they are dropping a merely average 5 liter engine in there and calling it high performace. Gag.
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seoultrain 12:05PM (10/25/2007)
www.youtube.com/watch?v=ShrOWznZbns
the LF-A looks (and sounds) pretty respectable so far. No need to pigeonhole manufacturers.
Johnny Rotten 12:10PM (10/25/2007)
Why not? They all have design and manufacturing philosophies. Lexus's is "quiet, boring, soulless." And give me a break on the don't pigeonhole lexus. People have been doing that to doestic manufacturers for years, and rightfully so in most cases. If you don't at least take into account past performance, you are deluding your view of future outcomes.
psarhjinian 12:30PM (10/25/2007)
The old IS300 was much sportier than it's 3-Series contemporary. But reviewers panned it as "Harsh" and "not Lexus enough" and buyers didn't appear. Hence the softer, 2G IS 250/350). The same reason exists for why the SC went from Supra-in-a-suit to Melted-bar-of-soap between iterations.
You can't fault Lexus for trying.
Lincoln hit the same problem with the LS. Brilliant chassis (generally better than the equivalent 5-Series). No buyers, hence the Zephyr/MKZ. While armchair racers want granite suspension and eight-speed manuals, the people with the money to actually buy these cars in volume are either bluehairs or BlackBerry-wielding urban professionals.
Lexus knows this. So does Acura, BMW, Infiniti and so forth. And that's why the high-dollars models are getting softer each year (3-Series, IS, G35), if they're available at all (RSX, NSX). The fact is, the market isn't nearly large enough. The Great Sports Car Die-Off of 1997+ should have been evidence of this.
HeyHuub 4:18PM (10/25/2007)
Name me a n/a 5 liter OHV ''torque monster" that puts down more torque then this engine.
Christian 7:52PM (10/25/2007)
More than 318 lb-ft? LOL. The old Windsor 5.0 had more TQ than that. As for DOHC same as this engine there are many with that much TQ or MORE. Jag Aj-V8 for example, only 4.2L and 310lbs. New mustang has 320lbs and its only 4.6L and 3v, the 4v version is 335 ft-lbs.
HeyHuub 12:56PM (10/26/2007)
What are you on?
It said it makes 320lb/ft at 1800 rpm, it makes 375lb/ft max.
The Mustang only gets 320lb/ft max from it's 4.6, Audi gets more from a n/a 4.2
Jon 12:23PM (10/25/2007)
Dan Roth, the 8-speed automatic does not have torque converter loss, if they dyno'd in manual mode.
The torque converter is locked from gears 2-8, which means there is no automatic transmission loss.
It's a direct link, same a manual transmission.
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Dan Roth 12:35PM (10/25/2007)
well yes, anything with a lockup torque converter is going to be pretty much equivalent with a manual trans when it's locked - but I'd still argue that 15% loss through _any_ drivetrain (that's counting transmission and differential) is nothing to sneeze at.
rem83 12:44PM (10/25/2007)
It may only be a 15% torque loss at peak torque RPM, but there's a 20% loss in HP at peak HP RPM. 333hp/416hp = 80%.
Dan Roth 12:46PM (10/25/2007)
I would expect the losses to be nonlinear across the rev range, too -
Christian 12:49PM (10/25/2007)
Weak. And this is on a dynojet. They always overrate HP. Try it on a Mustang dyno, and it'll be more realistic.
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BKadalur 1:24PM (10/25/2007)
i say do it on a mahle.
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