415 Hp...
08-06-07, 04:46 PM
#33
Lexus Fanatic
Join Date: Jan 2005
Location: A better place
Posts: 7,285
Likes: 0
Received 0 Likes
on
0 Posts
Lexus is commited to "kaizen", their continuous improvement in vehicle development. "The Pursuit of Perfection" is their slogan...and being this is their first serious entry to the niche market, they are strategically getting things done and making sure everything is right. When it's finally available to the public, I can assure everyone that this car will make a mark in Lexus history. 
BTW, I did confirm with my sources, the 415 hp number was a made up number which is NOT the final official output.
BTW, I did confirm with my sources, the 415 hp number was a made up number which is NOT the final official output.
Big thanks for the confirmation, I knew it couldn't be the final output
.
08-06-07, 10:18 PM
#34
Driver
Join Date: Jul 2007
Location: MD
Posts: 146
Likes: 0
Received 0 Likes
on
0 Posts
I'm hoping for 430+ hp, and my guesstimate still stands at 437 hp. I don't think they will have any problem getting that amount of power from that 5.0L motor. One thing we need to keep in mind is that output will be limited by the gas mileage and emission targets (no gas guzzler tax and ULEV II). 431 hp is the minimum because IS-F engine revs at least 500 RPM higher than the 410 hp regular 5.0L v8.
410 hp * (7000 RPM / 6500 RPM) = 441 hp
Even if the regular 5.0L V8 has only 400 hp, that would be
400 hp * (7000 RPM / 6500 RPM) = 431 hp
If Lexus created something like the M3s gas guzzler engine satisfying only LEV II emissions, the IS-F could easily have 475+ hp.
Plus, given the ULEV II emissions, I would bet that an aftermarket exhaust could uncork even more power, no problem. I wouldn't be surprised if this one simple bolt on added another 20+ hp, easily. I think the aftermarket will be very good for this car.
410 hp * (7000 RPM / 6500 RPM) = 441 hp
Even if the regular 5.0L V8 has only 400 hp, that would be
400 hp * (7000 RPM / 6500 RPM) = 431 hp
If Lexus created something like the M3s gas guzzler engine satisfying only LEV II emissions, the IS-F could easily have 475+ hp.
Plus, given the ULEV II emissions, I would bet that an aftermarket exhaust could uncork even more power, no problem. I wouldn't be surprised if this one simple bolt on added another 20+ hp, easily. I think the aftermarket will be very good for this car.
Last edited by is-fan; 08-06-07 at 10:31 PM.
08-06-07, 11:02 PM
#35
Driver School Candidate
Join Date: Mar 2007
Location: CA
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
I'm hoping for 430+ hp, and my guesstimate still stands at 437 hp. I don't think they will have any problem getting that amount of power from that 5.0L motor. One thing we need to keep in mind is that output will be limited by the gas mileage and emission targets (no gas guzzler tax and ULEV II). 431 hp is the minimum because IS-F engine revs at least 500 RPM higher than the 410 hp regular 5.0L v8.....
IS-fan, you are beyond doubt a genuine aficionado of the upcoming IS-F and like you I am confident Lexus can buff the base 389hp 5L up to some pretty impressive numbers while maintaining niche leading gas mileage performance. Aside from the hp, what also intrigues me is the thought of how much of the LF-A's performance engineering has been incorporated into the IS-F. Lexus has spent untold millions to develop their flagship performance model and surely a little bit of that has trickled down to the IS-F.
08-07-07, 01:21 AM
#36
Lexus Fanatic
Join Date: Jan 2005
Location: A better place
Posts: 7,285
Likes: 0
Received 0 Likes
on
0 Posts
IS-F and LF-A have used similar testing and development programs, which includes extensive track testing and tuning at the Nurburgring and Fuji Speedway, just to name a few tracks.
IS-F gets a unique cylinder head design, and overall development of all Lexus F vehicles is closely tied to Toyota's motorsport activities.
The LF-A as a supercar will likely have many unique parts. It seems not that much is shared with the IS-F. LF-A is rumoured to have an F1-derived V10 that makes over 500HP and revs to over 9000 RPM. LF-A is also rumoured to have an F1-derived sequential manual transmission.
The LF-A will prove what Toyota has learned from F1, and it will also be a pinnacle of Toyota's engineering and knowledge.
IS-F gets a unique cylinder head design, and overall development of all Lexus F vehicles is closely tied to Toyota's motorsport activities.
The LF-A as a supercar will likely have many unique parts. It seems not that much is shared with the IS-F. LF-A is rumoured to have an F1-derived V10 that makes over 500HP and revs to over 9000 RPM. LF-A is also rumoured to have an F1-derived sequential manual transmission.
The LF-A will prove what Toyota has learned from F1, and it will also be a pinnacle of Toyota's engineering and knowledge.
08-07-07, 07:15 AM
#38
Tech Info Resource
iTrader: (2)
I'm hoping for 430+ hp, and my guesstimate still stands at 437 hp. I don't think they will have any problem getting that amount of power from that 5.0L motor. One thing we need to keep in mind is that output will be limited by the gas mileage and emission targets (no gas guzzler tax and ULEV II). 431 hp is the minimum because IS-F engine revs at least 500 RPM higher than the 410 hp regular 5.0L v8.
410 hp * (7000 RPM / 6500 RPM) = 441 hp
Even if the regular 5.0L V8 has only 400 hp, that would be
400 hp * (7000 RPM / 6500 RPM) = 431 hp
If Lexus created something like the M3s gas guzzler engine satisfying only LEV II emissions, the IS-F could easily have 475+ hp.
Plus, given the ULEV II emissions, I would bet that an aftermarket exhaust could uncork even more power, no problem. I wouldn't be surprised if this one simple bolt on added another 20+ hp, easily. I think the aftermarket will be very good for this car.
410 hp * (7000 RPM / 6500 RPM) = 441 hp
Even if the regular 5.0L V8 has only 400 hp, that would be
400 hp * (7000 RPM / 6500 RPM) = 431 hp
If Lexus created something like the M3s gas guzzler engine satisfying only LEV II emissions, the IS-F could easily have 475+ hp.
Plus, given the ULEV II emissions, I would bet that an aftermarket exhaust could uncork even more power, no problem. I wouldn't be surprised if this one simple bolt on added another 20+ hp, easily. I think the aftermarket will be very good for this car.
Also, ULEVII has nothing to do with exhaust emissions. It's all about evaporative emissions which means the intake guys will have a hard (if not impossible) time making smog legal intake parts. As is typical Toyco, I would not expect more than 2.5 - 3% from an exhaust change and even that is quite a bit. Many exhausts do nothing but make more noise.
08-07-07, 11:42 AM
#39
Lexus Champion
Join Date: Dec 2006
Location: NY
Posts: 3,370
Likes: 0
Received 0 Likes
on
0 Posts
08-07-07, 12:53 PM
#41
Advanced
Yesterday I was exchanging emails with a internet sales manager at Lexus of Maplewood that my family and I have dealt with in the past. Here is what he total me about the ISF. The region that he is refering to is MN.
"The IS-F is going to be limited in our region we are getting one, they are going to be priced anywhere from 55-60 thousand. They are going to have around 450 horsepower 0-60 in low 4's....WOW this is going to be the machine and it will arrive between Dec 07 to March 08."
Based on this info and what other have said on this thread, I am guessing that the ISF is going to come in between 430HP and 450HP
!
"The IS-F is going to be limited in our region we are getting one, they are going to be priced anywhere from 55-60 thousand. They are going to have around 450 horsepower 0-60 in low 4's....WOW this is going to be the machine and it will arrive between Dec 07 to March 08."
Based on this info and what other have said on this thread, I am guessing that the ISF is going to come in between 430HP and 450HP
!
08-07-07, 01:15 PM
#42
Lexus Fanatic
Join Date: Jan 2005
Location: A better place
Posts: 7,285
Likes: 0
Received 0 Likes
on
0 Posts
At this point, I am 99.9% confident it will have between 430 - 450HP
. It would be quite a treat if Toyota surprises and goes above even 450HP 
.
08-07-07, 08:33 PM
#45
Driver
Join Date: Jul 2007
Location: MD
Posts: 146
Likes: 0
Received 0 Likes
on
0 Posts
IS-fan, you are beyond doubt a genuine aficionado of the upcoming IS-F and like you I am confident Lexus can buff the base 389hp 5L up to some pretty impressive numbers while maintaining niche leading gas mileage performance. Aside from the hp, what also intrigues me is the thought of how much of the LF-A's performance engineering has been incorporated into the IS-F. Lexus has spent untold millions to develop their flagship performance model and surely a little bit of that has trickled down to the IS-F.
Yes, I am pretty excited about the IS-F. I've been trying to learn all that I can about it and am hopeful that it will be a nice alternative to the German competition. As far as my numbers go though, they are just guesses, and not really very scientific, as lobuxracer pointed out.
It's not that simple unfortunately. See graph below, and note how the torque is dropping very quickly above 4k rpm and even takes a turn for the much worse right at redline. Toyco will necessarily have to give up some torque at the lower rpm ranges and will likely need to raise peak torque about 250 rpm (or so) to get the numbers you want. There isn't any reason they couldn't do this, and with 8 gears in the gearbox, I doubt it will be a big issue, but still, it's not just simply adding 500 rpm and getting more.
Also, ULEVII has nothing to do with exhaust emissions. It's all about evaporative emissions which means the intake guys will have a hard (if not impossible) time making smog legal intake parts. As is typical Toyco, I would not expect more than 2.5 - 3% from an exhaust change and even that is quite a bit. Many exhausts do nothing but make more noise.
Also, ULEVII has nothing to do with exhaust emissions. It's all about evaporative emissions which means the intake guys will have a hard (if not impossible) time making smog legal intake parts. As is typical Toyco, I would not expect more than 2.5 - 3% from an exhaust change and even that is quite a bit. Many exhausts do nothing but make more noise.
I did oversimplify a bit, but I still believe it will have very, very close to 437 hp. The other [unscientific] reason I think it will have 437 hp is based on a formula using the 3.5L V6 in the IS350:
I know this is unscientific, but if Lexus was able to get the exact same output per liter from the big 5.0L V8 that it gets from the 3.5L V6 in the IS350, then the IS-F would have 437 hp.
306 hp * (5.0 / 3.5) ~= 437.14 hp
I think they can, and this and the other unscientific information that I have is what I'm basing my estimate on. All anyone can do at this point is guess, but that's what makes it fun, and it's all we can do right now. I agree that they will likely sacrifice some torque for more power.
You are probably right about the benefit of an exhaust. I would guess that 15-20 hp would be typical, but more is possible. I gained close to 30 hp on my old (1997) Mustang Cobra with an aftermarket exhaust, but it had a supercharger on it and made 420 whp.
Last edited by is-fan; 08-07-07 at 08:40 PM.