View Poll Results: What will be the IS-F final HP number
400-405
8
5.00%
405-410
7
4.38%
410-415
13
8.13%
415-420
25
15.63%
420-425
56
35.00%
Over 425, I was thinking like 600.....
51
31.88%
Voters: 160. You may not vote on this poll
What will be the IS-F hp?
07-18-07, 07:41 PM
#46
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Bad news for the high rpm lovers. The 2UR-FSE in the LS600h has the following specs: 94.0 × 89.5 (3.70 × 3.52) bore & stroke.
So, instead of boring the engine or boring and stroking, they just stroked it out to 4969cc and called it good enough to be 5 liters.
The block does have 6 bolt mains just like the 2GR series, and there is a very complete explanation of VVTi-E on the TIS website in the new car features book. Apparently Toyco have discovered that using oil pressure to operate VVTi is not nearly as reliable as using an electric motor that works very similarly to the motor in the throttlebody.
There's a lot more, but without a TIS subscription, well,... it would take a long time to retype it all...
What will be really interesting will be checking the part numbers for the 2GR-FSE, 2UR-FSE and 2UR-GSE pistons. If they are all the same, well, no big deal, but if they are different, we know they're all 94mm bore, but the compression ratios could be different and might be what we'd need to lower compression in the 2GR for boost. Food for thought anyway.
So, instead of boring the engine or boring and stroking, they just stroked it out to 4969cc and called it good enough to be 5 liters.
The block does have 6 bolt mains just like the 2GR series, and there is a very complete explanation of VVTi-E on the TIS website in the new car features book. Apparently Toyco have discovered that using oil pressure to operate VVTi is not nearly as reliable as using an electric motor that works very similarly to the motor in the throttlebody.
There's a lot more, but without a TIS subscription, well,... it would take a long time to retype it all...
What will be really interesting will be checking the part numbers for the 2GR-FSE, 2UR-FSE and 2UR-GSE pistons. If they are all the same, well, no big deal, but if they are different, we know they're all 94mm bore, but the compression ratios could be different and might be what we'd need to lower compression in the 2GR for boost. Food for thought anyway.
Something to keep in mind: the IS-F redlines at 7000 RPM, higher than any other Lexus at the moment, and the 2UR-GSE does so likely without breaking a sweat. Also, I don't know for sure but I am willing to bet that just like the 2GR-FSE, the 2UR-GSE will have cold-forged rocker arms, high tension chain, and high-strength connecting rods allowing for high RPM operation. I'm also willing to bet some of the parts of the 2UR-GSE will differ from the 2UR-FSE, again allowing for higher RPM operation (apart from the obvious differences that will be present in the cylinder head).
After all the TSIBs for VVTi oil control valves failing, and another TSIB for the 4GR-FSE to replace the VVTi unit on two of the four cams, I'd say they're not pleased with the reliability of the oil controlled VVTi system.
Last edited by TRDFantasy; 07-18-07 at 07:45 PM.
07-18-07, 08:05 PM
#47
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International was supposed to release a cam-less engine in 2007 for over the road trucks. It's only a matter of time, the hard problems have been solved, they just need extensive reliability testing to prove the new system's worth. It will be awesome to be able to infinitely optimise cam timing for rpm, load, and power/economy.
07-18-07, 08:09 PM
#48
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hmmm 6 bolt mains. Thought it was 4, I never noticed that it was bolted laterally. Is the crank forged? what about the rods?
Not sure about boost, as this particular 2GR remains naturally aspirated. What I can tell you is the 2GR-FZE (supercharged 2GR-FE) over in Australia in the TRD Aurion makes about 325HP. I'm guessing it can handle boost quite well, although in N/A form the 2GR-FSE can reach very high figures.
Go to www.teamlexus.com/default.html and click on "car". It actually lists the specs at 470+ HP and 350+ lb-ft. The Lexus Quarterly Magazine also had some info on the GT2 cars, but it looks like Lexus.com has taken down that info.
Go to www.teamlexus.com/default.html and click on "car". It actually lists the specs at 470+ HP and 350+ lb-ft. The Lexus Quarterly Magazine also had some info on the GT2 cars, but it looks like Lexus.com has taken down that info.
07-18-07, 08:38 PM
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I'm still trying to dig up the info directly from Team Lexus about the engine and what mods they did to it. The info may have been posted on the Lexus Magazine, and seeing as any IS350 GT2 info seems to have been taken down, unfortunately I may not be able to get a link for you, but I'll see what I can dig up.
International was supposed to release a cam-less engine in 2007 for over the road trucks. It's only a matter of time, the hard problems have been solved, they just need extensive reliability testing to prove the new system's worth. It will be awesome to be able to infinitely optimise cam timing for rpm, load, and power/economy.
Last edited by TRDFantasy; 07-18-07 at 08:45 PM.
07-18-07, 09:42 PM
#51
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Both the crank and rods are forged. I'm quite sure this applies to all of Toyota's new generation engines.
I'm still trying to dig up the info directly from Team Lexus about the engine and what mods they did to it. The info may have been posted on the Lexus Magazine, and seeing as any IS350 GT2 info seems to have been taken down, unfortunately I may not be able to get a link for you, but I'll see what I can dig up.
I'm still trying to dig up the info directly from Team Lexus about the engine and what mods they did to it. The info may have been posted on the Lexus Magazine, and seeing as any IS350 GT2 info seems to have been taken down, unfortunately I may not be able to get a link for you, but I'll see what I can dig up.
Back on topic......
About the retired supra GT and it's modified 3UZ engine...
The racing car's 4.5-liter gas engine develops 480 horsepower and 376 pound-feet of torque...
After a lot of calculations, I've figured that the specific output of the UR series engine is at least 20.5% better than that of the older UZ series.
In theory, a similarly modified UR *should* produce at least 635hp. Making a few assumptions and taking a few liberties with the calculations, I've concluded that the IS-F will ring in at 435hp, +/- 10hp (for the amt of rounding off I used along the way). Any takers?
07-18-07, 11:36 PM
#52
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I want to quote the press release on another forum, but there are numbers missing, a case error or two, etc. I won't be able to verify its authenticity without a link to the original.
.
07-19-07, 10:24 AM
#53
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Its ok. I read all of the magazine releases with the build. I can't recall what mods they did to the engine, if they did indeed state. Lovely to know that both Crank and Rods are forged. Hmm forged internals and dual injection..... does anybody have low compression pistons and a turbo kit in the making for any of these engines yet?
I'm hoping that the IS-F would at least match the C63 within 5hp, however, being more practical, I decided to do a few calculations.
After a lot of calculations, I've figured that the specific output of the UR series engine is at least 20.5% better than that of the older UZ series.
In theory, a similarly modified UR *should* produce at least 635hp. Making a few assumptions and taking a few liberties with the calculations, I've concluded that the IS-F will ring in at 435hp, +/- 10hp (for the amt of rounding off I used along the way). Any takers?
I'm hoping that the IS-F would at least match the C63 within 5hp, however, being more practical, I decided to do a few calculations.
After a lot of calculations, I've figured that the specific output of the UR series engine is at least 20.5% better than that of the older UZ series.
In theory, a similarly modified UR *should* produce at least 635hp. Making a few assumptions and taking a few liberties with the calculations, I've concluded that the IS-F will ring in at 435hp, +/- 10hp (for the amt of rounding off I used along the way). Any takers?
One thing that slipped out of my mind is that Lexus likely does not want the IS-F to qualify for the gas guzzler tax. With that in mind, they'll have to tune it a bit conservatively/towards fuel economy.
And I agree: a race spec 2UR should very easily exceed 500HP. The UZ series has been out for almost 20 years, and there has been a lot of development on those engines. With each passing year, the UR series engines will only get better and we will see more and more of their true potential.
07-19-07, 10:17 PM
#54
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07-20-07, 06:26 PM
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07-20-07, 08:56 PM
#57
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More grist for the hp mill......Several months ago someone posted these general specs for the 2UR-FSE to be used in the IS-F. Not sure how accurate they are, specially the estimated power figures....
5.0L 90 degree V8 with dual VVT-i
Aluminum block and heads
Lightweight forged and sintered connecting rods for greater efficiency, revability, and reliability
Forged steel crankshaft with 8 balancers
Lightweight moly coated pistons
Direct injection and air assisted port injection
Larger intake and exhaust ports and slightly larger valves for increased performance
Performance tuning
Estimated power
430-450hp
400-440lb-ft
Now this is probably the mother of all stupid mechanical questions, but if it does have slightly larger valves, would that not be an indication they achieved the extra 0.4L by enlarging the bore rather than stroking? Please be gentle with your answer, I freely admit to being "wrench" challenged.
5.0L 90 degree V8 with dual VVT-i
Aluminum block and heads
Lightweight forged and sintered connecting rods for greater efficiency, revability, and reliability
Forged steel crankshaft with 8 balancers
Lightweight moly coated pistons
Direct injection and air assisted port injection
Larger intake and exhaust ports and slightly larger valves for increased performance
Performance tuning
Estimated power
430-450hp
400-440lb-ft
Now this is probably the mother of all stupid mechanical questions, but if it does have slightly larger valves, would that not be an indication they achieved the extra 0.4L by enlarging the bore rather than stroking? Please be gentle with your answer, I freely admit to being "wrench" challenged.
07-20-07, 09:50 PM
#58
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No, most engines will go 2mm over on valve size without any additional bore. Street heads focus on velocity at lower rpm, so the ports tend to be smaller. Making them bigger gives more top end, which is why we port and go oversize on valves, but it also takes away from the streetability because the low port velocity in the bottom end of the rpm scale means less torque until the engine revs up. Hopefully this will be possible to "fix" with increasingly variable valve timing and (hopefully) lift.
BTW, most of the features you are describing are available right now in the LS600h. Only the description of the ports and valves is different.
BTW, most of the features you are describing are available right now in the LS600h. Only the description of the ports and valves is different.
07-20-07, 11:37 PM
#59
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Yes, that description above basically fits for the LS600h, as well as the LS460. That description does not give details on the IS-F's unique cylinder head design. Also, the IS-F's exhaust will differ from the IS350. That description also doesn't mention that the engine will have VVT-iE on the intake.
