Camouflaged Lexus LFA Spotted at Nürburgring

[Faisal Sheikh]

I just read it in an interview of Tanahashi saying, he wanted the LFA to have a 10,000 rpm redline, but Lexus did not approve it. Given how over engineered the 1LR engine is, I am sure it could handle 10,000 rpm for its lifetime without issues. I think it was to avoid any potential lawsuits or liabilities arising due to something that has never been done before.

The LFA 1LR was durability tested quite a bit up to 11,000 or 12,000 RPM (can't recall). So a 9000 RPM redline is still exceptionally high, but it gives the 1LR very high durability and reliability as good as any standard Lexus model. To this day the 1LR remains the most reliable high RPM large engine.

So bean counters had very little to do with the decision. It was a decision made for reliability more than anything. Don't forget the LFA project had no defined completion timeline and no specifically defined budget.

 

[ssun30]

Doesn't the 1LR need a five-valve head to take advantage of the extra rpm?

 

[TheNerdyPotato]

Doesn't the 1LR need a five-valve head to take advantage of the extra rpm?

I don't think that going past 4 valves does much for performance, since it doesn't increase the maximum valve area. Probably the best reason to go with more than 4 valves would be a variable lift system that could control the individual valves, similar to what some VTECs do. This is an option on the Freevalve heads by that K-something supercar maker that I don't feel like spelling right now...

 

[Faisal Sheikh]

Doesn't the 1LR need a five-valve head to take advantage of the extra rpm?

Adding more valves is not directly correlated with how the high rpm can be utilized. The 1LR already has an incredible powerband. Over 90% of the peak torque is available from 4000 rpm to 9500 rpm. Even close to redline, torque never drops off. At 10,000 rpm, I am sure it is still holding on the torque band very well.

1LR has one of the highest piston speeds in a production car. Piston speeds, internal inertia and cylindrical capacity as well as how well the headers flow all contribute to how high the engine can rev, how quickly it can get up there and also how the engine can continue to build more and more power beyond the rpms where 99% of the engine are gassed out etc.

 

[ssun30]

I stand corrected. Well engineered modern 4V heads can have good breathing at 10k+rpm.

Also interesting to me 11k rpm 4AGE builds are mostly 4V instead of 5V. Anybody knows why?

 

[maiaramdan]

TMG will never stop
And it's part of many TMG/ GR projects

 

[TheNerdyPotato]

I stand corrected. Well engineered modern 4V heads can have good breathing at 10k+rpm.

Also interesting to me 11k rpm 4AGE builds are mostly 4V instead of 5V. Anybody knows why?

I've never worked with those engines, but my google-fu is decent.
http://www.ae86drivingclub.com.au/f...d-vs-16v-head-Big-cams-and-serious-flow/page2

he is talking about the theory of 4 vs 5v not comparing the different 4age models. The 5v head is inferior to the 4 in non boosted form for these size of engines because of multiple things like middle intake valve shrouding, small bucket + spring diameters, poor quench zones/large chamber surface area and split chambers on the earlier engines.

However when Toyota went from the 16 to 20v design they made the intake port shape massively better, added a basic intake VVT, raised the compression and of course that awesome intake. So most of the time the head design that theoretically worse ends in one aspect ends up being superior in use. Take a 16V with the same design upgrades say like a 3sge BEAMS with a quad throttle conversion and you have something that makes real good useable power.

Interesting stuff, and they also reference "billzila" which lead me to this site: http://www.billzilla.org/4agmods.htm
Warning: that site has lots of engine pr0n and neked metal bits

 

[F1 Silver Arrows]

If only the photographer gave any feedback about the sound of the car, the mystery would be solved.

Hey. I can help with that. I found this. Skip to 2:20, 6:40, and 9:25.


This is definitely a prototype testing for aerodynamics, tires, and chassis for future F cars or it could possibly be the beginning of a new second generation Lexus LFA.

 

[GSCT]

The new LFA will probably take 10 years to develop like the first one did. So maybe a 2030 release?

Half of the 10 years is because they scrapped the aluminum chassis was changed to carbon fibre. So, hopefully a new LFA (LFB?) within 5 years.

 

[JJohn341]

I cant wait for next gen F cars. I am pretty sure Lexus does not want the new Supra to be better than the F models, probably one of the reason we are seeing all these testing out of nowhere on the Nurburring.