Derestricted RCF

[tomRCFcarbon]

Does anyone know if this is possible...little point I know, but I wonder what the top speed would be without the electronic intervention?

[I did do a topic search before posting this but the site-wide search is seriously backward and  after being warned not to perform another search for nine seconds(!?!) I gave up!]

[NemesisUK]

Someone with Techstream should be able to find out, see if there's an option to remove it.

Is the RC-F limited in all regions?

[MNMJ]

The limiter was quite noticeable at 177 mph on the speedo. My guess is that 185 would be no problem. What that is in real mph is anyone's guess.

[Guest]

It's irrelevant really unless you fit very very expensive tyres. The Michelin are rated for 169 I believe.

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[tomRCFcarbon]

1 hour ago, Comedian said:

It's irrelevant really unless you fit very very expensive tyres. The Michelin are rated for 169 I believe.

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I wrote exactly that in the topic description...there’s a lot that’s irrelevant about the car - but it’s still coooooool - on that basis please can we pursue the theoretical (if entirely irrelevant) top speed of the car without electronic interference...? Please let me have that fun..?

[J Henderson]

Y-rated tyres are good for 186mph.

 

[Guest]

Y-rated tyres are good for 186mph.
 

Thought it was fitted with W - my mistake. Must have got that from looking at suggested fitments by suppliers.

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[Guest]

I wrote exactly that in the topic description...there’s a lot that’s irrelevant about the car - but it’s still coooooool - on that basis please can we pursue the theoretical (if entirely irrelevant) top speed of the car without electronic interference...? Please let me have that fun..?

Of course, but you can work it out. Measure rolling distance of rear tyre. Find out gear ratio in 6 and add in the Peak revs. Do the maths - assuming car has the power to turn the gear it will tell you the top speed.

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[Guest]

8th oops

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[Guest]

Need the diff ratio too.

Colin Barber might have all that.

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[NemesisUK]

https://lexusenthusiast.com/2018/05/09/video-lexus-rc-f-hits-top-speed-of-176-miles-per-hour/

 

[tomRCFcarbon]

Well there’s a video of an RCF on dyno that shows the speedo at 325kph. So the theoretical maximum of gear x rolling distance isn’t going to help us...as i think air resistance x lack of HP will be the limiting factor...

[NemesisUK]

Here's a max speed calculator. Fairly meaningless as it ignores drag etc, etc..

http://www.boosttown.com/gearbox_differential/speed_calculator.php

RC-F tech spec

http://media.toyota.co.uk/wp-content/files_mf/1418052436LEXUSRCFUKtechnicalspecifications.pdf

 

[Linas.P]

Just looking to 286km/h runs it seems that they only got into 6th gear at 254km/h , that is just supports what @tomRCFcarbon say - gear ratios will not be the limit. If he does 254km/h @7000rpm in 5th we still have 3 gears to go. if gear rations are anything to go by ( I know they don't translate to real speed, but just as indicator).

5th Gear :    1.231 @7000rpm 254 (I used more realistic road speed of -10% ~228)
then 6th Gear :    1.000 @7000rpm ~281
then 7th Gear :    0.824 @7000rpm ~341
then 8th Gear :    0.685 @7000rpm ~410

https://www.conceptcarz.com/s23539/lexus-rc-f.aspx

0.685 is actually very aggressive overdrive, so no surprise that theoretical speed can be something mental like 400km/h +.

[NemesisUK]

This is the gizmo one needs

http://www.tomsracing.co.jp/products/parts/detailseng.php?mprID=334

 

[Mark G]

The GSF final gear ratio is 40mph per 1000rpm, it revs to approx. 7000rpm so it pretty obvious it wont pull peak revs in 8th gear, or 7th for that matter, you can only max out the car in 6th. 

[Guest]

Well there’s a video of an RCF on dyno that shows the speedo at 325kph. So the theoretical maximum of gear x rolling distance isn’t going to help us...as i think air resistance x lack of HP will be the limiting factor...

Not on its own. 350hp is enough to go 200mph. It's the other losses that add up.

So there is no top speed really if you take the limiter off as air resistance will always change.

A top speed of anything can only ever be in a hypothetical situation unless it's a vacuum.

So you have 2 options. A theoretical gear speed you can never achieve or an approximate window of speed depending on conditions. Mind you thinner air being easier to move through also gives less power to the engine.



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[Flytvr]

Would you have to use super unleaded? 😜

[Linas.P]

super diesel if you have used parts of IS220d...

[Guest]

Would you have to use super unleaded? [emoji12]

Aaaaghhhhhhhhhhhhhhh lol

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[tomRCFcarbon]

I understand that the compression isn’t high enough to warrant super unleaded...

 

🤐

[Linas.P]

At least it is not FWD, otherwise we would need to calculate pushing... and pulling... and pushing.. and would need to get laboratory with soft walls.. 

[Guest]

I know the member who needs accommodation with softwares :D

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[Guest]

Soft walls. Bloody phone

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[Linas.P]

14 hours ago, Comedian said:

I know the member who needs accommodation with softwares 😄

funny enough I was proof reading some T&C for another department and they had a line there:

"... you should not copy or alter any documents, software or hardware we send you via e-mail to you..."

Took me some explaining to do that unfortunately you cannot send hardware via e-mail... sort of related with you "software accommodation". I am sure if that member would transfer himself into software reality - then pushing FWDs would not be an issue there.