Ls430

[jsj24uk]

Goodevening everyone.

I was just thinking the other day about the top speed of my 2004 LS430. Is it electronically limited to 155mph or will it go quicker than this if the limiter is removed? That is if it has a limiter.

[Gord]

Goodevening everyone.

I was just thinking the other day about the top speed of my 2004 LS430. Is it electronically limited to 155mph or will it go quicker than this if the limiter is removed? That is if it has a limiter.

What rpm are/will you be doing at that speed ???

[jsj24uk]

When it is doing 70mph, it does 1,800 rpm.

[Chris Skelton]

At THAT speed, make sure 'Dr Bones' has balanced your car perfectly, and tyre pressures are perfect. One flick and you're history. (I know a guy who cartwheeled a Citroen SM at 120......and all 4 survived)

[jsj24uk]

Don't get me wrong, I'm not planning to max it on the next bit of motorway I go on, I was just wondering (in a top trumps kind of way) what it's maximum speed is. My licence is my living.

[Chris Skelton]

Oh well, in that case......it's unregulated and will do 202! (Shhh!)

[Anuj]

are u joking chris. ive wanted to know this aswell. is it really capable of those speeds

[GoldfingerLS]

your ls430 is most probably a 6 speed one since it does 70 mph at 1,800 rpm, whereas the earlier 5 speed ones in the LS400 Mk4 and LS430 Mk1 will do 70 mph at 2100 rpm if im not mistaken.

on the 5 speed autobox cars 155 mph will come up at 4850 rpm. So i'd imagine that on your 6 speed car its a shade less (maybe 100 or 200 rpm less).

Unrestricted my estimate is that it could possibly hit 175 mph ? reason why i say that is because the drag co-efficent is very low on these cars (0.26). Also depends on how accurate the speedo is at the uppper end.

An empty airfield is the place to go ;)

[Anuj]

ours is the 6 speed facelift 2004 one id say around about 175 aswell. no chance of 200s thats m5s e55 e.t.c

[jsj24uk]

Well, if Father Christmas was feeling really generous and sent us the Tom's Supercharger then I would bet that 200 would be a posobility.

[trooper00]

You can work out the top speed but you need some data.

Power, frontal area, drag coeficient, and track. I think this is all you need.

My estimate would be about 160-165 just off the top of my head but I'd have to do the sums

[JellyBean]

Try:

V = cubed root of: 2P divided by rCdA

where:

V= max velocity (m/s)

Cd = coefficient of drag

P = max power at flywheel (w)

r = approx density of air (kg/m3)

A = frontal area (m2)

And multiply answer by 0.92.

Can be surprisingly accurate. Forgive me the laboured presentation but I could not write the formula in properly.

Weight has nothing to do with top speed. (Maneesh, are you paying attention?)

[Dave-Ellen]

fairly sure they are limited (on gearbox ECU to 155) TOM's ecu removes that limiter

[GoldfingerLS]

How would you go about removing the top speed limiter without changing the ECU ? is there anywhere where you could get it flashed ?

[maneesh]

Yes, Jellybean, I'm paying attention. Hazarding a guess with no science behind it but just experience of owning a Mk1 LS, and what I've read about the LS430. I'd guess that with no limiter, it would get to 165.

I have reached an indicated 155 (In Germany) on my old LS only to have to move over for a Supra that wanted to go faster. Yep, the aerodynamics of the LS really help the car accelerate above 120mph.

The LS has always been limited electronically to 155 in this country (the US folks got LS models which were limited sometimes to 134mph!).

[Dave-Ellen]

How would you go about removing the top speed limiter without changing the ECU ? is there anywhere where you could get it flashed ?

To the best of my knowledge you can't get Lexus ECU's "flashed"

The TOM's ecu changes the mapping as well