Power Band.....

[D19AKO]

Hi all been six weeks with the car now and enjoying it but my only real major concern/ adjustment is that I want to find a way of making the power band more usefull --- its so high up the rev range as well as the torque I find lacking, so dont really go anywhere unless Im above 5000rpm and then the redline is quick and unless you keep the power on,it drops off too easily. If you can keep the power on its absolutely great but my roads are rarely clear enough to allow me to do so....

Coming from a Gs450h - the hybrid and 300bhp from engine meant i was always able to put my foot down at any point and go..... And the is f doesnt do that at all. No regrets tho.

So does anyone recommend how i can get more low down torque ??...

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[Stuno1]

You can't change the power delivery of the engine in the way you want. There are no maps to alter power delivery. Being a NA power plant it's just the way it is.

Only thing I am aware of is the Apexi throttle controller which sharpens up initial acceleration. Also, if you want more 'on tap' power just leave it in sports mode as the car will hold lower gears for longer.

Stu

[D19AKO]

Yeah i figured this will be the case but was seeing if anyone had a mod which helped in low down torque ..

Will have to enjoy it the way it is ! Thanks

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[noby76]

Hi all been six weeks with the car now and enjoying it but my only real major concern/ adjustment is that I want to find a way of making the power band more usefull --- its so high up the rev range as well as the torque I find lacking, so dont really go anywhere unless Im above 5000rpm and then the redline is quick and unless you keep the power on,it drops off too easily. If you can keep the power on its absolutely great but my roads are rarely clear enough to allow me to do so....

Coming from a Gs450h - the hybrid and 300bhp from engine meant i was always able to put my foot down at any point and go..... And the is f doesnt do that at all. No regrets tho.

So does anyone recommend how i can get more low down torque ??...

Sent from my iPad using Lexus OC

GS450h produces instant torque at relatively low speeds from the batteries so long it has full charge i believe it can discharge it at relatively any speed. i guess thats why you can plant your foot at lower speeds and the GS takes off having a CVT transmision might also contribute to this since there are no flat spots like a normal transmission might have when gears are changed. ..

with the IS-F not having batteries to give it that instant shove when you plant your foot at lower rpm might give the sensation of being sluggish at lower rpm but based on performance figures of both cars the IS-F might not be as sluggish as you might think. for starters it generates more torrque than the 450h Battery and engine. and most VVT-i engines are capable of generating 80-90% of their overall torque from around 1500rpm lets just say the enigine makes 80% of its overall torque at 1500rpm thats still 400NM of torque which is still higher than what the GS450h's Battery discharges on its own at lower speeds. if 90% OF 500NM of the tourque comes in at when the secondary valves open to allow more air which i believe is 3600rpm thats makes it 450NM being generated by the engine.

so long as the right gear has been selected at lower speeds/rpm in M mode, the IS-F will out accelerate the GS450h in pretty much any situation..you might not feel it as much but you are accelerating pretty quickly.. if it does 0-60mph in around the 4.6 sec mark then the torque is there at lower rpm.. :)

[Stuno1]

Nice post, power is more accessible in manual as you can keep the car in lower gears if you want for a more instant response.

Stu

[Peter P18]

The Apexi throttle controller produces a sense of greater urgency when accelerating, but this is purely down to less pedal input being required to get the throttle to respond.

It won't alter the torque or HP you produce, but it does make the car feel more responsive to your right foot.

Coming from some big HP turbo'd cars, the ISF does feel slower to accelerate, but it isn't. I think the build quality/level of refinement makes you less aware just how quickly you are picking up speed.

Plenty of M3 owners who can vouch for these being no slouches up and down the M25! ;) Lol.

[ColinBarber]

I think the build quality/level of refinement makes you less aware just how quickly you are picking up speed.

Not compared to a GS though, the GS should definitely feels slower based on refinement and a higher level of disengagement from the road.

The GS is pretty quick off the line and at low speeds. It essentially has a 2 speed transmission together with the CVT so when it is in the low gear the acceleration is impressive for the amount of power it has available.

[noby76]

I think the build quality/level of refinement makes you less aware just how quickly you are picking up speed.

Not compared to a GS though, the GS should definitely feels slower based on refinement and a higher level of disengagement from the road.

The GS is pretty quick off the line and at low speeds. It essentially has a 2 speed transmission together with the CVT so when it is in the low gear the acceleration is impressive for the amount of power it has available.

I agree besides the level of disengagement from the road, i recon pound for pound the GS450h is a fine automobile. if one factors in things like performance, mpg, road tax, practicality..as an everyday car with sprint performance under 6 secs i would have a GS450h.. but one gota love the sound of the IS-F V8 on full throttle.. why does any one need Takeda intake and exhaust lol these F's sound ridiculous even in stock form stick it in Sport M mode and be gone lol

[VamboMan]

Definitely a personal choice comparing the performance of a V6 hybrid with a V8 but for me the sound alone wins the day even with the standard exhaust on the F.

Having spent my pocket money on a H&S exhaust then I can whole heartedly recommend the upgrade for three reasons; the NASCAR rumble, nor more fake tips and the NASCAR rumble. Yes, the upgraded sound needs two mentions.

[D19AKO]

Many thanks all, some usefull points.... But....

Think i may have somehow given the impression I was debating a comparison between the Gs450h and ISF , which i was not doing .

Was after ways of increasing the low end torque or repositioning the torque curve for increasing the responsiveness in town / lower speeds.

Cheers for the tips ....

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[ColinBarber]

There isn't much you can do. Some of the aftermarket exhausts provide an increase in power from around 2,000 rpm all the way up, they may make a small noticeable difference at lower speeds. Aftermarket intakes don't provide any gains at best, most make things worse and are just for show and sound. The IS-F engine is designed to have maximum torque at a high rpm to match power output.