13FSPORT

iTrader: (1)

So why does the stock exhaust sound much better on the LC when the LC, RCF, and GSF have the same motor what did Lexus do diff with the LC? Also the aftermarket exhaust that are being made for the LC sound diff then the ones that are made for the GSF and RCF............

So I was told by a vendor that if I do the Apexi mid pipe with the Tom's axle back on my GSF it will not sound like this LC check out this link let me know what you think.............

Hoovey689

iTrader: (16)

Lexus gave it 4 more hp and 9 more lb-ft

13FSPORT

iTrader: (1)

I knew that LC has a slight increase in power but I don't see 4hp and 9tq would make that big of diff I can see if they increased it by 20-30hp....

05RollaXRS

To be honest, that is proving to be a marketing strategy. The power difference is negligible,. All of the LC dynos seem to show a max of 390 whp, which is similar to what on the average RCF dynos at. Some RCF stock even dyno at 401 whp.

Vitveet

Have to agree here.
Hell, the small amounts if hp they squeeze out if the RCF and GSF over the same motor in the ISF was only to make up the extra weight the RCF/GSF had over the ISF.....😶

V.

05RollaXRS

To a certain degree, I would tend to disagree with that it was only to negate the additonal weight and not to improve upon it. Though not a huge difference, from the stock vs stock videos, the RCF at higher speeds has proven to be significantly quicker over 100 mph. Though, the peak power difference is 51 HP for the added weight, the rev range also stretches wider and the torque band starts lower at 4800 rpm so the area under the curve is broader on the RCF (from 4800 rpm to 7300 rpm where it delivers most of its torque). Dyno wise, I have seen stock ISF have a huge spread between 333 whp to 350 whp so it did not give me a clear median of where most of them usually dyno at.

ForzaF

iTrader: (3)

I wouldve thought the lc got the extra hp bump from the dual intake system or just recalibrated tune.

05RollaXRS

I thought exhaust probably contributed to that as well since my only complaint with my RCF is that the exhaust is too restrictive and too muted (stock seems it is 90% high strung engine induction noise) while LC500 exhaust sounds amazing almost like a straight pipe. The dyno numbers are showing very insignificant difference between RCF and LC500 dyno numbers. Even with dyno variation, LC500 has not dyno'ed over 390 whp while some RCF have max dyno'ed at around 401 whp

LC500 390 whp dyno


Pakeeno's 401 whp TVD RCF dyno

ForzaF

iTrader: (3)

Yes but there would be so many variables in looking at how ppl measured their car on dyno, gear, wheel/tire diamater, temp, da, smoothing factor...Not so many variables as a SAE method a manufacturer would use with their engine dyno procedure.

Some good reading
http://www.pencilgeek.org/2009/09/ex...s-how-the.html

Kramer

iTrader: (15)

LC's have a 10 speed tranny, correct? Possibly a "load" difference with the extra gears in the tranny, power range etc., translating to a sound difference in the exhaust......just thinking out loud! Obviously those factors makes no difference when the car is at a stand-still.....

ForzaF

iTrader: (3)

The difference in stock form is this.

"The engine in the LC 500 uses a dual intake inlet that help improve breathing and allow the engine to produce its fantastic sound. The new coupe features an active exhaust that opens baffles in Sport mode to help give the car a more aggressive exhaust note even in start-up. In fact, even when the vehicle is in Normal mode the exhaust baffles open above 3500 rpm. During acceleration, a Sound Generator involving tuned acoustic plumbing enhances the engine’s raucous melody into an aural thunder that helps distinguish the LC 500 in its competitive segment."
I would think that exhaust tubing route and different length would also generate a slightly different result in sound.
Gsf would have the longest exhaust from them all.

GSFDreams

Guys, I will be getting the Toms Axle back and Apexi mid pipe at the end of May on my GSF. I will be posting three videos once that is done 1) stock, 2) just Toms axle back, 3) Apexi Midpipe with Toms axle back.

LXSDO

Can't wait to hear it..

luislopezt

I had a non-resonated apexi midpipe with a magna flow axle back and it sounded very similar (almost identical) to that video clip I since replaced the midpipe wit a apexi resonated one and the sound is kind of similar but a little more quiet.

Apone

Ditto

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