FR-S/BRZ vs. Genesis Coupe

[tranzformer]

Originally Posted by fatoni

from a performance standpoint the solid axle and 115mph driveshaft (which i have never heard before) are only disadvantages if the was was slower, which it isnt. a solid axle is lighter and reduces unsprung weight. ford has made this an advantage imo

1) http://jalopnik.com/5869650/why-do-2...keep-exploding

2) http://www.autoblog.com/2011/12/19/w...ails-at-135-m/

3) http://www.autoguide.com/auto-news/2...mph-video.html

You are right, it isn't really 115mph more like 140mph.



[u2b]-qWhxYElSW0[/u2b]

[fatoni]

Originally Posted by tranzformer

1) http://jalopnik.com/5869650/why-do-2...keep-exploding

2) http://www.autoblog.com/2011/12/19/w...ails-at-135-m/

3) http://www.autoguide.com/auto-news/2...mph-video.html

You are right, it isn't really 115mph more like 140mph.



[u2b]-qWhxYElSW0[/u2b]

i wonder if they have addressed this yet. that last post wasnt sarcasm by the way. i had no idea

[tranzformer]

Originally Posted by fatoni

i wonder if they have addressed this yet. that last post wasnt sarcasm by the way. i had no idea

I know you weren't being sarcastic; neither was I. I was just showing you a few links with info about the issue and a video. Just thought I would be helpful.

[ZDan]

Originally Posted by fatoni

from a performance standpoint the solid axle and 115mph driveshaft (which i have never heard before) are only disadvantages if the was was slower, which it isnt. a solid axle is lighter and reduces unsprung weight. ford has made this an advantage imo

Solid axle *greatly* INcreases unsprung weight. That's one of the major advantages of IRS. With a live axle, the entire rear axle assembly including the differential is unsprung mass. With IRS, the differential and half of the halfshaft weight, ~2/3 of the control arm weights are sprung mass.

The overall weight penalty for IRS is very small, often tremendously overstated. I think this might have to do with how much weight it added on the last-gen IRS Mustang Cobras. But that weight gain included an added-on subframe for mounting.

For a dedicated IRS design (as opposed to IRS added on to a car designed for a live axle), the real weight penalty isn't that big, if it exists at all.

On the Mustang Cobras, the additional required hardware made the IRS version 80 lb. heavier. But unsprung weight was reduced by 125 lb., according to this source, anyway:
http://www.mustangmonthly.com/featur...a/viewall.html

Here's a shot of the Mustang IRS:

[edit: no idea why I can't load this pic! Click on web address below or just search the interwebz for Mustang Cobra IRS images]
Note that the loads from the control arm mounts have to be beamed over to the existing hardpoints in the chassis for the live axle. VERY inefficient load path, resulting in a heavy subframe. With a dedicated IRS car, you'd simply have chassis hardpoints located right at the control arm pivots.

Source for pic also reports 125 lb. reduction in unsprung mass. Seems like a lot, but then a live axle is a heavy assembly...
http://www.miracerros.com/mustang/t_suspension2.htm
"Ford designed this IRS so that it attaches to the 1979-2004 Mustang's stock suspension mounting points. That somewhat compromised the performance of the IRS, but it means that the unit can be bolted into any late model Mustang chassis. The IRS subsystem is about 70 lbs. heavier than a solid rear axle, which contributes a better front/rear weight distribution, and it reduces the car's unsprung weight by about 125 lbs."

[pastuch]

Originally Posted by Deslock

"FR-S/BRZ vs. Genesis Coupe, a narrative by SUB-FT86"

Sub-ft86 has contributed many useful posts to this thread and while I may not always agree with him he does stay on-topic unlike many of you.

[fernan2]

Originally Posted by pastuch

Sub-ft86 has contributed many useful posts to this thread and while I may not always agree with him he does stay on-topic unlike many of you.

+1

[SVTSHC]

Originally Posted by pastuch

Sub-ft86 has contributed many useful posts to this thread and while I may not always agree with him he does stay on-topic unlike many of you.

Agreed, although I also agree with him 99% of the time. (the 1% being the bit about the stang v6 propeller shaft speed load limit.)

[tranzformer]

Originally Posted by SVTSHC

(the 1% being the bit about the stang v6 propeller shaft speed load limit.)

So what are your thoughts on the V6 Mustang driveshaft issues?

[Tbxgz]

wow gotta say the 3.8 has one hell of a rumble

[u2b]NpWgp1AsgRM[/u2b]

[Exage]

I was expecting a Crown Vic with Lights and Sirens 5 seconds after the start of that video.

No idea why...

[SUB-FT86]

Originally Posted by SVTSHC

Agreed, although I also agree with him 99% of the time. (the 1% being the bit about the stang v6 propeller shaft speed load limit.)

Yeah I meant to say Ford put a limiter on the car to 115 mph in fear of the driveshaft issues with the V6 model.

[vq37]

Review from autoguide

[fatoni]

Originally Posted by ZDan

Solid axle *greatly* INcreases unsprung weight. That's one of the major advantages of IRS. With a live axle, the entire rear axle assembly including the differential is unsprung mass. With IRS, the differential and half of the halfshaft weight, ~2/3 of the control arm weights are sprung mass.

The overall weight penalty for IRS is very small, often tremendously overstated. I think this might have to do with how much weight it added on the last-gen IRS Mustang Cobras. But that weight gain included an added-on subframe for mounting.

For a dedicated IRS design (as opposed to IRS added on to a car designed for a live axle), the real weight penalty isn't that big, if it exists at all.

On the Mustang Cobras, the additional required hardware made the IRS version 80 lb. heavier. But unsprung weight was reduced by 125 lb., according to this source, anyway:
http://www.mustangmonthly.com/featur...a/viewall.html

Here's a shot of the Mustang IRS:

[edit: no idea why I can't load this pic! Click on web address below or just search the interwebz for Mustang Cobra IRS images]
Note that the loads from the control arm mounts have to be beamed over to the existing hardpoints in the chassis for the live axle. VERY inefficient load path, resulting in a heavy subframe. With a dedicated IRS car, you'd simply have chassis hardpoints located right at the control arm pivots.

Source for pic also reports 125 lb. reduction in unsprung mass. Seems like a lot, but then a live axle is a heavy assembly...
http://www.miracerros.com/mustang/t_suspension2.htm
"Ford designed this IRS so that it attaches to the 1979-2004 Mustang's stock suspension mounting points. That somewhat compromised the performance of the IRS, but it means that the unit can be bolted into any late model Mustang chassis. The IRS subsystem is about 70 lbs. heavier than a solid rear axle, which contributes a better front/rear weight distribution, and it reduces the car's unsprung weight by about 125 lbs."

sorry i didnt mean unsprung weight, just weight. i was on the way out the door to work. the point is that while solid axles potentially are at a disadvantage, in this new mustang it is not

[Deslock]

Originally Posted by pastuch

Sub-ft86 has contributed many useful posts to this thread and while I may not always agree with him he does stay on-topic unlike many of you.

You may have taken my comment too seriously. Though we don't always agree, we're all here because we share an enthusiasm for cars. It's all in good fun, and I hope SUB-FT86 laughed at what I intended to be a little light hearted teasing.

Originally Posted by vq37

Review from autoguide

Thanks for posting that. Here's a transcript from 3:00 into the video, when he made his main comparison between the FRS and GC 2.0T:

Originally Posted by autoguide_GC2.0T_video_review

Now a question a lot of people are going to be asking is, how does it compare to the Scion FRS? Well I have say, you really can't compare the two cars. Now Hyundai will tell you that the Genesis Coupe 2.0T actually has a better power to weight ratio, but there's just such different vehicles. You know, the Scion FRS really is more of a momentum machine, and in this you feel like more of a serious sports car, but it doesn't... it lacks some of the purity that the Scion has.

And some quotes from the related written review: http://www.autoguide.com/manufacture...ideo-1880.html

Originally Posted by autoguide_GC2.0T_written_review

2.0T models have a better power to weight ratio than the Scion FR-S, while the V6 model beats out the BMW 335i and Infiniti G37.

Originally Posted by autoguide_GC2.0T_written_review

A bragging point for Hyundai is that the new 2.0T has an even better power to weight ratio than the Scion FR-S. The comparisons between the two should probably end there, however. As solid a car as the new Genesis is, it’s a more substantial vehicle and lacks the purity of the FR-S, which excels at communicating with the driver through the chassis and steering.

Originally Posted by autoguide_GC2.0T_written_review

All these factors combine with the unique value packaging of Hyundai’s rear-drive sports car to make it not just a stand-out, but a stand-alone pick. True, in the entry-level range it doesn’t offer the purist appeal of the Scion FR-S, and in top-trim it’s still no G37, but in each comparison there are strong arguments to be made for the Hyundai, be it price, style or the fact that when compared to a car like the FR-S it has an edge when it comes to the level of sophistication.

For reference, their Scion FRS review: http://www.autoguide.com/manufacture...ideo-1809.html