Commodore rear end setups

[HSV,_I_GOT_ONE]

Hi All,

I was just thinking (yes dangerous I know), and wondering about what lets these high powered commodores and even falcons (427, Walkinshaw, KPM, HDT, Herrod) down when it comes to 0-100km/h times and 1/4 mile times in comparrison to the Euros (AMG's and M's).

With the amount of power these cars have they should be blitzing the european competition even in just the roll on department. Unfortunately I don't have the magazine in front of me but I know there was a comparison between a fully spec'd walkinshaw, GTR and Porsche in either Motor or Wheels and I know that the first two cars are real first class sports cars but I would have thought the Walkinshaw with around 100kw more than the porshce (claimed) and a bucket load more torque would at least hold it's own on a roll on drag but this wasn't the case.

But not only that even compared with c63 or s63 the walkishaw gets walked in the acceleration dept with once again way more grunt under the bonnet. So my question is whats letting the high powered commodores down? Suspension geometry, differential types, tricky traction controlls, tyres? Is there anything from the modifying point of view that anybody can do to try and even the score? I know from my own experiences and of watching other Commodores that on the street they seem to be limited to 0-100 sprints in around 4.5sec. I know guys at the drags can get into the 3's but thats with MT's. I'm trying to compare street spec to street spec. If you want to throw MT's into the equation I wonder what 60ft'ers the Euro's could pull. Anybody seen it done on an AMG or M?

Cheers!

[Podge]

i'd put weight up as a factor, the VE is (with driver) is almost up at the 2 tonne mark, thats a shitload of weight to get moving

[peter b]

to be fair that really isn't a fair comparison. Have a look at the weight difference between the cars that will be more the reason as the merc's porsches are smaller and lighter than our the commodore and not just by a little bit.
They have carbon fiber and what not and we have extra big bumper bars made out of composite plastic and not to mentiong adding weight with big seats so might be something to keep in mind. Our cars take more power to get going

[HSV,_I_GOT_ONE]

to be fair that really isn't a fair comparison. Have a look at the weight difference between the cars that will be more the reason as the merc's porsches are smaller and lighter than our the commodore and not just by a little bit.
They have carbon fiber and what not and we have extra big bumper bars made out of composite plastic and not to mentiong adding weight with big seats so might be something to keep in mind. Our cars take more power to get going

Pretty sure s class mercs are up there with the VE if not heavier. Even the C63's would be nudging VE weights. But that aside with the massive power difference in a roll on drag weight shouldn't be as much of an issue as the momentum is already there pulling the weight along.

[sjhugh]

As mentioned, weight is a big factor, better build materials is a part of what you’re paying for. There is a bit over a 100kg difference between a C63 and a Commodore. The E63 is a better comparison.

Most Porsche variants are a true sports car, designed to get around quickly.

The N/A AMG’s are not short on torque, 600Nm plus for a stock car. The new turbo jobbies are even more impressive with minor mods.

The M3 is well setup.

Still a modded Commodore will push the Euro Sport Saloons in a straight line but at the end of the day there is more to these cars than just power and you get what you pay for.

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[HSV,_I_GOT_ONE]

Still a modded Commodore will push the Euro Sport Saloons in a straight line but at the end of the day there is more to these cars than just power and you get what you pay for.

.

Thats the missing piece I'm wondering about. I want to know what it is that euros have got in the way of setup that can get these cars moving off the line and at pace when there is a distinct power advantage.

HSV seems to have it covered in the braking department now with comparable stopping distances to Porsches. So now in the evolution of things what do they need to get these things moving quicker if the power is already there.

But on that take a modded VT-VZ for instance. They would be as heavy as a C63 maybe even a smidge lighter but you won't get a VT-VZ accelerating harder than 4.5sec 0-100 no matter how much power you have or street tyre footprint. Whats the limiting factor there?

[sjhugh]

The AMG does go like a scalded cat, the C63 feels considerably lighter. The unsprung weight in the rims is noticeable, the AMG makes power straight up and the list goes on. These cars are put together to a plan, they are not just a collection of performance parts. You almost need to ask AMG and the other Euro manufacturers to get a definitive answer. I’m guessing you’ve driven some, if so, you’d would have instantly felt the difference. The whole cars are built different to a Commodore and HSV are stuck with the donor car.

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[sjhugh]

On another note, AMG no longer mods a Mercedes-Benz. The cars are now built from the ground up. The C63 is based on the C Class interior and panels, the rest is different, longer Chassis Rails and such. M cars and other performance Euros do the same, they have a big advantage over the Commodore which is designed as a family sedan.

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[HSV,_I_GOT_ONE]

The most impressive rwd car I have driven is a ferrari 360 and yeah thats what amazed me the most was just the amount of grip you had in the back end. There was no messing about just plant the foot and go. Hit the next gear and no wheel spin just pinned into the seat and watch that white line start to blur. Do that in my clubby (head and cam combo) and I'm practicing for powercruise power skids.

I've been thinking about chasing more power but I think the chasis is more than stretched as is. Was thinking of upgrading to a VE but even they seem to be limited in how fast they would accelerate as well.

I'm now thinking is there much price difference in modifying a VE or just buying a stock second hand V10 M5 or an Audi RS4 for the amount you would spend on a new commodore or falcon and modifying it that could do the exact same thing without the compromise. Yes I know maintaining one would be a different story.

[Vulture]

I remember when I was younger my dad used to talk about "German kilowatts" being different from other makers' kilowatts. i.e. Porsche in particular seemed to understate their output figures on sales brochures. Now the Japanese makers are in this category also (GTR etc).

The BMWs, AMGs Porsches etc are all designed more comprehensively to perform; from the tyre choice, suspension setups, R&D is much higher, more engineers, more cost, they are just a more cohesive setup from the get go. Walkinshaw is a great outfit but they could hardly be testing their packages to the same degree as the Germans do with AMGs etc. But I must admit to being disappointed as you say, with a roll on. Horsepower should count for something there (if indeed they are making the claimed HP).

[Vulture]

Do that in my clubby (head and cam combo) and I'm practicing for powercruise power skids.
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Your clubby would be making a fair bit more at the treads than the Ferrari though! But it shows how a matched overall package can be damn fast and do more with less.

[AGIT8D]

You are comparing a MASS produced chassis which is used for a run of the mill Omega entry level family car, to a high end European sports car with history, experience and huge dollars worth of R&D.

That alone should assist you to conclude that the time differences are acceptable. Holden sedan's are not built and tuned to get lots of power to the ground and handle corners nicely at 160km/h - remember also that Euro roads do allow these types of speeds, so the cars need to be safe there. Aussie's (broadly) like a V8 note and lots of tyre smoke, and Holden provides that at a good price. For anything else the Commodore will never hold a candle to a Euro sportscar.

[ls1 VN]

Check this out

http://ls1tech.com/forums/street-racing-kill-stories/1468007-best-drag-race-ever.html

[AndrewMSS]

Awesome video - great find

[BLACK 346]

I feel your pain mate, my H+C LS1 was undriveable at anything more than half throttle and quite dangerous in the wrong hands. I ended up spending nearly $700 getting Pedders to fix it. I am sure it doesn't grip like a Ferrari, but it is a massive improvement over what the VT is from the factory. Have a read of my comments at the end of this thread if you have time :)

http://www.ls1.com.au/forum/showthread.php?t=149365

[HSV,_I_GOT_ONE]

I feel your pain mate, my H+C LS1 was undriveable at anything more than half throttle and quite dangerous in the wrong hands. I ended up spending nearly $700 getting Pedders to fix it. I am sure it doesn't grip like a Ferrari, but it is a massive improvement over what the VT is from the factory. Have a read of my comments at the end of this thread if you have time :)

http://www.ls1.com.au/forum/showthread.php?t=149365

Thanks for that. I already have a camber kit fitted by Fulcrum and it was a slight improvement traction wise but only slight.

So what else can be done to try and get some reasonable rear end grip in our sedans? Tru Trac diff? Bigger tyres on the back? They are the only two things I can think of to modify? Would there be a noticebale difference in doing this or will it only be marginal?

Ideally I just want to find out if its humanly possible to get a commodore to accelerate 0-100 in around 4.0sec or faster. Or is this out of the realms of physics full stop?

Sorry if it sounds like a silly question but I'm just wondering if it is possible and what sort of mods would be required.

[spiv]

It's not just the KW figure that matters, it the torque curve which has the greatest influence for standing start acceleration, take for example Fords supercharged Coyote motor in the GT & GS fords it develops 545nm's from just 2,200 rpm and holds this all the way to peak power. Compare this to the HSV clubsport which has more torque 550nm's but at 4,600 rpm, this is the reason why the Ford is consistently quicker than the HSV Clubsport even though on paper it has less peak torque and HP. The area under the torque curve is most telling and NOT the peak HP figure. The expensive European vehicles usually have rear suspension set ups that can fully utilise the power that they make, unlike a Commodore which is much more of a compromise. I know first hand I have spent bulk $$$ on getting my HSV to hook up, without axle tramp on the street and I am happy to say that I can launch hard off the lights and my Clubby hooks up hard, just remember that the better your car launches the less power it will need to run good times. For example my brother has a 2009 911, it is rated by the factory at just 245kw's for it's 3.6 liter engine but due to it's light weigh and well designed chassis it can crack 0-100 bang on 5 seconds, just goes to show you how important a well designed chassis is in the real world......:1peek:

[Vulture]

So what else can be done to try and get some reasonable rear end grip in our sedans? Tru Trac diff? Bigger tyres on the back?

Wider and higher quality tyres WILL make a big difference. With my XR6 turbo it has made a big differnce going from the 245 harder stock tyres to a high quality Yokohama tyre in 275 with a 9.5 inch rim - big difference when accelerating in 1st gear. An example of how much quicker properly chosen tyres and rim size beats bling every time.

[duke5700]

Tyres will be your biggest improvement for dollars spent.

[BigJim]

I would put it down to traction control/launch control that contributes to 0 to 100 times. My bosses S65 AMG launches awesome and is seamless to 100 and more. I think it comes down to the electronics of the European cars over the Aussie ones.