CLA45AMG2.0

Posting picture soon!!! Can't wait to test it out at the canyons!!

mctonyb

That's pretty hardcore! What do you figure the weight savings are?

Iggy Higgins

Never mind the weight savings... Imagine what the exhaust will sound like inside the cabin without the seats!!! ha

CLA45AMG2.0

The weight savings is about 50 pounds!!! Yes, the exhaust sounds AMAZING now lol!! Didn't think the exhaust sound could be improved but wow, this just brings the car to life!!!

CLA45AMG2.0

http://www.sn95mustangs.com/index.ph...ar-Seat-Delete

Considering to do this with a lighter material, maybe just some time of drywall or something. Wouldn't mind seeing a custom CLA45 AMG with a rear seat delete kit

Going to get rid of that kidnapping button as well... jk haha

vaelin

Good lord, I remember doing my seat delete on my 1999 Mustang following that guide. My Cobra I ended up buying an aftermarket kit. You can also just give the measurements to a plastics place like TAP Plastics (for west coasters) to fabricate a lightweight set of panels for you.

CLA45AMG2.0

Thanks Vaelin

Btw, the seat delete helps a lot at the canyons!

Trail braking is definitely much easier now as the car doesn't want to push as much, this is with the camber set at -1.5 degrees. I got the SPC camber bolt for the front but I am beginning to wonder if I could have just done it with the stock bolt. Anyways, hope you guys try some extreme things out with your car as well! This was most likely the best mod i've ever done to a car, ohhh and it was free

msk74717

Our rear seats on CLA45 in Australia all fold down so we can lay one side down to achieve beautiful sound throughout the cabin. Worth a try if you have that option.

J_Maher_AMG

Best mid you've ever done!? Really? REALLY!?!?!

Car doesn't have a really low centre of gravity to begin with, and you removed weight in between the wheel base... Thus effectively making the F/R weight distribution to become even slightly MORE biased towards the front end...

I absolutely do not believe you can notice anything different. Professional drivers have a hard time noticing a big difference from lightweight alloy wheels, and that makes a MUCH higher difference than removing static weight inside the vehicle...

Personally, I think the exhaust probably sounds much louder and you are tickled pink by that which is fine, but to say handling is 'much improved' by the removal of 50lbs Max out of the back seat, is in my opinion ridiculous, and I don't mean to offend, but it is.

CLA45AMG2.0

Sourced this from other sites on "MIDS" lol
the answer, of course, is "it depends." there are many factors, besides weight distribution, that define the understeer/oversteer nature of a vehicle (aka the "understeer gradient" or USG).

in general, it is the non-linear nature of the friction-versus-weight behavior of automotive tires which allows us to change the handling of a vehicle with things like (fore-aft) weight placement and (side-side) anti-roll bars. for any total vehicle weight, maximum cornering force can be generated by four equally-loaded tires -- if the tires are all the same size. uneven weight distribution can be balanced with different tire sizes, different inflation pressures, alignment specifications, etc. i don't believe there's a magic weight distribution number that will automatically be better than another, because everything can be balanced with proper tire / wheel / spring / bar selection.

as far as being able to brake later, that's purely a function of how sticky your tires are and the balance of your brake system at the max decel that your tires will support.

are you in a professional field where your employer might pay for you to take a course from the Society of Automotive Engineers? i'm an assistant instructor for the SAE's "Applied Vehicle Dynamics" course, and in this class we spend three days alternating between classroom lectures and on-track exercises, to bridge the gap between textbook and track.



The ideal weight distribution depends on a lot of factors. A lot of the decision depends on how much tire you have to work with. If you are using very limited grip tires, you may want to have more rear bias to get higher cornering speeds. The downside is it reduces acceleration capability, which IMHO is more important. If you can get enough tire, I think that the ideal bias is as much as possible on the front of the car. When I say enough tire, I mean a tire with enough grip to lift the inside front wheel. If you have enough grip to reach the physical limitations of the mass and width of the car, then you are just giving up acceleration by having more rear bias.

As an example, my 86 Civic EP racecar can corner at around 1.7g. This is the point where the whole inside lifts off the ground. That is the physical limit of the car's CG and width, but I have enough tire to genrate that much force on a good surface. I have intentionally moved as much weight as practical to the front of the car to reduce the polar moment and increase the acceleration traction. I am at around 70 / 30 F/R. In my case, the limiting factor is not the tire's ability to generate cornering force, it is the roll stability of the physics of the chassis. Even if the tires do saturate before the physical limit, they may still pick up more acceleration ability than they lose cornering ability as you add weight to the front.

If you can move weight around easily, I'd recommmend trying a few setups and see which is faster.

-Chris





And interestingly, a few engineers I've talked to say that it's more important to get the weight on the front tires equal....rather than the cross weights. From there, you also don't have to worry about moving a bunch of weight from the front to the rear...moving the weight further towards the rear than the car's CG will actually increase the car's polar moment...making it turn slower.







Hope you guys find this enlightening! LOL Haters everywhere these days

CLA45AMG2.0

I actually did research before considering this and spoke to HG motorsports founder and was told what tire pressures they use. DO your hw and don't flame people for knowing their ****. All cars do better stripped out lol what planet are you from bro? lol

There car is stripped out in the rear, i wonder why? lol

J_Maher_AMG

Duplicate

J_Maher_AMG

Just because I don't agree with buying a Mercedes (terrible track car to start with) with four doors and then ripping the rear seats out, effectively ruining the interior and functionality of buying a 4 door sedan to begin with, all to remove less than 50lbs of static weight that's nearer the rear axle, doesn't a make me a hater. Don't be so ignorant.

And where did I say anything about a stripped out car not being ideal for track use? If you wanted a track car, you bought the wrong car to begin with. You will spent countless time and money stripping your car out, making it lighter, modding it, etc only to be destroyed on track by a stock Base Stingray.

Ever look under our fenders? Notice how there is almost no room for significant meat under there? Therefore, your theory destroyed. More weight up front with a power distribution as we have it = more understeer on power and more understeer on corner entry.

You really just quoted a statement made by a guy running a setup for a lightweight track FF car... There's NO POWER going to the rear, of course rear bias wouldn't be helpful then...

Call me a hater all you want, which is ridiculous, but the fact is you have your information mixed up and you should do your own homework before calling others out for flaming. Lol

CLA45AMG2.0

Actually our cars are fwd the majority of the time
Unless there is slip detected, technically making this a fwd car most of the time.

J_Maher_AMG

Actually, you should probably do some more research so you actually know how your car works.

The AWD system is not based only on slip... It sends power to the rear during steady state cornering, full acceleration, cornering acceleration, and when slip is detected. The ONLY time the car is FWD only is during steady state cruising for fuel economy...

Sounds like you need to slap some sense into your own head.

CLA45AMG2.0

Yeah why don't you go tell that to all the race teams that modify a street car and strip out the rear seats bro
Weight distribution, power, awd system, 4wd, rwd, they all strip out the rear seats and pretty much anything they can. Why flame me for doing the same thing ? Want me to bow down to your preconceived notions ?

BTW, this isn't permanent and was purely something that I knew I could do on MY OWN time. To flame someone for doing something they love goes against what this forum is all about. If you think you're going to tell me that taking out rear seats will worsen the handling of any car, i'm sad you are mistaken.

If you live in CALI i'd be glad to hit up the canyons with you anytime. We will see what you really know. Take care buddy, go flame your friends. I'm not one of em.

CLA45AMG2.0

Taken from Corvetteforum.com

If 10 pounds makes any difference in a quarter mile, i'm sure the effect it has on turning is much more noticeable than it is in a straight line.

So many damn haters.



Effect of weight on quarter-mile trap speeds
Most of you are probably aware of the never ending debate on LS2 power that pops up from time to time. Some interesting figures were presented from Chevy charts in the last one from which I made some comparisons. Initially my intent was to prove the LS2 had more than 400 hp, but instead I ended up with some interesting figures concerning the effect of weight on quarter-mile speeds. My calculations actually worked, at least for the C6 Corvette. I may be approaching this all wrong and if I am the mathematicians here can tell me so, but don't let this turn into another horsepower debate. If you read this, take your time to digest the figures. I was surprised it worked out like it did and might end up being useful for those wondering what effect weight reduction will have on quarter-mile runs.

The effect of horsepower and weight on quarter-mile trap speeds for C6 Corvettes

My observation is that there is a one mile-per-hour trap speed difference in the quarter-mile for every ten flywheel horsepower if all other factors are equal. Variables that affect this correlation are weather and track conditions, driver skill and overall weight of the vehicle, which includes driver weight and gasoline volume. Therefore, getting a good comparison between vehicles is difficult without using controlled conditions. This is exactly what GM does when testing the performance of their cars. Corporate drivers make performance runs with all conditions, including overall weight and weather, adjusted to a standard and then the averages of numerous runs are used to come up with advertised performance figures. Using Chevrolet’s performance data for Corvettes is the only way to make a fair comparison between different models of the car.

Listed below are horsepower and weight figures as well as quarter-mile performance numbers for the C6 Z06, 2005 to 2007 model years of the base C6 and the enhanced 2008 Corvette C6. All horsepower ratings are derived using the SAE Certified standard, however Certified ratings for the 2005 to 2007 cars were never published. The 411 hp rating used here comes from a combination of insider information and calculations using the best information available. Accuracy cannot be verified but it should be very close to what the rating would be under the newer standard as it is the only rating that correlates to Chevrolets performance figures after calculating the effects of horsepower and weight on quarter-mile trap speeds.


C6 Z06 – 505 hp & 3132 lbs. (11.7 sec. @ 125 mph)

2005 to 2007 C6 Z51 – 411 hp & 3179 lbs. (12.5 sec. @ 115)

2008 Z51 with NPP exhaust – 436 hp & 3217 lbs. (12.4 sec. @ 117 mph)

Comparison 1 – Z06 vs. ’08 Z51

Quarter-mile speeds are 125 & 117 mph per Chevrolet. With a 69 hp difference (505 – 436) the Z06 should be 6.9 mph faster, but is actually 8 mph faster as a result of a 85 lb. weight advantage.

Comparison 2 – Z06 vs. ’05 to ’07 Z51

Quarter-mile speeds are 125 & 115 mph per Chevrolet. With a 94 hp difference (505 – 411) the Z06 should be 9.4 mph faster but is 10 mph faster as a result of a 47 lb. weight advantage.

Comparison 3 – ’08 Z51 vs. ’05 to ’07 Z51

Quarter-mile speeds are 117 & 115 mph per Chevrolet. With a 25 hp difference (436 – 411) the ’08 should be 2.5 mph faster but is only 2 mph faster as a result of a 38 lb. weight disadvantage.

These comparisons show the effect of weight and horsepower on speed. From my calculations, every ten pounds of weight affects quarter-mile trap speed by .12955* miles-per-hour. However, a pure mathematical formula will never be completely accurate because of variances in real world factors and the probable use of rounded horsepower and speed figures by Chevrolet. However, I believe the results are close enough to show a fairly accurate correlation between horsepower and weight on trap speeds for C6 Corvettes.

*Calculated by subtracting expected mph from actual mph and then dividing by the number of 10 lb. units of weight difference between cars being compared. The resulting figures for each comparison are then added together and divided by 3 to get the average miles-per-hour effect on quarter-mile speed from weight in 10 pound units.

Calculations:
From Comparison 1 – 8 mph minus 6.9 mph = 1.1 mph/8.5 lb.=.1294117
From Comparison 2 – 10 mph minus 9.4 mph = .6 mph/4.7 lb. = .1276595
From Comparison 3 – 2.5 mph minus 2.0 mph = .5 mph/3.8 lb. = .1315789.

.1294117 + .1276595 + .1315789 = .3886501/3 = .12955 average mph change per 10 lbs. of weight

Checking accuracy of speed difference per 10 pounds of weight (.12955)

Comparison 1 – 8.5 (10 lb. units) x .12955 = 1.101175 mph difference due to weight
Calculated speed difference of 6.9 mph + 1.1 mph for weight advantage = 8.0 mph calculated speed difference.
Actual difference using Chevy’s numbers is 8 mph.

Comparison 2 – 4.7 (10 lb. units) x .12955 = .608885 mph difference due to weight
Calculated speed difference of 9.4 mph + .6 mph for weight advantage = 10 mph calculated speed difference.
Actual difference using Chevy’s numbers is 10 mph.

Comparison 3 – 3.8 (10 lb. units) x .12955 = .49229 mph difference due to weight
Calculated speed difference of 2.5 mph minus .5 mph for weight disadvantage = 2 mph calculated speed difference. Actual difference using Chevy’s numbers is 2 mph.

J_Maher_AMG

You are really full of yourself aren't you? Where was I flaming? Where was I being a hater?


Who do you think YOU are? Someone is a hater/flamer because they don't agree with your SUBJECTIVE OPINION? Read my original post genius and stop talking out of your ***. I disagreed with your exaggerated opinion regarding "MUCH IMPROVED HANDLING".


Please show me where I said that it is BAD to remove weight from a car? Where have I said that it will be detrimental to the handling of the car? Do I think that its retarded to say removing 50lbs warrants an "OMG WHAT A DIFFERENCE" statement to handling like you tried to play off? Yup. It is just like someone installing a Muffler and acting as if they gained 50hp... Makes them sound like an idiot.


If you weren't blind you would have noticed in your original thread you created about weight savings, that I SUPPORTED your goals. My only comment was the fact that you claimed it was the "best mod you've ever done to car" and that "handling was much improved", which I thought was ridiculous which is MY OPINION and then you got all damn butthurt calling me a hater and flamer for raining on your glory. And then you have to link a bunch of unrelated articles with different platforms that have NO RELEVANCE to our cars, just to try to justify yourself.


Not everyone is going to agree with your decisions, or your exaggerated opinions of results of what you do to your car; doesn't make them a hater or a flamer.. Pretty damn immature if you ask me.

soolman32

Man... this escalated quickly lol

You are both taking this way too seriously.

AA717driver

Yeah, some of my "dates" are getting resourceful...


TC

AA717driver

This. Numbers don't matter given the variability of driver talent.

Dick measuring contest.

TC

Exotic-metal55

You just need a vacuum formed fuex carbon fiber panel to cover the rear and yes, just like the mustangs have . I found most the parts alone on a mercedes are pretty light, there are just a lot of parts that add up.

10lbs is equal to about .01 quicker ET time in the 1/4 miles on average, so not much. It it usually easier to remove spare, keep fuel real low, drain water sprayer, remove all papers, sun glasses, wallet, loose junk etc and remove as much bodilly waste as possibel, then 100 lbs can be removed= .10 tenth. Don`t ask me how I know all this.