Looking to the guys who know. 50/50 Weight Distribution the Best?

[Iamtheonlyreal1]

Well I have some preliminary weight figures for Volvo X, and I wonder if anyone would have some experienced setup feedback to offer? Now is the time to get this thing setup properly, and any insight would be apprecitated.. As a comparison to stock, I also have some figures from a 39,000 mile original car, so we should get a great preliminary indication here.. I must say that I am very pleased with the outcome so far, I think this car is going to hit the mark I was shooting for..

With these weight figures, I have an all original car first, and it is as stock as you can get, so this is a great comparison car.. Volvo X has all its running gear in the car, simulated Fuel weight, seats, complete suspension, Steering Column, Guages, bumpers, ect.. It is really only missing the basic wiring, windshield/back glass, insulation and carpet, so we should be in 200-300 pound difference margin for the added accessories. We are figuring that, by the time we add the missing weight of the missing interior/insulation components, Windshield/Back Glass, HVAC to the central part of the car, that will actually get the Distribution ratio even closer to 50/50.

Here are the two cars in question.. Volvo X has the complete drivetrain and exhaust, unlike the pictures below, that were taken at an earlier date.


http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/001-43.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/030-2.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/026-3.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/030-1.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/022-6.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/020-6.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/022-3.jpg
http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/018-6.jpg




Original Car ________________________________Volvo X
Total Weight 2386lb_____________________________Total Weight 2465lb
Front Weight 1270lb________________________Front Weight 1275lb
Rear Weight 1116lb________________________Rear Weight 1190lb
Weight Distribution___________________________Weight Distribution
Front 53.2% Rear 46.8%_________________________Front 51.7% Rear 48.3%





http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/weight3.jpg




I had a problem getting Volvo X totally level, and that is why you will see the variation in the cross weight, and that is cause by the floor affecting the contact points on the scales.. It was way to cold to switch the cars around, but I will definitely do that on the final weigh in..


http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/weight4.jpg



Something to consider in all of these figures, is that I have added additional weight in areas like the wheels and tires, along with some heavy duty parts like the rear end assembly and other items, so I think a major achievement was made here.. Keep in mind we are at 540 horsepower, with a V8 and heavy duty trans/Rear end assembly.. Also I am running 14in Front and 13in Rear Brake assemblies, ect, so we are gaining alot, with minimal over all weight difference. On the next weigh in, I will probalby put some original style wheels on the car, along with a few other less bulky things, and I think we will find that there really isnt any notable overall gain in suspension and drivetrain.



I was trying to keep this car at about 2700 pounds, fully accessorized and loaded, and it appears I might meet that mark. I wanted to keep the stock body, and not do the drag racing drilling, insulation removal, ect, because I wanted it to be a fully functional daily driver, with even more insulation, accessories, and comfort. I think I am missing between 200-300 pounds of additional necessity to achieve that level of daily driver function, so it looks like it will happen.

With the horsepower here, I actually think that additional/proportional weight would be a positive in performance, so it might be that I voluntarily add more weight at a later date, but I wanted to showcase that it was possible to get all of the listed upgrades, in the same basic package. The additional weight is actually coming from items like the heavier wheels/tires, and a few other bulkier/strength items like the 31 Spline large Axles/9in rear end, and not the fact that there is V8 motor with 5 times the horsepower, or stronger components to hold up.

[214Chevy]

Don't know diddley squat about weight distribution. :( All's I do know is you car is so sick. :yes: I love what you have done to it. :thumbsup: Something out of the norm. :hail: Been following your build thread. :bow: Keep up the good work.:woot:

[Iamtheonlyreal1]

Don't know diddley squat about weight distribution. :( All's I do know is you car is so sick. :yes: I love what you have done to it. :thumbsup: Something out of the norm. :hail: Been following your build thread. :bow: Keep up the good work.:woot:

Damn.. I appreciate the chime in though.

I have done some research, and I am sure that 50/50 is what people strive for in most cases. I am also sure there is nothing better than real experience, and I am sure the level of experience in here might offer just a bit more information to consider, and now is the time to make adjustments.

[GregWeld]

Why don't you ping David Pozzi if he doesn't chime in.... He's real good at this stuff.


L O V E the friggin' awesome Volvo!!! WOW!

[Ron in SoCal]

Herb Adams will tell ya...50/50 is what you want. Also in some cases you can actually increase available traction by adding weight to the rear.

Who'd a thunk?

[Che70velle]

I'm building my first "performance" street car build, so I'm not so sure about street cars, but I owned and drove NASCAR asphalt late models for many years, and I always wanted 50.5% rear weight. Those cars would turn better with a tad more rear weight. Seems unlogical, but its simple physics. I do know that Corvette engineers are striving for 50/50, so there must be something there for street cars also.

[Iamtheonlyreal1]

Herb Adams will tell ya...50/50 is what you want. Also in some cases you can actually increase available traction by adding weight to the rear.

Who'd a thunk?

I have actually run into that information, and am thinking that as light as the car will be, I will be able to add the necessary rearward weight that I wanted..

I am running the Fuel Tank right below the back window, and it is mounted Jaguar style, so it spans accross the car, and is about a 17 gallon tank.. I removed the Mustang Style trunk floor mounted fuel tank, and have a delete plate that centers the battery, in a sub-floor position, right behind the rear axle.. I will have minimal overhange weigth hanging off after the rear axle, which I think is a gain, but I guess that would be an assumption on my part?


Here is the first Mock Up setup, but the production tank will be stainless steel..

http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/008-12.jpg

http://i290.photobucket.com/albums/ll255/Iamtheonlyreal1/Amazon/009-11.jpg

[Iamtheonlyreal1]

Why don't you ping David Pozzi if he doesn't chime in.... He's real good at this stuff.


L O V E the friggin' awesome Volvo!!! WOW!

I am hoping he and a few others chime in, that is what I am nicely soliciting here.. LOL

Appreciate the love for the Volvo, because the Volvo's could use a bit of Real Car enthusiasm also, eventhough they arent Camaro/Mustang/Chevelle/ect. That way they arent the cute car in the back lot of the car show that no one really expects anything of.. LOL I am just hoping this thing will keep up with some of the other notable Pro-Touring cars out there, and I am sure there will be some potential obstacles with weight and wheel base.

[Matt@BOS]

What a cool car!

I follow along to what you're up to every so often, and man, it is looking good.

I'm no engineer but I did stay at a holiday in express, and while I was there I went to a Good Guys show and had a brief chat with the folks at DSE about the weight distribution of my Camaro which has all the go fast parts from their catalog.:lol: My takeaway from the conversation was that cross weight was far more important to them. This isn't to say that front and rear weight bias aren't important, rather a car's suspension setup must be built around that weight bias.

There are cars out there with near 60/40 and 40/60 splits that handle well.

[David Pozzi]

50/50 is a good number. I would up the rear percentage to 55 if it had a lot of horsepower.

[Sieg]

Robert that car is going to be a head turning sleeper! Very impressed with the build. :thumbsup:

My 1800 from back in the day.............
http://sieg.smugmug.com/Other/Cycles-Cars/i-Qm3sf4R/1/M/File0016-M.jpg
Lady I sold it to totaled it three weeks later. :(

[Iamtheonlyreal1]

50/50 is a good number. I would up the rear percentage to 55 if it had a lot of horsepower.

I am running 538 horsepower in this one, at 2700lb or less total weight, and that is why I was thinking that I might actually be adding weight to the rear. I am running 265/35/18in B.F.Goodrich G-Force tires in the rear, so I am thinking I will need to do something to help with the grip in this case, and that might be strategic weight placement.. I didnt want to mini tub, so I cant get the 12in wide rims in that little body, but I think it is a pretty large tire by proportion for this car..

[Revved]

I know you'd love more tech advice but I've just got to say that I love the car! What a great off-beat project! It looks great and I love the sheet metal fab work you've done! 538hp in a 2700 lb car is going to be quick!

Good Luck!

[byndbad914]

here was a thread from a couple months ago on the subject. Getting beyond 50/50 with more rear bias is pretty hard with a front engine car, but the implication is to get as much rear as you can without biasing by hanging weight behind the rear axle - creates a different issue.

I couldn't recall the thread but searched for the Aventador I recalled mentioning :thumbsup:

http://www.lateral-g.net/forums/showthread.php4?t=38643&highlight=aventador

[David Pozzi]

I am running 538 horsepower in this one, at 2700lb or less total weight, and that is why I was thinking that I might actually be adding weight to the rear. I am running 265/35/18in B.F.Goodrich G-Force tires in the rear, so I am thinking I will need to do something to help with the grip in this case, and that might be strategic weight placement.. I didnt want to mini tub, so I cant get the 12in wide rims in that little body, but I think it is a pretty large tire by proportion for this car..

I didn't realize you had that much, so yes, try for more rear bias. You are going to need rear traction & the rear weight will help.

[sik68]

With 265 rear, what tire width are you running on the front? IMO, 50/50 weight distribution needs to be accompanied by relatively balanced front to rear tire widths too if you are looking for the easiest way to get midcorner 'neutral.' Although, once you accelerate on corner exit with 538hp, that 'neutral' will quickly go to 'oversteer' and you're going to need to take care of the throttle or perhaps dial in some steady-state understeer (via more rear weight, and/or tire) if you want to be more aggressive coming out.

For sure, driving style will play a big role in how neutral the car feels.

[Ruslow]

Rear bias is good with that hp level BUT also keep in mind that as you brake, turn, accel, all of those wieght numbers change to.As it will when you have fuel level changes and driver, pass weight changes.Weight disturbtion is also dependent on use of vehicle. A car set up for drag racing will not handleas well on the road or in the twistys.Stan

PS you are talking static weight but keep in mind dynamic changes.

[Iamtheonlyreal1]

I am running a 18x8 front, with a 235/35/18 tire, so and I think that works about to be about a 1.5 inch overall footprint difference, but I would have to look that up.

With this setup, I am actually looking for the best of Daily Driving/Road Course fun, or atleast easy set up for each, by being able to easily add or remove weight if necessary. I will be daily driving this car, and I would like to be able to drive it to what ever event, and the just hit the track within minutes.

[preston]

In a front engine car you will never be able to obtain too much rear weight bias. I'd be impressed if you even made it to 50/50. Bottom line, move everything to the center and low as you can.

[Iamtheonlyreal1]

In a front engine car you will never be able to obtain too much rear weight bias. I'd be impressed if you even made it to 50/50. Bottom line, move everything to the center and low as you can.

Judging by the preliminary numbers, I am going to be right at 50/50 (Front 51.7% Rear 48.3%) initially, and I will have the luxury of adding a bit of strategicly placed weight.. Most of the weight I have to add now, will be in the center of the car.

[Kenny]

50/50 is way over simplified. A car with 55/45 dist with 100% of that weight inside the wheelbase would likely have an advantage over a 50/50 setup with 75% of that weight inside the wheelbase.

Now we have to look at what 50/50 measurement is actually beneficial. Since we are manipulating dynamic load changes of sprung mass(body roll), and that unsprung mass plays a far different role compared to sprung mass. So weighing the car without unsprung mass would give completely different results than the Corvette, even if they both had the same overall weight and distribution % on the scales when fully dressed.

So then to get a full picture you would want to "map" the mass density/location....IE, does the mass map out like a dumbelll, or a bowling ball?

You have a beautiful car and you are nearing the finish line.....For goodness sakes don't get bogged down in something as insignificant as the ultimate theoretical distribution. At this point of your build you are kind of locked in. Your distribution is perfectly usable:relax: