How can I lighten up '89 525?

[Gene in NC]

Want to follow Colin Chapman's advice, "To improve performance, add lightness." Even a little weight reduction makes a car feel lighter handling and a little stronger.

What is the lightest spare? 15" with worn, slick minimum size tire prob a good start.

Replace spare with 100 mi tow on AAA card and can of "fix a Flat"?

Fuel tank 1/2 full max? 11 gal x 6.7lb = 74.3lb

m20 is a peanut sized engine. What is smallest size batt that will do the job?.

Go on a diet? Body weight 170 at 70" so max pot maybe minus 10.

Change diff?
'89 525a already 4.10
'89 525m 3.73, 4.10 is possible.

Chip?

Trade on 535. Good idea but really like feel of lightness of 525.

Alum lower control arms. How much reduction?

2.7 m20 w 2.5 head and TD crank?

Remove engine and install in my 2002. That may be the real deal.

Korman m3 swap into 525. $25,000. Bull s***.

[Kalevera]

I forget the URL for the site, but a guy in germany was converting a 535iM to race car duty; his site has a clip of him doing a lap around the n'ring (maybe do a search on the forums? I forget where this came from). It was apparent that he pulled: all trunk insulation/accessories/spare tire, back seat/rear insulation/door panels, carpet everywhere except the front DS, headliner and trim panels, and I think the seats were replaced with something lighter (again -- I forget the exact details, I may be convoluting them).

There's a lot to remove from the stock E34 to get it lighter; the question is -- how much is worth it and what can you tolerate? :D


best, whit

EDIT: another thing you can do is relocate the battery from under the hood to the rear seat well or somewhere in the trunk (again -- how crazy do you want to get with it?), which should help weight distribution. Check late E30 325iSes out -- the battery's usually in the trunk, I suspect for that reason.

[pundit]

Want to follow Colin Chapman's advice, "To improve performance, add lightness." Even a little weight reduction makes a car feel lighter handling and a little stronger.

What is the lightest spare? 15" with worn, slick minimum size tire prob a good start.

Replace spare with 100 mi tow on AAA card and can of "fix a Flat"?

Fuel tank 1/2 full max? 11 gal x 6.7lb = 74.3lb

m20 is a peanut sized engine. What is smallest size batt that will do the job?.

Go on a diet? Body weight 170 at 70" so max pot maybe minus 10.

Change diff?
'89 525a already 4.10
'89 525m 3.73, 4.10 is possible.

Chip?

Trade on 535. Good idea but really like feel of lightness of 525.

Alum lower control arms. How much reduction?

2.7 m20 w 2.5 head and TD crank?

Remove engine and install in my 2002. That may be the real deal.

Korman m3 swap into 525. $25,000. Bull s***.
If you were going to track it and take out almost everything but the drivers seat you could probably cut out about 200kgs (440lbs) but it would probably no longer be street legal or, as Whit says, tolerable. You might be able to shed around 50ks (a little over 100lbs) without ripping out too much, but that would still involve leaving a lot of things at home that you may actually need from time to time... like a toolkit for example. Believe it or not the standard factory basketweaves are really very light and most aftermarket wheels actually increase the cars unsprung weight and worsen the performance. That's why I decided against replica M-Parallels and went for original forged Throwing Stars. Weight reduction is cheap if you take things out and don't replace them with anything else. It becomes very expensive to replace everything with a lighter version of the original. That means lots of little savings in weight... but not in $$$! Aluminum lower arms may save you about 2-3lbs max at 3 times the cost of standard arms. This will help reduce unsprung weight but so will lighter wheels & tyres. Vogtland springs are supposed to be lighter than factory springs. Factory electric seats weight a lot more than standard seats. Air conditioning systems probably weigh around 40-60kgs (85-130lbs) so rip out your air and save as much weight (and about $10,000) as 50 sets of aluminum lower arms!
Get my point? ;)

Every little bit counts but you need a lot of little bits to really make a difference. Not so easy on a street legal car.

[uscharalph]

Wow this post has got me thinking (I carry too much **** in my trunk and glovebox). I was also thinking about the extra hoses and belt for emergency (Maybe I'll get a carry bag for them and only take them on longer trips). Same for extra tools.

[uscharalph]

I had also heard about lightweight hoods & trunk hatches.

[Nick.Hay]

I reckon an E34 race car would be a HOOT!! Stripped out, caged, big brakes and stiff coilovers. :D :D E30-killer!! :)

[Randell]

is it really worth the effort? these cars are heavy comfortable cruisers, they're not really track demons... i'm sure you wouldn't notice the difference without the spare, but you'd notice when your can of fix-a-flat doesn't work as it says on the label! i can't tell the different in acceleration between having 80 litres of petrol in the tank or 10, so it's probably not worth the effort and inconvenience ripping everything outta the car to make it that little bit faster

my 535 would probably get smoked by the average family sedan in australia (holden commodore or ford falcon), but i sleep easy knowing their cars are crap, ours are not

just get a chip if you don't already have one, cheap and easy

[Lennyz525i]

Change diff?
'89 525a already 4.10
'89 525m 3.73, 4.10 is possible.




How's that diff working out?

[rickm]

Shed the AC.

Remove all of the insulation - that stuff can't be too light. Remove the carpet and liner from the trunk. AL arms would save you a little #, they're easily double the price.

Going AAA with the 100 mile tow is an option...the thing I hate is the wait, it's usually 1 to 2 hours out here for them during the week, not on weekends.

If you get ebola you'll drop from 170 to nothing very quickly. :D

[Gene in NC]

Which diff? Both are stock for year and model. 525a is non slip, 525m is open. Both work very well and were well speced IMHO.
'89 525a already 4.10
'89 525m 3.73, 4.10 is possible

[Anton CH.]

I reckon an E34 race car would be a HOOT!! Stripped out, caged, big brakes and stiff coilovers. :D :D E30-killer!! :)
Except you are forgeting that no one really makes coil-overs for our cars.

[RobPatt]

... and I DO notice a significant difference in acceleration between a full tank of gas and when running on vapor.... Also, just the insulation pad on the trunk side of the back seat weighs probably 7 pounds. I'd say for shedding weight the best bang for the buck would be:
- pull all insulation/carpet/toolbox from trunk
- (don't know difference between allow and steel spare tires, but everyone's selling a 15" bottlecap wheel cheap so you could save maybe 5-10 pounds there...)
- put in a nice head unit stereo (nice upgrade anyway) and pull out the factory amp (5 pound?)
- the power seats weigh a TON! be on the lookout for cheap and nice manual ones?
- move battery to under rear seat or into the trunk....?
- wash and wax so slips though the air better!
- vaccuum so it looks good inside and lose 5 punds of dirt!
- if change wheels get good ones, and quality tires... sometime cheaper tires add 4 - 5 pound for same tire size...
- clean out all the crap you may be hauling around....
- tune up the engine, clean throttle body, etc.
- if you need new exhaust could probably save 20 pounds on a performance one....
- could change PS and AC and alt pulleys for lighter ones w/different rotations....
- use quality fluids and change when needed!
- keep your tires properly inflated!
- could try just removing the power steering belt for a while to see how you like w/o power steering.... less load on engine...

just ramblings, but lots of little things could net you a hunderd pounds...not sure how much that is really worth... like an extra smaller passenger...?

[Gene in NC]

OK, I'll do the minimum battery vs factory spec savings if someone can tell me what the 2.5 plus 525 electrical really needs. For sure the fact batt is over speced.

[dmenheere]

Here's a battery that will save you ~35lbs ...

http://www.stealth316.com/2-dynabatt.htm

and coilovers ..

http://www.mpactmotorsports.com/catalog/product_info.php?manufacturers_id=29&products_id=205

hope that helps,

Dave Menheere

[ukm5]

OK, I'll do the minimum battery vs factory spec savings if someone can tell me what the 2.5 plus 525 electrical really needs. For sure the fact batt is over speced.

The M20 may be a small engine in the grand scheme of things regards power output but its still a big block to turn over, the size is there for a reason...perhaps you could remove the wheels that would save on some weight...after all it wont move half the time anyway with a flat battery.

Theres been a few posts regards this weight saving, however isnt whats in and on the E34 what makes the E34 so unique? remove it all and what have you got? a car that looks like it been parted out, a bare uncomfortable shell that rattles and breezes round the roads....i just dont get it

[RobPatt]

...'cause they're so nice and plush...

regarding "why do that"... he's just asking the question, looking for ideas... nothing wrong there and irrelevant whether I agree or not....

...personally i put the same thought process through, but have decided the returns were minimal and instead to appreciate the car for what it is...

[winfred]

i've seen gutted m5s forsale on the bay, sorta sad, who wants to buy something like that (except a nut like me with the stuff to reassemble on hand) that by dealer pricing is probably missing $20k worth of hard to find crap, plus the fact that it's probably had the snot beat outta it by some wanna be boy racer

[pundit]

Really if you want a substantially lighter car, the only way to really achieve this is to buy a lighter car.
As others have said, the E34 is quiet, smooth comfortable, well built etc. and much of that comes down to construction techniques that do add weight. If you took out all the body insulation and 'comfort' items you would have a noisy, uncomfortable car that may perform a little better but would not be a particularly nice commuter vehicle.
If you were racing one then you would strip the whole shebang back to a bare body shell and just add those 'bits' that would make it a racecar. But for a road car...??

[mikell]

Fill the tires with hydrogen, and the cooling system with tequila. Cheers.

[RobPatt]

....just stay home and fill the driver w/tequila! whoo hoo... :D

[pundit]

I reckon an E34 race car would be a HOOT!! Stripped out, caged, big brakes and stiff coilovers. :D :D E30-killer!! :)
Like this?...

http://home.swipnet.se/~w-104302/race/E34/shawn.gif

What I want to know is how does the driver see through the windscreen?

Yeah a stripped out E34 with a 'cooked' M30 running a 'mutha of a hairdryer' @ around 600bhp would be interesting in the Sports Sedan class.

If you could get the weight below 1200kgs it may be a goer.

[Anton CH.]

Here's a battery that will save you ~35lbs ...

http://www.stealth316.com/2-dynabatt.htm

and coilovers ..

http://www.mpactmotorsports.com/catalog/product_info.php?manufacturers_id=29&products_id=205

hope that helps,

Dave Menheere

Those are sleeves, I am talking about the real thing-a complete kit that just bolts on.

[Zeuk in Oz]

OK for track but think again for driving in traffic if the weight reduction is too huge.
I am going to sound like an old fart when I say this but one of the reasons I chose my '88 525i 5 speed was that it weighed more than the majority of newer ricers and Korean disposables. 1504 kg (approx 3308 lb) to be exact.
No matter how well made a car is, the laws of physics apply and, heaven forbid, if you are in a major accident your chance of survival increases substantially if you drive a car weighing more than 1300 - 1350 kg (2860 - 2970 lb).
According to most experts, this seems to be the magical number.
It obviously also depends on how well the car is made, what active safety features it has etc etc.
Enjoy what you've got, or if you want a Porsche, go and buy one. :D

[DanDombrowski]

That cast iron exhaust manifold wieghs a TON! I'd say if you found someone to weld you up some steel headers, the weight savings alone would be worth it, somewhere near 10-15 lbs.

[mattyb]

damn right. what a waste of time, and all for 525 to go how much quicker. no offense to all out 525 buddies out there.

[jiminEcricket]

i have an 89' 525m (grey market) i don't think they come much lighter than mine. from the factory it has no a/c-manual crank sunroof and rear windows-no cruise control-cloth seats-(they are manually adjusted) no factory alarm and i'm sure many other options that came on a u.s. bound car. for it's size the car is pretty quick. i guess all of those motors and electronics add up.