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?


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 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. 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.

[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