Itemized Weight Reduction

[djjerme]

Megatron -

There was a lot of changes in the basic unibody of the E30 over the run. As you start working on the different years in Racecar form (basically stripped body shells) you start noticing some of the area's that were different.

I can't point to a specific place that is significantly lighter than a later model, but you see the difference in the inner sheet metal of the trunk area, the underbody and in other odd places.. For instance, mine doesn't have the factory anchor points that were added in later bodies (used when transporting the cars from the factory.) While it may only add a half pound at most, it all adds up. But also, there is changes in the wiring (which was different from year to year) and on a fully outfitted car, materials for interior bits.

Like I said, I can't put my finger on an exact difference, but perhaps next time I have my racecar parked next to my buddies PRO3 car (his is an '88) then I can make notes of the variations..

[2mAn]

The thing that people aren't considering is that my car doesn't have power windows, power locks & no check panel among other things. All those little items add up

[megatron]

Interesting to learn on the early (84-85) cars.

So where's the weight? Is the unibody thinner steel or did the later cars simply come with more stuff?

The reason I ask is because I have been considering building a Street Modified autocross car out of a slicktop 91 318is I have. I like Street Modified because we're forced to have basically full interiors minus back seat, so building to that ruleset then backing off just a little makes for one heck of a sweet street car.

Should I go looking for a slicktop, manual window 84? The Street Modified rules allow update/backdate parts between any years of E30, so I could just do this to my 91, but perhaps it might be wiser to preserve this car and chop up an 84 to build?

FWIW, last Street Mod car I built was a 2720 E36 with an aluminum M52 / S52 and Eurosport Twinscrew. Aluminum doors, lots of carbon fiber, titanium exhaust, etc. I think an all-out approach with an E30 running the Hoosier 275/15 might be able to net a car that's maybe in the 2200s, which leaves 3.0L of effective displacement to make as much power as possible (pointing right at a stroker alloy M52/S52 or M54), or if can only make it to ~2300 maybe an N20. Turbo adds 1.4L of displacement in the weight formula, which is 1800+200*displacement. +1.4L for turbo. -200lbs for <=275mm tires.

[2mAn]

I went from a 2.7i M20 to an aluminum M52 with no gain in weight, but an increase in about 100whp

[whitebulat22]

Shouldn't it be a lot lighter than that? More like 60-70lb.

M20 is 178kg dressed, 165-170kg stripped.
Aluminium M52 is around 150kg fully dressed and I've seen people around the internet claim that the N52 is lighter than the M52/M54 by 20lb?

I haven't personally weighed an alum m52 but I wouldn't put money on it being lighter than an M20. I saw a thread where a guy weighed them and got those results, but the block difference is ~43 lbs (Metric Mechanic source) and that has to cancel out timing chain, timing covers, vanos, bigger head, extra cam and cam hardware which should make it about a wash. Would also make intuitive sense considering other 24v swaps usually report a very slight weight gain, which the aluminum block can overturn but not by a huge amount.

I've been curious about what all the different engines weigh, but through my google research what I've learned is that the most detailed and dedicated weigh-ins will still have a plus or minus 30 lbs attached to them, because none are ever weighed exactly the same way.

[Hooffenstein HD]

the N52, if I can pull it off, should be lighter than the M20 by 20-30lbs. less weight over the front is definitely a good thing.

Shouldn't it be a lot lighter than that? More like 60-70lb.

M20 is 178kg dressed, 165-170kg stripped.
Aluminium M52 is around 150kg fully dressed and I've seen people around the internet claim that the N52 is lighter than the M52/M54 by 20lb?

[J.Rizo]

Currently I have:
I haven't had a stereo in my car for a long time. actually, for more than half of my ownership, I didn't have one. who needs a stereo when you have the song of an inline-6?

exactly how I felt about my AC haha. more than half my ownership without it, and with the top down, who needs AC anyways?

but no no no, I absolutely need music. by myself yeah its 50/50, sometimes music sometimes all motor, but with my friends in the car or my girlfriend, I for sure need music, adds to the fun of my car.

[nando]

Currently I have:
No A/C
manual swap
CF hood
lightweight wheels
shortened strut housings (ix housings are really heavy, so a couple inches here helps!)
GC coilovers (stock springs are big/heavy)

since my car is no longer a DD I'm considering a bit of a diet. nothing drastic, but there's definitely things that I don't really need.

cruise control - I never used it when I drove it every day, and it won't be good for my swap anyway.

All the speakers, speaker wires, antenna, amp - I haven't had a stereo in my car for a long time. actually, for more than half of my ownership, I didn't have one. who needs a stereo when you have the song of an inline-6?

Lighter seats would be nice. Mine are in horrid condition anyway. I'll be keeping the rear seats since my kids love to ride in the car.

Some of the tar/insulation could probably go. I threw out that carpet thing below the rear seats, it was all nasty anyway. I also ripped out the vapor barriers (they were moldy) All of the A/C components are already gone, including the exchanger under the dash. I ditched the electric fan entirely, although I'll have to put that back when I put in the new motor.

the N52, if I can pull it off, should be lighter than the M20 by 20-30lbs. less weight over the front is definitely a good thing.

Currently at 2820lbs, which isn't too bad for an ix. the stock weight is listed at 3050lbs for a 1991, 4 door, automatic. I'd like to get down to 2750ish, which would put it at under 3000lbs with a full tank and me in the drivers seat.

[lcoleman]

Sparco driver, Kirkey passenger seat
No back seat or parcel shelf/rear speakers
No AC (condenser, lines etc), power steering, washer jug, stock airbox (CAI)
MS (no AFM, very slightly lighter)
No radio, QR and Momo wheel
Trunk and backseat tar gone
No spare, jack, trunk mat, etc

Without driver, 2419 lbs. I could still lose more. trunk lining, tool kit, dash, battery (easy 40 pounds!), front speakers, OBC, pin the hood, horns, lighter wheels (my 15x8s are 13.6 lbs)

I know this isn't really the point of the tread, just wanted to provide a data point. And brag. :p

[2mAn]

thats good to know. Ive been contemplating installing A/C in my car and that discourages me. More than the weight, I dont like an unnecessary pulley taking power away from the car.

[blazinxpk]

my most noticeable difference was when i took all the AC components out of the engine bay. i went for a drive and the car/steering felt different on turn ins, almost like it was a bit easier to turn.

[Nick_S]

my 91 318is with 24V, no a/c or PS, full interior, no stereo, spare or jack weighed in at just under 2600lbs with 3/4 tank. Since it's off DD duty again I'll probably take all the stuff out of the trunk again. It was a noticeable difference when it was as light as it could be.

[2mAn]

No freaking way.

way.

[MannyTranny]

I weighed my power steering set up and it was pretty close to 5kg. Pump, lines, belt, reservoir and fluid. That was from a 323i/M20B23.

If you delete AC and PS you can also delete the accessories pulley off the crank which would have to weigh at least 1lb.

Right on! That's not too shabby.

Yea mine (84 MY) has a full interior, 12" lukebox, no A/C, no power steering, and an aluminum 24v motor and weighs 2450 with a full tank.

No freaking way.

[TobyB]

you definitely need to be aware of what chassis you start with

Truth.

My 2/87 eta, sitting next to an 84, last weekeend, is #200 heavier. Kevin's #120 under weight, I'm nearly #100 over, and from looking at them, there is no difference whatsoever. Well, except for my beer belly...

t