Smaller engines are better drivers cars?

[littlefeller]

this is what i found - brought my z with the original 15 inch pepperpots (handling was ok ish) then i brought a set of 16 inch round 5 spoke wheels with 225 tyres - (handling now dangerous ish) took z for mot, it failed on lower arm ball joints, new joints fitted with polly bushes (used polly as i tore one of the rubber ones getting them on) handling now back to where it was. Then when i needed new rubber i decided to re-fit the 15 inch while i re-furbed the 16s WOW what a difference (the 15s with 205 tyres with the new lower arms) it was amazing how much difference it made. didn't like the look of the 15s so acquired a set of 18s 225 at front with 245 at rear (handling is not as good as it was) all wheels were correct off set exept the 18s which are 47 (correct) at the front but 50 at the rear, i just have to avoid large puddles now.

 

[zedonist]

Well where do you want the handling to take place...if your driving in a straight line then there is no handling, handling comes in, when you take bends, so the where is very important if you want to make a true comparison then weight and the proportioning of the weight and as is the track of the car and wheel base of the car all important, it all needs to be considered for an informed argument to manifest.

 

[littlefeller]

if you had driven my car with the 16 inch and duff lower arms you would change your mind on the idea no such thing as straight line handling it was scary.

 

[zedonist]

I have been there, spent a fortune on all the replacements and upgrades, but these cars are over 15 years old now so expected...

 

[littlefeller]

with the 15s i could throw it round corners like no other car i have owned, maybe this had something to do with the aspect ration, much taller side walls, maybe they were able to absorb some wheel twitch, so it may well have hidden some horrors, but gave me loads more feel and confidence.

 

[zedonist]

The flex in the side wall absorbs the side ways load so the prevent the rear breaking away, lower profiles don't absorb and just transfer through, hence the back end can break away easier, Low profiles are pretty, but you have to up your driving game...

 

[Dino D]

Searching the interweb brings up different weights but I came across this:

1.9 - 140 bhp - 1275 kg - 109 bhp/tonne

M52 2.0 - 150 bhp - 1345 kg - 111 bhp/tonne

Z3 2.8 Manual kerb weight 1302kg (192bhp) 150 BHP per ton

Z3 3.0 Manual kerb weight 1360kg (228bhp) 170 BHP per ton

Z3 3.2 Manual kerb weight 1393kg (317bhp) 231 BHP per ton

Z4 3.2 Manual kerb weight 1495kg (338bhp) 229 BHP per ton


The difference between the 1.9 and 2.8 seems very small given that apart from the bigger engine the 2.8 will have heavier gearbox, propshaft, brakes, driveshaft, wheels/tyres, battery etc.
Is the 6cyl made from aluminum and the 4cyl iron?
Surprised the 2.0 is heavier than 2.8 and even the 3.0l - must be different block as the rest is largely the same I would have thought?

Or are these weights are all wrong?

 

[zedonist]

Yes some of your weights are wrong, the ones i posted are from the manufacturers literature, but all things considered the extra weight will be mainly the engine, you have an extra two cylinders, and the crank shaft will be longer and heavier with two extra counter weights (I think they are all alloy), gear box i see as negligible, and wheels tyres, brakes and propshaft will be the same. While the BHP per tonne at WOT (Quoted RPM peak) shows an advantage of the six pots over the 4 pots, it is the BHP developed in each gear that needs to be looked at, and the 0-30 and 0-50 figures shows that bhp per tonne is comparable across all Z3.

IMHO handling characteristics of the cars can be put down to suspension geometry and type at the above speeds and not WOT performance, with the key ones being the ARB thickness, front and rear track, spring height & damper and castor, wheel and tyre choice. Now at higher speeds above 60 mph, as Brian has said the 3.0 feels planted compared to the 1.9 which i find becomes very light above 80mph, this then brings the weight of the cars into play and the positioning of the engine, with the six pot sitting further over the front axle compared to the four pot, and as clearly shown above the bigger engines have a greater power advantage.

The proof in the pudding would be a controlled test, we just need to find a suitable number of courses, twisty, straight etc and run the three main types down each, would be a .ORG Top Gear Top Test, we could even have our own Z3 Channel and of course some say he brushes his hair with a Hedgehog, or uses a blue loo as a breath freshener, all we now he is called BMG...to drive the cars

 

[Brian H]

@Dino D the weight of my car is on a sticker under the bonnet 1580kgs

 

[EnthuZiaZT]

In Some Respects the weight of the car is not as important as where the weight is position in the car. With the sixes the extra weight of the engine sits over the front axle, with the fours the weight is more evenly distributed between both axles. There is one other important aspect to vector into the equation, the ability of the driver to deliver the extra power from the larger engines, smoothly and at the right time when negotiating a corner. To much power into a corner can spell disaster if the driver is not used to driving by the skin of his pants and accurately predicting what the car is or is not about to do.

Mike

 

[Dino D]

@Dino D the weight of my car is on a sticker under the bonnet 1580kgs

That seems a lot more than the 2.8 which is 1406kg.

These are my actual weights below, will check what the sticker on mine says:
As weighed (with ballast for the driver):
Weight of driver: 75kg
1/4 tank fuel.
LF 335kg RF371kg
LR 338kg RR364kg
Cross weight 50,3%
Total weight 1406kg

I read somewhere that the BMW quoted weights are calculated with a full tank and 175lb driver (79kg).

My car has pretty much every option too including AC, electric seats, roof, sub and amp, 17inch wheels etc (and don't forget the high back booster seat for the kids!).

 

[Redline]

(and don't forget the high back booster seat for the kids!).

Kids! - How many does it seat?
We had to buy them one each

 

[littlefeller]

75kg driver try 90kg

 

[Jack Ratt]

75kg driver try 90kg

Try 115kg

 

[littlefeller]

yeh well at 115 your gona need a 2,8

 

[Dino D]

Kids! - How many does it seat?
We had to buy them one each

They have to take turns!

 

[Redline]

They have to take turns!

Make the most of it - its all too quickly before they're learning to drive and eying up your cars!

 

[Dino D]

Make the most of it - its all too quickly before they're learning to drive and eying up your cars!

My eldest has already forbid me to sell it (he's 7).
He loves American muscle and V8's so maybe I'll get round to that V8 conversion with him in a decade or so!

Maybe nows a good time to a couple extras for the other 2 and mothball them. Not sure if they make good first time drivers cars though!

 

[oldcarman]

I think that any zed is a great first car especially if the kid wants to learn how to maintain a vehicle. Get a bulletproof 1.9 z3 and they'll be happy for a long time as well as being able to put gas into it from a part time job. What v8 are you looking at transplanting? My kid brother has already measured mine up for my 600hp BBC but I think it would rip the little car to pieces first time I nailed it. Maybe will look at the 350 chev sbc out of my 57 chev 2dr and put the BBC into it. I'd love to find out how to get a six speed manual into my z3 in order to drop my cruising RPMS. JIM