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Tech Forum : More fuel efficient 323i - while keeping the Kjet

- BMW E21 Community
   - Tech Forum
      - More fuel efficient 323i - while keeping the Kjet
g323   Posted Thursday, May 3rd 1:31am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 136
   
California
323i 1982
Hey all, what are some upgrades i can make on my 323i 1982 to make it more fuel efficient? I want to keep my trans and diff how they are, and i dont want to take out the kjet. Ive heard something about putting a different block on the car? which one and what kind of difference would i be looking at?

any other suggestions?

BruceH   Posted Thursday, May 3rd 2:00am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 1123
   
Atlanta, GA USA
81 323 Baur, 85 745
There isn't much you are going to be able to do. You can lean it out some. Keep your right foot out of the pedal and it will do wonders.

Boost_me   Posted Thursday, May 3rd 2:32am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 201
   
Victoria, Australia
1981 BMW 323i
How long have you had the car for? I know that when I picked my 323i up that I gave it 'a bit'......Now I'm back to 'normal' everyday 'speed limited' style driving like all the other good citizen's around here....lol.....I did notice bit of a fuel effecency change when I converted from 'leaded' to 'unleaded' fuel's.....mind you I WILL NOT put anything in her but 98RON........it was running on 95RON in 'leaded' form......

You only need to 4000RPM really unless you want to 'hear that sweet exhaust note'......Dont worry it's a normal thing, I'm sure alot of the people that drive these car's will tell you they love the way they sound when you wind them up...... Doing 3500RPM in 2nd gear though, I'm doing at leat 60KLM/H and then doing 3500RPM in 3rd I'm going about 100KLM/H if not a little bit more. This is that MAX speed limit on all Australian road's until you get into the counrty-side when it raises ever so slightly to 110KLM/H WOO HOO 10KLM/H FASTER!!! "LET'S MASH THA PEDAL BRO".....ahh not quite, maybe these little car's are a bit too 'spirited' for Australian road's.......

Umm what did I just say?? Someone slap me......hahaha

Na man just feather the pedal unles your racing, public road's = danger at high speed's....Keep it for the track......You could also convert to 'unleaded' fuel if you havent already.....Other than that, the only other thing I can suggest is, if you love the 323i body shape so much park the 323i and go and find a cheap 320i with a M10 in her, less power = less fuel consumption, genrally anyway...(Driving style will always play a large role in fuel consumption).....Good luck dude, there the only thing's I can think of right now......

P.S: I am in no way saying that your are a 'hoon' or fast, dangerous or bad driver in anyway, I'm simply statng a fact that it is very tempting to just mash the pedal on these car's and I'm sure everyone has fallen culprit to it, more than once.....

aussie323i   Posted Thursday, May 3rd 3:51am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 567

australia
1979 323i
Boost_Me... your car will also run fine on 95 RON! I generally run 98 but I have also run normal 95 RON 'premium' and the 323i has never looked like pinging. I've never been game to even try 91 as my engine's compression is probably around 10:1 with a slightly decked block and shaved head + e30 9.8:1 pistons.

g323- As for fuel consumption- well I guess the block swap you're referring to would be to change your motor into a 2.0L M20.... I don't think the potential fuel savings would be worth the effort to do that!

My previous M10 320i used around the same amount of fuel as the 323i does... as Bruce pointed out- the lighter right foot does wonders. With the torque of the M20 I don't stick the boot in as much as with the old M10- hence the similar fuel economy.

I did get a slight improvement in fuel economy when I switched to the L-Jet injection of around 1L / 100km. A switch to Motronic may help even more, but you have already ruled that out I guess.

If you want cheap running costs, maybe switch to LPG (Propane!)... I have owned a couple of cars over the years on LPG and with modern systems, the performance hit is nowhere near as bad as the nay sayers claim. In fact, a nissan I owned with a properly sized system you could not tell the difference between petrol and LPG at all- and that was a 1200cc engine... not some enormous v8 with masses of torque.




ArnZ   Posted Thursday, May 3rd 3:51am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 93
   
Qld, Australia
BMW 323i
hey

if you read your owners manual theres a section in there that talks about driving fuel efficently, it shows shifting gears @ 2150rpm is the way to save fuel

ive tried this and has awarded me with good fuel consumption.

theres also a graph in the manual that shows the fuel consumption in each gear, 1st gear drinks down 17-20L/100kms if you drive upto its maximum speed.

it also says "Do not drive up to maximum speed in 1st gear - use it only for starting off."

and you can always lean out your mixture like BruceH said.

pjs323i   Posted Thursday, May 3rd 4:01am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 51
   
Canberra, Australia
'81 323i
ummm i like to change around 2500rpm for my 323i and about 3000 for my 318i. It offers good economy and is good for the car. But it also helps to change smoothly, if you drive a manual correctly you should not ride the clutch or drop it (dah!) but it will feel like a well tuned automatic... and be very efficient

Not to put you guys down about your driving, or sound like an arrogant so and so (i dont know how you drive after all) but you'd be suprised how many people can not drive a manual properly...

Just my opinion.

g323   Posted Thursday, May 3rd 6:43am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 137
   
California
323i 1982
Agreed on the lighter foot, what i really want the increase for though is a 600mile drive i do every once in a while, where i want to get there FAST because its a long drive and i get tired. However i also would like to cut down costs. I have heard that a bigger, strangely enough, block could allow me to get better mpg. Anyone heard of similar ideas?
Also what about a different exhaust?

Boost_me   Posted Thursday, May 3rd 6:50am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 204
   
Victoria, Australia
1981 BMW 323i
I 100% back you up when you say that alot of people simply don't know how to drive manual's.....I think it's quite funny when a 'good' driver comes to me and claim's to have done this or that, then put 'em in the seat and they just make the car cough splutter and jerk like a learner......

For highway driving at speed's I have read a feul consumption thing about the 323i and it claim's that if you drive at 90KLM/H you should get somthing like 7ltr/100KLM but then if you raise it too 110-120KLM/H your drinking somthing like 11.5-12ltr/100KLM.....In your case you would arrive a little later (approxamatly 1 and a half hours later) but your saving nearly half the fuel, and half the running cost by driving 20klmh slower.....Could get frustrating.....Maybe it's time to by some 'soothing' music so you can take the trip nice and calmy instead of 'FAST'......Take in the sight's, isn't that what a trip's for??


P.S: Another idea, why dont you cut the trip into 2 day's of driving and stop halfway at a motel or somthing?? Is there anything like that on the way?? Or you could get a freind with a caravan and just 'Park-up' somwhere for the nite......There's heaps of things you could change to make it 'easier' for yourself.....I just realised that your worried about running cost's so motel cost's could be a problem.....I just don't see why you would consider going to the trouble of changing the block for gas-milage, That's a fair amount of work there......

g323   Posted Thursday, May 3rd 7:04am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 138
   
California
323i 1982
Going back to my old home is 600 miles including a n international border crossing which is from 1-6 hours in line. I go there and back over a weekend. The sooner i get there, the sooner i have at home you know...kind of harsh, but I'm a full time student and I work. I have to go home for weddings, graduations, such, all the time....If i go 60mph i could technically get there in 10 hours if i average that. If i push the average to 90mph i can get there in 6 hours 45 minutes(best i ever did was 7)(LA traffic sometimes hits bad too!)

You do this 2 times back and forth, put term papers in there, and a 6 hour border line....You don't want to slow down. Its stressful i tell you. Usually i leave at 3pm on a Friday and come back at 12 noon Sunday.

But if there is any way i can get better gas mileage id really love to know! My mind is always on this topic, and i agree that I should probably get a more gas efficient car.... or start flying, the only thing is right now gas is still cheap in the US, even with the 92 premium gas(unleaded) that i put in it(the highest octane for sale) its 3.60$USD a gallon


g323   Posted Thursday, May 3rd 7:34am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 139
   
California
323i 1982
here, this is what i was thinking. Keeping the kjet, but buying and putting in the ETA block sometime.

The 2.7 L M20B27

wouldnt make a difference?

Hadrian   Posted Thursday, May 3rd 7:41am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 32

Australia, Melbourne
E21 323i
Do you have standard differential?
You could put a diff from an E12 and get a taller ratio...

AlaskaBimmer   Posted Thursday, May 3rd 7:52am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 20
   
Anchorage, Alaska
1981 323 Baur, 1978 320i, 1979 320i,
I have a 2.7 L stroker in my 323i and it gets about 17 mpg on a good day cruising on the highway....I'm tuned a bit on the rich side and I admit the pedal goes to the floor more often than it should...

TJ   Posted Thursday, May 3rd 8:37am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 24

NY, USA
82 528e2i 84 320i/4 80 320i
Going to an overdrive transmission if you don't have one already would help. Sounds like you wanted to avoid swapping the trans but I would expect that to be easier than the block. And a 2.7 block is for torque, it isn't going to get you better mileage unless you buy a whole 325e

melloh   Posted Thursday, May 3rd 10:20am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 549
   
California, USA (San Jose)
1980 320is, 1991 318is
Here's what I do. Southwest.

Gas has become expensive enough and my time valuable enough that flight costs makes economic sense.

aussie323i   Posted Thursday, May 3rd 3:31pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 568

australia
1979 323i
pjs323i wrote:
ummm i like to change around 2500rpm for my 323i and about 3000 for my 318i. It offers good economy and is good for the car.
Just my opinion.


Your BMW handbook says that you should rev the car past 4500 rpm from time to time to ensure you don't get any carbon deposits... especially if you get stuck in heavy traffic.

My old German friend who rebuilt my motor for me (and has been reconditioning BMW and Mercedes engines for 40 years) told me with my new engine to give it a rev sometimes. Quote... "it is what it is MADE to do, if you give it a thrash occasionally, your motor will love it and it will love you". Now you must picture the quote with a 65 year old German accent.

Just my 2 cents

*for the record... no I don't thrash my car all the time, generally I change gears around 3000rpm, but I certainly see north of 5500rpm occasionally with a nice warm motor and a clear stretch of road

*No while pulling 6000RPM you are not getting good economy


g323   Posted Thursday, May 3rd 6:58pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 140
   
California
323i 1982
ha, so it looks like the 2.7 block is out. melloh, i often want to do southwest, but adding renting a car and it comes out more than gas, and it takes 1.5h to the airport, 1.5 hour wait, 1 hour flight, 1 hour bag and car, 1.5 hour drive there. 6.5 hours

Im thinking the differential if i have to swap either engine or diff would be easiest. whats the most gas efficient diff i could get then that is plug and play?

realcrouton   Posted Thursday, May 3rd 9:19pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 121
   
Washington, USA
1977 320i, 1981 323i, 1991 325ic, 2000 328i
I see two issues here that you are not going to make a significant difference about no matter what you do. The main issue being that you are moving the same amount of mass (size and weight of the car) whether you have an M10 an M20, an ETA, Motronic etc... Because you are moving the same amount of mass regardless of what power plant you have it is going to take the same amount energy to get your car rolling down the highway, and thus use a comparable amount of fuel. The suggestions given will change your fuel consumption a little, but I don't think you are going to see the gains you are hoping for.

The other major issue is driving 90 MPH. As you probably know driving at speeds like that is extremely inefficient. I can't think of a car off hand that even claims to get good fuel economy while maintaining speeds of 90 MPH.

You might consider getting a VW diesel Rabbit (and keeping the E21 of course!) for the purpose of commuting and stick to 60 MPH. Actually, you won't have much choice as I doubt a VW Rabbit would go over 60 if you wanted it to!

Anyway, good luck!

-Dave

BarryA   Posted Thursday, May 3rd 10:39pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 187

Sacramento CA
81 320
No matter what you do, you're probably only going to get a small incremental improvement in fuel economy for any given over-the-road speed.

Three primary factors affect fuel economy - aerodynamic drag, engine efficency, and rolling resistance. Aerodynamic drag becomes an increasing factor as speed increases - don't remember the formula, but it's not a linear increase (drag increases as a square of speed??)

Unfortunately, there's a limited amount that can be done to reduce the drag coefficent (CD) on a 30 year old body design without massive body work, and not many options for reducing rolling resistance, either - if you don't already have one installed, a front air dam can help manange airflow around the body, and inflating tires to optimum pressure and insuring the aligment is correct can reduce rolling resistance a bit.

As posted elsewhere, if your car's currently a 4 speed, installing an overdrive 5 speed can help, as will going with "taller" gears in the differential (3.64 in place of a 3.91 or 3.45 in place of a 3.64) and/or larger diameter tires on the rear, all of which reduce the RPM per mile (bear in mind that either the higher geared diff or larger rear tires will have a negative effect on acceleration).

Realisticly, probably the best you can do to maximize mileage is to keep up with all the small stuff (filters, plugs, tire inflation, alignment, synthetic fluids in the trans and diff), and try to find the best trade off in speed between decent milage and getting to where you need to go in a workable time period.

g323   Posted Friday, May 4th 1:13am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 141
   
California
323i 1982
Ok, so keep car tuned, will do

Increase aerodynamic efficiency-

does lowering the car help this?

lastly, i like my dogleg(5 speed), but i can deal with a different differential, what diff should i look for optimaly? ive got stock, i think 3.64 right now, what is the best i could find that would pop right in?

thanks again for all the help!

g323   Posted Friday, May 4th 1:20am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 142
   
California
323i 1982
actualy, citing the gearbox m20 page of this website;
If fitted with a sport gearbox, the ratio was 3.25:1.

my car is the 323i with the dogleg sport, so i should have the 3.25:1 right? can i get a more gas efficient differential than that?

Greg323i   Posted Friday, May 4th 5:14am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 335
   
Melbourne, Australia
1982 Hennaröt 323i
Nah, but you can get a standard 5 speed, with a proper overdrive, and give me your dog-leg!!

Boost_me   Posted Friday, May 4th 7:17am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 205
   
Victoria, Australia
1981 BMW 323i
Not to sound noobish but how do you tell if you have a dog-leg box?? I have a 5 speed and have always wondered what version it is.....

Greg323i   Posted Friday, May 4th 7:49am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 336
   
Melbourne, Australia
1982 Hennaröt 323i
On a dog-leg box, first is under reverse, ie to the left and down. Second through fifth are in the rest of the 'H' pattern.

NSR21L   Posted Friday, May 4th 1:27pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 29
   
Sydney NSW
BMW E21 323i
Boost_me wrote:
How long have you had the car for? I know that when I picked my 323i up that I gave it 'a bit'......Now I'm back to 'normal' everyday 'speed limited' style driving like all the other good citizen's around here....lol.....I did notice bit of a fuel effecency change when I converted from 'leaded' to 'unleaded' fuel's.....mind you I WILL NOT put anything in her but 98RON........it was running on 95RON in 'leaded' form......



I used to fill up normal 95RON in my 320 but i always used a high octane addative, just that made my car all that more better and when i removed my spark plugs for inspection no black carbon there just beautiful peachy colour

although this has not much relation to this topic but thought i would share that with you all

Hadrian   Posted Friday, May 4th 3:06pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 34

Australia, Melbourne
E21 323i
g323 wrote:
Ok, so keep car tuned, will do

Increase aerodynamic efficiency-

does lowering the car help this?

lastly, i like my dogleg(5 speed), but i can deal with a different differential, what diff should i look for optimaly? ive got stock, i think 3.64 right now, what is the best i could find that would pop right in?

thanks again for all the help!

3.45 is the tallest. Then you can cutoms fit another differential... which will probly cost more than you will save in petrol money...



Buy a Corolla

Marquis_Rex   Posted Friday, May 4th 7:59pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 526
   
UK
BMW 323i 2.7-as featured in Total BMW Nov 2002,Porsche 911/993TT
My E21 gets over 30 mpg regularly while maintaining high average cruising speeds of about 130 km/h-80mph. That's 30 miles to the Imperial gallon. I have no idea what it is to the US gallon- I think the US gallon is 3.8 litres and the Imperial is about 4.54

Lets be honest there IS a world outside the USA, and the cars were designed in Germany. 90 mph is dog slow.

I don't know why my car is much more economical than the original 2.3 litre.
It runs standard K Jet, but slightly leaner.
I have standard transmissions- however I use syntehtic gear box oil. I have an Alpina front air dam- you have to rememeber on an E21 with its aweful 0.46 Cd value almost any change will improve it quite significantly.
The other change you can do to make some siginifcant gains to the aerodynamics is to blank off the grill at the front on the inside where it's NOT ducting to the radiator- as the air enters here and simply buffets around under the bonnet for no good reason. The VW golf Mk2 did this to very good effect- it achieves a CD value of 0.34 even retaining its bluff boxy shape.
The engine is a 2.7, however it's running around a 10.8:1 Compression ratio- this will give about 4 % benefit. I use thin viscosity Mobil 1 oil- this will make some difference, and I used a long duration schrick 284 camshaft which will HELP fuel economy at part load by reducing pumping losses/increasing residual gas content at part load.
For a fuller spec check my profile/viedw car.

The other point is that I use an modified E30 ignition distributor. It has a bigger part load advance capsule and is running ALOT of ignition advance at part load and quite alot at full load- on the borderline of knock (about 28/29 degrees at 3500-4000 rpm) on 95 RON octane.
I have no other explanations as to why my fuel economy has gone up disprotionately and has stayed good.

g323   Posted Friday, May 4th 10:09pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 143
   
California
323i 1982
Ok, so the runing questions that i have are.

how much is 30mpg(imperial) in US gallons?

Will changing from a bbs to any other front end spoiler make my car more aerodynamic and thus better gas mileage?

Will lowering my car get me better mpg?


melloh   Posted Saturday, May 5th 3:16am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 550
   
California, USA (San Jose)
1980 320is, 1991 318is
Dont quote me on this, but I doubt those changes will make a big enough difference for you to notice. Maintenance and driving behaviour are probably your most effective mileage boosters. The front air dam would probably do more for aesthetics and some high speed stability than reducing drag, but I could be wrong. Let's hope someone here has an answer based on actual science, though.

Greg323i   Posted Saturday, May 5th 6:45pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 338
   
Melbourne, Australia
1982 Hennaröt 323i
You could put some 155R13s on.

Seriously, if you're that worried about economy then you should get a Daihatsu Charade. Half the engine equals have the fuel.

melloh   Posted Saturday, May 5th 8:31pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 551
   
California, USA (San Jose)
1980 320is, 1991 318is
Along those lines... something I am seriously considering is a motorcycle for short commutes (like schol and maybe work). Don't get me wrong, fun- and cool- factor are definitely part of the motivation. But, low insurance, low fuel consumption, ease and economy of parking (no parking fee @ school!), and option as a traffic-slicer are also great motivators.

g323   Posted Saturday, May 5th 10:36pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 148
   
California
323i 1982
thinner tires makes a big diffreence? Yea definatly thinking about the moto too. good luck on exames btw mellow

BruceH   Posted Sunday, May 6th 12:01am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 1124
   
Atlanta, GA USA
81 323 Baur, 85 745
Skinny tires inflated to the max will make a noticable improvement to your MPG along with all of the other suggestions.

The best idea is to buy a newer more fuel efficient car if MPG is a major consideration.

g323   Posted Sunday, May 6th 9:13am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 149
   
California
323i 1982
So, hehe, for the moment then the best I can do is put my 13x5.5 175R13 instead of my 185R13 13x6

we'll see what difference it makes! they will no be my safety against hidroplaning and gas mileage tires!

Boost_me   Posted Sunday, May 6th 11:57am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 209
   
Victoria, Australia
1981 BMW 323i
You may slide, but at least it wont cost you much.....
I am seriously thinking about putting my baby in the garage for everyday commuting too, But instead of 2 wheel's I'm going to opt for 4 still, Likley somthing 1500cc like an Nissan Pulsar/EXA (Maybe even an ET Turbo)....

I also have a Dogleg box (In my 323i atm) I didnt know that until now, lol
Although in my box reverse is next to 1st, so to the left and up.....Still I dogleg?? I think so??

I really don't think going from a 185 to a 170 will show much improvment in fuel consumtion.....As depending on the sidewall hight they'll likley be that same rolling radius.



melloh   Posted Sunday, May 6th 5:59pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 552
   
California, USA (San Jose)
1980 320is, 1991 318is
In addition tot he radius, I think he was also referring to tread width and hence contact patch size. Less contact = less friction = less resistance = less fuel. Also not sure if it would be noticable, but I'm betting it would if it were between 205 vs 175, though.

g323   Posted Sunday, May 6th 9:09pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 150
   
California
323i 1982
Dogleg is pattern is

134
r25

hehe when i first got the car it didnt have the emblem,,,man i thought i had a "'''d transmission hehehehe

hehe yea i don't expect much gain, but some! ill be getting thinner via the thinner rims, and by the thinner tires! its a cheap option as I already have the rims and tires sitting around.

EDIT: Oops I wrote that Wrong,
Dogleg pattern is

R24
135

Boost_me   Posted Monday, May 7th 9:23am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 210
   
Victoria, Australia
1981 BMW 323i
Yeah my shift patturn goes....

R135
-24-

What's this called? Just a 'Normal' 5 speed??

I can see where your comming from with the tread width being smaller, but wont the rolling raduis change things also?? e.i higher overall height= more road cover than a smaller diameter??
Example, you would cover only say 80-90% the same distance on a smaller rim e.i 13 than you would on a 15-16inch rim because the overall size of the wheel is bigger you will get more road covered for you 1 rotation of the axel??

I think this would play a part in it too??

pjs323i   Posted Monday, May 7th 11:02am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 51
   
Canberra, Australia
'81 323i
aussie323i wrote:
pjs323i wrote:
ummm i like to change around 2500rpm for my 323i and about 3000 for my 318i. It offers good economy and is good for the car.
Just my opinion.


Your BMW handbook says that you should rev the car past 4500 rpm from time to time to ensure you don't get any carbon deposits... especially if you get stuck in heavy traffic.

My old German friend who rebuilt my motor for me (and has been reconditioning BMW and Mercedes engines for 40 years) told me with my new engine to give it a rev sometimes. Quote... "it is what it is MADE to do, if you give it a thrash occasionally, your motor will love it and it will love you". Now you must picture the quote with a 65 year old German accent.

Just my 2 cents

*for the record... no I don't thrash my car all the time, generally I change gears around 3000rpm, but I certainly see north of 5500rpm occasionally with a nice warm motor and a clear stretch of road

*No while pulling 6000RPM you are not getting good economy


Yeah i have heard that...and i do that (with a nice clear stretch of road or course...a few bends in the mix just ad's to the fun)

pjs323i   Posted Monday, May 7th 11:06am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 51
   
Canberra, Australia
'81 323i
Boost_me wrote:
Yeah my shift patturn goes....

R135
-24-

What's this called? Just a 'Normal' 5 speed??

I can see where your comming from with the tread width being smaller, but wont the rolling raduis change things also?? e.i higher overall height= more road cover than a smaller diameter??
Example, you would cover only say 80-90% the same distance on a smaller rim e.i 13 than you would on a 15-16inch rim because the overall size of the wheel is bigger you will get more road covered for you 1 rotation of the axel??

I think this would play a part in it too??


Boxes are as follows:

SPORTS
R 24
135 (or something like that, i know that first is where 2nd usually is)

ECONOMY
R135
24

4SPEED
R13
24

pjs323i   Posted Monday, May 7th 11:07am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 51
   
Canberra, Australia
'81 323i
correct formatting errors:

Boxes are as follows:

SPORTS
R 24
-135 (or something like that, i know that first is where 2nd usually is)

ECONOMY
R135
-24

4SPEED
R13
-24

g323   Posted Monday, May 7th 8:23pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 152
   
California
323i 1982
mmm, i think there is a sports, and that there is also a dogleg sports.

the dogleg is always the sports haha

R.24
-135

hdx   Posted Tuesday, May 8th 7:11pm [Edit] [Quote] [IMS] [View car]
Junior Member
Post nr. 8

ca. usa
323i + 320 race car
lean in way way out count the # of turns on the co and the bypass screw so you can turn it back when you want to run it hard and dont rev past 4000. Make sure all your fuel pres. are right on. Thats what I do to mine and I got big gains in mpg. I also use 87 fuel for day to day driving.When I want to drine it hard I richen it way up to were it almost wont idle and swich to 92 fuel wakes it up a lot takes about 30 seconds 3mm allen and a flat head. keep them in your tool kit.

imaradiostar   Posted Tuesday, May 8th 9:01pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 1043
   
Nashville, TN
81 323i, 82 525i, 85 524td, 90 535i
A properly tuned fuel system makes a huge difference- if you can borrow a wideband oxygen sensor and a CIS pressure test set you can really carefully tweak how the fuel system works. My car runs about 16:1 under moderate load but goes to around 13:1 with the throttle down thanks to the vacuum compensation in the WUR. Yes, I had the warm up regulator apart a LOT of times before I achieved this. The other thing you can do is use 6 clear bottles and adjust the cylinder to cylinder flow so that all 6 cylinders get equal amounts of fuel.

As mentioned above the ignition distributor has a large effect on partial throttle operation- it can make a big difference in fuel consumption.

jamie

nsbone   Posted Sunday, May 13th 5:10pm [Edit] [Quote] [IMS] [View car]
Member
Post nr. 453
   
KL, Malaysia
e21 323/6 316, e34 520i, e32 730i
Yup...

I got myself 2 small bikes under my garage.. a 1984 GPZ550 and 1984 GS(X)550ES... and now,i commute everyday to work.. it's doing someting like 10L for 200km, or about over 40mpg.. and cutting through the traffic jam...

On making the engine more fuel efficient, perhaps putting a lightened pistons, 288 cam, make any difference, could it? put lightened everyting, means good throttle response=heavy on foot= NO fuel efficent.. haha..


melloh wrote:
Along those lines... something I am seriously considering is a motorcycle for short commutes (like schol and maybe work). Don't get me wrong, fun- and cool- factor are definitely part of the motivation. But, low insurance, low fuel consumption, ease and economy of parking (no parking fee @ school!), and option as a traffic-slicer are also great motivators.

pjs323i   Posted Monday, May 14th 2:52am [Edit] [Quote] [IMS] [View car]
Member
Post nr. 51
   
Canberra, Australia
'81 323i
imaradiostar wrote:
A properly tuned fuel system makes a huge difference- if you can borrow a wideband oxygen sensor and a CIS pressure test set you can really carefully tweak how the fuel system works. My car runs about 16:1 under moderate load but goes to around 13:1 with the throttle down thanks to the vacuum compensation in the WUR. Yes, I had the warm up regulator apart a LOT of times before I achieved this. The other thing you can do is use 6 clear bottles and adjust the cylinder to cylinder flow so that all 6 cylinders get equal amounts of fuel.

As mentioned above the ignition distributor has a large effect on partial throttle operation- it can make a big difference in fuel consumption.

jamie


yup i just leaned my motor down with the throttle bypass screw because i've been spending about $AU80 (around $70US or 65L of petrol) a week on petrol, and thats being a conservative driver!!

Now i'm using a lot less i've just started my first full week since the tune down so i'll come back with some figures soon. I expect it to be around $40/50 which is still a fair bit compaired to some of my friends, but when your used to paying $80 its a huge improvement


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