Author Topic: M43 upgrades list wanted! (Read 20652 times)

e30m3_sportevo · « **on:** July 10, 2007, 05:32:07 PM »

Hi everybody! I'm new here... This is probably the only one forum where to discuss my problem:

I must make track car from E46 318i with M43 1.9 engine. There's no other possibilities because in this class there's only 1.6 16v or 2.0 8v engines alowed.

There's no any info over the web about upgrading thouse engines. Only things that I found is that it is possible to put M47 (88mm) crank and get ~ 2000cm3 capacity.

I can use only original BMW parts. They might be from other models, but they must be BMW no some tuners racing parts.

Will appreciate any info! Thanks!

e30m3_sportevo · « **Reply #1 on:** July 10, 2007, 05:38:40 PM »

Other way is to destroke M42/M44 to 1.6 and upgrade it, but will it be better than 2.0 M43? M43 in stock already has more better torque. I'm just not sure, is that torque that important on the track...

Boyracer · « **Reply #2 on:** July 11, 2007, 11:53:00 AM »

I'm quite sure M43 is 8 valve engine, making it bit inferior to M42/M44 with 16 valves in what comes to generating power...

M43 does feel quite torquey low down but it has been optimized that way. To make big power out of it (or any other small displacement engine) you need to rev it high and that is something 8 valve heads are not very good at

How about 2 liter M52 straight six with plenty of valves hence breathing cpacity? Is it prohibited by rules? I guess you could destroke it to achive smaller displacement and then rev shite out of it :cool:

EDIT: just read that only 1.6 16v and 2.0 8v are allowed... Could be a hassle to fit M42 to E46 due electronics so stroking M43 to 2,0 liter might be more sensible afterall.

EDIT 2: I think it also comes down does extra 8 valves overcome handicap of 0,4 liter displacement? I see some Honda and Toyota 1,6 liter 16 v engines producing around 160 -170 hp in slightly tuned form, after that it gets difficult.

Closest thing to stroked 2 liter 8 v M43 I could think of was 2 liter 8 v Alfa Romeo Twincam and they seem to be capable of 160 with some mild modifications.

I would think first destroking M42 to 1,6 and then fitting it to E46 is bigger hassle than taking already mounted M43 and stroking it? Power capability seems to be quite similar for both.

Master · « **Reply #3 on:** July 11, 2007, 12:11:21 PM »

Hello, nice car you have there,
M43 is a 8 valve engine, I know because I have one.
There are 3 variants of this engine the M43B16 M43B18 M43B19

You should calculate the exact displacement you will get if you install a M47 crank into a M43B19 engine, because I'm not sure you will get 2.0liters.

E46 weights quite a lot, so you should tune for more torque if possible, so 2.0 liter I think would be a better choice for the e46 .

Will they allow diesel engines?, because I know BMW has been very successful with their E46 2.0 diesel engine (it outputted ~300N/m) wining Nurburgring 24h race (in its class) as well as lots of other races.

Boyracer · « **Reply #4 on:** July 11, 2007, 12:22:29 PM »

Quote from: Master;29430

E46 weights quite a lot, so you should tune for more torque if possible, so 2.0 liter I think would be a better choice for the e46.

That is very good point! :eek:

Master · « **Reply #5 on:** July 11, 2007, 12:31:43 PM »

I don't know what to say, it seems this class is not very favorable for BMW.
If they won't allow diesel engines, then I think the only other option would be to build a 1.6 16valve engine, and rev the hell out of it, I don't think that will be easy with stock bmw parts.

engine mod list as I imagine it:
-M43b16 bottom end
-M42/44 head port and polished
-solid lifters stiffer valve springs, etc
-regrind cams maybe (better of course to use most aggressive cams from dbilas)
-light flywheel from a M20 maybe
-M3 ITB's
-well to go further you really should build custom exhaust and intake, but I don't know if it's allowed
-Standalone engine management (if not allowed then find a good tuner to reprogram the stock ECU)
-lots of other stuff you can do to the engine using bmw parts

if you can make custom intake and exhaust, use custom cams, and do a really good head job, then I think you could rev the engine to 8k rpm and pull off close to 150rwhp, and i don't know how much torque that will be either, but knowing the handling a BMW 3 series can achieve, I think that will be enough

e30m3_sportevo · « **Reply #6 on:** July 11, 2007, 04:06:25 PM »

Quote from: Master;29430

Hello, nice car you have there,
M43 is a 8 valve engine, I know because I have one.
There are 3 variants of this engine the M43B16 M43B18 M43B19

You should calculate the exact displacement you will get if you install a M47 crank into a M43B19 engine, because I'm not sure you will get 2.0liters.

Already done. It is 2007 cm3 with +0.25mm pistons. We are alowed 2015, so it is ok.

Quote

E46 weights quite a lot, so you should tune for more torque if possible, so 2.0 liter I think would be a better choice for the e46 .

It weights 1205kg originaly

Car with driver and petrol must be at least 1100kg, so it will be deweighed a lot.

Quote

Will they allow diesel engines?, because I know BMW has been very successful with their E46 2.0 diesel engine (it outputted ~300N/m) wining Nurburgring 24h race (in its class) as well as lots of other races.

No, just atmosferic engines, so turbo diesel not allowed.

I think that way:

Almost all participants drive E30's 320i. At that point E46 is with much more better handling car, it has 150mm longer wheelbase and ~75mm in the front and rear. That M43 is behind(!) front wheels, so handling will be 200% more better than E30's with that 6 cylinder engines. And M43 is just 83kg's while M20B20 ~ 117. Thats a big difference on race car. Also we can drive just 15" rims. It means that E30's must have original 260mm brakes, while E46 has 286mm brakes.

About engine tuning. First of all delete air con, power steering. Increase CR to 10.5 (max), displacement to 2007cm3 with M47 crank, cone sport air filter, some lighter flywheel and polish head/ehaust. Longest diff avaliable (~ 3.9x). Increase rpm a bit. I think there will be ~ 150hp/200nm. 320's have ~ 150-160hp. With almost the same power, i think E46 must feel a lot better.

Is there some more aggressive cams to put in from other BMW's?

What do you think about that?

e30m3_sportevo · « **Reply #7 on:** July 11, 2007, 04:10:43 PM »

Quote from: Master;29432

I don't know what to say, it seems this class is not very favorable for BMW.
If they won't allow diesel engines, then I think the only other option would be to build a 1.6 16valve engine, and rev the hell out of it, I don't think that will be easy with stock bmw parts.

engine mod list as I imagine it:
-M43b16 bottom end
-M42/44 head port and polished
-solid lifters stiffer valve springs, etc
-regrind cams maybe (better of course to use most aggressive cams from dbilas)
-light flywheel from a M20 maybe
-M3 ITB's
-well to go further you really should build custom exhaust and intake, but I don't know if it's allowed
-Standalone engine management (if not allowed then find a good tuner to reprogram the stock ECU)
-lots of other stuff you can do to the engine using bmw parts

if you can make custom intake and exhaust, use custom cams, and do a really good head job, then I think you could rev the engine to 8k rpm and pull off close to 150rwhp, and i don't know how much torque that will be either, but knowing the handling a BMW 3 series can achieve, I think that will be enough

Sadly though no custom intake/exhaust. What is most aggressive cams from BMW that fits in M42/M44? Maybe 262 degree from M3 Evo II? In stock there's 240 i think.

Actually we have one E36 with 1.6 engine. And it goes better than 320's M20B20. The only thing, we are not sure that this is legal engine, so it will be opened soon

Master · « **Reply #8 on:** July 11, 2007, 04:14:02 PM »

No sorry, E30 M3 cams won't fit M42/44, as m3 has different cylinder spacing

I haven't tried though

Master · « **Reply #9 on:** July 11, 2007, 04:25:03 PM »

Yes you're probably right, 4 cylinder engine indeed is behind the strut towers compared to a 6 cylinder, I guess in a e46 that is even more so.
If wheel spacers are not allowed, then yes e46 is better
Also didn't know that stock e46 was that light

Quote

1205kg

Sorry I don't know anything more that can help you

Author Topic: M43 upgrades list wanted! (Read 20652 times)

e30m3_sportevo

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