M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => General Topics => Topic started by: nomad on June 06, 2007, 12:43:53 PM
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I have been reading through some books on E30s I picked up. The E30 Restoration book I have is written by some British guys. It has info on body and engine specs, just a few basic writeups on some hands-on work to the cars.
What cought my eye was where they mentioned the M42 engine was a detuned engine so as not to take anything away fom the upmarket 6cyl and M3 variants.
They mentione the engine does a lot better with a chip (we know this) and the stock header is good (we know this) and a good cat-back is a good addition (most agre on this). What they also mentioned though was that they saw good gains with an increased throttle body bore. Either have the stock one bored out with larger throttle plate or adapt the 6cyl throttle to it. I have not seen anything mentioned about larger TB's or adapting the 6cyl version or a later version to the M42.
Can anyone shed some light on this? It is mentioned that with chip/exhaust/TB they see 155bhp? Can this be all attributed to the chip?
Please enlighten me. I'm down for a junkyard TB finding mission.
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bigger throttle body = more air in so it makes sense. especially since the intake is the bottle neck on these things. I've never seen anyone go to the trouble of adapting an m20 throttle body to it. I know a few of us are going towards individual throttle bodies though. All you'd need for an m20 throttle body is a simple adapter plate made, i believe the TPS is the same on both.
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E30Zone here in the UK can source you one from their online shop... Not advertising, just advising.
Mine is the 4mm overbored stock item and I noticed a small gain, definately. I have the advantage of a chip that was written with the TB in mind though!
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so did you notice a gain from the chip and tb together or the Tb seperatly?
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I think it is advisable to have custom chip if you enlarge the TB diameter.
On part throttle engine measures how much air it is actually ingesting with the help of VAF (and lambda checks if engine is running rich or lean). So when the larger TB increases airflow it is compansated by injecting more fuel -> more power! :cool:
To my understanding on full throttle VAF and lambda are totally ignored and ECU is injecting fuel as it was programmed to do from the factory. The problem is that now it get's more air to cylinder but the same amount of fuel as when it was stock. This means engine is running lean which is dangerous! :eek:
You could avert this by fitting slightly larger injectors or preferable fitting adjustable fuel pressure regulator. So you could increase the pressure of fuel going to injectors. This is not a problem on part throttle, engine will adjust injetor duration to match the pressure. On full throttle it would inject fuel for factory programmed time but since the pressure is higher, there would be more fuel to burn on cylinder.
Best way is to get custom chip made for larger throttle body in my opinion.
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You could also get an M30 AFM case and switch your electronics. The M30 AFM has a bigger in/out diameter so you'll have more air going in. That's what i'm about to do. :)
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You could probably use the M42 TB heater as an adapter plate for the M20 TB.
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i believe the TPS is the same on both.
No, the TPS on the M42 is a potentiometer not a switch.
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I just can't see how a bigger tb on the M42 can benefit as long as there is the barn yard door ahead of it.
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I just can't see how a bigger tb on the M42 can benefit as long as there is the barn yard door ahead of it.
+1
Has anybody megasqirted on of these engines yet?
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I was wondering if anyone has succesfully mounted a m30 AFM, as stated previously? If so, how difficult was it, and did it net any noticable gains? I ask this because many guys running the m20 motor perform this mod and they say it is rarely effictive.
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From my understanding the TB and a M30 AFM are both worthless mods. There really isn't much of a restriction on the intake side of things. If you were to compare opening surface area on the TB I am pretty sure its equal to the M20 TBody, just 2 throttle vales instead of one.
The M30 AFM on the M20 is a mild improvement, but nothing radical.
The AFM itself really isn't that bad as far as being a restriction, its biggest issue is the delay in throttle response.
I know there is at least one turbo M42 that is running MS. I know from my M20 experaince the throttle response on Megasquirt is much better. For the price if you wanted to remove the AFM just megasquirt it, will be cheaper and work better then any other MAF hack.
One thing I am working on is making a pulse manifold like Metric Mechanics sells for 1K. I have a spare intake and got the price from a guy to do a prototype, about 300. I might just do some of hte work myself for the 1st one. MM claims 15% increase in low and midrange torque
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^^^ Good info. Thanks!^^^
Everything I've read about MS is from turbo volvos that seem to thrive on the system. I'm not really interested in turbo M42 but I suspect MS+S and cam adjustment (we have adjustable cam gears from the factory) could unleash a lot of potential from this engine. Sure theres all sort of chips out there but I like to tinker.
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For anyone who has MS experience, how difficult is it to tune? I'm assuming that a dyno is necessary.
Also, instead of spending big bucks on the larger TBs, I have heard of people using a Dremel or something similar to grind it to a larger size. Not sure what they did about the plate size though. Any ideas how this would work? I have an extra TB in my garage right now, so I may give it a whirl.
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For anyone who has MS experience, how difficult is it to tune? I'm assuming that a dyno is necessary.
Also, instead of spending big bucks on the larger TBs, I have heard of people using a Dremel or something similar to grind it to a larger size. Not sure what they did about the plate size though. Any ideas how this would work? I have an extra TB in my garage right now, so I may give it a whirl.
Some people taper the lip at the entrance to smooth airflow. This is different than porting the entire throttlebody since you're not changing the overall diameter and not using a larger throttle plate. This little mod has proven minimal gains in some cars/engines. But I suspect with our square and primitive barn yard door design, it would probably have very minimal or no noticeable effects. Also for the fact that we have oval tb w/2 stage butterfly plates sort of throws that idea out as well.
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Megasquirt is much better. For the price if you wanted to remove the AFM just megasquirt it, will be cheaper and work better then any other MAF hack.
If you would like to remove AFM, It's easier to use piggy pack like Link Electromotive's AFM Link or Intercept Link boxes.
Also Perfet Powers SMT6 will do the trick. With these boxes you can use either MAF or MAP sensors.
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While Megasquirt is a good option. It is not for many.
I have seen and ridden in megasquirt cars of various flavors but not on an m42.
Road tuning, then dyno tuning are the longest arduous tasks. I would also not suggest doing this to a daily driver car unless you have a fully functional base map and A LOT of time to tune. The most optimal megasquirt settings will take a while to attain.
Factor in the cost for Megasquirt, Dyno time and tuning time as your 3 variables.
G.luck.
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If you would like to remove AFM, It's easier to use piggy pack like Link Electromotive's AFM Link or Intercept Link boxes.
Also Perfet Powers SMT6 will do the trick. With these boxes you can use either MAF or MAP sensors.
WIll either of these piggybacks work with a chip, say a markD chip, instead of requiring a bespoke chip to interpret the new signal or acting as a chip? I'm assuming that they don't. I looked at the SMT6, isn't it similar in concept to MS?
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All of these boxes will work with most of the chips available. I have used AFM Link installed to Porsche 944 Turbo with several different chips without problems. SMT6 is a piggback box and cannot compare to MS. I prefer VEMS, which is better than MS. You can tune also VEMS with Megatune.
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While Megasquirt is a good option. It is not for many.
I have seen and ridden in megasquirt cars of various flavors but not on an m42.
Road tuning, then dyno tuning are the longest arduous tasks. I would also not suggest doing this to a daily driver car unless you have a fully functional base map and A LOT of time to tune. The most optimal megasquirt settings will take a while to attain.
Factor in the cost for Megasquirt, Dyno time and tuning time as your 3 variables.
G.luck.
+1
I fully agree. In addition to dedicating a LOT of time to part throttle maps in various situations, one will also need to invest in wideband and egt to do it "right" to be able to obtain the most efficient and refined street map.
I've tried to do it on a previous car and I would say I was only 75% successful and had a long way to go before I ended up selling it.
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From my understanding the TB and a M30 AFM are both worthless mods. There really isn't much of a restriction on the intake side of things. If you were to compare opening surface area on the TB I am pretty sure its equal to the M20 TBody, just 2 throttle vales instead of one.
The M30 AFM on the M20 is a mild improvement, but nothing radical.
The smaller butterfly is 35 mm across and and the second is 54 mm across if that helps work out the difference.
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I just can't see how a bigger tb on the M42 can benefit as long as there is the barn yard door ahead of it.
Not true. I did a MAF conversion on mine and saw NO power gains. From looking at datalogs of flow data, no more air flows with a MAF. The trap door would intuitively seem restrictive, but it is not. It is perfectly fitted to the motor, and elimintaing it does nothign for power. Sucks, but it is true. The M20 responds well because the meter was badly undersized for it.
+1
Has anybody megasqirted on of these engines yet?
Yes. Pain in the ass, and it did not really give much more power. Fun project, and better throttle response (same with a MAF), but nothing more really on a stock motor.
From my understanding the TB and a M30 AFM are both worthless mods. There really isn't much of a restriction on the intake side of things. If you were to compare opening surface area on the TB I am pretty sure its equal to the M20 TBody, just 2 throttle vales instead of one.
The M30 AFM on the M20 is a mild improvement, but nothing radical.
The AFM itself really isn't that bad as far as being a restriction, its biggest issue is the delay in throttle response.
I know there is at least one turbo M42 that is running MS. I know from my M20 experaince the throttle response on Megasquirt is much better. For the price if you wanted to remove the AFM just megasquirt it, will be cheaper and work better then any other MAF hack.
One thing I am working on is making a pulse manifold like Metric Mechanics sells for 1K. I have a spare intake and got the price from a guy to do a prototype, about 300. I might just do some of hte work myself for the 1st one. MM claims 15% increase in low and midrange torque
Very correct. I am actually very interested in the pulse intake manifold technology. What will you be managing your motor with? I cannot imagine it will run right at WOT with this drastic of a change (though I can always hope).
I KNOW people here have ported the TB. I have a machine shop to do it in should I want to. Did it do anything for you? Thanks.
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Not true. I did a MAF conversion on mine and saw NO power gains. From looking at datalogs of flow data, no more air flows with a MAF
Have to disagree with You. We have dyno tested Porsche 944 Turbo first with AFM with AFM LINK piggyback box and after that the same system with Bosch MAF. We used the same chip and same boost. we got over 20 dyno proofed additional horses. Of course with N/A engines this benefit would be smaller.
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I am sure you did. A 944T flows a LOT more air, and a lot of cars that flowed a lot that used an AFM ended up getting restricted there. There is a limit to the size of the flapper door just out of consideration for inertia/momentum effects on the response speed. This, and possibly possible emissions and power-related taxes could limit air flow, or create a need to limit it.
Now the M42 is a small NA motor. It does not really flow that much aur. The AFM on it is just fine. I was just saying that on the M42 you will get no gains. The M20 would see some gains if a MAF was put on in place of its (undersized) AFM.
The M42 DOES get better throttle response with a MAF, better idle stability and better off-idle response. I have been driving on my MAF conversion for ~9000 miles now and have no reason to stop! Well, heck the stock AFM was on its way out anyway!
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944 T has a 2,5 liter engine, so volumes are larger as you said. I know one 944 NA project going on which has AFM replaced with SMT6 and Bosch MAF sensor. I'll report here what the results are when owner of that car have it dynoed.
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It does seem that this mod would be best used in conjunction with a chip that is set up for it.
Without a chip I can see the computer not metering it properly. Then again, with the stock MAF it should be metering all the air that is coming in correctly. At part throttle it may not be an issue but I wonder about WOT in the closed loop stock mode going lean.
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I just checked what Metric Mechanics use for throttle body on their engines (upto 210 hp in NA configuration)...
Stock TB! Not even a single mention about enlarging it anywhere :eek:
I think that indicates it is large enough for mild tuning we usually deal with in our street engines. Same for intake runners...
The real restriction is the cylinder head and valves. But they are quite big mod.
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Stock TB! Not even a single mention about enlarging it anywhere :eek:
They even have the stock TB heater in place. Makes you think :D
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Not true. I did a MAF conversion on mine and saw NO power gains. From looking at datalogs of flow data, no more air flows with a MAF.
I never said the barn door was restrictive with a stock tb but there will be a point when you increase the tb size where the barn door will act as a bottle neck. Your research just dealt with the stock tb which I'm sure the BMW engineers designed the barn yard flow accordingly. :)
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I was thinking about duplicating the MM pulse manifold and interested how your prototype is going to turn out. Please keep us in the know!
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just to add my experiences. bigger throttle body gives a little more on full throttle but really is a bit of a waste of time - you'd be hard pushed to tell the difference. i have the same +4mm one that omi has, ian (alpina357 on uk forums) uses an engineer friend of his to add a 4mm larger butterfly to the large butterfly, the body is nicely drilled and ported to flow with it. it's nice to have a recon'd unit though, it opens very smoothly etc.
SMT6 = waste of time. Didn't work well with our AFM. I also tried to use it for a MAP conversion, this was tedious and didn't work that well.
MS is very good. I'm now running an MS2 extra which is even better. I don't agree with bmwman about the gains on a standard M42, I fitted MSNS+HR on dan318is' standard M42 a few months ago, and just running an old map of mine it feels more lively, faster with better response.
When I had my 1.8 on the rollers, I managed to squeeze nearly 10hp on factory by using megasquirt, and that's not the whole story - throttle response etc was much better.
I agree on it being a pita to get the hang of, but once you know what you're doing you can come up with good maps in no time.
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SMT6 = waste of time. Didn't work well with our AFM. I also tried to use it for a MAP conversion, this was tedious and didn't work that well.
SMT6 does not work well with MAP sensors, this is a well known problem. With MAF sensor it works much better.
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just to add my experiences. bigger throttle body gives a little more on full throttle but really is a bit of a waste of time - you'd be hard pushed to tell the difference. i have the same +4mm one that omi has, ian (alpina357 on uk forums) uses an engineer friend of his to add a 4mm larger butterfly to the large butterfly, the body is nicely drilled and ported to flow with it. it's nice to have a recon'd unit though, it opens very smoothly etc.
are you interestid in selling the TB? seems like you wouldnt have a use for it
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So what's the verdict here? Big bore is a waste of time?
I'm doing a re-map for my M44 and was going to throw a bigger throttle in but now I'm not so sure?
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just to add my experiences. bigger throttle body gives a little more on full throttle but really is a bit of a waste of time - you'd be hard pushed to tell the difference. i have the same +4mm one that omi has, ian (alpina357 on uk forums) uses an engineer friend of his to add a 4mm larger butterfly to the large butterfly, the body is nicely drilled and ported to flow with it. it's nice to have a recon'd unit though, it opens very smoothly etc.
SMT6 = waste of time. Didn't work well with our AFM. I also tried to use it for a MAP conversion, this was tedious and didn't work that well.
MS is very good. I'm now running an MS2 extra which is even better. I don't agree with bmwman about the gains on a standard M42, I fitted MSNS+HR on dan318is' standard M42 a few months ago, and just running an old map of mine it feels more lively, faster with better response.
When I had my 1.8 on the rollers, I managed to squeeze nearly 10hp on factory by using megasquirt, and that's not the whole story - throttle response etc was much better.
I agree on it being a pita to get the hang of, but once you know what you're doing you can come up with good maps in no time.
Was the 10hp gain versus a stock chipped M42? A Conforti chip adds almost that much power.
Now as far as all the other benefits of stand-alone and a MAF I totally agree. The car feels better than new with the MAF on there as far as liveliness. On a stock-internal M42, the AFM flows enough. On a modified engine, you might want to consider ditching it.
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Wow im a noob and you guys have me so lost.......what is megasquirt?
MS and MS2??
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MS stands for MegaSquirt. MS2 stands for MegaSquirt 2. Megasquirt is custom tunable ECU I believe. It's known to be cheaper than the big company names.
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Was the 10hp gain versus a stock chipped M42? A Conforti chip adds almost that much power.
Now as far as all the other benefits of stand-alone and a MAF I totally agree. The car feels better than new with the MAF on there as far as liveliness. On a stock-internal M42, the AFM flows enough. On a modified engine, you might want to consider ditching it.
yeah, was about 7hp at the wheels iirc, something like that, was a few years back now! and yeah i don't doubt that a chip would do pretty much the same! A good chip i'm sure would do pretty much exactly what we altered on the rollers - i suppose the difference is it's not off-the shelf and will be spot on for your actual car etc., also I use EGO control and AFR targetting, so i know it will get that optimum AFR every time.
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So what's the verdict here? Big bore is a waste of time?
1+
I'm thinking about doing this, but I don't want to wast my money. I'm keep my AFM for smog reasons. Right now I have a DASC and exhaust. I have a unichip wired up but not installed with a good base map that needs some fine tuning.
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There was a guy over on bf.c. who had a dinan TB on his m42. Anyone heard of this?
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I read that tread a while ago and I’ve been trying to find it. I remember he did say throttle response was better, but I can’t remember if it was installed on an m42 or m44
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It was on an m42, and he didn't even realize it was on the car until he took the intake apart to clean it or something.
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I have the Alpina527 enlarged throttlebody. To be honest, I don't feel any difference. A friend of mine put one on his M43B19TU and had a superb increase in throttle-response.
I think the M42 TB already flows enough air.
I had the chip replaced, and that made a big difference. Better spend the money on a good remap.
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So M42 TB's are different to M43/M44?