N42B20 Sports Cam

sacunha

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portugal
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bmw e46
Hello, can someone help me with a question?
i have an e46 318ci with n42b20.
Im a newbie in engine modding and i wanted to get a bit more wp from my engine. I heard about add sports cams. I serched about sports camps for my engine and had no results. Do cams have to be made to a certain engine? If not can u help me choose ons for my engine?
 
This guide is a good read...

The cam opens and closes the intake and exhaust valve and is measured in degrees of a full rotation. As long as the timing of spark and cylinder piston travel match you are spot on. The profile is chosen to match where you want the power band. Manufacturers set this up for economy and a good wide power band but on a track you want it all at the top end, and can live with a very lumpy low RPM engine.
 
ty for the reply.
My car has double-vanos and valvetronic, i heard that i cant change can when it has this tecnologies. Is it true?
 
BMW did a pretty good job on the cam profile on these so I don't think you'll gain much.

Variable vale lift and Vanos don't rule out a performance cam - but you can't go very far with it and must ensure the lift remains the same - many cams are ground down and list suffers as a result.
 
A supercharger might work out easier to fit but you'll need to lower the compression ratio, increase the fuelling and fit stronger engine parts to cope. It will give you the best bang for your buck but it will cost quite a lot of money to achieve this.

Have you looked into weight reduction? I know a few BMW owners have swapped heads and intakes over and made a bit more power after they've done a little head flowing and porting work on the donor head.
 
my car at the moment has around 170hp, it was mesure at 145whp so its not stock. i dont know what has been done to it. stock 0-100kph is 9.3s and its doing 8.7 with really *#*#*#*# tyres and stock 80-120kph is 6.6 and its doing 5.6. All of this tested in a staight road with 0 incline (does the same time on both directions).
 
About losing weight:
This version of the e46 is alrealdy the lightest sold (200kg less than the m3). this version is even lighter than the e46 m3 csl.
Thats why i was thinking of turboing it with 0.7/0.8 bar boost and keep the stock internals. That would give me around 300hp
 
I didn't know that, that probably explains why the e46 is so sought after.

Will this engine cope with 300bhp on stock internals? Also the compression ratio is too high IMO for 0.7 bar of boost.

Bore and stroke is 84.0 x 90.0 mm giving 1995 cm3 - compression ratio is 10.2:1 which is already quite high I'd prefer to see 7:1 or 8:1 before boosting it.

The Bosch motronic ME9.2 will also need upgrading.
 
e46 engines are know to handle less than e36 ones but still can handle 1bar with stock internals. About the compression, this engine is similiar in composition (per cilinder) to the m54b30 found in e46 330i. There are a lot of projects with 330i with stock internals running to 1bar. About the ecu, yah im still loooking for the better option (i dont want to spend a lot). i was think on using an eletronic boost controller and have 0.3 bar for dailly and 0.7/0.8 for special occasions.
 
Keep it simple - that always works.

I should have known that these engines are multi point direct injection so can handle higher compression ratios that I was assuming.

I must get my BMW brain out and dust it off again, we've suddenly had lots of BMW owners on here, which is great but I've been playing with Audis for far too long now, it must be time for a change!
 
i have 0 experience turboing cars, so im preparing things with time. Im after the most oem look as possible.
here is my list so far:
Exhaust manifold: Made in a shop (can only find with a complete turbo kit for my engine)
Turbo: Gt3076
Wastegate: ???
IC: Maby the one found on 330d? it would look oem
Ecu: ???
Injection: ???
else?

If u could help me prepare this list?
 
The Link/Vipec ECUs are very well liked Haltec has quite a bit of support.
DTA might be worth looking cos they can control dual vanos.

Why not get a kit as they are setup and come with all the parts you'll need. Laurent motors do one for many BMW's
 
couse where i live, the law is very stright and i dont want to cause the atention of the police. i couldnt use most of parts of the kit like the ic, tubing, etc...
(thats why i want to use the 330d ic)
 
I like your plan. Keep it sleeper style, under the radar but it's nice knowing the power is there when you need it.
 
yah, i already have an exausrt bypass if i want my car to make some sound. the plan is to have around 215hp for daily and 300hp for special days.
Can u help me with my list? do u thing that a 330d ic would be enought? should i use a smaller turbo? my exaust is 52mm and i know it will hurt hp numbers, but can i keep it?(if i only have 280hp instead of 300hp cause of this i woulnd mind)
ty for ur help
 
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If you ask 3 people that question you will get 3 very different answers. There are things that seem fine on paper and in theory but in the real world you can run into problems and issues. Unless someone has done the exact same build you cannot know for sure how everything will work together.

Each turbo comes with a comprehensive map showing flow at rpm etc... this needs to be matched to your injectors and probably your fuel pump, OEM pumps rarely push enough fuel for adding forced induction.

The person that sets up your ECU with all of this is the one who's opinion matters the most as he is the one that has to make it work for you.

Specify a smallish turbo, look over the flow characteristics of the turbo and chat to the mapper about this, he will let you know what the fuelling requirements are.

I think you'll be fine with a 330d intercooler, unless you are running at full boost for extended periods of time the intercooler size is not that important IMO.

Small exhausts can flow faster than larger ones which can have performance benefits. I know this sounds strange but I see lots of people adding large exhausts and wondering why the power dips without realising the dent they have made in the scavenging effect.
 
How is this project going? Have you found any useful parts or put together a plan?
I have never received a notification for this comment. I paused this project at the end of 2020 and resumed at the start of this year. I heard of a company that was developing supercharger kits for 8, 6 and 4 cylinder bmws. I talked with them and they told me that they were releasing their kit for this engine at the end of this year. So i decided that i wanted to get as much na power as i can while the kit isnt available. I bought schmiedmann headers for it, 320si intake, maf and throtle body. Before all of that on the 24 of january i went to a tuner that helped multiple friends of mine build their cars and measured my car there. Its a maha dyno and its well known that that dyno in question reads low. It measured 155hp to the crank and we found out that i had not got a tune on it and the fuel mix was really bad (we suspect that the previous owner just ported the head and didnt tuned for it). I remaped and after that it measured 181hp. I have not measured it after the headers, 320si intake, maf and throtle body but it gained alot so i believe it is around 200hp.
 
That sounds really good. I wish you all the best in this project, and please keep us posted, your experiences really helps out others with similar ideas and project cars.
 
I have never received a notification for this comment. I paused this project at the end of 2020 and resumed at the start of this year. I heard of a company that was developing supercharger kits for 8, 6 and 4 cylinder bmws. I talked with them and they told me that they were releasing their kit for this engine at the end of this year. So i decided that i wanted to get as much na power as i can while the kit isnt available. I bought schmiedmann headers for it, 320si intake, maf and throtle body. Before all of that on the 24 of january i went to a tuner that helped multiple friends of mine build their cars and measured my car there. Its a maha dyno and its well known that that dyno in question reads low. It measured 155hp to the crank and we found out that i had not got a tune on it and the fuel mix was really bad (we suspect that the previous owner just ported the head and didnt tuned for it). I remaped and after that it measured 181hp. I have not measured it after the headers, 320si intake, maf and throtle body but it gained alot so i believe it is around 200hp.
How is it going? Does the 320si intake fit allone or do I need to put in MAF and throttle body in too?
 
How is it going? Does the 320si intake fit allone or do I need to put in MAF and throttle body in too?
u dont need the 320si MAF and throttle body, but the 320si throttle body is bigger and is pnp so for me is a must. The maf is only needed if if install cams as i did, for the maf u need to tune the ecu as they have diferent charactristics curves.
 
Quick resume on how its going:
I payed for someone to costum build an exhaust for it. bought for cheap a catless header on ebay, bought a cheap maxpeedingrods cat. Full stainless steel 63mm exhaust with stock center muffler opened and rebuild for 63mm, and end muffler opened, converted to 63mm and bypass valve both exiting at the tips.
Bought cheap n4x cams on ebay and sent them to dbilas to regrind for a better spec.
Learned the basic of tuning and tuned myself the car and i was going pretty good. 80-120 is around 5.1/5.2s.
At the moment im supercharging it. Supercharger is in place, just waiting on some parts for it. For now it will run on stock ecu, but later im going to switch to ecumasters black.
End goal is 300-350hp in this unopened engine.
At the moment im building another n4x with n45b16 ported head, b20 crankshaft, pistons and rods from the n54b30. Going for 400-450hp on that engine
 

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u dont need the 320si MAF and throttle body, but the 320si throttle body is bigger and is pnp so for me is a must. The maf is only needed if if install cams as i did, for the maf u need to tune the ecu as they have diferent charactristics curves.
So can I put in the 320si intake header allone to begin with? Does it fit plug and play?
 
Thanks for all these updates, it is proving to be a really interesting project.

What was the cam profile you ended up with in the end?
 
Wow, that ist impressive. Would you mind sharing the object file with us?
im selling that model for a long time, as it took me some time to develop https://cults3d.com/en/3d-model/various/bmw-n42-n45-n46-adapter-for-320si-intake

Thanks for all these updates, it is proving to be a really interesting project.

What was the cam profile you ended up with in the end?
intake: 280º 10.5mm
exhaust: 272º 10.5mm
For na build this is to much unless u have ported n45b16 head, 270 intake and 262 exhaust would be the best.

And how did you learn about tuning?
there is a discord where most bmw tunners meet. There is alot of help there. but this ecu is the most complex on the e46 line up. It took me alot of tme to understand it
 
What are the best ECU mapping/tuning upgrades on these engines? The reason I'm asking is that my article on this engine is way out of date and far too general in nature I would really like to make this article more useful especially as it is quite popular.

I am also interested to know your thoughts on fuel upgrades, and where the limits are on the stock setup when you need to start upgrading it.

The article is at... https://www.torquecars.com/bmw/n42-tuning.php
 
What are the best ECU mapping/tuning upgrades on these engines? The reason I'm asking is that my article on this engine is way out of date and far too general in nature I would really like to make this article more useful especially as it is quite popular.

I am also interested to know your thoughts on fuel upgrades, and where the limits are on the stock setup when you need to start upgrading it.

The article is at... https://www.torquecars.com/bmw/n42-tuning.php
Do u want want to make it really deep? i would love to help u. The stock fuelling setup is more than enough for any na build. U can boost it to around 0.4/0.5 on stock engine and stock fuel setup.

If i were u, i would take a look at some bds projects. You would be amazed on the stuff possible here.

just some small examples
 
you need an adapter. I designed and 3dprinted one.
im selling that model for a long time, as it took me some time to develop https://cults3d.com/en/3d-model/various/bmw-n42-n45-n46-adapter-for-320si-intake


intake: 280º 10.5mm
exhaust: 272º 10.5mm
For na build this is to much unless u have ported n45b16 head, 270 intake and 262 exhaust would be the best.


there is a discord where most bmw tunners meet. There is alot of help there. but this ecu is the most complex on the e46 line up. It took me alot of tme to understand it
Thanks. So I can expect around 20-30 hp with the intake header allone and a remap?
 
Thanks. So I can expect around 20-30 hp with the intake header allone and a remap?
yes, maby a bit more with a good remap. Also the throtlebody is cheap and worth around 2/3hp peak hp and an average of around 5hp (cause it will extend your peak hp for 100/200rpm). For me is a must, even on stock intake. I paid 30 euros for one here in portugal. The main diferences between the 150hp version and the 143hp version is the throtlebody, the maf, which are bigger, and a newer version of the ecu, so...
 
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yes, maby a bit more with a good remap. Also the throtlebody is cheap and worth around 2/3hp peak hp and an average of around 5hp (cause it will extend your peak hp for 100/200rpm). For me is a must, even on stock intake. I paid 30 euros for one here in portugal. The main diferences between the 150hp version and the 143hp version is the throtlebody, the maf, which are bigger, and a newer version of the ecu, so...
So you put in a newer ECU?

I am not shure. In this offer it looks like the throttle body of the N42 and N45 Engines are the same. or is there a 150 hp version of the N42?

 
yes, maby a bit more with a good remap. Also the throtlebody is cheap and worth around 2/3hp peak hp and an average of around 5hp (cause it will extend your peak hp for 100/200rpm). For me is a must, even on stock intake. I paid 30 euros for one here in portugal. The main diferences between the 150hp version and the 143hp version is the throtlebody, the maf, which are bigger, and a newer version of the ecu, so...
The difficult thing will be to learn how to edit the ecu. Could you please link the discord or other pages on how to tune it?
 

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