N42B20 Sports Cam

sacunha

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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?
 

thexav

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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.
 

sacunha

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bmw e46
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?
 

obi_waynne

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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.
 

obi_waynne

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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.
 

thexav

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sacunha

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bmw e46
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).
 

sacunha

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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
 

obi_waynne

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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.
 

sacunha

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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.
 

obi_waynne

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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!
 

sacunha

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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?
 

thexav

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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
 

sacunha

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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)
 

sacunha

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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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obi_waynne

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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.
 

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