velocity stacks on a M42 engine?

[chadb08]

what are pro's and con's of velocity stacks on an engine? the only thing i know is they look cool. and i've seen them on a few GTR's

http://farm8.staticflickr.com/7017/6543049871_6c72733994.jpg (http://www.flickr.com/photos/66663286@N06/6543049871/)
301107_10150311029706297_382348171296_8455768_1675 815196_n (http://www.flickr.com/photos/66663286@N06/6543049871/) by Edirty6 (http://www.flickr.com/people/66663286@N06/), on Flickr

[xlDooM]

I suppose it's a method of intake tuning to create the correct pressure wave at the intake port for maximum power at a certain RPM. So the benefits *could* be a more race-tuned intake that gives more top-end power (don't expect more than a few percent though) at the cost of some torque elsewhere in the rev range.

But the OEM intake is already tuned with a velocity stack (which you will kill off when you debaffle it) and you can be pretty sure that the BMW engineers have had a more thorough look at the diameters, bends and pipe lengths than even a moderately serious racing outfit will do for you.

If you just slap on ebay parts, you can be sure you'll be losing torque where you don't want it, and you may not gain anything anywhere. Might as well buy a sticker set, it's visible more of the time and it might help keep the thing together.

I think the car is at least 10 years too young to put this kind of thing on it :)

[DailyE36]

velocity stacks with no air filter will decrease the life of the engine. velocity stacks come in many different lengths. choosing the right length is important. also the design of a velocity stack changes between brands ect. if the velocity stack is design correctly then it should be able to let the engine inhale air through the itb with least resistance. there for if the bell end on the velocity stack is the wrong shape than you will not get all the benefits.
also the correct tuning and having to delete the AFM will be needed.
the best and most reliable intake for the N/A engine will be having the itb connected to a plenum with a airfilter.

[e36 8 ur rice]

I used to have plans on rebuilding my m42.. What sort of gains have you seen and where did you find them stacks

[chadb08]

i didnt built mine. thats just a photo i found online. im looking for more power out of my car but at the cost that its gonna take, i could just save up and get a used M3 for that price. 20-30 hp isnt gonna cut it. im looking to have at least 250+ horsies under the hood. my 318 has about 2 dying ones:(

[fast84gti]

If you do it right, a turbo is similar in price to a full race set up ITB. And you get a lot more power.
And you are still lighter than a 6 cylinder.

[chadb08]

the thing is with the turbo though is that it would put a lotta stress on the engine with more power. i just broke 240,000 miles on mine and it still runs strong but a turbo might be to much. thats why im looking to do other mods for hp.

[ChuckDizzle]

velocity stacks won't really yield much more power, and to do so you'd have to invest a lot of money.

[drtye36]

I was looking into a turbo for my 318 but I called around and they said you couldn't reprogram the computer and I would have to get a stand alone computer for $2600

[Grey318is]

If you are OBDI you cant reprogram, but you should be able to put in a chip that will do the job for far less cash. I think turner would be a place to start.

[drtye36]

Alright thanks I didn't even think of a chip