What power can I expect from adding cams

[J10B]

Will I have to remove them if I get blown? YEs feel free to move this post I am to lazy to find the right forum so i just picked door number 1 .
I have a 99 mroadster

[Dark Helmet]

this could go in general or FI...

you will get about ~300hp from cams and they CAN be used with a blower, but that would require a lot of time on the dyno.

I'd say one or the other. the cams are a great addition to the plethora of mods available, and in my opinion represent the most reliable way to make big numbers with the S52. you can get more power from the blower but you will also loose a lot of it to heat soak. the cams will give you more power on a hot day and the same power on a cool day.

I also think that they are a little cheaper than a blower (stage 1) but likely require more installation $$$.

I'd probably pick the cams over the blower.

[SilverStreak]

Blasphemy! :devillook

Both or just the blower... :D

[J10B]

I saw cams for a s54 for 1100. what do you think the install would be?

[J10B]

How much power do you guys think I will add? What will be affected? What about engine software like a Shark inj. or even something like a CAI?

[SilverStreak]

Install of cams ain't cheap, BMW or not, it won't be cheap. Anyone done this recently, can help him out?

Give the folks here the year and model of your car again, Jon...

[J10B]

99 Mroadster s52 engine, how will cams affect longevity. Dave I swear I saw shrick cams for 1100 for an s54 M3 you prolly have to buy 2 to get that deal though

[John (PA)]

60 HP from a cam swap? Surely everyone would be doing it. :dunno

Why wouldn't this be the first and foremost thing people do, and why would it be so rare that people do it if that is true?

[BMWguy206]

I dont think you can just put S54 cams into a S52 block. Both the intake and exhaust cams are identical and can only be identified by the impulse wheel at the end which cannot be read by a stock DME MS41.2

[J10B]

I wouldnt put s54 cams in, I was using them as a pricing guide. I figure if s54 cams where 1199 ( i think it was for the pair ) then s52 must be less. I cant see how adding s54 cams would help either.

[Wheel Kinetics]

Originally posted by John (PA)
60 HP from a cam swap? Surely everyone would be doing it. :dunno

Why wouldn't this be the first and foremost thing people do, and why would it be so rare that people do it if that is true?

Cams are one of the most radical changes you can make to an engine-- FI being more, displacement increase being less. They shouldn't be treated like an airfilter mod.. here's why..

As you all know, cams control the valve's lift and duration. The longer you can hang/open that valve, the more air that can be injested during the intake stroke. However, what you gain on top you will sacrifice on the lowend. With a longer duration comes a greater valve overlap (time between the exhaust and intake strokes where all valves are open) This overlap is great when the engine is turning a high RPM, but at lower RPMs it tends to choke the engine. (The piston is moving too slow and the vaccum isn't right to pull the correct amount of air in. ) This is why you hear cars with aftermarket cams lope/surge/shake at idle. Also, this valve overlap promotes poor combustion and hurts emissions.

On a FI engine, the game changes a little bit. No longer do you need to depend on intake runner lengths, plenum design, etc for efficent flow. (Technically, it does matter, just not nearly as much. A poor intake design means the turbo will have to spin more RPMs to make the same pressure. More RPMS=more heat) Now you're primarily concerned with abolsute flow numbers, not so much the efficency. In an FI engine, you want to look at a cam change when the head flow limit is reached. You'll know when that limit is as you continue to increase the boost and the power is no longer proportional. The problem with cams on an FI engine is a big loss in the low end. The valve overlap simply blows the boost straight through keeping the engine from making usable boost. My car lost 500 RPMs on spool simply from cams. However, it gained 150 HP on the big end because of the flow restriction.

As was mentioned, on a lifter cap/shim set up, they are very very difficult to install. Could take 5 hours to the better part of a weekend depending upon how lucky you get with the shimming. Not fun. :)

[Dark Helmet]

I should qualify my earlier claim... I believe the Jim C cam kit gets about 300hp from the S52... it is not, however, JUST cams.

[Dinanify]

for those of you in the bay area, Dynospot racing does cams, I think they're $1100 installed, 20HP to the rear wheels. I Want, I want....

Those guys seem really cool...

http://www.dynospotracing.com/

[SilverStreak]

$1100 installed ain't bad at all. Phil (aka ///M Roadster) is gonna do some checking on the pricing of the Jim C stuff, but the figure I heard being tossed around was $3000... :eek:

[Keda]

Originally posted by kitwetzler in this thread (http://bimmerforums.com/forum/showthread.php?s=&threadid=31370&perpage=25&pagenumber=3)
Actually, Superchargers LOVE cams. Overlap in turbos is bad, because there is so much backpressure in the exhaust manifold. An inefficient turbo can see 150 psi there! When there is too much overlap, that overcomes the pressure of the intake charges and replaced good cool intake air with 1600 degree exhaust. Yikes. Causes all sorts of nasty problems with detonation, etc.

Superchargers don't have the problem with reversion. High overlap cams (properly tuned of course) only serve to help fill the cylinders. Fourfa is right, after a certain amount of overlap, you end up not pressurizing the cylinder, but most street cam kits are pretty benign in that respect.

Dynospot Racing has seen really good results with cams on superchargers, not even using a custom program at all. Since they are relatively mild, they don't affect idle, etc... but, you do get more efficient cylinder filling, which results in a 20-30 rwhp increase. (on blown cars, so about 10%) Not bad!

This is what I have heard about SC cars as well.

[kitwetzler]

JimC's cam kit includes a LOT.

Schrick cams for the S52 are around $1200 for the pair, plus installation, which is going to run $500-$1000. You'll see some power from them.

[BAADDOG]

What would adding cams to a 97 M3 OBD II Dinan S/C V2 performance gain?

Would the performance gain be across the power range, low to high?

What would be the downside?

What would be the cams of choice?

TIA

[scottycs]

Installation is about a 4-6 hour job. Expect to pay $300-$500. While I do not have a m3, with mild engine work and cams, I put out more power than my FI buddies with 325s.

[BoostFed325]

cams can do alot if done right, thats for sure ;)