Any cam choices?

[brusk]

All the bolt ons and other things being discussed here I haven't seen a single discussion about cams. Does any body make any options for this engine? I'm also assuming that's the bottle neck of why most of these engines are completely dropping power at 6200 or 6500 as I've seen on most graphs. It would be nice to actually make power all the way up to the 7K redline.

[RnmEvo9]

Cams may play a role in that aspect, but I would say the small snails aren't up to the task of making power at high revs.

[brusk]

Originally Posted by RnmEvo9

Cams may play a role in that aspect, but I would say the small snails aren't up to the task of making power at high revs.

I don't see that as being an issue. You would see the boost drop off at high RPM's and I haven't seen that as an issue. The turbo's have no problems running more than double the pressure so another 500 RPM's won't be an issue.

[Colt]

I've wondered about this too

[bogart]

Too expensive and difficult to develop with the VANOS. You could always do the Stage 3 head upgrade by VAC

http://store.vacmotorsports.com/e82-...alog-c244.aspx

[brusk]

Originally Posted by bogart

Too expensive and difficult to develop with the VANOS. You could always do the Stage 3 head upgrade by VAC

http://store.vacmotorsports.com/e82-...alog-c244.aspx

Head work is nice though other than a really nice valve job have minimal gains on most turbo engines that start with a decent port design. Plus that won't help much if the cams aren't letting enough air in at those RPM's. It shouldn't be that expensive to do it plenty of other car manufacturers have variable valve timing and off a selection of cams. They've had Nissan VQ35DE within a few years of it's release and cams for it are still cheaper than what we pay for down pipes. I would think that a performance cam manufacturer that has experience in these areas would easily be able to make a set.

[RnmEvo9]

Originally Posted by brusk

I don't see that as being an issue. You would see the boost drop off at high RPM's and I haven't seen that as an issue. The turbo's have no problems running more than double the pressure so another 500 RPM's won't be an issue.

Do you actually have a boost gauge to monitor this? Because I do, and the boost tapers at high rpms to ensure turbo longevity. These stock snails are good for low end torque which is suitable for a great daily driver, however they fail completely for making gobs of power at high rpms. The only turbo upgrade that I've seen that keeps making power up to redline is the Vishnu single turbo which still isn't sold to the public.

Heres a good link that explains the stock turbos efficiency range: http://www.e90post.com/forums/showthread.php?t=256804

[MilehighM3]

+1
Boost taper is the culprit, not cams. With 50+ degrees of variable cam timing, duration is not exactly a problem...

[brusk]

Originally Posted by RnmEvo9

Do you actually have a boost gauge to monitor this? Because I do, and the boost tapers at high rpms to ensure turbo longevity. These stock snails are good for low end torque which is suitable for a great daily driver, however they fail completely for making gobs of power at high rpms. The only turbo upgrade that I've seen that keeps making power up to redline is the Vishnu single turbo which still isn't sold to the public.

Heres a good link that explains the stock turbos efficiency range: http://www.e90post.com/forums/showthread.php?t=256804

Stock I can believe that but with all the people running a tune and FBO i would not expect that to be the case, all the lower HP or high HP dyno's I've seen seem to drop off at 6200 or 6500.

A turbo does not care about RPM it move air volume. If it's able to move enough air to produce 15+ PSI at 6000+ RPM then it shouldn't have any problems maintaining enough flow at lower boost to get past 6500.

[brusk]

Originally Posted by Bmw135er

+1
Boost taper is the culprit, not cams. With 50+ degrees of variable cam timing, duration is not exactly a problem...

With how much lift? Does anybody have the cam specs for the stock cams?

[Todd135i]

Cams may help some but what you're not seeing is turbo efficiency. 16 psi in a turbos efficiency range is completely different than our turbos running that psi out of its efficiency range. It basically comes down to a point where all its doing is blowing hot air.

These small turbos are made for low grunt, and virtually no lag. They just can't keep up and are definitely out of their efficiency range at high rpms and high boost

[eric@helix]

Unless you are doing a huge project with different turbos, don't bother, the volumetric efficiency of the stock snails will hinder top-end performance.

[brusk]

Originally Posted by eric@helix

Unless you are doing a huge project with different turbos, don't bother, the volumetric efficiency of the stock snails will hinder top-end performance.

I'm not disagreeing with that I'm just surprised more people with FBO+ don't want some more rpm range.

[Vigilante375]

Its strange to see how no one has made any type of cams variants. Coming from the LSx engine world, people have FI cams just for the purpose of the S/C or Turbo setup. Same goes with the Modular engines in Ford. I guess different engines call for different things. But it would be nice to see some try this, unless they did a long time ago and then gave up because the cost would be to much.

[pnosker]

The VANOS system has so much variability it will just compensate with different cams. The car's variable cam profiling lets it be the most effective cam through the whole rev range. It has over 50 degrees of variability and processes at over 1000 hz. You won't see any gains. There have been no significant BMW cams since Double VANOS.

[brusk]

Originally Posted by pnosker

The VANOS system has so much variability it will just compensate with different cams. The car's variable cam profiling lets it be the most effective cam through the whole rev range. It has over 50 degrees of variability and processes at over 1000 hz. You won't see any gains. There have been no significant BMW cams since Double VANOS.

I would have to disagree with this. Variable cam designs are flexible and definitely are better for street cars but aren't without their problems. One of the best benefits is obviously a wider powerband but if it weren't for the emissions benefits I don't know if manufacturers would have cared as much. You can only do so much with the original cam grind no matter how much you re phase it, play around with adjustable cam gears on a non variable valve car and you'll see it only adds so much power.

I'm not saying cams are the best choice of upgrades for the money, but they would sell look at the other tuner cars, every decent build I've seen for boosted: Eclipses, Hondas, EVO's, STI's, Supras, MR2's, Z's, stangs, vettes and camaros cams were always on the to do list.

[MrBlonde]

Variable cams are not just for emissions. You set them up right and you get much earlier boost and great top end.

The stock turbos are definitely the bottleneck.

[Vigilante375]

I see you can upgrade the N54 turbos or so single turbo swap, what hasn't anyone done that for the N55 yet? Is it not ok to upgrade the turbo in the N55 to a bigger one? It doesn't seem that hard to me.

[NYC6]

Originally Posted by MrBlonde

Variable cams are not just for emissions. You set them up right and you get much earlier boost and great top end.

The stock turbos are definitely the bottleneck.

Agreed. The turbos are the weak link in the package. If larger turbos are used, different cams would likely unleash more power. the stock cams are designed to work in concert with the OEM snails to produce good power through out the entire powerband.

[brusk]

Originally Posted by MrBlonde

Variable cams are not just for emissions. You set them up right and you get much earlier boost and great top end.

The stock turbos are definitely the bottleneck.

I didn't say they were just for emissions. Power is the benefit for us but the auto manufacturers probably wouldn't have cared as much if it weren't for emissions requirements.

[brusk]

Originally Posted by NYC6

Agreed. The turbos are the weak link in the package. If larger turbos are used, different cams would likely unleash more power. the stock cams are designed to work in concert with the OEM snails to produce good power through out the entire powerband.

I agree with that at higher boost levels but i'm not buying that at low to mid boost levels on a tune. Unless as previously stated that its boost cut and none of the tunes can override this. I find it hard to believe that the turbo is the bottle neck at 7-10PSI when people are still getting power. I agree bigger turbos would be more efficient I have yet to see a dyno sheet make usable power to redline.

[M///1rider]

check out rb turbo dynos and you will see when you just build a hybrid solution you will hold boost and power to 6500-7000 k, if yur really looking to have a fast n54

full bolt ons
rb turbo
methanol injection
race gas or e85 mix