S54 advice and considerations

[nando]

Simply put, vanos lets you perfect cam timing at every rpm and load of the engine. Anything you can do with locked cams, you can do with vanos. The only big difference is the amount of tuning involved, but i'm thinking it wont be that bad with some additional data & knowledge. Its like being ale to pick a different cam for idle, mid range and high rpm - no compromises!

[Bimmerman325i]

realized the dyno I posted wasn't showing up, so I fixed it.

[Wanganstyle]

realized the dyno I posted wasn't showing up, so I fixed it.

do you happen to have one of the s54 motor tuned by same tuner/ems with VAC delete vs OEM active vanos? it would be really neat to see where the vanos is making power happen with the same tuner behind it.

[Bimmerman325i]

do you happen to have one of the s54 motor tuned by same tuner/ems with VAC delete vs OEM active vanos? it would be really neat to see where the vanos is making power happen with the same tuner behind it.

Unfortunately I don't, sorry. I only know of that dyno for that car. I've also looked for dynos of the VAC/KMS/Schrick setup, but can only find "oh I make 330whp ;)" kind of statements.

However, here's a dyno of an E30 M3 with S54 swap running the factory MSS54 computer with vanos enabled, on an Epic Motorsports tune. Bone stock internals in the motor but it has intake/exhaust mods.



The dyno numbers are lower than many I've seen with similar exhaust/intake mods, but the important take-away is the shape of the powerband. Holy flat torque, Batman!

Vanos is good.

[hoveringuy]

Bimmerman,

Your previous dyno plot showing VANOS disconnected and VANOS active seems completely hosed; it looks like VANOS is locked in the advanced position because the low-end plots match well... dropoff is at higher rpms. I would rather see the comparison with the cams locked in the advanced position, where the the differnce on the low end wouldn't be as substantial.

Nonetheless, I had a dyno run where I mistakenly programmed a glitch into my VANOS controller and the cams slammed from one extreme to the other for 500 rpms... the drop in power was substantial.

I'll need to find that because it show really well how effective VANOS can be.

[Bimmerman325i]

Bimmerman,

Your previous dyno plot showing VANOS disconnected and VANOS active seems completely hosed; it looks like VANOS is locked in the retarded position because the low-end plots match well... dropoff is at higher rpms. I would rather see the comparison with the cams locked in the advanced position, where the the differnce on the low end wouldn't be as substantial.

Nonetheless, I had a dyno run where I mistakenly programmed a glitch into my VANOS controller and the cams slammed from one extreme to the other for 500 rpms... the drop in power was substantial.

I'll need to find that because it show really well how effective VANOS can be.

The first plot is of the same car running MOTEC standalone with VANOS enabled in all three curves. The different curves are of specific detunes to meet racing class hp/wt goals. He has selectable tunes. He can actively choose which tune he is running in real-time.

The MOTEC's control over VANOS lets him cut off high rpm power so that he has max torque everywhere else until he maxes out the hp/wt limit for GTS4 racing. He then can flick a switch or load a different map into the ecu to run an optimized tune for another racing class.

I was half asleep when I wrote the first post, my intention was to show what is possible curve-wise by electronically manipulating the VANOS to achieve certain goals.

[DaveSmed]

You cannot blame VAC; they are selling a complete package they know to work 100% similar to Bimmerworld, ABL etc......

Very true, and that certainly is necessary to maintain a decent reputation, but I just wish it offered more for the money. VAC, more specifically Steve Bailey has always done right by me even when dealing with a really shitty situation regarding an order I placed, paid for and their supplier went under after they paid them! That and he's an E30 guy to boot.


As far as the DTA, you are %100 correct, no knock, basically an electronic carburetor (AlphaN... I want my MAF!), buggy poor GUI, somewhat cryptic manuals..... It certainly is not perfect, but for the price and the capability, I'm satisfied with it.

[Bimmerman325i]

^agreed entirely. They have a solution that they know how to use and tune, and it works well for them. It's just not what I'd use.

My understanding is that Alex has a pretty slick knock sensor solution for his DTA kits. I didn't know they couldn't use MAFs though. Hm.

[hoveringuy]

This plot is kind of interesting.. it was a mistake in programming one of my advance profiles on the intake cam. Intake cam went from full retard to full advance for a period of 500 rpms.

Kind of startled me and I didn't realize what happened until a few hours after the session. It's loud when it does that..

Plot shows that power instantly went down by 25 hp and 25 torques. It went back up 35hp!

Waviness of the plots is because I was on a 4wd dyno and I was driving the front rollers but the link belt wasn't tensioned right.

[gobuffs]

The more you guys talk about other ECU solutions makes me reconfirm my Pectel decision was the right one. The only thing I need to add that wasn't included that isn't necessary is traction control via E46 M3 Mk60 Teves ABS system for traction control.

[Bimmerman325i]

That plot is ridiculous, it's awesome to see just how the vanos affects things.

The more you guys talk about other ECU solutions makes me reconfirm my Pectel decision was the right one. The only thing I need to add that wasn't included that isn't necessary is traction control via E46 M3 Mk60 Teves ABS system for traction control.

Out of curiosity, what makes you say that? What about the Pectel vs a DTA or Vipec or etc unit do you like?

[nando]

But what does a pectel cost? $5k or more? Thats rediculous for a car that costs $3k average.

[gobuffs]

My decision against the DTA was it wasn't quite ready for primetime when I needed an ECU. So the decision was Vipec vs Pectel vs stock. Stock ruled out due to not giving me any control- if I needed to change something the ECU had to be shipped out. The Pectel was about $1500 more (and yes it is high end) but included being able to run 4 maps, easily integrate traction control/ABS, definitely handles the Vanos, knock control. The KMS unit from VAC was never a consideration- I have never heard anybody running that on an S54. Same for Megsquirt.

Bottom line is it came down to who I was buying it from moreso than the actual hardware. I could have gone Vipec, but not having more than 2 maps ruled that out. The stock solution (for what I wanted) was going to be more than the Pectel (now I don't think that is the case as the stock solution is cheaper but would still be expensive due to more tuning time needed).

Oh, and the "the car costs $3k" doesn't hold water when you are talking about swapping in an S54.

[nando]

Why not? The price of the motors has come way down. I could pick up three right now for $3-4k. People were paying that for S5X's not long ago.

You must be primarily racing to need 4 maps? I could see the reasoning there for such a spendy ecu, but for us mortals with mere street cars..

[gobuffs]

An S54 in any E30 is at least 2 but more like 3x the cost of any S50.

Yes mine is a race car.