Headers vs stage 3 manifold

[1seriesFanatic]

Pretty self explanatory. Just wondering if a stage 3 manifold or new headers will yield the best power upgrade.

[Taskmaster]

Do you have a tune?

[1seriesFanatic]

I would get a tune after I buy the headers or stage 3 manifold

[AlexR6]

If you want power... then headers for sure!

[Blacksport]

I have both...Stage 3 is going to give you the most power; it's not even close. You'll pick up 25-35 with the S3, and maybe 10-12 with headers, most of that coming from the absence of pre-cats.

You will need a flash for the DISA valves in the S3 manifold to work properly.

[AlexR6]

Originally Posted by Blacksport

I have both...Stage 3 is going to give you the most power; it's not even close. You'll pick up 25-35 with the S3, and maybe 10-12 with headers, most of that coming from the absence of pre-cats.

You will need a flash for the DISA valves in the S3 manifold to work properly.

Mhhhh what is going to give you 25/35 hp is the tune, not the manifold itself!

You should compare stock vs tune + 3 stage with stock vs tune + headers...

[1seriesFanatic]

If I put the headers on after I get a tune do I need to get another tune?

[631twentyeighteye]

yes. catless headers require a different tune.

[Blacksport]

Originally Posted by AlexR6

Mhhhh what is going to give you 25/35 hp is the tune, not the manifold itself!

You should compare stock vs tune + 3 stage with stock vs tune + headers...

That is simply not true...you obviously are not familiar with the stage 3 manifold...it has 2 special hi-speed valves that direct the incoming air to the cylinder that is currently drawing the air in...this provides substantially more air to that particular cylinder than it would get if the air was not purposely directed to it. You engine already has the wiring to work the DISA valves, but you will need a re-flash to operate the them.

If you don't understand this, it's because you haven't tried it...Turner Motorsport says you go from 230hp to 260hp...ECS Tuning says your get 42hp...headers with no pre-cats and a straight-thru Borla muffler, might be another 12-15 maybe, I also have an aFe intake, which seems to have "freed up" some more horsepressure, putting me at 280-290 flywheel hp...that's what it feels like, too...

[Suprgnat]

Originally Posted by Blacksport

That is simply not true...you obviously are not familiar with the stage 3 manifold...it has 2 special hi-speed valves that direct the incoming air to the cylinder that is currently drawing the air in...this provides substantially more air to that particular cylinder than it would get if the air was not purposely directed to it.

This is simply not true. The DISA valve are either opened or closed to vary the effective length of the intake runners, all six at a time. Nothing about them tries to "direct the incoming air to the cylinder that is currently drawing the air in". Links to the BMW literature when I get home from work if you'd like.

[AlexR6]

Originally Posted by Blacksport

That is simply not true...you obviously are not familiar with the stage 3 manifold...it has 2 special hi-speed valves that direct the incoming air to the cylinder that is currently drawing the air in...this provides substantially more air to that particular cylinder than it would get if the air was not purposely directed to it. You engine already has the wiring to work the DISA valves, but you will need a re-flash to operate the them.

If you don't understand this, it's because you haven't tried it...Turner Motorsport says you go from 230hp to 260hp...ECS Tuning says your get 42hp...headers with no pre-cats and a straight-thru Borla muffler, might be another 12-15 maybe, I also have an aFe intake, which seems to have "freed up" some more horsepressure, putting me at 280-290 flywheel hp...that's what it feels like, too...

Very funny explanation but definitely not how it really works. You can find a good explanation through google.

Anyway what really gives you more power is the tune which alters the maximum valves lift (it changes the valvetronic parameters).
3 stage intake is not even that good if you are searching for pure performance... last time I have seen a N52 prepared for track use, it had no valvetronic and no 3 stage intake, only fixed valve lift and a very short air intake.. max hp were 325 and it was good only between 5000 rpm and 8000 rpm!

[Blacksport]

Taken directly from Turner's website:

"The system works, based on RPM range, to fill each cylinder with as much air as possible while the intake valves are open. This is done by diverting air away from cylinders that have their intakes closed."

Now, let me say that I don't give a rat's butt how the system works...

I had an AA tune when my car was stock, which basically amounted to nothing, maybe 10hp.

With an AA header install, the result was still luke warm at best, you could barely feel it.

I installed the S3 manifold and took it to Eurowerks for the re-flash...driving the car home was the most delightful experience...the sluggish, "I don't want to rev anymore" milktoast performance was gone and replaced with an engine, much like my S54 M Roadster, that just wanted to keep revving...the aFe intake since added apparently loosened up some more power that was bottle-necked by the stock intake.

Unless you've actually installed an S3 on your car, you simply don't what your talking about...

[Blacksport]

Originally Posted by AlexR6

Anyway what really gives you more power is the tune which alters the maximum valves lift

Valvetronic or VANOS cannot alter the valve lift, only the degree where the valve opens and closes...

[Suprgnat]

Originally Posted by Blacksport

Valvetronic or VANOS cannot alter the valve lift, only the degree where the valve opens and closes...

Valvetronic IS variable valve lift, and it replaces the throttle body except in the case of malfunction. VANOS is variable valve timing.

"The VALVETRONIC II consists of the fully variable valve lift control combined with the variable camshaft control (double VANOS). The valve lift is controlled only on the intake side while the camshaft is adjusted also on the exhaust side. The throttle-free load control is implemented by variable valve lift of the intake valve, variable valve opening timing of the intake valve and variable camshaft spread of the intake and exhaust
camshaft."

Originally Posted by Blacksport

Taken directly from Turner's website:

"The system works, based on RPM range, to fill each cylinder with as much air as possible while the intake valves are open. This is done by diverting air away from cylinders that have their intakes closed."

Now, let me say that I don't give a rat's butt how the system works...

Sadly, the Turner web site is mis-informed as to how DISA works.

"Stage 1 - Idle/lower engine speed range
The DISA actuators 1 and 2 are closed in the idle speed and lower engine speed range. The air drawn in flows past the throttle valve into the resonance pipe. The air mass is split in the resonance pipe and is routed further via the collector runner and the intake resonating runners into the individual cylinders. In this way, a comparably large air mass is
made available to three cylinders.

Stage 2 - Medium engine speed range
DISA actuator 2 is open in the medium engine speed range. In this example it is assumed that the intake valves of the first cylinder are just closing. The gas movement produces pressure peaks at the closing intake valves. This is continued via the resonating and manifold runners at the next cylinder in the firing order thus improving fresh gas charge of the next cylinder to be charged.

Stage 3 - Upper engine speed range
Both DISA actuators are opened in the upper engine speed range. Also in this case it is assumed that the intake valves of the first cylinder are just closing. The pressure peaks ahead of the closing intake valves are also utilized in this case. The intake air mass is now routed via the resonance, overflow and manifold runners."

To anyone that does care, here's a link to actual BMW literature. To learn how DISA works, see pages 49-50. To learn how Valvetronic works, see pages 42-48. http://lindvigs.com/obioban/spec.pdf

[Blacksport]

Yes, I understand what valvetronic is...was just playing around with the Italian guy a little bit...

Your reference material was very interesting though, and provided me with the best understanding I've seen of the S3/DISA mechanism.

I'm quoting: "In this example, it is assumed that the intake valves of the 1st cylinder are just closing. The gas movement produces pressure peaks at the closing intake valves. This is continued via the resonating and manifold runners at the next cylinder in the firing order thus improving fresh gas charge of the next cylinder to be charged."

Turner obviously didn't want to "over-tech" his sales pitch, but he still got the point of the S3 across, at least to me...

[Suprgnat]

Originally Posted by Blacksport

Yes, I understand what valvetronic is...was just playing around with the Italian guy a little bit...

Your reference material was very interesting though, and provided me with the best understanding I've seen of the S3/DISA mechanism.

I'm quoting: "In this example, it is assumed that the intake valves of the 1st cylinder are just closing. The gas movement produces pressure peaks at the closing intake valves. This is continued via the resonating and manifold runners at the next cylinder in the firing order thus improving fresh gas charge of the next cylinder to be charged."

Turner obviously didn't want to "over-tech" his sales pitch, but he still got the point of the S3 across, at least to me...

Well, I think Turner does it's customers a disservice by dumbing down the concept of resonance.

[AlexR6]

Originally Posted by Blacksport

Yes, I understand what valvetronic is...was just playing around with the Italian guy a little bit...

Playing around showing how poor is your knowledge about engines? Cool!

[Blacksport]

Originally Posted by Suprgnat

Well, I think Turner does it's customers a disservice by dumbing down the concept of resonance.

I don't know...ECS says pretty much the same thing: "A 3 stage manifold consists of 2 DISA valves that divert air to the cylinders that need it."

Both explanations are oversimplified but still to the point: the diversion of the charge to the next cylinder in the firing order only happens because of the DISA valves and the shape of the S3 manifold. This does not happen in a single stage manifold. The power increase, IMO, is equal to approximately 40-50% of forced induction...an incredible improvement considering the cost.

[Blacksport]

Originally Posted by AlexR6

Playing around showing how poor is your knowledge about engines? Cool!

Really...

I was building engines for my SCCA F production Triumph Spitfire in 1971. One of the engines I built had me running 3rd in F production at the SCCA National Runoffs in 1973...until I broke a stub axle.

[Suprgnat]

Originally Posted by Blacksport

I don't know...ECS says pretty much the same thing: "A 3 stage manifold consists of 2 DISA valves that divert air to the cylinders that need it."

Both explanations are oversimplified but still to the point: the diversion of the charge to the next cylinder in the firing order only happens because of the DISA valves and the shape of the S3 manifold. This does not happen in a single stage manifold. The power increase, IMO, is equal to approximately 40-50% of forced induction...an incredible improvement considering the cost.

It's more likely that the copy writers for the product advertisements have no clue what they're writing about.

[AlexR6]

Originally Posted by Blacksport

I don't know...ECS says pretty much the same thing: "A 3 stage manifold consists of 2 DISA valves that divert air to the cylinders that need it."

Both explanations are oversimplified but still to the point: the diversion of the charge to the next cylinder in the firing order only happens because of the DISA valves and the shape of the S3 manifold. This does not happen in a single stage manifold. The power increase, IMO, is equal to approximately 40-50% of forced induction...an incredible improvement considering the cost.

Come on... have you ever taken a look at the 3 stage intake and seen a dyno chart of an engine with that system?

It's just a variable intake which is optimized for low/mid/high rpm... you can see it also on a dyno chart, there are two perceivable dips in the torque line when valves are actuated....

That system is good for street driving and makes no more peak power than an equivalent intake optimized for high rpm... these are the basics of engine calibration

[smellthebeans]

Originally Posted by AlexR6

Come on... have you ever taken a look at the 3 stage intake and seen a dyno chart of an engine with that system?

It's just a variable intake which is optimized for low/mid/high rpm... you can see it also on a dyno chart, there are two perceivable dips in the torque line when valves are actuated....

That system is good for street driving and makes no more peak power than an equivalent intake optimized for high rpm... these are the basics of engine calibration

Power and torque are increased across the entire range. Intake resonance changes based on engine speed.

The N52 US intake is not optimized at the high end. I assume that's why North American N52s found in the sedans are referred to as Medium Output.

The 3 stage intake with a tune is an excellent modification.