Out of interest 2.8 vs 3.0

[t-tony]

I would be very interested in seeing the difference between a standard 2.8 and a modified one before I went that route. Get that place contacted Dave and encourage Roy to bring his car and compare with Reggie. That said, you said you wouldn't want to put Reggie through a dyno test so why would you bother looking for more power?
I wonder if there's a difference in manifolds between the Z4 3.0 SE and Si models? A similar difference in HP there too.

Tony.

 

[Lee]

I would be very interested in seeing the difference between a standard 2.8 and a modified one before I went that route. Get that place contacted Dave and encourage Roy to bring his car and compare with Reggie. That said, you said you wouldn't want to put Reggie through a dyno test so why would you bother looking for more power?
I wonder if there's a difference in manifolds between the Z4 3.0 SE and Si models? A similar difference in HP there too.

Tony.

With z4's theres a valvetronic system that tilts the cam on the Si and the 3.0 is a standard cam. Also with electric steering and electric water pump that's what gives us the extra bhp.

 

[Brian4]

With z4's theres a valvetronic system that tilts the cam on the Si and the 3.0 is a standard cam. Also with electric steering and electric water pump that's what gives us the extra bhp.

The N52 engine fitted to the Si has the valvetronic which does away with the throttle body but a separate vacuum pump . All your accelerator pedal does now is move the inlet camshaft too damn clever now.

Latest 3.0 engine is turbo now produces 335 hp and is the same crankcase as the diesel engine so all I have to do is change the head on mine and it's a petrol one

 

[Antm72]

Roys is the M52TU engine dual vanos where as Reggie has the M52 single vanos when you look at a stock 2.8 single vanos inlet and then look at a M50 you can see a very clear difference.
It gives a lot more bottom end grunt and it breaths freely at the upper end so where as they can feel alittle choked at 5k rpm plus this adds the ability to pull far harder to higer rpm with out the noticable loss of power and flatness.
M50 manifold

M52 single Vanos

M52 on left M50 on right

As you can see the inlet size difference is quite alot making a big difference the m50 matches the heads inlets air flows vastly different.
The M52TU is not much different when you change the manifold its not such a profound upgrade

 

[gookah]

I have had a 3.0 for a few years, and now have the twin vanos 2.8, which for half my ownership has had the M54 inlet conversion.
In standard form, it was not as dramatically fast as the 3.0, but it is now getting there, Certainly over 4k revs it feels very similar.
Just need a remap now to get the best out of it.

The difference between a standard 2.8 and a 3.0 in monetary terms is usually a lot, and that is for good reason.
However, if you get a £100 manifold conversion, it then gets you a lot closer for a lot less money.
Would I still swap mine for a 3.0?.....yes..... but not at the prices they are asking for them.

Here you can see the difference between my two manifolds, with the restricted oval ports on the old one and the full D shape on the new:

 

[5harp3y]

Surely it's not as simple as just putting an M50 manifold on - wouldn't everyone do it if it was?

It's a bolt on mod and a few small adaptations for 30bhp extra

 

[t-tony]

So what I'm thinking is what's stopping someone removing their original manifold and machining out the "D" shaped ports and "gas flowing" the manifold (making it smooth) like in the old days on a cyl. head?

Tony.

 

[5harp3y]

So what I'm thinking is what's stopping someone removing their original manifold and machining out the "D" shaped ports and "gas flowing" the manifold (making it smooth) like in the old days on a cyl. head?

Tony.

The whole runners are smaller not just the opening

 

[Rha]

Well It's time I put my views in and can say that even if I wasn't going to get mine on the rollers it's going as well if not better than the 3.0 Bertini I drove back from last years kit car show for Anthony Cherry. Been out again today in my Z and again it's a differant car performance wise. Is my seat of pants guage any recommendation?????? Well it's booked in for a rolling road remap on Thursday for a long session to try and get the most out of it, so if it doesn't snow on the day I should have a graph for you all to ponder over. Filled with 98 fuel, estimated 5-6x the original cold air ram feed, free flow cat back Powerflow exhaust, cleaned injectors, NGK iridium plugs, oil,water,tyres all checked so a quick warm up drive to the garage on Thursday and Bobs your uncle. This is worse than going for a MOT. Nervous??? Naaaaa, even if it only shows a small improvement on the original figures it's still a differant animal on the road. (But then I would say that wouldn't I.)

RHA,Roy.

 

[Rha]

The whole runners are smaller not just the opening

Don't forget the DISA cos that's a lot bigger. Go on google and put in, How the BMW DISA valve works to see how clever it is. To me the differance in DISA between the two models is as important as the size of the runners.
Could be wrong but have a look and see.
ROY?

 

[t-tony]

Well It's time I put my views in and can say that even if I wasn't going to get mine on the rollers it's going as well if not better than the 3.0 Bertini I drove back from last years kit car show for Anthony Cherry. Been out again today in my Z and again it's a differant car performance wise. Is my seat of pants guage any recommendation?????? Well it's booked in for a rolling road remap on Thursday for a long session to try and get the most out of it, so if it doesn't snow on the day I should have a graph for you all to ponder over. Filled with 98 fuel, estimated 5-6x the original cold air ram feed, free flow cat back Powerflow exhaust, cleaned injectors, NGK iridium plugs, oil,water,tyres all checked so a quick warm up drive to the garage on Thursday and Bobs your uncle. This is worse than going for a MOT. Nervous??? Naaaaa, even if it only shows a small improvement on the original figures it's still a differant animal on the road. (But then I would say that wouldn't I.)

RHA,Roy.

No mate you wouldn't just say that. You know the difference it has made to your car. I'm just playing Devil's advocate here.

Tony.

 

[Rha]

No mate you wouldn't just say that. You know the difference it has made to your car. I'm just playing Devil's advocate here.

Tony.

See my PM.

 

[Alan W]

I took my car out this evening and as the roads were very quiet l put the auto box in sport mode and give it some... jesus it was shitloads fast enough for me..

 

[t-tony]

Imagine it even quicker then Alan. I do like mine a lot but in sport mode it is a different animal too.

Tony.

 

[oldcarman]

Imagine it even quicker then Alan. I do like mine a lot but in sport mode it is a different animal too.

Tony.

I was wondering along the same lines Tony and also wondering if the D shape inlets match up with the heads or is there some port matching that could improve the flow even more. Polishing the inlets with maybe a bit of grinding to straighten the ports a bit with a polish could potentially give a bit more gain. If the entrance into the head is smaller than the inlet they can be matched with a die grinder and smoothed into the valve and allow a free through entrance rather than causing a restriction where the head and intake mate. Just my thoughts!!

 

[Simon Blythe]

The M50 manifold job is well worth doing it. Did it on my first 2.8 really frees up the engine making it more responsive and pull harder

Do you literally just change the manifold? I'm assuming there is a little more to it than that.

 

[5harp3y]

Do you literally just change the manifold? I'm assuming there is a little more to it than that.

on an M52 you have to

swap the manifold
space the injectors and oil dip stick tube
change some of the pipework
get a throttle body adapter plate

but kits are readily available with all the right parts

 

[andyglym]

on an M52 you have to

swap the manifold
space the injectors and oil dip stick tube
change some of the pipework
get a throttle body adapter plate

but kits are readily available with all the right parts

Thanks for the info. Where would one find such a kit?

 

[5harp3y]

eBay or google M50 manifold kit

 

[Lee]

Ben at hack engineering is a good place to get your kits.

http://www.hackengineering.co.uk/product/m50-manifold-fitting-kit-for-m52-engine/