home made vsr schrick manifold

[vr6turbo 27]

been looking at making my own vsr manifold from a stock one.

 

I work with a guy who has years of engine tuning and is a real boffin when it comes to tuning

we have been looking at how exactly the vsr manifold works, mechanically.

 

has anyone ever stripped the internal flap out of the  schrick/vsr  manifold for maintenance.

or has any photos of how the flap functions internally.

 

I have a feeling it splits the plenum chamber in 2 so you have 3 and 3 cylinders on each side when the flap is closed

and the full width when open

 

can anyone add to the topic even if they see pitfalls I don't

welding is not a problem as the lads at work are wizards with the TIG welder

 

 

[vr6turbo 27]

it would be great to have a variable inlet manifold for 

 

2 to 3 hundred quid

[Mk3highline 287]

http://www.volkspage.net/technik/ssp/ssp/SSP_212.pdf

I think it's a good idea

[ssaunders 199]

Hi mate, some details here (http://forums.fourtitude.com/showthread.php?6089382-Information-request-about-Schrick-VGI-working-s-for-VR6)

There is something about resonance so it pushes a pressure wave of air in, I have read somewhere that it can be upto 6psi! Equal length runners as well, apparently the stock mani can let the 6th cylinder run lean leading to bore wear. I am looking for links I have seen in the past.

My dyno plot shows the torque up till the flap opens, it's somewhere on the rolling road printouts.

Good luck

S

[VR6Pete 1,455]

gets my vote

[vr6turbo 27]

thanks guys the info is great a bit over my head

I think its going to be a long haul though

so bear with me

stage 1 get a stock manifold and cut it open

separate 123 and 456 cylinders along the length of the manifold up to the throttle body

then get  an electric or vacuum flap to separate the two banks

I am sure this is how the VSR works

had a chat with my guru at work and he thinks it will operate fine

because the firing order is 153642 only one cylinder is firing on each of the 2 banks at any one time

[Big J 283]

You've got a sale here if it works out for you. Just don't lean too heavy on the pen!

[Mk3highline 287]

The 24v inlets have two plenums the picture on page 14 on the link shows how it feeds the extra air from the other runners for the top end

As well as the resonance for the extra torque in the mid range along side the long inlet tract

[science 7]

Maybe worth bearing tin mind the 12v AAA and ABV manifolds have runner length compensation inside the manifold. 24v manifolds do not, but have compensation in the camshaft duration instead. Hence the plenum differences in variable inlet manifold design.

Edited January 31, 2015 by science

[Mk3highline 287]

Maybe worth bearing tin mind the 12v AAA and ABV manifolds have runner length compensation inside the manifold. 24v manifolds do not, but have compensation in the camshaft duration instead. Hence the plenum differences in variable inlet manifold design.

That I didn't know

[vr6turbo 27]

lots of info great thanks

anyone got a picture of the vsr/shrick plenum chamber flap setup

[vr6turbo 27]

considering splitting the manifold in two to create a separation between the 2 banks then having them linked externally

with a flap in between

[vr6turbo 27]

found a picture of the flap

sounds a bit rude

 

Edited February 1, 2015 by vr6turbo

[VR6Pete 1,455]

Flaps

[c00k 435]

Maybe worth bearing tin mind the 12v AAA and ABV manifolds have runner length compensation inside the manifold. 24v manifolds do not, but have compensation in the camshaft duration instead. Hence the plenum differences in variable inlet manifold design.

Very true words spoken, it's not just the upper 12v manifold either, the lower manifold has compensation as well. It's not just the shape where it meets the cylinder head either. The internal bores of the lower manifold are different. This is the reason why you shouldn't just gasket match the lower manifold. As you remove the compensation for the cylinders on the other side of engine.

(If running forced induction with a short runner intake things are different)

But for an NA engine never gasket match a 12V!

Edited February 2, 2015 by c00k

[vr6turbo 27]

going a bit slow stacked out at work

machinist is going to cut the top off next week

had a few more thoughts

anyone got a cad drawing of the vr6 manifold

would be good to club together and get one laser scanned

then share the data

for me especially right now

[vr6turbo 27]

still waiting for matey at work to get the milling done

[RBPE 198]

There was a good turbo diesel white paper I studied a while back that had a lot of info, here's some more;

 

http://www.google.com/patents/US20050188940

 

http://en.wikipedia.org/wiki/Helmholtz_resonance

 

I've never looked at a Schrick one but it looks similar to my old MR2 turbo and the newer TFSI ones that splits the air side ways in the runner unlike the VR 24V engines that has the runner length compensations but uses same size orifices down the entire runners.

 

It's pretty straight forward gas dynamics really but there are different ways to go about it - you can just use a short runner but time it off say the third air wave instead of the second - either way, whenever the throttle body is closed the air rebounds and reverberates about so it's about finding where you want the air forced in.

 

So what you need to work out is first and foremost - what is the peak torque level you are tuning too? That dictates a lot. What level of flow are you looking at - i.e. there is no point using an oem or Schrick mani if you want 700hp as the orifice dimensions will ultimately be too small as it is for low powered NA set ups.

 

You can also compensate for VR offsets in the tune as stated - here is the inlet manifold functions for the 24V/R32 engines - as you can see it has "flap 1 and 2" for the change over barrel function (which length of runners it is using) - you can also vary these changes in tuning the ecu too.

 

 

On the oem 12v ecu's you have;

 

Load/speed map for inlet mani

Upper and lower speed thresholds

Code words and blocking times

 

Would love to see what the Schrick ones have added in the maps.

 

EDIT: I've also done a lot of CFD tests over the years and by far and away the most profound thing I have seen in terms of gas dynamics tuning - are the bends. A tight bend seems to have dramatic consequences on the air flow but there are also packaging constraints you have to take into account too unfortunately.

Edited February 26, 2015 by RBPE

[RBPE 198]

P.S. I forgot to mention these are mainly for NA set-ups, FI obviously has forced air anyway and have to take into account far higher cfm's.

 

With the TFSI it needed to have ultimate flow - i.e. orifice dimensions needed to be wide enough to flow x (i.e. 30lbs/min 600+cfm for example) (the width of the runners in laymans terms and ultimate flow) but the down side is loss of low end torque due to a slower gas speed.

Whereas the VR/R32 ones have long runners as they were for NA, undersquare torque monsters, so needed quicker air up top so needed a way to speed up air there - these are the two main differences.

 

I would say that the main area that also aids better air flow would be the TB entrance - if that whole area is far more smooth it would make large CFD differences.

 

One final thing - without flap control in your ecu, it's all a fruitless exercise as you cannot control it!

[vr6turbo 27]

I agree its all about air flow and resonance

the project has taken a bit of a back burner for now

it will get finished after I fit my Vortech stage 2 into the track car I am building

[dox 3]

In America they got the VR6 engine in 2WD form in a MK4 VR6 (non 4motion), do their inlets fit our engines (the throttlebodys are different for sure so would need adapting). Has anyone looked into it previously?

[dox 3]

[RBPE 198]

http://www.volkspage.net/technik/ssp/ssp/SSP_195.pdf

[vr6turbo 27]

^{The ball which stopped for a rest, is rolling again.}

^{My mate at work is going to mill out the manifold this week}

Edited March 23, 2015 by vr6turbo

[WaynesVR6 2]

Any update on this?