N52 engine Velocity Stacks Project

[1536Z4]

This is something I have been following on a US forum . Getting velocity stacks to work on a N52 engine has been discussed for years but it has never really been realised as a kit that works . This however looks very promising .

https://www.youtube.com/watch?v=h17zY6P_feQ

[j3nks79]

Didn’t work really on the S54. Done for looks and noise really.

[1536Z4]

Done for looks and noise really.

Yes it would be the sound that would do it for me more than anything as long as it wasn`t less power Having mine tuned by Josh at Severn Tuning so not something I will be going for at the moment but good to see someone actually making it work on the N52 .

[Ed Doe]

Didn’t work really on the S54.

Please elaborate as to why it didn't really work? Seems to work fine for me?

[j3nks79]

Didn’t work really on the S54.

Please elaborate as to why it didn't really work? Seems to work fine for me?

They didn’t make the same power as a csl airbox.
Sucks in a hell of a lot of hot air and because of that didn’t make good power.
I ran a specialist M3 garage for many years and have owned bought and sold hundreds of E46 M3,s. Driven loads with stacks and apart from the noise they they didn’t make any more power. Infact lots of flat spots through the rev range.

The original stacks were lifted straight of the OEM air box and I think it was ps designs who started painting them and trying to sell on
Now the stacks sat in a nice box with a MAF setup so worked well in OEM form.
The the csl box done away with the mad and ran an IAT sensor.
Now the stacks don’t run a MAF and if you are to run an IAT sensor then this would sit right in the middle of a hot engine bay. So many just run a baseline map and quite frankly never really worked.
So it’s noise and looks you gained. That was it.

[Ed Doe]

They didn’t make the same power as a csl airbox.
Sucks in a hell of a lot of hot air and because of that didn’t make good power.
I ran a specialist M3 garage for many years and have owned bought and sold hundreds of E46 M3,s. Driven loads with stacks and apart from the noise they they didn’t make any more power. In fact lots of flat spots through the rev range.

aah right, so you're talking specifically about 'open trumpets', rather than ITBs - gotcha

Agree that yeah unless they have an airbox (like the CSL Airbox) enclosing them, all they do is suck in a load of warm air from under the bonnet and then pull timing resulting in naff-al power gains and generally s**t running.

Being completely honest, my understanding of ITBs was that it improved throttle response over a single throttle body on the end of a plenum, but having open trumpets was just as above a bit of a waste of time, unless they were enclosed from the engine bay air.

Irrespective of this, the N52 doesn't actually use throttle bodies at all to control the revs; it's all done on the valvetronic on the fly. So quite why they've gone and removed the (very clever) twin-disa inlet manifold (and therefore the associated benefits of harmonic resonance at intermediate rpms improving low/mid-range torque) is quite beyond me. Bit more noise, but unless they're planning on subsequently enclosing the trumpets in a csl-style airbox, it'll just pull in hot air as you say.

Very interesting, but its a no from me Geoff!

[j3nks79]

The original stacks were lifted straight out of the OEM air box and I think it was ps designs who started painting them and trying to sell on
Now the stacks sat in a nice box with a MAF setup so worked well in OEM form.
The the csl box done away with the MAF and ran an IAT sensor.
Now the stacks don’t run a MAF and if you are to run an IAT sensor then this would sit right in the middle of a hot engine bay. So many just run a baseline map and quite frankly never really worked.
So it’s noise and looks you gained. That was it

[Ed Doe]

The original stacks were lifted straight out of the OEM air box and I think it was ps designs who started painting them and trying to sell on
Now the stacks sat in a nice box with a MAF setup so worked well in OEM form.
The the csl box done away with the mad and ran an IAT sensor.
Now the stacks don’t run a MAF and if you are to run an IAT sensor then this would sit right in the middle of a hot engine bay. So many just run a baseline map and quite frankly never really worked.
So it’s noise and looks you gained. That was it

Yup, neat summary of my thoughts tbh; looks like it wasn't only me who clocked the PSDesigns 'Velocity Stack' kit was just posh painted standard trumpets with an IAT plonked slap bang in the middle of a hot engine bay then!!

[1536Z4]

Now the stacks sat in a nice box with a MAF setup so worked well in OEM form.
The the csl box done away with the mad and ran an IAT sensor.

I believe that once they have tested the stacks with a group of willing owners they are going to be working on a filter and cold air set up for the reasons discussed about hot air from the engine bay . Not sure if they have been able to get round a failsafe if the valvetronic/eccentric shaft fails which would be slightly concerning .

[j3nks79]

Now the stacks sat in a nice box with a MAF setup so worked well in OEM form.
The the csl box done away with the mad and ran an IAT sensor.

I believe that once they have tested the stacks with a group of willing owners they are going to be working on a filter and cold air set up for the reasons discussed about hot air from the engine bay . Not sure if they have been able to get round a failsafe if the valvetronic/eccentric shaft fails which would be slightly concerning .

Would 100% need a filter or socks. But as I said before I like the way they sound but ultimately performance is negatively affected.

[j3nks79]

Now the stacks sat in a nice box with a MAF setup so worked well in OEM form.
The the csl box done away with the mad and ran an IAT sensor.

I believe that once they have tested the stacks with a group of willing owners they are going to be working on a filter and cold air set up for the reasons discussed about hot air from the engine bay . Not sure if they have been able to get round a failsafe if the valvetronic/eccentric shaft fails which would be slightly concerning .

Would 100% need a filter or socks. But as I said before I like the way they sound but ultimately performance is negatively affected.
How are they managing air flow and intake temps?!
Would be a baseline Map would be my guess.

[1536Z4]

How are they managing air flow and intake temps?!
Would be a baseline Map would be my guess.

The only info so far that I am aware of is here https://www.e90post.com/forums/showthread.php?t=2063463 .