How far can you go with a stock or maybe modified Z4 35is N54 airbox?

[fmorelli]

We can talk about the airbox and filters all day long. But still where does that air come from? On the Z4 it has to go through that oblong thin pipe over the radiator support. It's a full path problem, not just an airbox/filter problem. I know you are not looking for more dyno time. One simple test might have been to disconnect that leading pipe and just leave the front of the airbox inlet open and see what happens.

 

[pbondar]

We can talk about the airbox and filters all day long. But still where does that air come from? On the Z4 it has to go through that oblong thin pipe over the radiator support. It's a full path problem, not just an airbox/filter problem. I know you are not looking for more dyno time. One simple test might have been to disconnect that leading pipe and just leave the front of the airbox inlet open and see what happens.

Hi..we (I) inadvertently did this early on in our V6 dyno runs…I hadn’t seated the corrugated transfer pipe from the inlet duct to the airbox..as a result it was detached from the airbox, so the airbox was sucking air from the engine bay …as far as I can recall there wasn’t something material in the dyno runs that stood out about it…

By implication therefore subject to hot air issues in the engine bay / benefit of ram air at high speed that part of the system seemed de minimus…

Thats not to disagree with the general sentiment…

 

[ShocknAwe]

Cool to have something that looks factory. Answer is the 750i box and 3" hidden inlets.

For the rest of us... I'm even ditching my aFe Momentum GT closed box shortly. Switching to DCI with velocity stacks but Im front relocated and rear stock location, both 3".

 

[pbondar]

Cool to have something that looks factory. Answer is the 750i box and 3" hidden inlets.

For the rest of us... I'm even ditching my aFe Momentum GT closed box shortly. Switching to DCI with velocity stacks but Im front relocated and rear stock location, both 3".

Well something must be working as we’ve achieved the same hp and torque as TTE showed in their benchmark demo with a little less boost 21.5 psi vs 23 psi .obviously I’m not aware of their induction set up but guess it wasn’t a stock air box n filter ..

 

[fmorelli]

I completely like the second inlet approach. @NoQuarter and I were looking at running it do an entry point further in front, which is tricky given packaging. Above is a working version and I like it. I have an AFe setup sitting in a box (that will never go on) and a 740i box which I was considering for the conversion ... I digress. Nice to see this work done and once I'm relocated, this is motivating to get that done.

 

[ShocknAwe]

Well something must be working as we’ve achieved the same hp and torque as TTE showed in their benchmark demo with a little less boost 21.5 psi vs 23 psi .obviously I’m not aware of their induction set up but guess it wasn’t a stock air box n filter ..

Its good work with the airbox, though with the Z4 lid and addition of the additional filter area and piping via Mr5 style tract its not really stock anymore. You'd definitely see an additional increase if you increased your inlet size since you have hybrid turbos. Pressure volume flow resistance and pipe radius are all related and headroom could be gained in your case especially if youre on an E mix with more octane than I have.

Very cool regardless and lovely to see all the comparison plots here.

I completely like the second inlet approach. @NoQuarter and I were looking at running it do an entry point further in front, which is tricky given packaging. Above is a working version and I like it. I have an AFe setup sitting in a box (that will never go on) and a 740i box which I was considering for the conversion ... I digress. Nice to see this work done and once I'm relocated, this is motivating to get that done.

If I had to do it again I'd take the inlets straight up over the engine, removable clamps to make it detachable to remove engine cover/valve cover easily PRN. But, if I do it again it likely wont be with a N54/53 hybrid.

 

[pbondar]

Does the 740i airbox fit the E89?…Is that with a 750i airbox lid or an E89 lid?

FWIW the 50mm Mr.5 inlet is about as much as you can get in with the existing other pipes and routing ..on a RHD car..I did look at 68mm piping but it didn’t work in the availability space..

 

[ShocknAwe]

There's a user here who experimented with the 7er box and inlet setup but never finished if I recall.

 

[SlowE93]

Well something must be working as we’ve achieved the same hp and torque as TTE showed in their benchmark demo with a little less boost 21.5 psi vs 23 psi .obviously I’m not aware of their induction set up but guess it wasn’t a stock air box n filter ..

Nice data. Appreciate the time you have put into all of this. I run a stcok box on the slowmobile with an extra filter that I fabbed up as well. My dyno guy was impresssed by IATs and power delivery.
Anyway, not to take away from any of your experiments and comparisons but are there logs for the dyno graphs above ?
A simple slight overboost can change a 23 psi tune into actual 24 psi for a brief moment and dyno will read higher of course. But it doesn't mean it was a true 23 psi run.
Same goes for any psi set in a tune. So a 21.5 psi run can actually be 22+ or whatever just like a 23 psi run can underboost and not reach max power.
Hard to compare without seeing logs. Also was timing higher on one tune vs the other ? Ambient temps, elevation, etc?
Like I said, not taking anything away from you. My modified box works for me and looks pretty decent, was just pointing out the difficulty and other factors when trying to make comparisons.

 

[pbondar]

Nice data. Appreciate the time you have put into all of this. I run a stcok box on the slowmobile with an extra filter that I fabbed up as well. My dyno guy was impresssed by IATs and power delivery.
Anyway, not to take away from any of your experiments and comparisons but are there logs for the dyno graphs above ?
A simple slight overboost can change a 23 psi tune into actual 24 psi for a brief moment and dyno will read higher of course. But it doesn't mean it was a true 23 psi run.
Same goes for any psi set in a tune. So a 21.5 psi run can actually be 22+ or whatever just like a 23 psi run can underboost and not reach max power.
Hard to compare without seeing logs. Also was timing higher on one tune vs the other ? Ambient temps, elevation, etc?
Like I said, not taking anything away from you. My modified box works for me and looks pretty decent, was just pointing out the difficulty and other factors when trying to make comparisons.

No worries on your questions…

Data logging only started with the custom tune ..so all the N20, MHD V9 and V10 tunes were not data logged..all the custom tunes are logged here on this site.

i can post the detailed dyno run graphs here if people are interested…all the custom tune dyno runs already have been posted I think.

Dyno is at sea level and most runs have been in ambient temperatures of around 15c to 25c max I think

From what I’ve seen on the tunes the requested boost has almost always been in excess of the delivered boost..usually by 0.5 to 1 psi..

The 14+ tunes have started very conservatively and then boost, timing , VANOS have all been tweaked by carabuser.

Todsy I’m doing a pull on V14+ (spicy) which I drove yesterday for 300 miles..feels ‘perky’ and smooth..I’ll post the logs later today 🏎🏎

I understand he’s trying to close the gap between requested boost and actual on this version..

 

[pbondar]

Here are a few historical dyno files for the Yellow Peril for comparison..enjoy..apologies to the clarity and formats over time..

 

[pbondar]

I did find our MHD V10 stage 2+ log which we used to check the integrity of the systems before the big turbo upgrade…stock save decat pipes, fox exhaust system and Nexsys B58 coil system ..ignition timing pulls then..

Z4 E89 35is V10 stage 2+ first attempt at data logging prior to fitting TTE500 turbos

www.spoolstreet.com

 

[pbondar]

So here’s the answer to ‘well how does it compare to DCIs?’…

Today’s dyno runs..

The chart with 3 lines is tune V17 (iteration 19) which has been tweaked to reduce timing corrections and improve spool..peak power is slightly down on the earlier v13+..torque up..two versions one with the Mr.5 mod and one using DCIs…compared to v13+ with the Mr.5 mod…

The chart with 5 lines is version 6 of the tune ..revisited twice..once with a Mr.5 mod and one with DCIs

 

[studio54]

Thanks for testing !

It looks like DCI give nice results, the torque is really good up to 5000rpm.

I think that DCI are probably more a matter of sound and/or look then.

But I also still think that the Mr5 will be more consistent after multiple runs. As I previously said I always been impressed by first pulls or during winter on DCI, but after a few moments, if you have to stop/slow down (traffic and things), it will not perform as good (maybe in my head cause only buttdyno).

 

[pbondar]

Thanks for testing !

It looks like DCI give nice results, the torque is really good up to 5000rpm.

I think that DCI are probably more a matter of sound and/or look then.

But I also still think that the Mr5 will be more consistent after multiple runs. As I previously said I always been impressed by first pulls or during winter on DCI, but after a few moments, if you have to stop/slow down (traffic and things), it will not perform as good (maybe in my head cause only buttdyno).

Wear and tear logically should be an issue with the poorer filtration of gauze filters..I used K+N filters on my bikes for many years..I never wracked that many miles on them so wear was not obvious.

I intend to keep my 35is for a very long time so longevity of the engine is a concern..hence why I went down trying to avoid any modifications to the very good stock air inlet system..hopefully my Mr.5 version will still offer pretty good filtration…

I drove back yesterday some 2 hours and 70 miles with the VSRF DCIs fitted and it confirmed my prejudice against DCIs based on inlet noise as well..

So Mr.5 being refitted this morning.

DCIs do seem to do well at peak torque..it can’t be flow rate as that’s a max rpm issue..I assume that in the pulses coming back from the turbos that destructive interference effects take place inside the limited volume of the airbox that don’t occur went venting to the engine bay with DCIs..

A lack of torque is not an issue with the current set up….