FREE Air-Intake Mod: Full Details on Page 6 of this thread

[sam1832]

Will this apply to a 3.0i?

Are the intakes the same?

I've not yet seen the air intake system of the 3.0i in person, but looking at the parts diagram, I expect that this mod will be applicable to the car.

For the purposes of this test though, I'm wanting to restrict it to the Z4M only, to reduce the variables and since I've done all the R&D on intake mods on the Z4M, I'd like to take one step at a time.

Once the testers have had an opportunity to test this mod during the month of June, I will then openly describe this mod on this forum for all to see and the testers can then give their opinions.

Cool

I will hold on till then then

Sent from my GT-I9300 using Tapatalk 2

 

[DONDP]

Im in too, email inbound...

 

[H2O]

I will be glad to be a US spec datalogger tester

 

[pilchardthecat]

Exdos - in a previous conversation you said that based on your datalogging tests, modifying the intake was pointless unless you de-restrict the exhaust - have you revised your opinion on this?

 

[exdos]

Exdos - in a previous conversation you said that based on your datalogging tests, modifying the intake was pointless unless you de-restrict the exhaust - have you revised your opinion on this?

Can you show me where I said that?

 

[Grizzly9]

Exdos - in a previous conversation you said that based on your datalogging tests, modifying the intake was pointless unless you de-restrict the exhaust - have you revised your opinion on this?

I don't know about being 'pointless'. However, generically speaking, It was my understanding that by modifying either Air intake or Exhaust on any Engine the whole system would be 'unbalanced' without modifying/adjusting it at the other end!!!! :idunno:
Thoughts!!!!

 

[exdos]

It was my understanding that by modifying either Air intake or Exhaust on any Engine the whole system would be 'unbalanced' without modifying/adjusting it at the other end!!!! :idunno:
Thoughts!!!!

The Z4M intake is a genuine ram-air intake, which means that when the car is travelling faster the air pressure (air density) inside the intake system is greater than when the car is standing still or travelling slower. At the redline at WOT in 2nd gear the engine consumes a lesser mass of air/fuel than it does in 3rd gear, (due to lower ram pressure) therefore, the Z4M's air-intake and exhaust can never be permanently "balanced" as you suggest. The exhaust system has to flow whatever the engine spews out. The OEM exhaust system has one of the least back pressures for a production car, but because its job is to "silence" it incorporates a "reverse-flow" system in the silencers to achieve this. By removing the "reverse-flow" pipework in the silencers, it's possible to reduce the back pressure some more to make the exhaust system 'straight-through" and even more free-flowing. Datalogging shows that the total performance gain is in the order of the sum of all the individual gains that can be made from modding the air-intake and exhaust systems, appropriately. The information that I will give to the testers on 1st June, is an air intake mod that can be done for free which is the first stage of improving the air-intake system. I found from datalogging, that modding the silencers without doing this free air-intake mod showed no gain.

 

[Grizzly9]

Thanks for posting that informative gem of info Exdos. Now a question for you as you got me thinking.

If I go for this 'mod' of by-passing the back box just to give her a bit more of a sporty sound, I assume I am reducing the Back pressure by doing this, but am I also increasing velocity/scavenge and giving her more power?

 

[exdos]

Thanks for posting that informative gem of info Exdos. Now a question for you as you got me thinking.

If I go for this 'mod' of by-passing the back box just to give her a bit more of a sporty sound, I assume I am reducing the Back pressure by doing this, but am I also increasing velocity/scavenge and giving her more power?

From previous experience with other cars, I thought that by gutting the silencers I would get more power in the way that you've described, but it didn't happen with my Z4MC. This really bugged me, but I eventually had a Eureka moment and I discovered the reason why and the free air-intake mod proved to be the solution. I've not yet looked at the air-intakes of any Z4s besides that of the ///M, so whether my mod is applicable to your car or not, I don't yet know?

 

[pilchardthecat]

Exdos - in a previous conversation you said that based on your datalogging tests, modifying the intake was pointless unless you de-restrict the exhaust - have you revised your opinion on this?

Can you show me where I said that?

In this thread http://www.z4-forum.com/forum/viewtopic.php?f=9&t=45999&p=664369#p663441

you said you started off at VE 102%, fitted modified exhasusts, still at 102%, changed the intake and went to 105.5%, then refitted the OEM silencers and it dropped back to 102% (ie no effect just changing either the exhaust or the intake independently

 

[exdos]

Exdos - in a previous conversation you said that based on your datalogging tests, modifying the intake was pointless unless you de-restrict the exhaust - have you revised your opinion on this?

Can you show me where I said that?

In this thread http://www.z4-forum.com/forum/viewtopic.php?f=9&t=45999&p=664369#p663441

you said you started off at VE 102%, fitted modified exhasusts, still at 102%, changed the intake and went to 105.5%, then refitted the OEM silencers and it dropped back to 102% (ie no effect just changing either the exhaust or the intake independently

I've found that modding the silencers alone, shows no gain. I've had to modify the OEM air-intake (Eureka mod) to get a gain from the modded silencers. Before I decided to do a MkII silencer mod to attempt to cure a slight drone in the MkI silencer mod, I reverted to OEM intake (minus Eureka mod) and OEM silencers and I found that VE went back to 102% which showed that the 105.5% VE was attributable to combined intake (Eureka mod) and silencer mod. Essentially, unless you can increase the ram-pressure on the air-intake side of the engine, there is no significant gain to be had from a more derestricted exhaust system.

I've found that by taking my air-intake mods to where they are at now, (well beyond the Eureka mod) that whilst the air intake mods show gains on their own, they show greater increases when combined with modded silencers. Is that clearer?

 

[pilchardthecat]

... Is that clearer?

Yes, thanks. I am pretty sure my intake mods have had a positive effect, even with stock exhausts

Out of interest, what did you do to the exhausts in your MkII version?

 

[exdos]

... Is that clearer?

Yes, thanks. I am pretty sure my intake mods have had a positive effect, even with stock exhausts

If you've managed to harness the ram effect better than OEM, then you most likely will have improved performance.

Out of interest, what did you do to the exhausts in your MkII version?

I reconfigured the internal layout from the MkI mod slightly. I've posted photos of it on here somewhere.

When do we get to see/hear about your intake mods?

 

[pilchardthecat]

When you reveal your "eureka" mod, I will post details, pictures etc of my carbon fibre bits and MAF improvements

 

[pilchardthecat]

ps; this diagram is interesting



Part #14 appears restrictive, and i had planned on removing it, but it was not actually present on my car. I would be interested to know if anyone else actually has it

I'm not sure if it's just a crude representation on the MAF screen (which looks nothing like that, and obviously was present)

 

[exdos]

When you reveal your "eureka" mod, I will post details, pictures etc of my carbon fibre bits and MAF improvements

Excellent I expect the Eureka mod will give your mods some help. 8)

Then again, you could always disclose your mods first, I've done nothing in carbon fibre nor to the MAF...

 

[pilchardthecat]

When you reveal your "eureka" mod, I will post details, pictures etc of my carbon fibre bits and MAF improvements

Excellent I expect the Eureka mod will give your mods some help. 8)

Then again, you could always disclose your mods first, I've done nothing in carbon fibre nor to the MAF...

I look forward to it.

You've done nothing to the MAF/screen? I have a treat for you then

 

[exdos]

You've done nothing to the MAF/screen? I have a treat for you then

No. I've removed them in the past and datalogged the airflow, and I didn't find a significant gain.

 

[pilchardthecat]

Removing it just introduces a load of turbulence, which whilst less restrictive, actually reduces the flow rate.

It is possible to significantly increase it though.

 

[exdos]

Removing it just introduces a load of turbulence, which whilst less restrictive, actually reduces the flow rate.

It is possible to significantly increase it though.

A few years ago, I did some calculations on the total area of the wires and plastic in the screens, and from memory, it was around 40% of the area inside the 87mm tube in which the MAF sits! However, the area of the holes in the screens is still significantly more than the area of the throttle into the cylinders, so there's not really a flow-restriction through the MAF which might be limiting flow into the cylinders. I'm sure that the flow rate could be increased though.