Cold air intake(s)

[WGB]

A post on the M-100 site yesterday about re-siting the battery in the boot for an LPG installation in a 6.9 led me to again contemplate using the twin intake 560 aircleaner and ducting that is gathering dust in my shed.

It is not difficult to mount the battery in the boot, arrange an earth and run an appropriately sized cable through the floor and along under the car to the starter motor. I have a separate feed to my seat heaters but that would not be difficult to link up. The most difficult part would be making a suitable cover for the battery in the boot and arranging safe drainage of acid laden fluid.

I even have a spare 116 battery tray although the original could be used.

Another suggestion has been to use the smaller 66amp battery ( I have a dead one lying around to use as a template) which might give enough clearance to allow a duct to get to the front of the car down the right hand side of the motor.

My questions are :-

1) Can the 6.9 be reliably used with a 66 AH battery - especially when only used once per week.

2) Is the increase in performance sufficient to warrant the effort and further removal of the car from originality - although it would be easy to reverse if needed in the future, particularly if the battery is not re-sited.

Bill

 

[Des]

Dear Bill

Firstly to see if there is any point to mucking around with this can you take the air cleaner off and give it a short drive?

This is a 6.9 with the 560 air cleaner fitted to give you an idea of how it has been done before



this is a super rare AMG air cleaner, in keeping with your car's AMG theme, you could have something like this made up by someone who can use a welder



some other thoughts...

If you could get another bonnet, keep your original, and have some vents like this, piped into the air intake





Or this




Or a shaker through the bonnet

 

[WGB]

Thanks Des.

The super rare AMG filter gives me food for thought as I am not unskilled with a welder and have another spare old air-cleaner body I could play with.

I would rather go for period mods if I can.

Bill

 

[SELfor50]

A post on the M-100 site yesterday about re-siting the battery in the boot for an LPG installation in a 6.9 led me to again contemplate using the twin intake 560 aircleaner and ducting that is gathering dust in my shed.

It is not difficult to mount the battery in the boot, arrange an earth and run an appropriately sized cable through the floor and along under the car to the starter motor. I have a separate feed to my seat heaters but that would not be difficult to link up. The most difficult part would be making a suitable cover for the battery in the boot and arranging safe drainage of acid laden fluid.

I even have a spare 116 battery tray although the original could be used.

Another suggestion has been to use the smaller 66amp battery ( I have a dead one lying around to use as a template) which might give enough clearance to allow a duct to get to the front of the car down the right hand side of the motor.

My questions are :-

1) Can the 6.9 be reliably used with a 66 AH battery - especially when only used once per week.

2) Is the increase in performance sufficient to warrant the effort and further removal of the car from originality - although it would be easy to reverse if needed in the future, particularly if the battery is not re-sited.

Bill

Bill, to answer your question (number 2) - I don't own a 6.9 so haven't been able to compare the air intake question for the M100 engine.

Though, I CAN testify that on an M117 engine you definitely notice the difference... Especially on a cold evening (as you no doubt know in general from the 6.9) if I floor it in 1st, remembering it's only a 4.5L k-jet engine, it'll light em up. With both tubes connected down to clean air in, it winds out quicker and easier (if that makes sense?). When the air is cold outside too I tend to notice the speed vs revs comparison to improve. Eg. faster speed for less revs.

Hope that helps with your choice.

Another option, as des said:
http://cgi.ebay.com.au/ALUMINUM-STR...yZ158509QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[WGB]

Thanks SEL450.

I also have a spare bonnet but the "Shaker" option probably doesn't fit with the middle aged/middle class purist in me

Bill

 

[John S]

SELfor50, I cannot understand how the outside temperature can change the revs/speed relationship, unless you are getting less slippage in the torque converter until it eventually heats up to operating temperature.

 

[SELfor50]

SELfor50, I cannot understand how the outside temperature can change the revs/speed relationship, unless you are getting less slippage in the torque converter until it eventually heats up to operating temperature.

I don't know either... not entirely sure. But I can tell you it seems to have more efficiency / rev range with cold air. Can't explain it, but I can guarantee you it's temp related..

 

[WGB]

Cold air is denser so I guess you are getting more oxygen in the mix and as the fuel flow is metered by the mass of air entering you get more charge and a bigger bang.

Most modern performance cars have cold air systems and all turbocharged cars have intercoolers as well now so there must be something in it.

Anyway I tried the 560 air filter today and the RH airhorn fouled on the aircon hoses so that is a no-go.

Bill

 

[Des]

Anyway I tried the 560 air filter today and the RH airhorn fouled on the aircon hoses so that is a no-go.

Bill

can you post a picture of your engine bay? or describe what is different to the car I show above with the 560 air cleaner?

 

[WGB]

Hi Des,

Here is the standard aircleaner in the first photo.



And here is the second photo showing the 560 aircleaner with the right horn (left side of the photo) sitting on the airconditioning hoses.



I think the LHD runs the hoses low down on the left side of the motor more like the 450 motor - whatever, they are not in the elevated position on the right like the RHD 6.9.

Bill

 

[Des]

It is hard to tell from the photos but could you lengthen the air con hoses and then poke the snorkel through them?

 

[BAR]

Of all the recommendations, I prefer the idea of attachine a snorkel to the existing air cleaner inlet trumpet. The existing unit can be cut shorter, allowing for a smooth section to which one can attach a length of flexible pipe, such as shown in the earlier photos.

The flexible pipe should be routed to the front of the vehicle, below and away from the radiator, thus avoiding any heated air from that source.

APart from spoiling the appearance of a W116, the shaker option may be illegal, depending upon the year of manufacture. The shaker was made illegal on noise polution grounds around about the mid '70s from my recollection.

 

[Mercules]

Cold air is denser so I guess you are getting more oxygen in the mix and as the fuel flow is metered by the mass of air entering you get more charge and a bigger bang.
Bill

At "X" rpm and "Y" engine load you will always have "Z" airflow - the depression plate on your Bosch Driptronic will always move the same increment, whether it is a stinking hot day or a freezing cold night...

... the only difference is on the hot day the oxygen particles will be less dense and on a cold day, more dense...

Now - if your Driptronic is out of adjustment and running rich (like mine is) , a cold intake charge will bring the air/fuel ratio closer to stoichiometric and produce a more complete combustion.


But if you are chasing that last tenth of a horsepower I would reccomend a good dyno tune and fuel injection adjustment before a cold air setup!

Cam

 

[Styria]

Hi WGB, yeah, you're right with the Air Con hoses being routed on the left side of the engine with left hand drive cars.

I did have a 560 Air Cleaner which "some punk" bought off me and he's happy with it.

Personally, I could never come to grip with the frustration in how best to fit the unit under the bonnet of Gleaming Beauty - it was all too much for me especially as I really did not know how much, and if any, benefit a I would gain from this modification. Regards Styria

 

[SELfor50]

I couldn't possibly begin to imagine trying to fit it on a 6.9.... You made a good decision to get rid of it Styria!

 

[Styria]

On the 560 body, it is a great modification because Mercedes left enough space in all the right areas to perhaps really get some benefit from the fitting of the twin intake snorkels. As I said, I looked long and hard, many many times and in the end gave the idea away.

If I remember correctly, I have seen a pic. of your installation, and you have certainly put the Air Cleaner to good use. Regards Styria

 

[Michel]

At "X" rpm and "Y" engine load you will always have "Z" airflow - the depression plate on your Bosch Driptronic will always move the same increment, whether it is a stinking hot day or a freezing cold night...
... the only difference is on the hot day the oxygen particles will be less dense and on a cold day, more dense...
Now - if your Driptronic is out of adjustment and running rich (like mine is) , a cold intake charge will bring the air/fuel ratio closer to stoichiometric and produce a more complete combustion.
But if you are chasing that last tenth of a horsepower I would reccomend a good dyno tune and fuel injection adjustment before a cold air setup!
Cam

Thank you Dr Cam

Very well put

 

[Des]

Something like this would look the part also

 

[WGB]

Des,

I've already got the wheels and I do have a spare bonnet....

Bill

 

[Des]

Dear Bill

Now this is the scoop I was talking about earlier, from an American muscle car,

look how sinister it is, peeping up out of the bonnet, you know something bad is going to happen when you plant that right foot and leave the commodores in your tyre smoke