Author Topic: Metric Mechanic Pulse Chamber Intake Manifold is in... (Read 5856 times)

Nivola · « **on:** September 28, 2008, 10:22:31 AM »

Finished my install of the MM Pulse Chamber Intake manifold, as well as a Samco throttle body boot, Walbro fuel-pump, fuel pressure regulator (raised the fuel pressure to 3.5bar / 51 psi), and a new intake system.

It all took some massaging, as many surprise vacuum leaks were found as well as a leaky top o-ring on the injector for piston #4.

Now, she runs very nicely and pulls very hard.

Very happy with the results -- I still need to find time to dyno her. :rolleyes:

More info can be found on my website: nivola368s

Cobra Jet · « **Reply #1 on:** September 29, 2008, 10:24:44 AM »

explain the "Pulse Chamber" - how is it supposed to work and what are the details on it?

Nivola · « **Reply #2 on:** September 29, 2008, 11:00:54 AM »

Quote from: Cobra Jet;57518

explain the "Pulse Chamber" - how is it supposed to work and what are the details on it?

The best explanation is from Metric Mechanic themselves:

M42 pdf booklet see page 14

SheldonJace · « **Reply #3 on:** September 29, 2008, 12:30:25 PM »

Do you think its worth the 1k? Or was it $750?? I've been thinking about buying this too but I don't want to spend the money and not feel much difference. I know its suppose to increase torque quite a bit right?

Looks damn good though. Did you ask them to paint it normal black? I saw that Febi's was textured black.

Either way good job.

Oh and where did you buy that samco boot? Is it any cheaper than the $40 factory boot?

GrindCulture · « **Reply #4 on:** September 29, 2008, 03:50:37 PM »

That is a very pretty looking engine bay. Would be interesting to see if anyone else could fabricate a similar intake mani. using the ideas of pulse chambers.

vpilarry · « **Reply #5 on:** September 29, 2008, 06:40:28 PM »

If anyone here is old enough to remember CanAm racing you'll remember the unequal length velocity stacks on a lot of cars. See pic. The length and diameter of all intake systems are tuned to give a pressure peak at a particular engine RPM. You factory manifold is tuned that way. The question is at what RPM do you want the biggest boost because the effect peaks at 1 RPM and 1 RPM only and dies off below and above that RPM. The CanAm cars actually used 2 lengths so that 4 cylinders peaked at 1 RPM and the other 4 peaked at a different RPM (these were usually Detroit V8's). These "pulse chambers" give the same effect - pulses hitting the atmosphere (beginning of tube) is the same as pulses hitting a dead end as far as swiftly flowing air is concerned. So, yes anyone could fabricate some chambers it just that they will be good for a narrow RPM band. It takes some calculations and trial and error to get it right. Of course you can broaden the band (although decreasing the peak) by having 2 cylinders peak at say 3000 RPM and 2 peak at 3500 RPM.

BTW Nivola, where do those covers for the shock mount nuts come from - looks nice and clean.

Nivola · « **Reply #6 on:** September 29, 2008, 09:06:24 PM »

Quote from: SheldonJace;57526

Do you think its worth the 1k? Did you ask them to paint it normal black? Where did you buy that samco boot?

Hi Sheldon,
Is it worth the money? That's always a relative term. It's worth it if you are willing to spend/experiment with the potential of being disappointed. By itself (if my car was completely stock), I would probably say "no" to buying it. It is one of those items that incrementally adds up with all the other small tweaks. :rolleyes:

Yes, I did ask MM to paint the manifold semi-gloss black, like my cam cover.

The Samco boot was ordered through sporthoses.com (who happen to be local to me and great people to work with) for $113.14 -- nearly 3x the cost of the OEM unit. If you've looked inside the OEM unit, there is a lot going on in that boot: texture, accordion bends, etc. The Samco boot is simply smooth inside -- much better airflow. The Samco boot is actually for the E36 M42 engine, so it's bend is ever-so-slightly different than the E30 M42 OEM boot (the Samco boot doesn't bend down as much as the OEM E30 boot). It was a custom order, as they had none in stock and it took about 1 month to get it made in the UK, as Samco makes these products by hand.

Quote from: vpilarry;57543

BTW Nivola, where do those covers for the shock mount nuts come from - looks nice and clean.

Hi Larry,
Interestingly, the shock mount nuts came with the car when I bought it from the previous owner. Just a bit of rubber/plastic cleaner and they look as they do.

Cobra Jet · « **Reply #7 on:** October 03, 2008, 12:50:02 PM »

(I posted this same thread in your bfc thread - did not know which one you would read or see first)

~~

just curious - upon viewing the pics of your engine bay, what electric fan is that that you are running in your 318? Is that a BMW factory component from another vehicle - or is it from another manufacuter?

Can you give me some specs on it (who makes it, how much expecting to pay and where to find)?

How is it's cooling capabilities?

~~~~

Also, is that an Accufab adj. fuel pressure regulator that is normally used on a Mustang application (and you have a custom bracket made up to mount it on your 318)?

Nivola · « **Reply #8 on:** October 14, 2008, 03:17:54 PM »

Well, the initial dyno figures are in:

124hp / 114tq at the wheels

You can do your own calculations for power at the crank (your preference between 15-17% loss).

Not bad for a 17 year old car with 216K miles, originally rated at 134hp/127tq at the crank when new!

fiftytakedowns · « **Reply #9 on:** September 07, 2009, 07:24:37 PM »

Did you do an ICV delete?
How much of an increase of torque did you feel
(graphs?)

ose30 · « **Reply #10 on:** September 08, 2009, 02:03:21 AM »

Quote

Do you think its worth the 1k? Or was it $750?

No it's not worth that much. I am sure that intake does what they promise, but material costs are only few $, so their profit is very high.
I have an extra intake around, i suppose i can easily duplicate such a intake.

fiftytakedowns · « **Reply #11 on:** September 08, 2009, 03:20:32 AM »

Sweet, send me one

Ramblin MAn · « **Reply #12 on:** September 08, 2009, 11:02:40 AM »

Well when you make the intake, make the pulse cans adjustable so you can vary the chamber length.

Oh wait, didn't BMW already do that with the 92+ m42s intakes?

318lotis · « **Reply #13 on:** September 08, 2009, 11:09:16 AM »

hey nivola, what size k n filter do have, it looks quite a bit larger than mine, is it ok to run a larger one thats recomendend???
thanx