M54 Madness, the remix

[2mAn]

That's not a bad price to do that!

[hoveringuy]

My throttle body is back from Maxbore, $150 to bore it from 64mm-->68mm.

The stock M54 has a 68mm TB so it makes sense to me that I should go to that size.

Between the bigger TB, a silicone intake boot, and the the 3.5" MAF with the HFM5 sensor, it'f running great. I need to spend some time tweaking the tune for the changed configuration, and then to the dyno!

[mike25]

That's really cool! I'm very curious to hear how that works out. I'm planning something very similar, but the tube it'll be incorporated into will be CFD designed and optimized for that awful 90 degree turn into the TB, built with CF layup and include the run to the filter down by the headlight.

Are you planning a rubber concertina section to absorb engine movement?
Photos of the finished article would be good too.

[hoveringuy]

That's really cool! I'm very curious to hear how that works out. I'm planning something very similar, but the tube it'll be incorporated into will be CFD designed and optimized for that awful 90 degree turn into the TB, built with CF layup and include the run to the filter down by the headlight.

I want...

[Jaker]

I'm still sorting some little stuff before I commit to another dyno. I've put together a 3.5" MAF using a generic housing and an HFM5 series Bosch MAF sensor.

That's really cool! I'm very curious to hear how that works out. I'm planning something very similar, but the tube it'll be incorporated into will be CFD designed and optimized for that awful 90 degree turn into the TB, built with CF layup and include the run to the filter down by the headlight.

[hoveringuy]

I'm still sorting some little stuff before I commit to another dyno. I've put together a 3.5" MAF using a generic housing and an HFM5 series Bosch MAF sensor.

The older euro 803 that I was using worked Ok but I think it was too susceptible to reverse flow error. The HFM5 series is more modern and should make it run a little better, although I'm not expecting more power with it. The actual sensor is Bosch 0280217007 which is used in Boxsters and Carerras.

Also, I've sent my throttle body off to Maxbore to be machined from 64mm to 68mm. The stock size for the M54 is 68mm so that only makes sense. The stock MAF on the M54 is also 3.5".

[TheAxiom]

Bump.

[hoveringuy]

Bump?

Having the battery disconnected so much recently killed my cluster. No tach, no temp, etc. It's been at Bavarian Restoration where Greg r/r the SI board plus a few enhancements.

I'll try to make a dyno visit in January.

[TheAxiom]

Bump?

[digger]

Oh ok, I looked at previous/first pic and there was optical illusion

[Jaker]

I'm not sure there is any true "choke" at the ends of the primaries. The 3-1 collector in the photo is 3 x 1.75" inlet and 1 x 2" outlet.

[digger]

They spec'd 2" secondaries into a 2 1/2" choke. Rest of the exhaust is 3". That's the size of my current setup and it seems to work very well.

i mean choke at end of primaries as you said you bought two 3 into 1 merge collectors.

[Jaker]

They spec'd 2" secondaries into a 2 1/2" choke. Rest of the exhaust is 3". That's the size of my current setup and it seems to work very well.

[digger]

I bought it from Dan at Pure Performance in Cali. The hub is from ATI as well. Complete replacement for everything OEM.



Mine will be stepped primaries, 1.5 x 9"/1.625 x 9"/1.75 x 9".



See above.

That photo was just to show the "equal length" style/design that my fabricator Zack envisions.

that would be would i would do except the 1.75" part. what size did burns choose for the choke and the secondary?

[ForcedFirebird]

Didn't see a size mentioned, but seems as you got the right stuff going on :) 1.5" initial primaries is a good choice.