M54 Madness, the remix

[ForcedFirebird]

No, it's cool. Any knowledge that advances the art is welcome.

Do you plan on a dyno trip? Seeing you went for comfort on the exhaust, am curious (I think the new exhaust would actually be better). Many thing "headers" instantly means more power, but usually the contrary. On the m20 we saw a couple wtq, 0whp gain, but it was just a side exit and cheesy y-pipe close to the collectors (not a car we bult, just one we tuned before and after).

[hoveringuy]

Do you plan on a dyno trip?

Yes! I just resolved my last issue this morning. It wasn't revving past 6000 because I'm using a Toyota 1JZ ignitor box which has smart dwell. I had my dwell at 3ms and the ignitor box was protesting at 6000 by cutting spark, not limiting dwell. I reduced my dwell to 2.4ms and now it spins to 7200.

So, I will schedule a return to the dyno.

-New exhaust. Car is 10x quieter and also stronger with the OBD2 headers and smaller diameter down pipes.

-Static cam timing. Intake cam had been retarded about 8 degrees. Dead-on now.

-VANOS seals. They broke into pieces when removed. Intake cam was not advancing nearly enough and was hard to control.

On the negative side I added a MAF which I didn't have before.

[Jaker]

Well since the OP said it was OK, here's my build. I won't be doing a build thread of my own. However, I will answer any questions that might come my way.

1993 325is - 2,380lbs no driver

3.0 build, M52 Z3 aluminum block, Vanos head
11.5:1 84.5mm Imagineering pistons (Paul Burke)
Metric Mechanic rally cams
Molnar rods
Ported head
1mm over valves
3.5" intake
540i MAF
Riot Racing 68mm TB
24lb injectors
22nd Productions remote tune (22rpd.com) on Bosch 413 DME
Lightweight S52 crank
UUC flywheel/M5 clutch
Raceland shorty headers
Custom 3" exhaust
Several oiling mods





And the start of the new header (I bought 2 of them):



Expecting something similar (but better looking) to this:

[craz azn]

^ Where did you source that style ATI damper from? Did it come with a hub made for it or uses the stock crank hub?

[digger]

that header for what looks like s54 looks alright, id be getting stepped primaries if i was you

[ForcedFirebird]

Primaries look a little large, but the design is bang up. People tent to over-size headers - but keep something in mind - NASCAR use 1.625" primaries (stepped up after) on a 4" bore and make 100hp per cylinder.

[Jaker]

^ Where did you source that style ATI damper from? Did it come with a hub made for it or uses the stock crank hub?

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

that header for what looks like s54 looks alright, id be getting stepped primaries if i was you

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

Primaries look a little large, but the design is bang up. People tent to over-size headers - but keep something in mind - NASCAR use 1.625" primaries (stepped up after) on a 4" bore and make 100hp per cylinder.

See above.

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

[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.

[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?

[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]

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]

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]

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

[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.