Markert Motor Works Dyno Thread (many inside)

[digger]

The location of the secondary merge appears to have a BIG effect on all inline6 power output.

fixed

[The Dark Side of Will]

The location of the secondary merge appears to have a BIG effect on S54 power output.

[digger]

Look at the different location of the merge/crossover....IMO that's more important than pipe size. Then They split it again 8" later wtf its just a weird x-pipe in effect

A short length of small piping isnt as restrictive as people think

[Bimmerman325i]

Your pic is dead

Weird, I don't see a dead image.

[2mAn]

Thanks for the pic and the answers. Im getting my game plan ready for a full exhaust system, and what I see is that the separate piping going into the cat makes a big difference.

[328ijunkie]

What makes you say that? Any pics to compare?

also, What cams does that car have?

Schrick street

Note the necking down from 2-1-2 on the OBD1 pipe. That area chokes down to a very small diameter with a thick wall.

Your pic is dead

[Bimmerman325i]

What makes you say that? Any pics to compare?

also, What cams does that car have?

Note the necking down from 2-1-2 on the OBD1 pipe. That area chokes down to a very small diameter with a thick wall.

[2mAn]

Obd2 midpipes aren't too bad. OBD1 ones are shit.

What makes you say that? Any pics to compare?

also, What cams does that car have?

[328ijunkie]

Is the stock midpipe (assuming E36) really that restrictive?
I've heard of cam + header + supporting mods S52's hitting 280 to the wheels.

Obd2 midpipes aren't too bad. OBD1 ones are shit.

[The Dark Side of Will]

Few good updates
4/19/16
Tuned a schrick cam S52 track car. Has 3.5" MAF and 24lb injectors. Headers to stock midpipe. Running OBD1. Unnamed tuners off the shelf chip vs MMW dyno tuning :P

Is the stock midpipe (assuming E36) really that restrictive?
I've heard of cam + header + supporting mods S52's hitting 280 to the wheels.

[328ijunkie]

Few good updates
4/19/16
Tuned a schrick cam S52 track car. Has 3.5" MAF and 24lb injectors. Headers to stock midpipe. Running OBD1. Unnamed tuners off the shelf chip vs MMW dyno tuning :P


Tuned a Turbo M50 E30 We OBD2 converted. running HX35 15psi tapering to 12 off WG spring, 140MLS 93oct. S50 cams


Tuned another S54 E36. Stock plenum, ZM3 airbox, CPI headers, nice dual all the way back exhaust

[JGood]

BMW dyno's every car that leaves their production line - they reject the ones that are lower than spec, but some of them end up coming out higher. I bet ones that are significantly stronger stock are fairly rare though.

weren't S54s hand built?

Not uncommon at all, specially when you get into higher HP/L. Also, these engines aren't that "new" anymore, the s54 is what 17yrs old already, with the youngest ones at 8yrs or so? They might be a bit closer if they were all tested at low mileage.

I was talking about the s65 dyno. But, yeah, points taken.

[digger]

there aren't strong outliers, there are normal ones proabbly fit within a normal distribution of sorts, but there are weak ones which simply have issues with one of the many complex systems. alot can happen in a few years

[nando]

Interesting. You'd think with today's precision manufacturing processes, there wouldn't be that much of a variance anymore. That's a 10% difference...

BMW dyno's every car that leaves their production line - they reject the ones that are lower than spec, but some of them end up coming out higher. I bet ones that are significantly stronger stock are fairly rare though.

weren't S54s hand built?

[ForcedFirebird]

Interesting. You'd think with today's precision manufacturing processes, there wouldn't be that much of a variance anymore. That's a 10% difference...

Not uncommon at all, specially when you get into higher HP/L. Also, these engines aren't that "new" anymore, the s54 is what 17yrs old already, with the youngest ones at 8yrs or so? They might be a bit closer if they were all tested at low mileage.