S54 Dyno Database

[0-60motorsports]

Engines with lang heads never seemed to do any better than stock head though ( all else equal)

interesting. never knew that.

[digger]

Always thought Langs was job was top notch and I know it was....Maybe quality has dropped since covid...

Engines with lang heads never seemed to do any better than stock head though ( all else equal)

[0-60motorsports]

Nope. Lang uses his own machinist across town and claims he does the work. My "Lang" head was drop shipped to my house from his machinist. Lang also claims leakdown of 2-3% or less which is bs because I got my head back wiht 3 valves leaking. My local machinist fixed it all. Dude sucks lol.

Always thought Langs was job was top notch and I know it was....Maybe quality has dropped since covid...

[thegenius46m]

Aren’t vac doing their heads ?

Nope. Lang uses his own machinist across town and claims he does the work. My "Lang" head was drop shipped to my house from his machinist. Lang also claims leakdown of 2-3% or less which is bs because I got my head back wiht 3 valves leaking. My local machinist fixed it all. Dude sucks lol.

[stash1]

Thanks for the input. It IS a single pipe system. When I detailed the specs to Karl, that was included. And I agree with comment about track use. Not sure if you saw the dyno trace I post a day or two ago, but the torque curve is nice. There is another dyno printout earlier in this thread that shows a REALLY flat curve from 2500 so I was curious about that.

I had a 98 M3 that I modded in a similar fashion. It had a 3" single system with a single 100 cell cat. Never dyno'ed it, but it was stronger than other similar M3s I worked on. I did barrow a similar 2.5 single system form an E36 325 that I had installed. I could really feel the power loss. I can't imaging a 3" single system flowing better on an S54 than a 3.5" single system. After all, Bimmerworld sell single pipe race systems for both E36 and E46 M3s, and they are 3" and 3.5" respectively. Not taking sides on the debate, but I tend to think they know what they are doing given their racing experience.

BTW, I miss living in Maryland SOOO much.

I started posting up a comparison graph, but realized that your torque numbers are actually pretty comparable to a similar vehicle above 3,500 rpms. (The bell shape of your curve was throwing me off-lol.) Under 3,500 rpms though, your torque falls off of a cliff...that's a characteristic of a large single pipe set up. A traditional well tuned twin-pipe set up will hold a pretty flat torque from just above 2,000 all the way up to red-line. I think my car was down around 50 ft. lbs. under 3,500 rpms...and that was w/tuning. Ha, it's an ok state, if you can avoid Baltimore City...think we're like #2 on the murder rate hit list now-UUGH!

[snaponbob]

The answer to your question is simple: it’s been proven by many (myself included), and many times over, that a single 3.5” pipe kills bottom end torque. You can compensate somewhat w/cam timing, but you will never get all of the low end torque back. Your tuner of choice should be able to compensate a bit for the single pipe. But I know many track guys prefer a single pipe for weight savings, and most track cars spend the majority of time over 4,500rpms…sooo, low end torque typically isn’t as critical on a track car vs. a street car.

Thanks for the input. It IS a single pipe system. When I detailed the specs to Karl, that was included. And I agree with comment about track use. Not sure if you saw the dyno trace I post a day or two ago, but the torque curve is nice. There is another dyno printout earlier in this thread that shows a REALLY flat curve from 2500 so I was curious about that.

I had a 98 M3 that I modded in a similar fashion. It had a 3" single system with a single 100 cell cat. Never dyno'ed it, but it was stronger than other similar M3s I worked on. I did barrow a similar 2.5 single system form an E36 325 that I had installed. I could really feel the power loss. I can't imaging a 3" single system flowing better on an S54 than a 3.5" single system. After all, Bimmerworld sell single pipe race systems for both E36 and E46 M3s, and they are 3" and 3.5" respectively. Not taking sides on the debate, but I tend to think they know what they are doing given their racing experience.

BTW, I miss living in Maryland SOOO much.

[stash1]

The tune is from Active Autowerks and are usually quite good. I have e-mailed them the charts to see what they think.

That said, I saw some earlier NA S54 dyno plots from similar setups as mine showing substantial torque coming in at rather low rpm. I wonder how that can be achieved.

The answer to your question is simple: it’s been proven by many (myself included), and many times over, that a single 3.5” pipe kills bottom end torque. You can compensate somewhat w/cam timing, but you will never get all of the low end torque back. Your tuner of choice should be able to compensate a bit for the single pipe. But I know many track guys prefer a single pipe for weight savings, and most track cars spend the majority of time over 4,500rpms…sooo, low end torque typically isn’t as critical on a track car vs. a street car.

[snaponbob]

Good HFC's only cost around 5HP vs. no CAT's, and a good custom tune is probably worth another 5-10HP max over a decent canned tune. Thanx for posting up btw!

The tune is from Active Autowerks and are usually quite good. I have e-mailed them the charts to see what they think.

That said, I saw some earlier NA S54 dyno plots from similar setups as mine showing substantial torque coming in at rather low rpm. I wonder how that can be achieved.

[snaponbob]

Does SCCA care where they are located? On the E46M, the best place for them is downstream in the section one like the Euro cars.

Yes, depending on class. Stock is stock, Street Tune allows alternate cats (no less than 100 cell) but no further that 6" down stream from the original outlet. Higher level classes do not require cats. Euro would not be allowed as only US spec would be allowed. No such restrictions are in place for SCCA or NASA Time Trials.

[Slideways]

First post into this thread. The questions will be opinions on the cost effectiveness of remote tuning vs a good drop in file, and what could be expected if good CATLESS headers are installed.

The car --- 2004 M3.
WPC bearings, full rebuild of the VANOS except the drive plate for the oil pump, valves adjusted.
Compression is 175-177 psi front to back. Leak down is 8%-18% depending on the cylinder.
New NGKs, new coils, new injectors.
No oil consumption. Three good Blackstone tests.
EVenturi CAI, triple underdrive set, fan clutch in place.
Drop in tune from Karl at Active Autowerkes.
Stock exhaust manifolds, except I cut out the OEM cats and grafted in same physical sized 100 cell cats. (SCCA Solo STU requires cats) I will never EVER do THAT again. NOT easy. Exhaust is a single 3.5" system with two resonators (as only one was skull crushing loud).
Dyno chart attached.

No dyno was done before the mods.
NO AFR was done as this dyno session was only for the purpose of SCCA Time Trials classing. This year will be running NASA TT so there is some room for some added power.

Does SCCA care where they are located? On the E46M, the best place for them is downstream in the section one like the Euro cars.

[stash1]

First post into this thread. The questions will be opinions on the cost effectiveness of remote tuning vs a good drop in file, and what could be expected if good CATLESS headers are installed.

The car --- 2004 M3.
WPC bearings, full rebuild of the VANOS except the drive plate for the oil pump, valves adjusted.
Compression is 175-177 psi front to back. Leak down is 8%-18% depending on the cylinder.
New NGKs, new coils, new injectors.
No oil consumption. Three good Blackstone tests.
EVenturi CAI, triple underdrive set, fan clutch in place.
Drop in tune from Karl at Active Autowerkes.
Stock exhaust manifolds, except I cut out the OEM cats and grafted in same physical sized 100 cell cats. (SCCA Solo STU requires cats) I will never EVER do THAT again. NOT easy. Exhaust is a single 3.5" system with two resonators (as only one was skull crushing loud).
Dyno chart attached.

No dyno was done before the mods.
NO AFR was done as this dyno session was only for the purpose of SCCA Time Trials classing. This year will be running NASA TT so there is some room for some added power.

Good HFC's only cost around 5HP vs. no CAT's, and a good custom tune is probably worth another 5-10HP max over a decent canned tune. Thanx for posting up btw!

[digger]

I do not know that. I only know of a few personal stories.

I used to wonder whether it was true as some of the marketing spiel is identical and I recall someone on here confirming it

[Tbonem3]

Aren’t vac doing their heads ?

I do not know that. I only know of a few personal stories.

[digger]

Dem leaky Langs

Aren’t vac doing their heads ?

[snaponbob]

First post into this thread. The questions will be opinions on the cost effectiveness of remote tuning vs a good drop in file, and what could be expected if good CATLESS headers are installed.

The car --- 2004 M3.
WPC bearings, full rebuild of the VANOS except the drive plate for the oil pump, valves adjusted.
Compression is 175-177 psi front to back. Leak down is 8%-18% depending on the cylinder.
New NGKs, new coils, new injectors.
No oil consumption. Three good Blackstone tests.
EVenturi CAI, triple underdrive set, fan clutch in place.
Drop in tune from Karl at Active Autowerkes.
Stock exhaust manifolds, except I cut out the OEM cats and grafted in same physical sized 100 cell cats. (SCCA Solo STU requires cats) I will never EVER do THAT again. NOT easy. Exhaust is a single 3.5" system with two resonators (as only one was skull crushing loud).
Dyno chart attached.

No dyno was done before the mods.
NO AFR was done as this dyno session was only for the purpose of SCCA Time Trials classing. This year will be running NASA TT so there is some room for some added power.