Black & Tan 332iT

[Bry5on]

No pictures but today I had two of my Mullet tune beta testers over with euro and SSv1 headers (thanks guys) to test the latest iteration of the mullet tune for non-US headers. A Euro Mullet if you will. I brought over and blended in some select cam timing and fuel timing changes from the euro M3 map and we tuned a few areas under 3k RPM to make throttle even smoother and more responsive than the original American Mullet.

Interestingly, heinzboehmer car (with identical mods, but no flap) and mine responded slightly differently to the tune under 1500rpm at mid and heavy throttle, so we ended up with two different files for us to spend time playing with before settling on what works best or if there is one to rule them all. It seems that the 1000-1500 and 2400-2900 rpm ranges are the hardest to get perfectly dialed in as each motor’s subtle differences shine in these areas.

Last, I softened the cam timing a bit at WOT above 5k rpm to make the car a little smoother near the top of the rev band. I think this may have given up a couple horsepower but it’s hard to tell from the butt dyno. It does sound a little more straight-six smooth instead of CSL tune raucous, but on balance I prefer the better running smoothness. If you are running a mullet tune with euro, SS or similar non-US headers, are reading this post, and we haven’t already talked, I’m happy to get you on the latest if you want to test before it’s perfectly hashed out. There’s just a little bit of fuel trimming to do but it does drive a hair better even without that complete. Overall, solid day.

[usdmej]

ah ok thanks, the antigravity website lists your battery at 20.75lbs so pretty close to what you weighed

[Bry5on]

any chance you remember the exact weight of the antigravity battery?

just picked up an H6 60AH battery from antigravity. their website says it should weigh 19.5lbs but i weighed mine at 15.7 lbs and am scratching my head as to why

I used a home scale to measure myself with each battery so I didn’t get a perfect number but I believe it mathed out to 19lb

[usdmej]

Antigravity battery measured exactly 30lbs less than the Bosch battery that came out on the bathroom scale. H7/94R size, 60Ah capacity. Currently 3550lb and 48.5/51.5% F/R
]

any chance you remember the exact weight of the antigravity battery?

just picked up an H6 60AH battery from antigravity. their website says it should weigh 19.5lbs but i weighed mine at 15.7 lbs and am scratching my head as to why

[Bry5on]

I am so happy you of all people published this. I've had the Xtrons unit for about a year but lack the knowledge on how to tune the EQ properly. The result is my audio performance is terrible, it felt like a huge downgrade vs. my stock HK system. I am going to start with your EQ settings as a baseline and see if I can tune it slightly to my speakers vs. your BAVsound versions.

I think the coupe and sedan/touring have different speakers, and low frequency resonances will be different due to the longer touring cabin, so the settings might not work super well for you. Welcome to give them a shot though!

[Albino09]

And the EQ settings:

Plus a little rear bass bump (not included in any of the EQ plots above) because the woofers in the wagon are on the rear channel, facing the tailgate:


Overall happy with the XTRONs unit now, and I prefer all of the response tweaks that the HK system adds even after EQing with it off - it really does appear pretty well tuned to the e46 cabin and speaker placements.

I am so happy you of all people published this. I've had the Xtrons unit for about a year but lack the knowledge on how to tune the EQ properly. The result is my audio performance is terrible, it felt like a huge downgrade vs. my stock HK system. I am going to start with your EQ settings as a baseline and see if I can tune it slightly to my speakers vs. your BAVsound versions.

[karter16]

I've routed the main snorkel feed with the ram air duct and I also have the post-flap ducting routed behind the bumper. According to my data logs, there is no downside in sport mode. I haven't tested comfort mode yet but I'd expect it to be similar. No downside as far as I can tell..

Good stuff - that's awesome!


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[Bry5on]

Unless I'm misunderstanding the flip side is potentially higher IATs when the flap is open? Although in practice when you're moving then it's probably negligible given the ram effect of the snorkel feed?


Sent from my iPhone using Tapatalk

I’ve routed the main snorkel feed with the ram air duct and I also have the post-flap ducting routed behind the bumper. According to my data logs, there is no downside in sport mode. I haven’t tested comfort mode yet but I’d expect it to be similar. No downside as far as I can tell..

[karter16]

Unless I'm misunderstanding the flip side is potentially higher IATs when the flap is open? Although in practice when you're moving then it's probably negligible given the ram effect of the snorkel feed?


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[0-60motorsports]

Yesterday driving over the mountain to/from Santa Cruz in the heat, the car started to creep up half way between center and the 3/4 dot on the gauge at 60mph in sixth. I wasn’t quick enough to think of turning on the datalogger, but I was able to reproduce it a couple times. Interestingly, I’ve never had a cooling issue at idle or low speed, only above 40-50mph or so on sustained uphill in the heat with AC on. I frequently see 10-15 C across the radiator at idle and closer to 7-10 C on the highway, both with AC on.

I’ve also been doing more research on aero and cooling and have convinced myself that the engine air duct is hurting cooling system efficiency when combined with the CSL intake. In a stock M3, the air intake routes to the air filter box and can only go to two places: 1) the engine or 2) the brake duct. Notably, neither of those two locations are connected to the low pressure zone behind the radiator. When you remove the stock airbox and leave that duct open, you’re effectively giving a path of least resistance for the high pressure air in front of the radiator to route straight behind to the low pressure zone behind. This means that all that air is not only not cooling your radiator coolant, but it’s also slowing down the remaining air that does cool the coolant. So I used some firm closed cell neoprene foam to block up the space and some soft open cell foam to make sure the gap stays well sealed. My first test drive hit two of the routes that are almost guaranteed to tick up the temps (it was 85F ambient) and the needle stayed dead center. So far so good.

Before:


Blocked up:


With softer foam layers:


Some photos of the seal against the radiator support:

Interesting, i'll have to give this a go, Once the car is ready, in our horrendous heat LOL

[Bry5on]

Yesterday driving over the mountain to/from Santa Cruz in the heat, the car started to creep up half way between center and the 3/4 dot on the gauge at 60mph in sixth. I wasn’t quick enough to think of turning on the datalogger, but I was able to reproduce it a couple times. Interestingly, I’ve never had a cooling issue at idle or low speed, only above 40-50mph or so on sustained uphill in the heat with AC on. I frequently see 10-15 C across the radiator at idle and closer to 7-10 C on the highway, both with AC on.

I’ve also been doing more research on aero and cooling and have convinced myself that the engine air duct is hurting cooling system efficiency when combined with the CSL intake. In a stock M3, the air intake routes to the air filter box and can only go to two places: 1) the engine or 2) the brake duct. Notably, neither of those two locations are connected to the low pressure zone behind the radiator. When you remove the stock airbox and leave that duct open, you’re effectively giving a path of least resistance for the high pressure air in front of the radiator to route straight behind to the low pressure zone behind. This means that all that air is not only not cooling your radiator coolant, but it’s also slowing down the remaining air that does cool the coolant. So I used some firm closed cell neoprene foam to block up the space and some soft open cell foam to make sure the gap stays well sealed. My first test drive hit two of the routes that are almost guaranteed to tick up the temps (it was 85F ambient) and the needle stayed dead center. So far so good.

Before:


Blocked up:


With softer foam layers:


Some photos of the seal against the radiator support:

[Bry5on]

Yeah I think I'm pretty much at the same point on the continuum as you are. I certainly wouldn't be changing up diff bushes or anything as the NVH would drive me nuts, however from your description and others, there is a pretty minor difference NVH-wise with the solid subframe bushes and I would certainly welcome more sharpness and connectedness. There is also the suggestion (although unsure whether anyone has actually verified it) that solid subframe bushes reduce undesired movement and hence loading on the RACP, which would also be welcome.

I agree with that hypothesis, the carrier/chassis itself should benefit in stiffness from the solid bushings too.

[karter16]

Do you want the car to feel sharper and more connected, or as quiet as possible for highway drives? I prioritized the former slightly above the latter. Easy recommendation of that’s your priority order as well. For me, there’s a very fine line of what’s tolerable. I didn’t like hybrid camber plates and I hated solid RTABs. Most people here don’t seem to notice NVH changes from those, but I would do solid subframe bushings again.

Yeah I think I'm pretty much at the same point on the continuum as you are. I certainly wouldn't be changing up diff bushes or anything as the NVH would drive me nuts, however from your description and others, there is a pretty minor difference NVH-wise with the solid subframe bushes and I would certainly welcome more sharpness and connectedness. There is also the suggestion (although unsure whether anyone has actually verified it) that solid subframe bushes reduce undesired movement and hence loading on the RACP, which would also be welcome.

[Bry5on]

Ugh - I chickened out and did mine in 2017 with new OE bushes. I'll be dropping my subframe when I do the 6 point RACP/RSM brace, and now I'm wondering if I should do this at the same time...

Do you want the car to feel sharper and more connected, or as quiet as possible for highway drives? I prioritized the former slightly above the latter. Easy recommendation of that’s your priority order as well. For me, there’s a very fine line of what’s tolerable. I didn’t like hybrid camber plates and I hated solid RTABs. Most people here don’t seem to notice NVH changes from those, but I would do solid subframe bushings again.

[karter16]

Driving wise, I'm very happy. Wish I hadn't chickened out earlier

Ugh - I chickened out and did mine in 2017 with new OE bushes. I'll be dropping my subframe when I do the 6 point RACP/RSM brace, and now I'm wondering if I should do this at the same time...