B5 S4, operation money pit. Forever evolving, never ending.

[WarpedRotors]

In for 1/4 mile times.

[Exodus_2pt0]

November 18th is the day. A friend of a friend is renting a track for the day and I got an invite. I'll be one of the slowest cars there, will be hanging out with 1000+ hp monsters.

5 new plug boots on the way (already replaced 1)
Starter, timing belt, water pump, thermostat done.

Running 19 psi and just about have my fueling perfect. Right at 11.5:1 and it Richens up to 11 flat at redline. Finally got it figured out where it hits 11.5 pre meth, and the fuel tapers off around the time the meth comes in, so no rich condition while spraying, I can't even tell when the methanol kicks in by watching the wideband anymore.

MBC will be here Thursday, so when that's here I'll start turning up the boost. Then timing. I feel much better now, before I was worrying about fuel, boost, and timing at the same time, trying to tune it all together.. Problem was things were happening very quickly, because the car was running extremely strong. But my fuel was less than ideal, boost pressures would change drastically with ambient temp, and I started to get very nervous about popping it. Now taking a step back and dealing with one thing at a time.

I would love to pull off an 11.5. I'll definitely be pulling the sub and spare out for the track. Also, will be putting the launch control to use. Go big or go home, if I break it, I break it.

GoPro will be going too.

[CorvallisBMW]

Sweet, plz post vids!

[Exodus_2pt0]

Took this for some people on AZ interested in the SSAC exhaust. Figured I would share.

[CorvallisBMW]

Exhaust sounds great

[Exodus_2pt0]

Ridealong! MBC is on, boost set to 24-25psi. Starting to bump the timing up, still pretty conservative at this point. Knock correction is at 3* or so and drops to 0 up top. Probably will end up around 22-23* in the top end.

Also glad for this video, scary how long I turned to check out the knock numbers watching back. Now, this is on a long flat empty road, but still. Self shame.

[Exodus_2pt0]

Exhaust sounds great

Thanks, not bad for a $400 system. I wanted to go Borla but in the end decided that half the cost AND being a true dual 2.5" system won the argument.

[Northern]

My buddy had one of these(except avant) for a while, and I think it's one of the few cars he's owned that I really liked. I think I'm just too scared of breaking shit to ever own one.

[325i]

i need bentleys ^^

[Exodus_2pt0]

Pretty sure my Walbro 450 is junk.

I have my partial and idle ltft's at less than 1%, AFR is solid 14.7, and drops to 11.5 as requested until I hit 20psi, and it leans out to 13:1. Added some fuel this morning, and it didn't make any change. Fucking Walbros can't handle the 4 bar base pressure + 25psi on top.

Going Bosch 044 and never looking back.

[Exodus_2pt0]

I lied, got a replacement 450 brand new for $30 coming tomorrow.

Also, my subwoofer is sacrificing its 10awg fused power cable to power the new fuel pump directly, with a 40amp relay that will be triggered by the factory wiring.

Turns out on top of the 80psi relief valve, the 450 will draw upwards of 20amps at high pressure. Stock fuel pump wiring is very thin, so hopefully this should help. I will also be modifying the new pump to hopefully fix the relief issue. I'm running roughly 85psi of fuel pressure at full boost.

Will post results. I just wanna go fast.

[dadsbmw]

Is that not weird? Why not just use properly sized injectors to run 45psi fuel pressure?

[Exodus_2pt0]

This car runs a 4 bar regulator stock. That with Bosch 550cc injectors is a proven combo for my power goals. No need to reinvent the wheel. I mean, I could go to a 3 bar regulator and some 750s, but this works... erm, did and will again. The lean condition wasn't happening when the pump was first installed.

It's a high draw pump, so I'm just going to take out all the weak links this time around.

The next phase (After we buy our house and this has a garage to hibernate in), will probably need a 3 bar and 1000cc injectors. But that's going to be an entirely different ball game. Thinking single 6262 or bigger, 6-700whp. Either that or VR swap and go crazy with it.... But again, that's a few years off. Once I get the current setup ironed out I'm happy for a while. If all goes well it should prove to be a mid 11 second car in full street trim come November.

[Exodus_2pt0]

Victory!

With no changes to the tune it was only leaning out to 12:1, added 3% and now I overshot the fuel, dipping in to the 10's.

Someone is getting up early in the morning to finish dialing this thing in.

[Exodus_2pt0]

Aaand, I finally found the missing piece in the puzzle.

I was maxing out the load value, which capped my injector duty cycle at 1.5 bar. The solution was to descale my maf load correction table, and scale my main fuel table in the corresponding load values.

Result is a low reading MAF, but a consistent 11-11.5 AFR across the board. Finally!

Videos to come. Last night was fun, ran into an lsx F-body and I don't think it went how they expected.


It's been a long learning curve, and I think I've finally got a decent grasp on it. It's been many nights of reading, but totally paging off.

Next step will be to sell my ecm and eurodyne cable, get a stock ecm and go complete home brew on the tune.... But I think I'll enjoy it for a while. Bumping timing back up now.