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Das Beast: My E30 track / street build

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    Hot Rod

    We're finally getting to the point that "working on the car" means hot rodding around the block, not fixing things.

    We'll except for this.Replaced the surge tank fuel pressure sensor so that dash light would turn off.

    Soldering in place. My least favorite thing.

    But the sensor works now. Surge tank low pressure light is off (one on the bottom, right of fuel pressure gauge). Top light is low pressure warning for main fuel circuit. Note the the fuel pressure is 60 psi without the car running. It drops to 50 for normal operation. There are programmable circuit boards controlling the low fuel warning level, low oil pressure and high water temperature. We have to tweak them at some point. Hasn't been done yet.

    Passenger seat in, belts installed. Looking very sporty

    Added a Longacre parabolic racing mirror. Why is it in front of the driver, not middle of the car? We found it gives GREAT visibility at this location, without obstructing forward view. You can literally see out both rear side windows, all the way to the back of the car. Rob said "Wow. I can see the drill press and metal bender at the same time" Makes a good sun visor too.

    Finally on the road. We have a license plate, insurance, turn signals horn etc, just not an inspection sticker. Good enough for laps of the neighborhood. Got lots of waves and thumbs up.

    I was the co-pilot, running Tuner Studio while Rob drove. This is VE Autotune showing history of where we are in the table. Just wanted to get a feel for it first.

    Then we turned on autotune. This adjusts delivered fuel to meet the AFR target for each cell in real-time while you drive.

    You can see what the changes were before applying them permanently. Red for more fuel, blue for less. Works pretty good. Note this is not a substitute for dyno tuning. We're just getting it bulletproof and "good enough" before going back to the dyno.

    We never felt any boost, so went back and checked some things. Verified the boost control solenoid worked with test mode. (See all the previous posts on that adventure) Turns out the boost control table was set to 0% for all ranges, meaning the valve was continually closed. Remember that more solenoid PWM = more valve open = more PSI keeping waste gate closed = more boost. (Go back and look, we have diagrams) We adjusted the boost control table to give us 50% boost at WOT, depending on RPM and 25% boost at 1/2 throttle. Goal is to see just a bit of boost, confirm that's working.

    Next time we'll do some data logging to verify key parameters: RPM, fuel load, throttle position, water temp, boost PWM duty cycle, boost PSI and AFR. We have these on a gauge cluster as well.

    Finally, we're going to take the car to a small local track "Harris Hill" for some test and tune. Will let us get better data than around the neighborhood.

    Pretty damn satisfying to have it running. Thanks to everyone who has chimed in with helpful tips.
    "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

    Das Beast build thread


      I’m just a lurker, but I’ve been following this from the start. I love waking up Monday morning to new updates. Huge congratulations! Sent from my iPhone using Tapatalk


        Getting closer.... much closer!



          Working on verifying the electronic boost control today. Here's the initial setup for open loop boost control. Overboost control is set to cut spark at 10 psi. (14.5 psi + 10 psi = 24.5 psi = 169 KPa) Waste gate has a 6 psi spring. Wow. that's a horrible picture. :-)

          Boost control table is set to open the boost solenoid 100%, sending max pressure to keep the waste gate closed. Just to see some boost.

          Did a roll on in 3rd gear. You can see me hesitating at partial throttle a couple of times, then finally going WOT. Would something break? Didn't know. RPMs got to 3900 and the engine cut out. What? Only I only saw a few psi on the boost gauge, verified by the log. 4.4 psi is still less than the waste gate spring.

          Then I remembered we had set spark cut to 4000 RPM a while back. Fixed that, and changed the boost control table. Set it up to spool the turbo fast at low RPMs, then back off boost pwm at higher revs. We're not tuning, just checking for good boost control.

          You can see the boost control PWM doing what the new table says it should. 100% for fast spool then down to ~30%, rising with RPM. This time we got to 4600 RPM at WOT, but as boost was coming on I heard a "pop!" and got out of the throttle. Uh oh. We hit 5.5 psi. Was that the waste gate spring opening?

          Nope. It was the unintentional "blow off valve". LoL. We forgot to tighten a boost hose clamp.

          Fixed that, did another pull. MUCH better. You can see the engine at WOT with RPMs ramping nicely. AFR is pig rich, but I want it that way for testing to avoid detonation. Boost solenoid pwm drops from 100% spool-up to 30-ish as set in the table. Boost psi starts to ramp, going non-linear as we pass 4K RPM and hits 10 psi. At this point overboost control kicks in and cuts spark. Perfect. 10 psi boost means we are exceeding the waste gate spring 6 psi static pressure and electronic boost control is working. Almost ready for dyno tune.

          Back to some fabrication. Sealing up the rear wheel wells to keep exhaust gasses out of the cockpit.

          Love aluminum. It's so easy to work.

          That will do. It fits better than it looks. Just placed in there for now.

          And finally, decided to change this boost gauge. Would rather know how much vacuum we're pulling at idle, and I'm never going to run 30 psi boost. Will get a -10 to 20 VDO boost gauge. Easy swap.

          Overall a really good day.
          Last edited by dvallis; 11-24-2019, 12:39 PM.
          "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

          Das Beast build thread


            Now I know why I went with that boost gauge. VDO doesn't have a -10 to 20 psi, or even a 0 - 20 psi. We might run more than 15 psi boost, so I didn't want to peg a 15 psi gauge. In fact, I couldn't find a -10 to 20 psi gauge by anyone. There are -30 to 30s, but you end up using a very small percentage of the dial sweep.
            "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

            Das Beast build thread


              Finished making the inside quarter skins today. Here's one prepped with VHB tape, ready to install

              Had to take out both seats to get inside the cage in the back seat. Tight quarters

              Both quarters installed. Looks pretty good. Not many things left on the punch list now before going back to the dyno

              "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

              Das Beast build thread


                You'll lose the VDO style points, but the Bosch boost gauge has the limits you're looking for (-30 -> 20) at a reasonable price point. It's not toooo far off the VDO gauge looks either.



                  On our car, we used rivnuts and made the rear quarter glass a bolt-in gig. Super easy access to the fuel pumps and/or rear seat area. Came in real handy at the Atlanta 14hr when we had a fuel issue.
                  Transaction feedback: Here, here and here. Thanks :D


                    Blow off What?

                    So, in all the time we've been building this car, nobody mentioned a blow off valve. In retrospect, yeah, it's obvious that when you lift under boost the throttle body slams shut and all that boost pressure needs somewhere to go. Hence this thing: 50 mm tial BOV with 10 psi spring. Are most E30 guys not running enough boost to need one?

                    Fits well just before the throttle body.

                    Running out of room on the intake manifold for boost references.

                    We were ready to go for a ride when I did a quick walk around. Looked under the car and said "Noooooo!". Oil puddle. Not so quick investigation revealed oil leaking from inside the transmission bell housing. Best case, oil pan. Worst case, rear main seal. Once we got the car up on jack stands and took off the front bell housing cover, here's what we found. There is less than 1/8" clearance between the oil pan and flywheel. The slightly over sized crank scraper was hard up against the flywheel, keeping the oil pan from sealing against the block. And I suspect serious heating from the last time we ran it.

                    Yes, you can remove the oil pan from the block without removing the steering rack or pulling the entire engine. We removed minimal components from the engine, disconnected anything that might not like the engine moving: downpipe, turbo plumbing etc.

                    From there, lifted the engine about two inches, unbolted the oil pan dropped the oil pump into the pan and pulled everything.

                    We amputated the crank scraper. Screw that. Too much trouble.

                    Luckily they had an an oil pan gasket at Autozone. Oil pan prepped and ready to go back in.

                    Oil pan reinstalled. Too easy. Put everything back on the engine and we're ready to go, but ran out of daylight.

                    "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

                    Das Beast build thread


                      24 hours later and still no oil on the floor so I think we're good to go. Test drive next time, check boost at 4000 RPM sustained and verify blow off valve operation.
                      "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

                      Das Beast build thread


                        I surely would have given up by this point. Das Beast needs to be on the track.


                          There is no Try. Ony Do. :-)

                          Next session is the fun stuff:

                          Set fuel pressure reg to 50 psi engine off. Verify pressure under vac & boost. (We fixed a loose vac ref fitting to the FPR)

                          Set boost cut to 12 psi and boost pwm to 0% for entire table

                          Drive around in autotune to dial in VE table. Confirm AFRs.

                          Confirm waste gate operation at ~6 psi

                          Confirm BOV operation on lift in boost

                          Tune open loop boost to 10 psi
                          1. Fill the target table completely to 100% DC.
                          2. Turn your overboost 1-2 psi above your target goal.
                          3. Go log a 4th gear pull.
                          4. Note the rpm you reach your target.
                          5. Second column pwm 100% with RPM set to target -200
                          6. First column 200 rpm at 100%.
                          7. Third column pwm 10% at target RPM
                          8. Log another 4th gear pull.
                          9. Keep increase the numbers 10% or so until you reach your target and maintain it.
                          10. if you notice a drop in boost, pinpoint the rpm and add a few % in that column.
                          11. Drive around in autotune to set VEs

                          This is just for practice. Open loop boost psi will vary with ambient temperature. Use closed loop

                          Tune closed loop boost to 10 psi
                          1. Set p, i, d to 0
                          2. Increase p until boost stabilizes below target at steady state
                          3. Increase i until steady state equals target
                          4. If unstable, increase p set i to zero and repeat 3
                          5. Increase d to achieve critical damping, minimize overshoot and undershoot
                          Last edited by dvallis; 12-18-2019, 09:41 AM. Reason: New boost tuning
                          "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

                          Das Beast build thread


                            Ready To Ride

                            Primed the engine oil and topped it off. Making 60 psi with the drill so looks Ok. No oil on the floor. Didn't drop the socket into the oil pan this time, LoL.

                            Got the seats in, belts reattached and interior ready to go.

                            Ready to ride. Re-fueled, re-oiled, fuel pressure adjusted, coolant system burped. No fuel, oil or water leaks.

                            Tomorrow will be a lot of fun.
                            "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

                            Das Beast build thread


                              Holy shit, nice ride.
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                              Divided Being Motorsports - Youtube Channel / Build Log


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                                It was a glorious day for cruising around. Slightly cool, nice and sunny. Perfect for tuning. Here's the Beast ready to go

                                Drove around with autotune for quite some time, letting it adjust the VE table. Tried to hit as many of the cells as possible. Ran smoothing on it later, then burned to the MS2. This is not "tuned". Just good enough for now.

                                Testing the waste gate and blow off valve. Here's a pull with the boost pwm set to 0%. You can see boost topping out at 6.5 PSI while the RPMs are still increasing, so the waste gate is open. BOV opens when I lift the throttle and dumps boost PSI. So far so good.

                                This time we're testing the boost controller to increase the waste gate opening PSI. Boost control is set to 50% for entire table. As I get on WOT you can see the RPMs ramping linearly. By 4K RPM boost PSI starts to go non-linear. Woah, 12 PSI and rising straight up! Time to lift! BOV dumps pressure nicely. So we know the boost controller is working correctly.

                                Changed the boost PWM duty cycle to 20% and did another run. It held 10 PSI at WOT. Good enough to verify the the setup can be dyno tuned.

                                VICTORY! What a fun day. going to the dyno soon.
                                "And then we broke the car. Again." Mark Donohue, "The Unfair Advantage"

                                Das Beast build thread