Das Beast: My E30 track / street build

[digger]

what exactly was changed this time? i know rods and slugs with high CR but is it still 2.8L (84 stroke) or 3L (bigger crank?) as per title of graph? other significant changes?

did you log boost curve for the run and have an overlay for the whole run?

extra cubes may cause the change in curve, as may non retarded cam timing depending on specifics or depending the boost curve may be different despite peak being the same

10psi isn't enough boost though

[Northern]

+1 for boost log, does boost taper off?

[Digitalwave]

Looking good and glad you finally got it tuned! Time to get back on the track!!

[dvallis]

Oops. Need to change the graph title to M20B28. It's still 84 bore, 84 stroke with M52B28 crank. Only changes were forged JE 10:1 CR pistons with deeper valve pockets, forged rods and Garrett GT3076R oil/water BB turbo. Timing is fixed at TDC, no variable cam gear.

New torque numbers are from a CSV. I had to pick the HP off a pdf printout so they're slightly wonky. Tuner is sending me updated CSVs today. I'll repost data. It has boost and AFR as well.

[Northern]

You could calculate the HP from the torque value ( Torque * RPM/5252 ) in the CSV as well, might save you a minute or two of staring at the graph

[dvallis]

Nice call on the formula. Magic number was a bit different for curve to overlay the PDF data but shape was exactly the same.

AND I'm an idiot. Surprised nobody called me out on it. GREEN is TORQUE, RED IS HP. I had the legend reversed. (it was late)

I don't have the boost data yet but remember seeing it on the monitor. I it hit full boost at or before 3800 RPM and stayed flat as a strap. Torque taper above 5K is octane limiting ability to add more timing.

[Northern]

Ok that makes more sense haha, I am dumb and was just wondering why the HP was dropping off aggressively at the top end. Makes sense that it was torque.

[digger]

It also seems the thicker lines cross at about 5000 rather than 5252. The thin ones seem to cross correctly

[dvallis]

Yeah. I'll compare when I get the run file

[dvallis]

Better Dyno Chart

We had an error on CSV export that goofed up the data. Here's a proper dyno sheet from the new data. HP and TQ cross at 5252. Added AFR and Boost data as well.

[Elysian]

Damn that car has got to be a hoot now.

[Northern]

I can imagine it is, that's a big increase in area under the curve

[dvallis]

I'll find out. Been driving at partial throttle the past 100 miles before getting tuned. Now I can go full Sasquatch and see just how much of a hoot it is : - )

[dvallis]

Final touch on the car. While we were doing full power passes on the dyno, waste gate hoses melted. Heat conducted from the manifold, through the waste gate, into hose barb fittings. Literally melted the hose ends like taffy.



Solution? Hard lines.

Inverted flare tube nuts and 3/16" brake line are the basis of the refit. There's a how-to way back in the blog. Requires a flare kit and tube bender.



Added inverted flare female fittings to the waste gate and boost controller..



Charge pipe got a new 1/8" NPT weld bung, then added 90 degree female flare fitting.



Boost controller, strain relief rubber tube sections and DEI heat shield.



And here's the final product. Boost control is still great, snaps to 10 psi at WOT. That's about it. Off to the track.



Almost forgot to mention how it handles. Will take some practice figuring out how fast to roll on throttle in 2nd. Too fast and it just spins the rear tires. Once you're in 3rd, it will take WOT immediately, then only 2-3 seconds to redline. I set up the sequential shift lights today so that will help.

[dvallis]

9Lives wing on order.