Das Beast: My E30 track / street build

[ForcedFirebird]

I would need to check your turbo spec again, but have dyno'd many m20's.

What I found is ~12psi on a 56mm compressor, t3, a/r of .48 is pretty much gonna make close or at 300whp/320wtq (think Super 60 stats). Increase the inducer approaching 62mm, that's going to bump up to ~400/400 at 12psi, but come in much later. Go in to a 6266 t4 and you can easily make an m20 go 500whp, but it boosts very late and you break stuff at that point. For 500whp you need high quality pistons, over-engineered rods, and hope you don't ever starve fuel or #6 piston rings lands will melt. Personal best on an m20 was 518whp/590wtq at 19psi on a custom 6267 t4 with a big housing. Took 5k to reach full boost, but tires would break loose at 130mph swapping gears.

For a road track car, this is way too unpredictable. Worse thing you can do is have boost surge mid corner and upset the car. Your pointy end will be facing oncoming traffic at a lot of corners.

[dvallis]

LoL, yes. Very familiar with big turbos late on boost. I had a Porsche 930 that would punish you severely for getting into it on the wrong part of the track. Don't ... lift. Was fast once you learned how to drive it though.

Truth of the matter is Rob & I really don't know what kind of HP the Beast will make. We pretty much did everything you can to an M20 without getting too crazy: 2.8L M52B28 crank, 6262 T4 turbo, 62mm compressor wheel 0.84 A/R, schrick 282/274 cam, HD rockers, ARP studs, MLS head gasket, balanced pistons/rods, 3" mandrel exhaust, MegaSquirt, wasted spark, electronic boost contol, 60 lb/h injectors, nuke fuel rail, boost ref FPR, P/S delete, A/C delete, brake booster delete, MAF delete, mech fan delete, big radiator.

Conservatively expecting 400 HP at 15 psi. We'll see on the dyno soon.

[dvallis]

Working through the punch list. Missing a few boost parts but its coming along well.

[zwill23]

I'm excited to see this thing hit the dyno!!

I'm currently working toward a boosted M20 myself (albeit modestly), and I'm wondering how you felt about having your down pipe ceramic coated? I imagine it would see very similar temps to the turbine housing and it's quite close to the ignition for the last few cylinders. I read the article you posted regarding ceramic coating and I was surprised to see a naked down pipe.

Maybe a simple wrap makes sense in this case?

[dvallis]

I did a lot of reading on header and downpipe wraps. NASCAR guys have data showing wraps trap heat causing metal failure, so no wraps. If you read back in the blog you'll see we heat shielded the bulkhead, tunnel and coils. Plug wires are also shielded. I might ceramic coat the downpipe later if heat still turns out to be an issue.

[Digitalwave]

Heat is an issue even with my NA track car. Every little bit helps!

[dvallis]

Back at it ...

Had to amputate the throttle position sensor, lengthen the cable. Soldering in place .. not my favorite.


That's better. FYI, the TPS and CPS sensors use exactly the same connector. That confused us for a few minutes :-)


Reworked the throttle body mechanism


Added the variable TPS


Turned out good, took a while though. Lots of minor fabrication required.


Finally oiled it up and primed the block with a drill. We are making 70 PSI .. great.


Ran out of time today. Next session we'll crank it up.

[dvallis]

Who can guess what and where this is .....

[Elysian]

So that's where I left that 10mm socket

[dvallis]

It fooking fell off the drill shank when we were done priming the oil. Dropped straight past the oil pump shaft with .0001" clearance on both sides, bounced UPHILL in the oil pan, OVER two ribs and stopped there. Had to drain the oil, find it with a fiber optic camera then fish it out with a magnet on a wire. Sheeh. Now we can start the car next time.

[MrScuba]

After you refill the oil.

[Old525i]

When it rains, it pours. Full steam ahead.

[Old525i]

Is there a rebuild kit for the Throttle Housing Assembly? Were there any seals to replace around the throttle shafts?

[whodwho]

...
Head torqued down. 22 ft-lbs for each nut per Bentley's pattern, repeat with 90 degrees x 2 for each
...

Curious why you chose to angle torque vs the recommended ARP torque specs?

Not sure that this procedure is valid for non TTY stock bolts and if you ended up with proper end torque. Do you plan to do a re-torque after any heat cycles?

[Digitalwave]

Yeah, I was wondering the same. ARP says 3 equal steps ending in 70ft/lbs. https://cdn2.arp-bolts.com/instructions/201-4305.pdf

Even on my NA M20, my ARP's definitely loosened a bit after a few heat cycles. It's worth re-checking the torque a couple of times after running the motor.

[dvallis]

Is there a rebuild kit for the Throttle Housing Assembly? Were there any seals to replace around the throttle shafts?

Just the throttle body to manifold gasket