My Hoopte30 Project Attempt #6 - the painless way to earn cash back every day

[AWDBOB]

here's my M20 2.7 on a DynoJet (it's been a minute)

I have been to this exact dyno many times (CarbConnection in Kirkland, WA) and have seen lots of other cars on it - it appears they have it calibrated correctly.

blue line was stock (I think I had some sort of knock off chip, maybe it was from Bavarian Autosport?), red was with the old IE short headers, and green is with the RD headers (I think)

for comparison, my 2006 330i totally bone stock put down 225whp :D

Thank you Nando, that is great data! And with iX drivetrain loss it's safe to say your 2.7 is very close to what I'd expect to see out of the stock motor and 2.7.

A friend ran his 3L m20 on a local DJ and then at Jake's and it was 10hp shy on Jake's dyno in the same configuration, but there have been other instances where it appears to be spot on.

I've never seen 6-3-1 design used for inline6 here. In which specific case it is beneficial over 6-2-1 ?

This is the most recent example of 6-3-1:

https://advancedautofab.com/p/aaf-m20-race-header-only/

All of my research about M20 6-3-1 suggested it doesn't gain "much" over a 240* pulsed 6-2-1 (1-3-2 together and 5-6-4 together), but can be slightly more efficient if the 3 pipes after the merged cylinders before the collector are equal length.

On my header, he grouped pulses 120*, aka just split the firing order in half, which isn't correct. How much that is hurting me, I won't know, as the next iteration of it will have the correct sized primaries and will (hopefully) be equal length.

I'm not going to have it redone in 6-3-1 format as the original design was botched so hard. I just want something that works this time around, which will be 6-2-1, grouped 1-3 & 4-6 with 28" long 1.5" primaries stepped to 1 5/8", to 1 7/8" collectors, merged 63"-71" from end of primaries.

[hasa]

I've never seen 6-3-1 design used for inline6 here. In which specific case it is beneficial over 6-2-1 ?

[nando]

Jake finished the hitch so I went up to finish the A/B header dyno and pick the car up to get it out of his way.

The header didn't do much of anything against the stock exhaust. The VE tables were weird with the header.

I originally went to him wanting a 6-3-1 Tri-Y design with smaller stepped primaries and he did his own thing and said "if it doesn't work I'll remake it".

I talked with Digger and Grooty about header design and they both gave me some great insight to present to the fab guy for when he hopefully remakes this.

The primaries are WAY too big, he combined the wrong cylinder groups, merged at the wrong spot, etc.

Hopefully he makes it right, but if I were a betting man, I wouldn't count on it.

Both 2.7s that I've dyno'd have produced almost exactly the same results, which have been 20hp under ForcedFirebird 's results. I really need to run the car on a dynojet for comparison.

compare_page-0001 by bimmertown, on Flickr
Untitled by bimmertown, on Flickr
Untitled by bimmertown, on Flickr

here's my M20 2.7 on a DynoJet (it's been a minute)

I have been to this exact dyno many times (CarbConnection in Kirkland, WA) and have seen lots of other cars on it - it appears they have it calibrated correctly.

blue line was stock (I think I had some sort of knock off chip, maybe it was from Bavarian Autosport?), red was with the old IE short headers, and green is with the RD headers (I think)

for comparison, my 2006 330i totally bone stock put down 225whp :D

[AWDBOB]

Jake finished the hitch so I went up to finish the A/B header dyno and pick the car up to get it out of his way.

The header didn't do much of anything against the stock exhaust. The VE tables were weird with the header.

I originally went to him wanting a 6-3-1 Tri-Y design with smaller stepped primaries and he did his own thing and said "if it doesn't work I'll remake it".

I talked with Digger and Grooty about header design and they both gave me some great insight to present to the fab guy for when he hopefully remakes this.

The primaries are WAY too big, he combined the wrong cylinder groups, merged at the wrong spot, etc.

Hopefully he makes it right, but if I were a betting man, I wouldn't count on it.

Both 2.7s that I've dyno'd have produced almost exactly the same results, which have been 20hp under ForcedFirebird 's results. I really need to run the car on a dynojet for comparison.

compare_page-0001 by bimmertown, on Flickr
Untitled by bimmertown, on Flickr
Untitled by bimmertown, on Flickr

[AWDBOB]

Thanks gents- it has felt good to lean into this car a bit more vs holding out for the next one. I may or may not have ordered an E30M GC kit on black friday for it.

Jake found a way to make the sandwich bike rack idea happen. It'll have a gusseted plate going down to the spare tire well to combat deflection once its done- there was no way to make it strong enough without a second attachment point, which unfortunately will involve some drilling. He's going to a run of 10 of them once I test it out a bit. I'll try to remember to link that here once its time. We're in full winter swing, so it'll be a few months.

Unfortunately none of the old design was useable at all.

Sneak peak

Untitled by bimmertown, on Flickr

[Northern]

Turned out very well

[2mAn]

Perfecting Hooptie status.

Bravo

[AWDBOB]

Thanks fellas, I'm glad the black quarter days are behind me.

She's all done and back to Jake's- I'm very happy with how it turned out.

Untitled by bimmertown, on Flickr

[e30m3s54turbo]

It came out good.

[patrick88m3]

That turned out great!

[AWDBOB]

Sneak peak of the patina blend. He just sprayed flat clear in this pic so it'll dry flatter than it looks. Stoked on how it's coming together! It's a perfect fit for the car. He matched the faded paint and sprayed that color first. Then brush worked it into the main color, which apparently was a shade darker than traditional Lachs






This is with the chip guard and shadowline done- I am thrilled with the outcome. He is going to flat clear the hood to lock in the look and it'll be ready to rip. Then back to Jake's for standalone conversion, LS coils, a/b dyno with stock exhaust and back to Indiana where I'll post more deets about the suspension once I have updates.

[AWDBOB]

My POS has some long-tube header setup, I will have to go look and see how they grouped it all...

I plan to do a dyno run pre and post cam/injector/chip swap too, very curious to see what this basic setup makes on mine...

The generic long tubes all group 1-3 together and 4-6 together. Even fancy supersprints, old IE long tubes, Bavauto long tubes, racing dynamics, BTB, hartge, etc all group front 3 and back 3.

Will be nice to have the data on a cam swap. I swear I can't tell a noticeable difference with a cam on a stock m20. May the powers that be award you more than 4hp!

[2mAn]

My POS has some long-tube header setup, I will have to go look and see how they grouped it all...

I plan to do a dyno run pre and post cam/injector/chip swap too, very curious to see what this basic setup makes on mine...

[AWDBOB]

That'll be interesting seeing the faux patina blend. I had a cirrus sedan with a really cool patina; some cars just wear it well.

With hoopty only needing to be at 80% you're able to really refine things you like vs. being budget constrained buying new everything or 9.5/10 condition stuff and realizing you don't like it or want to modify something expensive and prestine so you just don't and choose to live with it. Not that this allows you to be careless with things but there's less pressure to be at 110% with everything.

I'm still collecting parts and the M20 rebuild is pretty low on the list right now with a kid coming in January I doubt the wifey would be stoked to see a shiny new engine show up in the garage. The e90 needs some maintenance caught up and the M20 in the e30 is relatively healthy right now. Or at least I refuse to do a compression test because I don't need anything making me want to move it up the to-do list.

It really is the way to do things- takes the pressure off to make it perfect and shiny before using it, which is where so much time is lost. This way I can get things generally how I want them and clean it up as I feel like it. Makes for a much more enjoyable ownership experience for my preferences.

Totally get it re: kiddo&motor (congrats!)- your car ripped in NC! A well sorted m20b25 is hard to beat. Stroker will be great, but not worth stressing yourself out over.

Keeping the hood the way it is will keep you humble and keep it hoopty.

My name is 2mAn and I approve of this decision

This is the way! There may or may not be flat clear involved to seal in the hood look forever.......

[AWDBOB]

A trip to the dyno is never without incident. The car wasn't making power and the graph was indicating an ignition or timing issue despite everything being new. I swapped the injectors with new 19# genuine bosch units from a volvo which didn't change anything.

Then a bolt flew over my head when we started the car back up after the injector swap. It was a balancer bolt.... we sent a borescope down there and saw only two left. Saved by the bell.

I tore the car down to find it had snapped off the balancer dowel. Reassembled with new bolts and loctite, ran on the dyno again to make sure the balancer wasn't moving causing crank sensor/timing pickup issues. Graph still looked the same. We called it there instead of swapping the stock exhaust on it for the header a/b. When I go back up after the body work we're going to convert to standalone/LS coils, tune it with header on and then swap stock exhaust on for hopefully better results.

Header thoughts for you smart folks that know more than me:

The header is currently paired in two groups of 3. For a scavenged TriY header for a straight 6 with firing order of 1 5 3 6 2 4 you should have 1&6, 2&5 and 3&4 each paired together, then run those 3 into the main collector.

I don't know whether it's more efficient to time pulses 120* out or 240* out. 4 stroke = 720*/6 so:

1. 0*
5. 120*
3. 240*
6. 360*
2. 480*
4. 600*

He paired 1 5 3 and 6 2 4, aka, splitting the firing order in half, 120* between pulses. I'm not an expert and I'm just trying to figure out if this is an ideal combination or not for scavenging when running two banks of 3 primaries. The header is clocked clockwise at the collectors per the firing order.

I originally presented him with wanting a tri-Y and suggested that 1&6, 2&5, 3&4 be grouped together, but he wanted to do the two collectors of 3 primaries, clocked as such.

But it appears that 240* pulses are ideal, so if doing a 6 -2 header, 1-3 should be grouped and 4-6 should be grouped.

If you have engineer thoughts on the above, let me know and I'll send you my favorite gingerbread cookie recipe. I'm trying to figure out if this is the most efficient header design using 2 banks of 3 primaries.

Good news is that the body guy is a treasure and sent me a photo of the quarter dents almost completely pulled less than an hour after dropping the car off.

Untitled by bimmertown, on Flickr
Untitled by bimmertown, on Flickr



It was by shear luck

Untitled by bimmertown, on Flickr



Untitled by bimmertown, on Flickr