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

[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

[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

[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

[hasa]

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

[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 1.875" collectors, merged 63"-71" from end of primaries.