ACF Fabrication T4 Twinscroll Manifold

terryd5150

Corporal
Mar 4, 2017
103
39
0
Ride
2008 E92 335i 2009 E90 335i
Everything looks great. I am wondering what kind of spool difference you'd see between an equal length 'long' runner like this vs a short runner style like the speedtech/motiv/etc

Is it actually worth it to keep the equal length runners in practice? I know for optimal twin scroll spool you want equal length runners. But what happens if those runners were ten miles long?

I suppose I'm asking, all the turbo manifold design folks, at what point does it make sense to simply go with a mega short runner?

The length of those runners makes me curious on the transient response; however, I'm excited to see another bottom-mount option - particularly a twin scroll that can run EFR turbos.
 

Payam@BMS

Sergeant
Oct 27, 2016
412
265
25
33
I should have known

Been having issues with coding the injectors on my car is the main reason why this hasn't been announced. We want to post dynos, logs and pictures but we are having some weird technical difficulties.
 
Nov 5, 2016
615
624
0
Bay Area
Welcome to the club, we have a 1000WHP capable N54 that has been plaguing us with weird fucking issues since it made 870WHP. I'm so frustrated I haven't even touched the car in 2 -3 weeks.
 

Terry@BMS

Sergeant
Platinum Vendor
Jan 23, 2017
462
379
50
The good news is I think ACF can finally wrap up my kit now since Payam's is done. Spool is good on his little turbo, 3500rpm so far, with no tuning effort yet.
 
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cloud9blue

Sergeant
Oct 17, 2017
255
190
0
Ride
09 E92 335i
Been having issues with coding the injectors on my car is the main reason why this hasn't been announced. We want to post dynos, logs and pictures but we are having some weird technical difficulties.
what turbo you guys went with? 8374?

my top mount with 7670 is getting delivered today btw :)
 
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doublespaces

Administrator
Oct 18, 2016
9,303
4,331
0
AZ
Ride
2009 E93 335i
I went through all my old files and pictures and found the pic from over 2 years ago when I first coded the injectors. I was so happy I couldn't believe it was all there for me. I swapped them all to their original cylinders. So far so good and the logs are super clean. Hopefully we can dyno tomorrow? @Terry@BMS

Can't wait to see some numbers! Which turbo?