200whp with stock N/A rotating assay? by ForcedFirebird

By diyauto
( 3 )

3 minute(s) of a 31 minute read

9-30-2014

BMW E30 engine bays

BMW E30 engine bays facing each other


10-11-2014

Yeah, theoretical flow according to dynomation using rough math to convert from 1.5" Hg to CFM, a 40mm TB should flow over 200. And yes, you are absolutely correct. The most flow with the smallest CSA possible keeps the velocity up and makes for a good head. People tend to look at peak and high lift numbers (on head flow as well as dyno plots) and often miss the "area under the curve". This is why i like to include AVG flow numbers across the lift points.

On a side note, the Extrudabody throttles were quite out of balance. Your throttles share a shaft which should make them easier to balance since it's really three pairs where the EB kits are 6 individual throttle shafts with adjustments in between. After using a balancing, the EB kits became much easier to tune, and sound much better. Curious to see how well the RHD ITB's are in tune with each other.

If things keep going thew way they are, seems like we will be working together often. Would be great to have a hub on this side of the pond for support/sales, as well as the development of Motronic tuning for those that are looking for a plug and play setup.


10-13-2014

The biggest problem is going to be what Digger ran into with booster clearance. Really, the trumpets should have one throttle diameter clearance in all directions, and as they are now, they lay right on top of the booster.


10-22-2014

This. Thing. Sounds. Amazing.

Went with dual 2" exhaust, x pipe ~34" from collectors, twin 12" resonators.

10am appointment at dyno.

This one is staying Alpha-N Motronic 1.3.


Cam is broken in. Needs another oil change before dyno, but here is a free rev just for giggles.



More hooning.



Simple, effective and serviceable. The X-pipe that came with the headers are something to be desired.

BMW E30 M20 with x-pipe exhaust



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