Hey guys,
I had a chance to get on the dyno for some RB Turbo / E85 tuning. An extension of our R85/RB tuning thread.
The car is our 2008 steptronic 135i w/ JB4, BMS Flash (lol) , RB Turbos, BT/CX racing intercooler, and our downpipes, dci, and occ. Temps were in the low 90s.
We've been running a 50%+ E85 mix working on RB turbo only tuning (no meth), and have come to find we're operating at the limit of our low pressure fuel pump. It's not yet clear whether ours is just giving out or if this is indicative of some sort of wider fuel pump limitation. But work continues on that front. For this testing I installed a "boost a pump" on the low pressure pump and ran it at 100% which is around 17v.
Even with the BAP in place the low pressure was unable to keep up at higher RPM. Shown as "oil temp" in the logs below. It's targeting 72psi but dropping to around 45psi at peak power. When it goes south of 50 more often than not it takes the high fuel pressure down with it. With the BAP maxed out my options on the dyno were limited so I simply leaned it out and bumped up advance to allow for more output. Fortunately E85 enjoys running leaner.
The results are in the dyno below. Overall I'm very happy with the power potential. On a colder day 500rw E85 only should not be a problem. And as I've said in the other thread the drivability on these turbos is as good or better than stock. Instant boost and acceleration anywhere you want it. Just the way I like it.
After the E85 tuning I decided to kick on the meth kit for a couple runs just to see how it might effect the fuel pressure situation. No tuning changes were made other than restoring the normal AFR targets. Same boost and advance curve. It's around a 70% meth mix using a CM10 nozzle.
Not surprisingly with the meth flowing power dropped. Which is a fairly good indication that the E85 only tuning is about where we want it. You'll notice in the meth log the supplemental fuel provided by the meth kit was just enough to keep high pressure fairly normal to redline.
In other news, during a couple of the earlier runs the trans started slipping again. It's been doing this off and on since its nitrous days years ago. Might be time for an upgrade soon.![Click here to enlarge]()
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I had a chance to get on the dyno for some RB Turbo / E85 tuning. An extension of our R85/RB tuning thread.
The car is our 2008 steptronic 135i w/ JB4, BMS Flash (lol) , RB Turbos, BT/CX racing intercooler, and our downpipes, dci, and occ. Temps were in the low 90s.
We've been running a 50%+ E85 mix working on RB turbo only tuning (no meth), and have come to find we're operating at the limit of our low pressure fuel pump. It's not yet clear whether ours is just giving out or if this is indicative of some sort of wider fuel pump limitation. But work continues on that front. For this testing I installed a "boost a pump" on the low pressure pump and ran it at 100% which is around 17v.
Even with the BAP in place the low pressure was unable to keep up at higher RPM. Shown as "oil temp" in the logs below. It's targeting 72psi but dropping to around 45psi at peak power. When it goes south of 50 more often than not it takes the high fuel pressure down with it. With the BAP maxed out my options on the dyno were limited so I simply leaned it out and bumped up advance to allow for more output. Fortunately E85 enjoys running leaner.
The results are in the dyno below. Overall I'm very happy with the power potential. On a colder day 500rw E85 only should not be a problem. And as I've said in the other thread the drivability on these turbos is as good or better than stock. Instant boost and acceleration anywhere you want it. Just the way I like it.
After the E85 tuning I decided to kick on the meth kit for a couple runs just to see how it might effect the fuel pressure situation. No tuning changes were made other than restoring the normal AFR targets. Same boost and advance curve. It's around a 70% meth mix using a CM10 nozzle.
Not surprisingly with the meth flowing power dropped. Which is a fairly good indication that the E85 only tuning is about where we want it. You'll notice in the meth log the supplemental fuel provided by the meth kit was just enough to keep high pressure fairly normal to redline.
In other news, during a couple of the earlier runs the trans started slipping again. It's been doing this off and on since its nitrous days years ago. Might be time for an upgrade soon.
