If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.
ALL Prices Displayed in USD ENGINE PARTSFLY WHEELSLINKAGE ACCESSORIESTHROTTLE BODY KITSTRUMPETS SPACERSMANIFOLDS PLENUMS Race Head Development We offer porting and head flow development, flow testing & much more. See Everything We Do PRECISION PERFORMANCE COMPONENTS Our range of individual throttle bodies, race components and performance products are all designed, tested and assembled in house right from the first prototypes to Continue Reading
89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
There is a local guy here planning to use the WAR chip and Miller MAF to tune his RHD throttles. He has spacers so that the OEM B25 Throttle switch can be mounted on the front to retain correct rotation direction and clears thermostat housing and will make a plenum/airbox with MAF leading to it. Im interested to see how it works out
89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
Basically I am doing the same here. The OEM TPS switch and the m50 variable TPS are both on there with the TPS (m50) going back to AFM input. To do this, he will have to rotate the TPS to match the AFM voltage. Still working out bugs.
Basically I am doing the same here. The OEM TPS switch and the m50 variable TPS are both on there with the TPS going back to AFM input. To do this, he will have to rotate the TPS to match the AFM voltage. Still working out bugs.
i think he is retaining the OEM TPS as a switch only
89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
i think he is retaining the OEM TPS as a switch only
Right. Otherwise the Motronic won't go into idle maps. Not sure how one would tune out the AFM completely, the ECU bases the fueling directly from it's input.
just gotta change the transfer map and constants to match the linear output of the tps.
should be fun tuning the ignition and fuel maps though since the afm measures air flow (obviously), so 25% throttle @ 2500 rpm =/= 25% throttle @ 6500 rpm
Right. Otherwise the Motronic won't go into idle maps. Not sure how one would tune out the AFM completely, the ECU bases the fueling directly from it's input.
he has the Miller MAF and WArchip so its the "same" as with the single throttle but the switch has moved.
89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
After lots of playing around, found a happy medium for AFM input using the TPS. We still haven't done any actual tuning as we wanted the ECU to recognize idle and WOT and it now is. Idle is stable and as long as it goes directly to WOT, it will free rev (AFR's still need some work, but it's a start). Holding partial throttle, get's all wacky. This means we have our minimums and maximums worked out and can change some maps to get it to behave on the street.
Flowing the throttles today. Interesting enough, the m20 head is efficient enough to max the 40mm TB's in terms of flow, which is probably a good thing when taking velocity into consideration (a 40mm throttle with butterfly should flow 167-ish CFM). Here's some data. Bare head with a port entrance fixture attached, ITB's attached, then stock mani attached.
Here's a graph showing the flow difference. Kind looks like RHD's test mule dyno plot.
Comment