Minisprint 4EFE
Posted: Sun Mar 11, 2012 4:42 pm
edit: more info on the class can be found here: http://www.minisprints.co.nz/
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I got involved in this project to try and get the car competitive and run with the pack.
Currently the class consists of ex-Midget chassis with a carbureted 1300cc 8valve engine usually on methanol.
The engines are getting expensive for what they are, getting near $30k for a front running engine to be built and the old A12/A13 and 4K engines are getting thin on the ground these days.
So Speedway New Zealand decided to allow a trial of EFI engines and see how they went. The owner ran the car with the eom ecu for a couple of seasons and had a hard time keeping with the pack, mainly due to the lack of power and inability to pull enough rpm down the straight - which meant he had to gear it up and sat too low in the rev range to pull out of the corners effectively.
I have put my S80 on it for now, but long term it will run an S60. Tefzel/DR25 harness, logs the basics only plus Lambda.
Roughly 5% gain throughout and probably more at part throttle as he says it feels super responsive now. Quite conservative tune as I'm unsure of dead time table and runs total loss at the moment (no alternator) - which made it hard to tune on the dyno with jumper cables/chargers etc...
Changes to the oem setup are we fitted a 4EFTE (the turbo version from a Toyota GT Starlet) as the have 24+1 in Distributor (12+1 crank) to give enough teeth to keep the DTA happy. Also new TPS as oem is switch type, did a calibration for the oem MAP sensor and used Bosch Water Temp which was direct fit.
MAP based load, 3 hours steady state and 2 power runs only before off to racing and this is what we ended up with.
Blue line is oem ECU which limits at 6k rpm, Red is DTA letting is rev to 7K. Some slight gain to be made there still as ran out of time but still drops off cam. Lets him rev it at end of straight though which helps immensely. The owner/driver says it feels completely different to drive even at moderate throttle so we must be on the right track.
-----------------
I got involved in this project to try and get the car competitive and run with the pack.
Currently the class consists of ex-Midget chassis with a carbureted 1300cc 8valve engine usually on methanol.
The engines are getting expensive for what they are, getting near $30k for a front running engine to be built and the old A12/A13 and 4K engines are getting thin on the ground these days.
So Speedway New Zealand decided to allow a trial of EFI engines and see how they went. The owner ran the car with the eom ecu for a couple of seasons and had a hard time keeping with the pack, mainly due to the lack of power and inability to pull enough rpm down the straight - which meant he had to gear it up and sat too low in the rev range to pull out of the corners effectively.
I have put my S80 on it for now, but long term it will run an S60. Tefzel/DR25 harness, logs the basics only plus Lambda.
Roughly 5% gain throughout and probably more at part throttle as he says it feels super responsive now. Quite conservative tune as I'm unsure of dead time table and runs total loss at the moment (no alternator) - which made it hard to tune on the dyno with jumper cables/chargers etc...
Changes to the oem setup are we fitted a 4EFTE (the turbo version from a Toyota GT Starlet) as the have 24+1 in Distributor (12+1 crank) to give enough teeth to keep the DTA happy. Also new TPS as oem is switch type, did a calibration for the oem MAP sensor and used Bosch Water Temp which was direct fit.
MAP based load, 3 hours steady state and 2 power runs only before off to racing and this is what we ended up with.
Blue line is oem ECU which limits at 6k rpm, Red is DTA letting is rev to 7K. Some slight gain to be made there still as ran out of time but still drops off cam. Lets him rev it at end of straight though which helps immensely. The owner/driver says it feels completely different to drive even at moderate throttle so we must be on the right track.