[Diy_efi] Re: Diy_efi Digest, Vol 1, Issue 524

[Tlsalt at aol.com]

 Axel wrote,

The BMW F1 turbo engine worked this way, by-wire throttle before the turbo
and no wastegate at all with an enormous turbine housing, but this engine
was known to have a *huge* turbo-lag and a narrow powerband
making it almost undriveable.

Hello Axel,

I saw this engine up close and running several times in the early 80's and 
wondered why BMW took a different path than the other turbo engines.  All of 
the versions I saw and photographed had a mechanical throttle ahead of the 
turbo compressor and all of them had wastegates on the exhaust turbine. There 
were no other throttles on the engine.  While Honda and Ferrari were using 
EFI injectors, BMW used a timed mechanical injection at over 400psi and 
replaced the normal throttle linkage to the injection pump with an electric 
servo motor. At least they didn't have to connect the turbo throttle plate to 
the injection pump on the other side of the engine under the manifold.  They 
were the only ones throttling the compressor, but I've never seen an 
explanation for it, have you ?  In that application, the throttle was usually 
open or shut. It was the highest specific output of the turbo motors (perhaps 
of all GP engines), but I think that was largely due to chemistry. It did 
make a nice sound echoing off the buildings in downtown Detroit.

Paul Saltwick

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi