pressure regulator

i am working on my blow thru setup and was wondering if anyone knows of a valve i could regulate my pressure to "trick " my msd 6btm to think at 5 pounds of boost that it is only seeing 1 pound than from that point it could be 1-1 pressure so it reduces my timing 1-3 degrees per pound of boost ?
thanks

Maybe some kind of pneumatic poppet valve between the BTM set at 4 PSI?

It's not exactly what you are after because when the poppet valve opens at 4 to 5 pounds of boost you will loose 4 to 5 degree's of timing instantly, if set at 1 to 1. It will delay it though, and you can go 1 to 1 or whatever setting you chose.

Maybe you could compensate with a little higher intial timing setting, if you are after lower boost drivability/power?

Just an idea

If you are planning this for the SR-71 deal the upside is your timing widow is likely between 17 and 27 degree's total timing, I would think, so only a 10 degree window to deal with anyway.

https://www.google.com/search?q=adjustabe+air+pressure+poppet+valve&oq=adjustabe+air+pressure+poppet+valve&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIKCAEQABiABBiiBDIKCAIQABiiBBiJBTIKCAMQABiiBBiJBTIKCAQQABiABBiiBNIBCTM5NTM3ajBqN6gCALACAA&sourceid=chrome&ie=UTF-8

why yu say timing window from 17to 27 you think with 20 # boost i only need to retard my timing to 17 max? or even 30 pounds boost ?

supervel45 wrote:Maybe some kind of pneumatic poppet valve between the BTM set at 4 PSI?

It's not exactly what you are after because when the poppet valve opens at 4 to 5 pounds of boost you will loose 4 to 5 degree's of timing instantly, if set at 1 to 1. It will delay it though, and you can go 1 to 1 or whatever setting you chose.

Maybe you could compensate with a little higher intial timing setting, if you are after lower boost drivability/power?

Just an idea

If you are planning this for the SR-71 deal the upside is your timing widow is likely between 17 and 27 degree's total timing, I would think, so only a 10 degree window to deal with anyway.

https://www.google.com/search?q=adjustabe+air+pressure+poppet+valve&oq=adjustabe+air+pressure+poppet+valve&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIKCAEQABiABBiiBDIKCAIQABiiBBiJBTIKCAMQABiiBBiJBTIKCAQQABiABBiiBNIBCTM5NTM3ajBqN6gCALACAA&sourceid=chrome&ie=UTF-8

maverick172 wrote:why yu say timing window from 17to 27 you think with 20 # boost i only need to retard my timing to 17 max? or even 30 pounds boost ?

supervel45 wrote:Maybe some kind of pneumatic poppet valve between the BTM set at 4 PSI?

It's not exactly what you are after because when the poppet valve opens at 4 to 5 pounds of boost you will loose 4 to 5 degree's of timing instantly, if set at 1 to 1. It will delay it though, and you can go 1 to 1 or whatever setting you chose.

Maybe you could compensate with a little higher intial timing setting, if you are after lower boost drivability/power?

Just an idea

If you are planning this for the SR-71 deal the upside is your timing widow is likely between 17 and 27 degree's total timing, I would think, so only a 10 degree window to deal with anyway.

https://www.google.com/search?q=adjustabe+air+pressure+poppet+valve&oq=adjustabe+air+pressure+poppet+valve&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIKCAEQABiABBiiBDIKCAIQABiiBBiJBTIKCAMQABiiBBiJBTIKCAQQABiABBiiBNIBCTM5NTM3ajBqN6gCALACAA&sourceid=chrome&ie=UTF-8

I was using those numbers for a ballpark starting point with 10-12lbs. of boost in mind.

Is there anyway you can engine or chassis dyno your setup with the higher boost you mentioned?

When you say blow through I ass/ume it's carburetored?