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?

ya so i got my car up and running just doing some final jet changes as i do short test hits.right now running just on the street doing 4-5pounds boost and running gulf 112 octane fuel . . car is crazy even with 4-5 pounds boost it spins the 15"wide tires at any speed 70 or even  80 mph . cannot wait to get it to track , but did not some numbers and i feel car is making around 900 hpbut i will be turning up the boost more at the track my plan is too probably go too around 8-9 pounds this season which i think will put me right at 8.5 seconds which is as fast as car is certified for . i am pulling 2 degree's timing right now per pound of boost and have my base timing at 26degree for saftey i am around 10-10.8 air fuel  WOT .but like i said i can only do very short pulls on highway (dont need a speeding ticket )
just thanking for the help as this has been a fun project getting this blow thru setup setup .

supervel45 wrote:

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?

You're welcome and looks good.
Those numbers seem pretty fat and retarded but, get it to the track, see how it runs and work into your tune from there.
Pull some spark plugs also and make sure you instruments (Timing Light and air fuel gauge) are not lying to you.
Be careful not to put it into the wall, sounds like a pretty hairy ride.