How much ignition retard per pound of boost?

[F-BIRD'88]

Don't get to wrapped up in the DCR stuff for supercharging.. Better to look at the BDS blower site fir non intercooled boost vs compression ratio on various fuels octanes. Your non intercooled blow thru will be similar..
You want to sneak up on the tune anyway..

Boost and timing...

cam it to go fast.

[plovett]

Don't get to wrapped up in the DCR stuff for supercharging.. Better to look at the BDS blower site fir non intercooled boost vs compression ratio on various fuels octanes. Your non intercooled blow thru will be similar..
You want to sneak up on the tune anyway..

Boost and timing...

cam it to go fast.

Here is the BDS chart. Thanks.

[In-Tech]

Here is the BDS chart. Thanks.

Garbage chart, boost is simply a restriction of flow.

[plovett]

Here is the BDS chart. Thanks.

Garbage chart, boost is simply a restriction of flow.

Here's a plain old web link.

https://www.blowerdriveservice.com/TechnicalCharts

[bill jones]

---what are you using for a distributor?

---have you given any thought to the rotor index--and what happens when the electronic retard happens and the rotor is still in the same spot

---need to get a witness hole into a spare donor cap where you can shine the timing light inside there to see just where that rotor index actually is at various rpms---before---and during the boost retard conditions

---you could set up an adjustable low air pressure source to create the pressure to manually retard the spark for testing for checking at various rpms without having the blower actually hard enough to operate the boost retard

[plovett]

---what are you using for a distributor?

---have you given any thought to the rotor index--and what happens when the electronic retard happens and the rotor is still in the same spot

---need to get a witness hole into a spare donor cap where you can shine the timing light inside there to see just where that rotor index actually is at various rpms---before---and during the boost retard conditions

---you could set up an adjustable low air pressure source to create the pressure to manually retard the spark for testing for checking at various rpms without having the blower actually hard enough to operate the boost retard

I have an MSD 8594 and a 6AL. I just got a 6BTM. No vacuum advance. Naturally aspirated I was running the black bushing for 18 degrees advance. I used 18 initial and 36 total. It was all in below 3000 rpm. I can't remember what springs I had in there. One heavy silver and one light silver?

I had not thought of how to verify the true ignition retard. Those are good ideas. Thanks!

[plovett]

Here is the BDS chart. Thanks.

Garbage chart, boost is simply a restriction of flow.

How do you figure what octane is need for what compression ratio and boost (or flow) then?

[F-BIRD'88]

I have another better chart at home.. Will post later.

[af2]

Here is the BDS chart. Thanks.

Garbage chart, boost is simply a restriction of flow.

Exactly!!! And to go further read the plugs at the end of the run to see what is really going on. All this retard shit is crazy. When you have the correct setup to start with you are golden!

[plovett]

I have another better chart at home.. Will post later.

I would like to see the chart if don't mind posting it. Thanks.

paul

[F-BIRD'88]

Boost Fuel CR When on GOOD pump gas the idea is to keep the effective CR below 12.5:1

[Orr89rocz]

I still dont have much faith in compression charts and boost. A lot of combinations i have seen wouldnt work according to those

[F-BIRD'88]

Can you post the details of a combo that did not work?
Starting with what specific fuel was in the tank

[af2]

I still dont have much faith in compression charts and boost. A lot of combinations i have seen wouldnt work according to those

Same here all the methanol blown running 35lbs+ between 13:1 and 14.5:1 CR are at between 25 and 28 degrees at 9500 rpm. All Hemi's with a 6-71. They run in the high to low 6's.

[plovett]

Boost Fuel CR When on GOOD pump gas the idea is to keep the effective CR below 12.5:1

Thanks!