[blueghoast]

[QUOTE=charlie66;5875574]Seems like you're off a tooth maybe. To not be able to idle at 30 degrees sounds wrong.
I idle mine at 8 degrees..[/QU

I'll know more when I get it in the car this week end.
This combination don't seam to be as bad as the iron head and HFT cam was.
Just don't seam to be all that responsive with the timing so low.
I didn't play as much on the test stand with this one as I did the other
combo. It's pulling 15 inch's of vacume Idles well. I started out with 20"
valve lash and tighten to 8" int-exs


GT.

[blueghoast]

I was talking about total timing too not initial timing.
Right now initial timing is at 12 degrees.

GT.

[charlie66]

At 30 degrees it shouldnt pop through the carburator ...

[GTOGEORGE]

Originally Posted by charlie66

At 30 degrees it shouldnt pop through the carburator ...

I agree with Charlie.
You must have something else going on!



GTO George

[blueghoast]

It wasn't poping true the cabs it was just lazy with real low timing.
This combo seams to be a lot better timing wise. Like I said I didn't
run this that long on the test stand. This combo doesn't seam to be
so lazy at 8* of timing but it did improve with a little more timing.


GT.

[johnta1]

Go mechanical injection?

[Tom Vaught]

Originally Posted by blueghoast

It wasn't poping true the cabs it was just lazy with real low timing.
This combo seams to be a lot better timing wise. Like I said I didn't
run this that long on the test stand. This combo doesn't seam to be
so lazy at 8* of timing but it did improve with a little more timing.

GT.

See nothing wrong with 12-16 degrees of initial timing at idle (as even stock RA cars ran that initial advance on the street). RA-IV at 16 degrees

Just need to be in sync with the fuel and compression ratio when in boosted mode so you do not hurt stuff getting aggressive with timing.
Pump Gas/ E-85 being different vs Methanol fuel.

Tom V.

[blueghoast]

That is something I need to do. I've got a boost controller that I want to
install, I'll have to get on MSD's sight and see what it takes to hook it up
to my MSD box. I have boost refrence carbs that's a plus.
It's almost together and should be running in a few hours.
This thing should be pretty wild with all the upgrades. Will let ya know.

GT.

[blueghoast]

charlie66, Do you take timing out as your boost raises.
And how are you doing it.
I'm starting to learn more and more about this boost stuff.
And what do you run for intial. timing Thanks.

GT.

[Curious George]

Originally Posted by charlie66

Every dynamic load and speed state of a given engine will have an ignition timing point that yields maximum brake torque. Also very simple. Advancing the ignition past this point will create pressure spikes, negative torque, and detonation, and retarding it from this point will cause loss of efficiency and excessive exhaust temperatures. Too retarded is mechanically safer than too advanced, but neither is optimal. Running an engine with excessively retarded timing is, well, retarded. There just isn't any reason to do it given modern accurate electronic engine controls, especially those with knock control capabilities.

Retarding timing excessively just to use a higher boost pressure than you normally could for a given dynamic state is counterproductive. No good tuner does this. A book could be written on the how and why, but just think about the things written above and give them careful logical consideration.

I think I'm retarded, lol. Agree with too retarded being safer than too advanced with obvious consequences, but what are long term effects of too low of timing? I'm aroung 15 degrees at 15psi, I added a couple degrees and didn't really pick up anything so I was hesitant to keep going. Trying to keep things together as budget only allows for limited testing. Any information given would be greatly appreciated as I am still pretty new to this boost thing.

[Tom Vaught]

LET THE ENGINE TELL YOU WHAT IT WANTS.
READ THE PLUGS.

If you have a fast burn combustion chamber you do not need as much "Lead" (as in lead the troops) vs say a big block chebby that might want 10 degrees more timing minimum at the same load point.

Has been posted before that engines are the happiest with max cylinder pressure pushing down on the pistons about 10-12 degrees past top dead center. With a slow burn deal a NA Chebby might need to have 40+ degrees of timing to be at that sweet spot.

EVERY BOOSTED COMBINATION is DIFFERENT.
Dont Compare your engine to your buddies engine unless they are EXACTLY identical.
Just saying, READ THE PLUGS.

Tom V.
ps As Charlie posted massive timing retard is bad too.

[charlie66]

Originally Posted by blueghoast

charlie66, Do you take timing out as your boost raises.
And how are you doing it.
I'm starting to learn more and more about this boost stuff.
And what do you run for intial. timing Thanks.

GT.

Yes i do .

I raise and lower it from my laptop ..

I run 8 degrees ...

[wreckmastr]

Originally Posted by blueghoast

Do you take timing out as your boost raises.
And how are you doing it.

If you are running EFI its easy to do. If not it can be done through a MSD Power grid with a boost reference module. As it has been stated always read the plugs

[charlie66]

Originally Posted by Curious George

I think I'm retarded, lol. Agree with too retarded being safer than too advanced with obvious consequences, but what are long term effects of too low of timing? I'm aroung 15 degrees at 15psi, I added a couple degrees and didn't really pick up anything so I was hesitant to keep going. Trying to keep things together as budget only allows for limited testing. Any information given would be greatly appreciated as I am still pretty new to this boost thing.

I dont know all of them , but Too retarded timing will give low power, lousy emissions and excessive bore wear. You can burn up the turbin wheel on your turbo too. I dont know what heads you have and where your piston height and head gasket thickness is, but 15 degrees sounds kind of low.. Im not saying it is. I would need more info to have a better idea....

There are guild lines to follow as you tune for optimum timing while reading the plugs...

With out them its playing russian roulette if you ask me.

[charlie66]

Originally Posted by wreckmastr

If you are running EFI its easy to do. If not it can be done through a MSD Power grid with a boost reference module. As it has been stated always read the plugs

Is this your actual map that you use?

[wreckmastr]

Originally Posted by charlie66

Is this your actual map that you use?

Yes, But everyone's stuff is different

[wreckmastr]

Yellow is the timing during a run

[charlie66]

Originally Posted by wreckmastr

Yes, But everyone's stuff is different

Yes i know.

I was just interested in knowing because of your unique cyclinder head..

Thanks for sharing...

[Curious George]

Originally Posted by charlie66

I dont know all of them , but Too retarded timing will give low power, lousy emissions and excessive bore wear. You can burn up the turbin wheel on your turbo too. I dont know what heads you have and where your piston height and head gasket thickness is, but 15 degrees sounds kind of low.. Im not saying it is. I would need more info to have a better idea....

There are guild lines to follow as you tune for optimum timing while reading the plugs...

With out them its playing russian roulette if you ask me.

Thank you charlie66. I have Edelbrock D port heads, I think .040 gaskets, and not sure on piston height. Where is a good place to accurately learn more about tuning and reading plugs?

[taff2]

On my turbo 421 combo-7.5 to 1 compression, big plenum dual carb manifold, custom turbo cam- I run 42* initial timing! It starts easily with a separate starter/ignition switch set up and runs fine, I start pulling timing at 5psi of boost and at max boost of 18-19 psi(so far) its at 27 degrees. The footbrake launch and throttle response was vastly improved when I bumped the initial up from 32*. I religously read plugs (usually cutting a couple open) and all is good. I am on a C16 type fuel and use water/meth as a chemical intercooler.