Directfreak

Who on the list is successfully using a

Boost Retard Mechanism from MSD, or a 12AT Distributor?



I've heard the 12AT distributor will only retard a total of like 6 degrees, so it may not be enough when running 17psi+



I already own a few MSD6AL's & MSD Blaster II coils and don't want to change them unnecessarily.



I am not sure if I can add a Boost Retard

to them (MSD6AL's) so I could retard BOTH Leading and Trailing simultaneously.



I am asking, because I figure it's better than just using a locked distributor for off boost driveability, which seems to be what Iwill be using with my Holley 650 for a while, until I get my Haltechback from Australia.



Any ideas?

j9fd3s

well heres my thoughts on the subject. we looked in the manual and computed the total timing and split for the gsl-se (its in the book). so full mechanical advance is like 8 degrees or so @2000rpms (i'll post the spread sheet on monday), and with the vacuum advance its like 13degrees. the split also changes with load, it runs about 8 degrees cruising and 10degrees under wot.



so under boost all you get is mechanical advance, which is about 8btdc, all the turbo guys say you can run about 15degrees, so you can actually advance it over stock and be safe

Directfreak

But won't the car run like crap off boost with the timing off?

j9fd3s

but thats just it, the timing is stock, and still turbo safe. it wont let me upload an excel sheet





-5 0 5 8.75 8.75 8.75 8.75 8.75 100mmgh

0 5 10 13.75 13.75 13.75 13.75 13.75 250mmgh

0 5 10 13.75 13.75 13.75 13.75 13.75 350mmgh

0 5 10 13.75 13.75 13.75 13.75 13.75 400mmhg

0 5 10 13.75 13.75 13.75 13.75 13.75 500mmgh



-5 0 5 8.75 8.75 8.75 8.75 8.75 centrifugal

500 1000 1500 2000 2500 3000 3500 3500+







leading btdc

see under wot they only run 8degrees of advance, thats plenty turbo safe, and thats the stock settings

setzep

so at 3000rpm I see 13.75 deg @ 500mmhg and I see 8.75 of centrifugal. Do they both add together to make 22.5 deg total advance?

Racer X

I think you add them setzep.Mikey where you at??