first WOW. something that works like it should and as advertised
just changed from running locked out timing (24or 26 depending on fuel) to
actually having a timing curve again and while the car has been reliable and made
good power for 6 years there is a huge difference in overall performance with
this box.
motor sounds happier driving around town
EGT temps @ cruise was 1300-1400 now 1050-1100
transition to boost is almost violent , the car used to try and hook on the street, not no more
355 cu in w/ twinT-3's / 10" converter (tight) / 40 degree timing @ 0 boost> 22 degree @ 15 psi

i attatched a screenshot of the curve , remember it is in PSIA, 14.7ish is 0 boost

 

That's good to hear. They should've have come out with that box years ago!

 

you aint got to sell me. Ive already got one on my wishlist.

the pic you posted, does that show that you start retarding at 15psi boost? or is that 0.3 psi boost

finally, which MAP sensor are you using and how is it installed?

 

Can you explain the run curve ?

0psi is actually around 14.5 at or near sea level depending on barometric pressure .

Hes at 40º at 0 psi and is pulling it back to 22º at 13psi and continues at 22º everything above 13psi .

 

Think of run retard as mechanical advance in the distributer. His distributer is locked at 40 and at 0 rpm it pulls 24* as a start retard. I set mine a little higher for vacuum advance effect. I run about 8* more timing than what I ran total timing when normally aspirated. It starts retarding at 10" of vacuum and pulls those 8* by 0 psig.

My local pressure is usually 13.75psi and 14psi on a good day. I have been using a 6530 for a while and it is a good value for people that don't have a budget for a Digital7.

 

ok, I get the run retard graph. starts at 22, all in (40) at 3000 rpms.

just wanna make sure Im getting the boost retard right. atmospheric pressure is on the top and retard is down the left side right, so at 4.5 psi its retarded 12 degrees, and at approx 10psi its retarded 16 degrees? too cool.

 

CyanJaguar : used a map from orielly's for a buick turbo v-6, had to use an
exacto knife to remove alignment pins in inside electrical connector of map sensor

it is a very easy box to use, there are simulated gauges for RPM,current retard amount
and PSiA. after driving around to see where the car was at under part throttle looking
at the simulated gauges i was able to be fairly close on the shape of timing curve.
then i used the chart, it has a realtime indicator bar, to pinpoint where it starts
detonating and reshape at that point .

 

Ok , I got it .

Why not use the boost retard to do the same thing ?

 

blown385, not sure if I understand your question.
The Run Retard screen sets up the base simulated mechanical timing curve
that the boost retard screen modifies depending on load/boost.
on this paticular car I did not have to modify the vacuum side of the
boost retard screen for problems such as detonating while climbing hills
under part throttle.
The only issue I had in the end was I could not eliminate detonating
above 12# boost due to 91 octane gas unless i just removed so much
timing it killed power excessively.
now if I can just talk the owner into a wideband.
355+small twins+control over timing=

 

I understand . Thanks .

 

Does this box have a start retard function? and are you having a hard time starting the car with 40 degrees locked when it warms up?

 

It does have start retard. The first graph shows 24* of retard at 0 rpm.

 

That is a nice ignition box turbotater and like Project X said, they shoulda came out with that damn box along time ago . I know a guy that was using a MSD6AL box that did run 8.20's at 174 MPH with a add on boost retard though and then bought the mega million dollar Digital 7. This gives us smaller guys a great option of a street/strip ignition box that won't kill the wallet and you have the ignition retard and run curves that of the bigger ignition boxes.

Great job that MSD did .

 

zooq: it took me moment to get it sorted in my head when i looked at the
instructions about the Run Retard graph. you have to think backwards, instead
of building a timing curve starting at whatever intial timing and then adding
some amount more in the program. you set the distributor at the most you
would timing you would ever want to have and then take away from that
number to arrive at a timing curve. that is why it starts out at 24 degree retard
@ 0 rpm>to no retard @ 3000 rpm.. 40-24=16degree intial timing ramping up
to 40 degree as less is retarded.

 

I have mine set to run 36º all the time until it sees 5psi , then it starts to retard .

I will probably look at running more timing at cruise and lower RPMs but I thought the boost retard would be a better way .

For instance , I could run 40º at 15" of vacuum , then as there is more load on the motor the vacuum decreases and timing will come back to 36º at zero vacuum . It will maintain 36º until it sees 5 psi , then start pulling timing .

If you don't need the start retard , wouldn't it be better to make a timing curve according to load rather than RPM .

And wouldn't the best indication of load be vacuum / boost ?

Just curious myself so I can do a little more fine tuning in the future .

Thanks , Dave .

 

Im seeing some websites advertising for $250s but jegs and summit are in the $370-410 range? I heard that msd just relaxed pricing policies so are these $250 prices as a result of pricing policy changes, or just fraudulent sites?

 

i originally thought I would have to use the vacuum side of the Boost Retard graph
to yank out some timing for part throttle loads such as climbing steep hills in traffic
but so far there has been no detonation under those conditions so i am just .

blown385: i think you will have to use the Run Retard for the base curve or you will
be trying to start the car with 35-40 degrees of timing (no vacuum)

 

I have a digital 7 programable and it has a seperate start retard and run curve retard.isnt this box suppose to do the same thing?

 

That's what I meant when I said , " if you don't need a start retard " . My motor turns over fine with 36º to 38º . Its only 8.8:1 .

It likes the timing , especially off idle . I want to try more like 40º at 800rpm until there is enough load to pull it back to 36º then when it sees 5 psi it will pull more .

 

gotcha