Chambers look great! and nice job on getting the springs set up. $500 is a gift. Your going to love the nitrous power. Which MSD box are you going to use? Paul
got the msd 6al 6425 http://www.jegs.com/i/MSD+Ignition/...eNCQNslVX1ylhplLAjqxOvvsCW7V22GEMcaAmhP8P8HAQ
Hey Steve Yeah i shaved the holes still got the trims here for the case i wanna go vinyl one day.. i was really debating..
since i had the msd6al before i decided to go for the bottle i was thinking to get a add on retard box.. any suggestions?
The MSD 8987 is the least expensive and the most simple add on unit that I know of. http://www.summitracing.com/parts/msd-8987 What size shot of nitrous do you plan on using?
The reason for asking is, at 175 hp shot you don't want the nitrous on before 3500 rpm Nitrous adds torque inversely proportional to rpm. At 2600 rpm with a 175 shot is an EXTRA 350 ft lbs of torque. When we were racing with a lot of nitrous I used an rpm window switch to insure the nitrous couldn't come on early and also to shut it off about 200 rpm before the rev limiter. Nitrous is one of the hardest power adders on an engine. Like you said, This just got real! OK so its a slight miss quote. LOL Paul
Be cautious about converter rating. Some are rated at max rpm for biggest basest big block. So it will stall much lower on a mild small block. So look at ones rated for small block . I ran tci 2800 converters that stalled 2400 on my 350. Ran 3500 small block converters on a 455 and seen 4200 stall. .
Good point a safe bet is a converter rated for 3000 stall if you are looking for a 2500 stall... Keep in mind the nitrous will make the converter flash higher as well.
Seems it equates to about 25 ft. lbs. per 100 RPM, give or take. Testimonies on a trusted name brand 2000 converter indicate between 1600-1800 stall on 325-375 ft. lb. engines. Using the above information, we can deduce that it would take 425 ft. lbs. to achieve an actual 2000 RPM stall. A typical Buick 350 would probably stall it between 1700-1900 RPM (350-400 ft. lbs.), while a typical Buick 455 may stall it around 2100-2300 RPM (450-500 ft. lbs.). This comes to 'typically' about ~400 RPM (or ~100 ft. lbs.) difference between a 'small block' and a 'big block'. It's accepted to expect between 300-500 RPM difference between the two, and this scale shows up to 600 RPM difference. I'm sure it varies from converter to converter, but I suppose you could use this as a general rule of thumb. Gary
Gary, you're going to hate me! I suspect the converter follows a linear scale along a narrow range with similar vehicle specs. Same vehicle example with torque estimated from mph data (but too long ago to remember entirely accurately) , same converter (9"). 325 lbs-ft tq sbc was 3000 rpm 480 lbs-ft tq bbc was 4800 rpm 550 lbs-ft tq pontiac was 5900-6000 rpm I don't believe the pontiac made 750 lbs more torque. Many select the converter for NA street driving and are surprised when it runs down the track at max rpm.
Just to reiterate. Nitrous adds torque inversely proportional to rpm. A 175 shots adds 175 ft lbs of torque at 5200 rpm. At 2600 rpm that is an additional 350 ft lbs on top of what the engine is already producing. It would drive right through a regular duty converter. I've been there where we not only drove through the converter but toasted the tranny plates also.
so i guess i should go with a 2800 stall to get true 2500 Has anybody worked with a retard add on adjuster such as the MSD 8987 on here... i just talked to Msd and it obviously works with my 6al box but i see no wiring diagram for HEI dustrib. ?!
Go to page 14 of the 6425 instructions where it shows how to wire the unit to the ignition coil. It will also show you how to replace the ignition module with the MSD PN 8861 Harness. Now go to the 8987 instructions where they show how to wire the 6425 and the 8987 together. The exception will be that the 8861 harness from the distributor will plug into the 8987 Mag Pickup cable that is shown as (Not Used) instead of the white wire connection. Which distributor do you have? Paul
i have a regular HEI That came with the car in good condition i updated it with a crane advance vacuum kit
I have my 6a and digital 7al run off an hei and I just use the trigger inside distibuter. Take out hei module and run the harness into distibuter to pick up wires. That harness usually comes with the msd kit that elimates the coil being inside cap.
No hate here, I'm glad others chime in with their input. My thoughts were meant as a simple guideline using a common street converter and an average or typical engine; and as I said, it would probably vary from converter to converter...not to mention car weight, gear ratio, powerband, whether or not you use nitrous, etc. etc. eeeettttcccc...
