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  #1  
Old 03-01-2005, 09:59 AM
jcrvette Offline
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High gear retard

What is the purpose of the high gear retard? I see most msd boxes are set up for this but not sure when it is used or what combinations could benifit from it. Thanks
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  #2  
Old 03-01-2005, 01:01 PM
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In a lot of applications people feel a motor makes more torque with more timing yet can not spin as freely at high rpm with that same amount of timing. In these senarios you are able to pull timing on top gear and increase your mile per hour without losing on the 60 to 330 ft.

This chain of thought goes all the way back to early Corvettes that had timing retard switchs on the 3-4 shift lever.

Some people also like to pull timing out on the top end on nitrous motors to lessen the load on the motor.

I am not saying yeah or neah to either of these, just answering the question as to why.
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Old 03-01-2005, 07:36 PM
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A high load on the motor(high gear) will burn the fuel more quickly and efficiently than a motor that is revving quickly and not loaded by the drivetrain. Typically you can get away with more timing when the motor it not as loaded as it helps burn the "extra" fuel. A lot of times when you see guys pulling timing in high gear it is because they are running the timing a little higher than usual in the other gears. Best thing I can compare it to is a fuel car--when they are spinning the tires or driving thru the clutch, they are usually dropping cylinders because the fuel can't burn fast enough when the motor is revving up so quickly.


Last edited by nosfrog; 03-01-2005 at 07:42 PM.
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Old 03-01-2005, 08:07 PM
jcrvette Offline
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makes sense. Do you think it would help this combo, and if so how much is a baseline amount to remove? 3200lbs, 14.79:1 sbc,4.56's with 32" tire, 9.70's on motor working my way up to 250-300 shot nos.Should be around 7500-7800rpm on nos.I run a fairly safe tune, timing mark mid point on ground strap curve and nice color on porcellin. Thanks
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Old 03-01-2005, 08:34 PM
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I'm going to assume you're running a glide. If so try running an extra couple degrees in low gear, and when the car goes into high gear, pull the timing back to where you normally run it.

You may be able to get away with an extra 4-5 degrees when you're in low gear but I would start conservatively and work your way up.

Last edited by nosfrog; 03-01-2005 at 08:37 PM.
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  #6  
Old 03-01-2005, 08:42 PM
jcrvette Offline
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no, it's a th400. I guess I should run it in first and second only with a few extra degrees to check plugs with the extra timing then run it all the way down with the timing back out to check the plugs with retard. Is this right? How much roughly would this combo pick up? Maybe its not worth the hassel? Thanks
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Old 03-01-2005, 08:55 PM
nosfrog Offline
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It's hard to tell someone over the net how aggressive to get with their stuff. There are sooo many variables and every combo is unique and reacts differently You seem to have a solid approach so I would follow your thoughts.

If it was mine I would run an extra 3 degrees in low, 1.5 in 2nd and go to your normal timing when she goes into high. See how it reacts and go from there.

Hard to say how much it's worth but I wouldn't expect more than a tenth. I have seen some pick up a little more and others barely any.
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Old 03-01-2005, 08:59 PM
jcrvette Offline
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Thanks for the info. With all the wiring and more chances for somthing to go wrong, maybe its easier to use more n2o jet.LOL
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Old 03-01-2005, 09:11 PM
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Funny you should say that....I know you were joking around about using a bigger jet but that is one of my biggest pet peeves with a lot of guys who use nitrous. I see too many people just throw more nitrous at it instead of trying to fine tune their combo. I'm around a lot of T/S type cars and I've seen cars that have a finely tuned 1 system setup go faster than similar combos running 2 stages. It takes a lot time, patience and experimenting but eventually all those small gains start adding up.
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Old 03-01-2005, 09:19 PM
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Mike C Offline
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Use either an add on MSD Programmable Timing box on your current ignition or use a Digital 7 and then you don't need any more wires or switches.
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  #11  
Old 03-01-2005, 10:45 PM
jcrvette Offline
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I know what you mean about the fine tune. I try to be fanatical (to the best of my ability anyway). My car runs as good as a friends car with a lot less cubes, 300lbs more and a n20 converter to boot. Leaves the line straight and smooth and almost drives itself. I figure I paid for all that hp and suspension, the better it all works, its like free et. Plus, with guys like you all teaching me I really have no excuse to have it anyother way. Thanks
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  #12  
Old 03-01-2005, 11:00 PM
nosfrog Offline
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Sounds like a good combo you got going there. Runs damn good considering the weight.

Over time I've learned most of the things I try don't usually do much but if you don't try, you'll never know. It the few that do work out that are important.
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  #13  
Old 03-01-2005, 11:08 PM
jcrvette Offline
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Thanks. Shaffiroff short block, some of the best money spent. Told them what I wanted, they gave me the occasional "no you dont" and let their experience pave the way. Alot can be said for buying a proven combo from someone reputable. Then I ask the pro's (you guys) and try to have some common sense then put it all together in one pile and let it rip. Seems to be working.LOL
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  #14  
Old 03-02-2005, 12:05 AM
nosfrog Offline
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Good Luck. If you get a chance to try any of the timing stuff, post your results.
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Old 03-02-2005, 08:52 AM
jcrvette Offline
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Mike, This may be a dumb question, but won't I still need to wire switches onto the shifter for the retards? My 7al3 box has a few leftover retard circuits that I could use, does the programable msd retard box do somthing mine doesn't or just do it better?
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  #16  
Old 03-02-2005, 10:09 AM
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The MSD Programable Retard box basically converts your 7AL3 into a Digital 7. The software used is just like what is used in a Digital 7 and it knows when you shift gears and can be programed to apply retards at those points. I am on the road so I don't have the part number of the actual box with me but if you go up on www.msdigintions.com and go to the Digital Products section and find it then you can download the software from that website via the "download Section" and put it on your computer and see how it works.
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  #17  
Old 03-02-2005, 10:31 AM
jcrvette Offline
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Sounds like a plan. Thanks. I am practicing saying "honey, I NEED a new trans and another Chance converter. And a ign. box" . Let ya all know how it works out.LOL
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