Red Box vs black Box

[RickyBobby]

I run a black box ignition system that came with my car.  Everywhere I look there are different combinations of red box and black box, however every report I see on the 1200 motor is that is starts loosing power after 9500 rpm.  My question is if you are at a fine line of needing more straighline bandwidth would you go up a gear or put in a red box?

[Tom Cole]

http://www.legendsracer.com/index.php/topic,118.0.html

Hey RB, that link takes you to a thread where I got a little education on the different boxes.   Maybe that will help you decide.

Generally, I play with gear and setup until I get the fastest lap time.  If you notice that the cars at your track with more top end speed can't make the pass before the next entry, then acceleration will probably be more important.

[knoxracing]

There are two black box systems and one red box.
1)Old style black box with vacuum module mounted next to it, max 10,300(aprox).
2)Newer style black box 9900 ropm(approx)
3)Red box system 10,300-10,500 (approx)

The 9900 system is a rookie system, there are situations you need the extra 300-500 rpm to bury the car in the corner, yes the band peaks at about 8500-9000 rpm, but you have to carry the momentum further, and if you gear the car to run out of gear 9300 rpm at the end of the straight you will lose too much bottom end (off the corner),  generally off the corner is where you gain momentum to pass. You really need to use all you can get, especially on short tracks.

[RickyBobby]

The black box I have is an older original system and the reve limiter is at 9500 RPM.  I get a great jump on the field coming out of the turns but I hit the limiter before I dive into the corner.  Some of the guys have said to go to a bigger gear as I will get more rolling speed in the corner as well but my Father in Law who build drag cars for many years said keep the same gear as I do get that great jump on the field but I need more RPM's for starightline speed.

[JGRacing]

Is the vacuum box a vacuum ignition advance, or a feature that is not use but just identifies the box? 

[knoxracing]

The vac advance is used on the Legends car, the boxes with vac advance will have a vac module next to the box, under it or near it. The vac line goes to the intake area behind one of the carbs. This system is a very good system, the problem is it is an old system and parts are very hard to find, so the alternative is the red box system.

[JGRacing]

Is the FJ box available from a Yamaha dealership, or is a legends specific part?

[RickyBobby]

knoxracing....you say that is I gear the car to hit the rev limiter at the end of the straight I will not have anything coming out of the corner.  Can you expand on this?  My thinking was I would be at a higher RPM than the guys running a taller gear when I exit the corner.  I think it is around 6000 where the other guys would be even lower.  Wouldn't I have more pull out of the turn then?

[RickyBobby]

or anyone else who may have some insight..........

[thunder938]

Now we gear the car to just tap the limiter just before lifting for the turn.  If we drop the revs back we will say a grand you would still have the same pull off but you would be hitting the limited 1/2 way down the straight, or if you change the gear so you dont hit the limiter until the end of the striaght the gear would drop the rev coming off so much other guys would just pull away

[RickyBobby]

again I am confused.  you say you set up the car to hit the limiter jsut before hitting the turn but you also say that if you set it up to hit it at the end of the straight (which is the start of the trun) you will be too low in the revs.  With the black box right now I hit the limiter for a little bit down the front stretch and just hit it as I start the turn on the back stretch.  I am running a 3.73 gear and the other guys are running 3.58.  I get more pull currently coming off the turn to start the straight away than the rest of the field.  I can usually gain 2 spots just on the green flag drop.  So my thinking is with the red box I willl maintina that pull and gain more top end RPM's that I won't run out as I go down the straight away.  However with a shorter gear it pulls you back more in the corner so am I loosing rolling speed in the corners.

[thunder938]

If your car pulls good with the gear you have and just need a some more RPMs at the top then good. I dont know what kind of tracks you race at, here in ohio we run and 2 tracks with tight turns and one that is like 2 drag strips and a hairpin.  at that track if you have a gear to get off the turn without shifting you MAY run out of revs at the top.  With the red box you have extra rpms.

Now there is a movment afoot to maybe someday limiting the rpms back down with a maybe a inline limiter of some kind.  I just talked to our local dealer who stated that 600 sent some motors out to some cup teams to test and see why cranks were braking.  The report came back and stated that we, 600, should pull the rpms back to make the motor last longer.

If 600 can do this and sell the limiter and maybe more gears to racers that have to change to get the rpms in the sweet spot 600 will make a change some day..

Dave

[qweedqwag]

RB,

Are you running the same gears as everyone else at the track? Just curious was wondering if you are maybe running the wrong gear, another advantage to the Red Box setup is you can change out spark plug wires, on the older systems you could not.....anyway double check to see what gear other are running it may surprise you.


Mike.

[JGRacing]

Does anyone shift on ovals?  If the transmission would take it, I would think that it would help on tracks with long straight aways.   Never was an option for me before, but with the inline shifters it should be pretty easy to go up a gear.   

[thunder938]

I raced with a guy that did not have time to change the gear and he had to shift.  It worked he was still fast.  I dont know how much the trans could take, but it does work