delete - see previous

 

Well, rear is quiet and has survived some more runs (without the trans brake so far). Best run so far is 11.20 @ 119mph in the warmer humid air we have been having. Looks like I might have to wait until cooler weather in the Fall to try to get into the 10's - hot humid air really saps the power out of the engine (lower oxygen content per volume so cannot burn as much fuel). But I still don't know if and how much the trans brake will help. Right now I am leaving off the light at about 1500rpm. My peak torque is around 4500, so there is some potential for reducing the 60" time when using the trans brake to get up into the power band - exactly how much remains to be seen. Still haven't been able to put my eyeball on the A/F meter during a run ALL THIS YEAR - it's very strange - I think about it while staging but once I hit second gear it's long forgotten!

Wife bought me my birthday present early - a Daytona Sensors CD-1 Ignition Box and coil. This box not only does the CD multi-spark ignition, it also is a three step rev limiter (engine max, burnout, and stage), a limited data logger, interfaces with a laptop, and does programmed timing curves. Also has MAP sensor input available for 3D timing curves and ignition retard when you have a turbo (which I don't), but you can also program a timing retard during starting. You can build custom advance curves for a distributor with locked out mechanical advance and download them to the box. I intend to use the staging rev limiter to control my engine to a specific rpm 3000 or above while on the trans brake, instead of just going full throttle against it. My converter actually stalls at 4100 rpm when full throttle against the trans brake, so there is a range from 3000 - 4100rpm where I can investigate in 100 rpm increments what might be best rpm to leave at.

Once I lock out the centrifugal advance in my distributor and unplug the vacuum advance, I can change my timing by simply downloading a different advance curve (instead of turning the distributor). Pretty nice I think for investigating even 1° difference at a time in total timing!! and easy to return to exactly the same place!

As far as data logging I can hook up my wideband A/F gauge and digital speedo sensor and log engine RPM/Timing/fuel mix/vehicle speed - and download it to my laptop later for analysis to look at converter efficiency, wheel spin off the line, fuel mixture during the run, and know exactly what RPM it actually shifted.

I'm not planning on it, but you can set the box up to control relays to actually shift your trans at programmed RPMs for individual shift points. You see that happening on the Street Outlaw cars where they shift themselves during a run. Of course theirs is also controlling their fuel injection system where mine is not.

Probably much more I could do with it, but I think it's a pretty cool little box to play with. Hope to get it installed soon.

CD-1? Ignition Systems Overview | Daytona Sensors?

Here's the 11.20 run from two weekends ago. Note that shock adjustment on the front is keeping the front wheels down a bit more when doing the hit using my off-idle staging technique. We will have to see what the front end does using the trans brake. Should be interesting. Maybe spin and slower time? Maybe hook and really go!!

 

Nice run.

For the starts it will be interesting to see what will happen with your trans-brake.
Looking forward to see the results and how the suspension will react. As always it may come down to find the best balance. I could imagine that the transfer of force to the rear and downwards helps grip but at the same time de-stabilizes the front.

For a stranger. Would you consider this to be a nice drag strip? Looking good, new pavement?

 

Weit's a very old drag strip started in the 1950s still run by the same people. Old surface and definitely not perfect but they do prep it, even for test and tune on Fridays. It is IHRA sanctioned. Not many small 1/4 mile tracks out there these days - most are 1/8 mile to keep speeds down and that is not preferable to me. We consider ourselves to be lucky to still have it. They have a live Facebook feed on most race days if you want to watch sometime. Osceola Raceway. Just a bunch of locals.

 

Some success with the data logging, but have been fighting it for several weeks now. Here is AFR vs RPM. Seems a bit noisy and I have yet to get the driveshaft speed logging to work. Getting zero help from Daytona Sensors so far. I really disappointed in that after having spent $600. Haven't tried hooking up the 2-step rev limiter for use with the trans brake, or tried locking out the distributor and using the programmable timing curves yet - but that seems to be something I can go ahead and try with this box next. I've been to distracted in trying to get the noise down and the VSS working, but I guess I'll go ahead and try some other things working.

Interesting to follow these plots through a run. Mostly 12.5 to 13.0 AFR through the three gears with a brief temporary leaning out to around 14.0 right at each of the two shifts. I have read that this is actually an known artifact of the weight of the fuel in the larger passages in billet metering blocks (seen in machined vs cast passages). In pro built race carbs I understand they fill the larger passages with epoxy and then drill them out to a smaller size. It makes as much sense as anything, and mine already has the secondary jet extensions. I'm not worried about it. Also looks like I could do with a slightly smaller accelerator pump shot - goes rich as soon as the torque converter flashes to stall speed.

 

Nice run's and good to have some data to work from.

Can you export into an excel sheet?

It seems to me that a data normalization could smoothen out the curves. You can still interprete between the peaks for trends.
Nice to see that the 3rd gear would pull far more. If the track is long enough I guess it would become scary.
AFR sometimes does pulsate but rpm should have a smoother curve IMHO.
I'd continue on that way.

We learn every day from every bit of data that comes in.

Cheers

 

Actually the sheet shown is in Excel. Had to do that in order to apply the formula to convert voltage output of the gauge to AFR. I do not feel I should have to apply smoothing to the data, and box should perform as shown in their own software examples.

Since last post I have gone on to try other things I wanted to do with the box. I locked out my distributor centrifugal advance, set timing to 37°, built an electronic advance curve, and uploaded it. Idea is to be able to accurately change my max timing at the track by 1 degree at a time (without timing light). This is done as a delay to a reference timing (37° in my case), and I have 22° max of delay to play with. So curve I made for 35° timing starts at 15° and advances to 35° between 1500 and 3000 rpm. Doesn't really matter for my purposes what timing is under 4000 rpm, so for practical purposes the actual curve just allows engine to start more easily.

Found more issues with using the box. Although timing was indeed a nice stable 35° at above 3000 rpm, delay program never took timing all the way back to 15° at idle - only back to around 18-23° and very unsteady timing. So it seems the more I expect the box to do, the worse it performs.

For $600 I expect more. Admittedly could be something about my installation or even my distributor. Could also be something about the box is bad. Finally got some customer support out of Daytona Sensors and they are sending a box for me to switch out and see. They certainly have much smoother and less noisy data in the real data example files that they provide with their software. The inaccurate timing at high-delay is a deal-breaker to me. It has to work better than that in order for me to trust it.

 

Aha! Found something in generic instructions for the box!! I have my battery relocated to the right rear of the bed. Need to try this capacitor next. This has to be something to fix EMI

Power connections. Connect the 12 AWG red
wire to the battery disconnect switch or the battery
cable at the starter solenoid. If the battery is
mounted outside the engine compartment or the
CD-1 red power wire must be extended, a filter
capacitor is required and minimum 12 AWG wire
should be used for the connection. You can use a
10000 UF 25V electrolytic capacitor such as our
P/N 102007 capacitor kit or Mouser

 

I got the $50 102007 capacitor kit from Daytona Sensors and installed it. So many different capacitors to choose from in electronics supply houses - good to know one that is made in USA and is specifically supposed to work for the application (all of the capacitors with same approximate specs for were $35+ anyhow). Also rewired installation to keep power wires completely away from the sensor and distributor trigger wires. Put the capacitor across main power and ground within 1 ft of the box. Did a quick log of AFR in my garage and both RPM and AFR seems to have much less electronic noise. But until I get an actual run down the track I won't know for sure. It has been electronically the noisiest under hard acceleration and high rpm. Can't do that in my garage, especially with open headers. I can say that the timing at idle seems much more stable when checked with my timing light, and it indeed was at 15° - having it jump around a bit before and be higher than programmed at idle was of concern to me. Wife comes home from visiting her parents in Europe this weekend, so no racing then - maybe next!

https://shop.daytonasensors.net/prod...-capacitor-kit Here's the capacitor kit. My ignition box is the 102003 at the bottom

 

"Can't do that in my garage, especially with open headers."

Well, you may but by risking the neighbors good relationship and your garage windows.

Nice work. Looking forward to see if it has cured that noise.