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Old 08-04-2020, 06:18 PM   #160
IROCZman15
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Join Date: Dec 2004
Location: Roxbury, NJ
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Thanks Matt

I decided to call Andre at Edge Racing converters this afternoon just to settle my thoughts and ask his expert advice. I had a few questions which have been rolling around in my head, and the topics have been covered here and with other friends of mine, but I figured it would only help me to speak with him. he built my converter with the most important aspect being the "STR factor" or "street" parameters setup that his company calculates. The street nature of the car along with all the car/engine specs were taken into account along the way. He knew that my future plans did/do include nitrous use so he made the converter tighter so that it doesn't "flash through" when nitrous is in use next year.


He confirmed that the converter flashing at 2,800 rpm after leaving off of a high idle at 1,200 or so, is normal. He described the converter in having a " true-stall of 3,100plus ". He stated that if I wanted to have the best/highest converter flash-stall, I would be best leaving off of a dead idle (mine idle is set at 920 rpms). More important than flash-stall is true stall of the converter. Flash-stall is not necessarily where I need to launch the car every time. I was not doing this during the session this past Saturday when I had the 300 lbs in the trunk, I now will try this next time). As for my rpm drop between shifts, he stated that for the street car aspect that this car is, that the 1,500 rpm drop between shifts is normal. If the car was a full blown 1/4 mile car he would want the rpm drop to be only about 1,000 rpm.. and for an 1/8th mile car the rpm drop would be only about 800 rpm. If the car was setup for drag race only he would have the converter stall speed at 4,000-4,200 rpm. The best for me now (with plans for nitrous this winter) is keeping this 3,400 converter as is. "Nitrous will cause a higher flash and higher K factor". As for the 8.6% converter slip (that Matt calculated with the extra weight in the trunk) this number is pretty good. He said to do some fresh passes with no weight in the trunk and launching from an idle and then calculate slippage again. I also asked him if there would be any benefit to me manually locking-up the converter at any time during the run. He said it wouldn't cause any problems mechanically with the converter because it has high-carbon internals and would not ever glaze or depreciate. It would get closer to 1:1 ratio when in lockup, but this would then get me more "out of the sweet spot", and would cause even more of a drop in rpm's between the shifts, so basically "it would be a slow dog" if I locked it up during a pass. (I did actually try this back on June 6th, and i remember that it did exactly this so I never re-visited locking it up during a run but wanted to ask him anyways). I asked him about the wheelie aspect, and he recommended that for this I would be better off launching completely opposite as discussed before. My 60ft and et would suffer negatively, but I would have a better chance of lifting the nose up if I brought the rpms up as high as possible on the foot-brake and then pouncing on the throttle.

So, launch from as high rpm as my brakes can hold for a wheelie attempt, but for the best/quickest drag pass possible, leave from a 920rpm idle.


He is confident that with nitrous on this converter the car will fly. It is currently doing fantastic with street manners, its right there at the autocross, and is doing moderately well for N/A drag racing.. but when I get the nitrous into this car...this converter will come alive. This sound right? basically I am currently just experiencing the results of having a mutli-use car but the "slower" N/A drag passes will give way to much better use of the converter when the 200 shot starts flowing.*



comments questions concerns are always appreciated!
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Last edited by IROCZman15; 08-04-2020 at 09:33 PM.
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