MadMarv
Jun 26th, 04, 4:07 PM
After I talk with Baer on monday about my rear discs and regular pro stars (versus the heavier, more expensive pro star XP), I am gonna dive in for some 28*12.5 ET streets.. but thats not what this post is about.
The company that made my 9.5" torque converter says you cannot use chassis dyno numbers as an indication of true hp, saying the numbers will be lower than they would be behind a locked converter or stick, and on some dyno's it will have a skewed torque curve.
Here is the thing though: I have had my eyeball on this torque converter for a while, especially since my tranny fried from metal that came from somewhere outside the transmission (tranny guy said either from the converter itself, or there was metal in the converter because the company may have accidentally sent me one from a guy who blew his trans), but he said he looked everywhere in my trans and said he couldn't find a place where that much metal could possibly have come from.
But when I sent the converter to the torque converter company, they looked at it and said the converter was fine, charged me 150 just to cut it open and look, which I suppose is fair seeing as they charge 225 for a stall adjust.
Getting more towards the point: I have done two chassis dyno's with the car. One with a stock 12" converter that was just given to me so I could get the car home before the converter was inspected.
Then one more time with the 9.5" converter, where when I floored it at 2500 it just jumped to 5200rpm and then "grabbed" and did like a 3 or so second run to 6800.
The numbers themselves were about 35hp different and 34ft-lbs different, but ft-lbs is a little harder to compare because the run started at just the point where my torque starts to fall from its relatively stable +-5 ft-lbs from 3500 to 5200.
I know some folks here loathe dyno's and stuff and say just get it to the track, but I have and now I am suspect of this thing. Every performance calculator (yet another thing you guys don't like) says I should be right at 120, as does the guy who did my cam.
I know my car is a pork rind, but its just not adding up. The engine dyno was extremely conservative-- done with alternator and water pump being spun by the engine, and through my own entire exhaust. Even if you take those numbers just as they are, they say I should be able to get to 120 in the 1/4.
The only thing between the engine and the pavement that is voodoo here is the converter, and its got me wondering.
Or do you think the cam guy is wrong and so are the performance calculators, and there is probably nothing screwy with my converter? Or is it possible I just have a bad apple converter with nothing really "wrong" with it per say, but its not working like it should?
Matt
The company that made my 9.5" torque converter says you cannot use chassis dyno numbers as an indication of true hp, saying the numbers will be lower than they would be behind a locked converter or stick, and on some dyno's it will have a skewed torque curve.
Here is the thing though: I have had my eyeball on this torque converter for a while, especially since my tranny fried from metal that came from somewhere outside the transmission (tranny guy said either from the converter itself, or there was metal in the converter because the company may have accidentally sent me one from a guy who blew his trans), but he said he looked everywhere in my trans and said he couldn't find a place where that much metal could possibly have come from.
But when I sent the converter to the torque converter company, they looked at it and said the converter was fine, charged me 150 just to cut it open and look, which I suppose is fair seeing as they charge 225 for a stall adjust.
Getting more towards the point: I have done two chassis dyno's with the car. One with a stock 12" converter that was just given to me so I could get the car home before the converter was inspected.
Then one more time with the 9.5" converter, where when I floored it at 2500 it just jumped to 5200rpm and then "grabbed" and did like a 3 or so second run to 6800.
The numbers themselves were about 35hp different and 34ft-lbs different, but ft-lbs is a little harder to compare because the run started at just the point where my torque starts to fall from its relatively stable +-5 ft-lbs from 3500 to 5200.
I know some folks here loathe dyno's and stuff and say just get it to the track, but I have and now I am suspect of this thing. Every performance calculator (yet another thing you guys don't like) says I should be right at 120, as does the guy who did my cam.
I know my car is a pork rind, but its just not adding up. The engine dyno was extremely conservative-- done with alternator and water pump being spun by the engine, and through my own entire exhaust. Even if you take those numbers just as they are, they say I should be able to get to 120 in the 1/4.
The only thing between the engine and the pavement that is voodoo here is the converter, and its got me wondering.
Or do you think the cam guy is wrong and so are the performance calculators, and there is probably nothing screwy with my converter? Or is it possible I just have a bad apple converter with nothing really "wrong" with it per say, but its not working like it should?
Matt