MadMarv
Apr 7th, 04, 8:09 PM
Ok. I am starting to pull my hair out. I got a call back from the converter company (precision industries). I bought the converter long before I joined TC and before I had heard about other companies. I had it restalled last year for a little more juice.
Anyway, last time I was at the track the thing wouldn't shift from 2-3. So I retired the car for the year (it was the end of the year anyway), and while I was getting a cam swap, I had the transmission fixed. The cam swap shop sent it out to his transmission guy (he puts 1250hp through a 4L80E so I figure he must know what he is doing). The cam swap shop said metal bits had clogged the filter, preventing line pressure from building or something like that, and smoked the 2-3 clutches. I forget what he said verbatim.
Anyway, the cam swap guy insisted he figure out to his best knowledge why the trans failed. The trans guy said in his best opinion there was absolutely no way that the metal he found could have come from anywhere in the transmission, period, and that it came from the converter, either broken parts in the converter or stuff that was already in the converter when it was shipped to me.
Converter company calls and says there is nothing wrong with the converter whatsoever, and if I want them to just put it back together its going to be $150, $225 if I want a stall change. I said whatever just put it back together (3400-3600 stall I think, I am unsure of it exactly).
The metal had to come from somewhere. But thats beside the point now. I am out for the trans rebuild and converter "check up" (which isn't the worst deal, any local shop wanted $200 to open it up and check it out).
But here is the kicker-- and I know I toss around dyno #'s too much. The cam swap shop said there was some serious component missing from my setup to be producing 113mph traps when it should be alot closer to 120. I figured it was the converter.
I know dyno #'s don't mean alot, but, hear me out. Dyno test #1 same engine as it is now but with 9.6:1 CR and UD HR4 296/233 .621 HR said 564 hp, 574 ft-lbs. 113.8 mph (would have been mint for a procharger..). Dyno test 2 (engine problem that required rebuild) 286/230 comp .639 HR 10.14:1 565 hp 555 ft-lbs 113.3. Dyno test 3 563 hp, 555 ft-lbs but with my air filter, my headers, my exhaust, my mufflers, my alternator, my water pump, full running water temp and 88* dyno room air for the engine, 38* timing 287/295 256/260 SR. The cam swap shop says that the way they run their dyno makes for atleast 40hp difference vs. a dyno operated in a less 'real world' manner. I have yet to run the car because the track isn't open yet, (as far as I know), I have a 12" converter in there that causes whiplash when I put it into gear and when it shifts, and a few other minor tweaks that are going to take another few hours or days to remedy.
here is my question: my 70SS full steel, full interior TH400 12 bolt 3.90s 4020lbs with driver and 1/3 tank of gas (anyone else ever had a problem with gas flying out of their tank under hard acceleration??). Does 550hp with 4000lbs = 113mph? Or is there a missing link here?
The cam swap shop highly suggests that if I do do a chassis dyno I do it before the converter swap, but I need to raise my car up about 1/2" to make it driveable on roads I don't know and I need to fiddle with the motor mounts to stop the header to steering column clearance issues (that was not there before the engine was pulled this time, and was not there all the other times I pulled the engine myself, any idea how this could have happened??)
matt
Anyway, last time I was at the track the thing wouldn't shift from 2-3. So I retired the car for the year (it was the end of the year anyway), and while I was getting a cam swap, I had the transmission fixed. The cam swap shop sent it out to his transmission guy (he puts 1250hp through a 4L80E so I figure he must know what he is doing). The cam swap shop said metal bits had clogged the filter, preventing line pressure from building or something like that, and smoked the 2-3 clutches. I forget what he said verbatim.
Anyway, the cam swap guy insisted he figure out to his best knowledge why the trans failed. The trans guy said in his best opinion there was absolutely no way that the metal he found could have come from anywhere in the transmission, period, and that it came from the converter, either broken parts in the converter or stuff that was already in the converter when it was shipped to me.
Converter company calls and says there is nothing wrong with the converter whatsoever, and if I want them to just put it back together its going to be $150, $225 if I want a stall change. I said whatever just put it back together (3400-3600 stall I think, I am unsure of it exactly).
The metal had to come from somewhere. But thats beside the point now. I am out for the trans rebuild and converter "check up" (which isn't the worst deal, any local shop wanted $200 to open it up and check it out).
But here is the kicker-- and I know I toss around dyno #'s too much. The cam swap shop said there was some serious component missing from my setup to be producing 113mph traps when it should be alot closer to 120. I figured it was the converter.
I know dyno #'s don't mean alot, but, hear me out. Dyno test #1 same engine as it is now but with 9.6:1 CR and UD HR4 296/233 .621 HR said 564 hp, 574 ft-lbs. 113.8 mph (would have been mint for a procharger..). Dyno test 2 (engine problem that required rebuild) 286/230 comp .639 HR 10.14:1 565 hp 555 ft-lbs 113.3. Dyno test 3 563 hp, 555 ft-lbs but with my air filter, my headers, my exhaust, my mufflers, my alternator, my water pump, full running water temp and 88* dyno room air for the engine, 38* timing 287/295 256/260 SR. The cam swap shop says that the way they run their dyno makes for atleast 40hp difference vs. a dyno operated in a less 'real world' manner. I have yet to run the car because the track isn't open yet, (as far as I know), I have a 12" converter in there that causes whiplash when I put it into gear and when it shifts, and a few other minor tweaks that are going to take another few hours or days to remedy.
here is my question: my 70SS full steel, full interior TH400 12 bolt 3.90s 4020lbs with driver and 1/3 tank of gas (anyone else ever had a problem with gas flying out of their tank under hard acceleration??). Does 550hp with 4000lbs = 113mph? Or is there a missing link here?
The cam swap shop highly suggests that if I do do a chassis dyno I do it before the converter swap, but I need to raise my car up about 1/2" to make it driveable on roads I don't know and I need to fiddle with the motor mounts to stop the header to steering column clearance issues (that was not there before the engine was pulled this time, and was not there all the other times I pulled the engine myself, any idea how this could have happened??)
matt