testees... one, two
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Team Owner
Joined: Apr 2001
Posts: 54,204
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From: S.W. Ohio. . . . . . NRA Life Member
testees... one, two
For those not knowing me... when it comes to mods, I don't necessarily look for a "percent of change". Instead I start out with a goal, and then do what it takes to reach that goal. And that most of the time I take an unconventioal approach. Now that I have covered how weird I am... 
An example; when I upgraded to the 3.42 ratio from the 3.15; many will say it's too small a jump (and they are correct in that is is a small change). But I had a goal, and the 3.42's took me exactly where I wanted to be. It didn't matter how far away or how close I was to the goal; I zero'd in on the goal because I knew exactly where I want to end up at.
My 2002 LS1 A4 developed a transmission seal leak, so rear transaxle would need to be dropped for the repair. I've already done the carrier swap myself, but didn't want to do it again (gettin' old...
) and a trusted Corvette mechanic had recently opened up a local shop. With the car up on his rack, he asked me if I had even considered a higher stal converter... especially since he would be in that area of the car anyways (it would make sense to do the converter upgrade at the same time).
I said no... that I was not interested in ah high stall converter. He asked me why, and I gave him the list:
a. prices of aftermarket stall converters are rediculous.
b. I don't want to add an external cooler.
c. I don't like the feel of a high stall converter during normal driving.
d. Since I personally will always have run-flat type tires on this car, I didn't want to lose all
hopes of usuable traction. I like my Corvette to be a no-brainer to drive.
e. Presently, I could only powerbrake up to 1400rpm; that I would like to increase that.. but no more than a couple hundred RPM increase (because of requirement "c").
I knew this would stop my mechanic dead in his tracks... as I was being too picky, and that there was no way in hell he'd be able to sell me anything.
But he threw me a curve ball; he said there was a GM converter used in their truck line that would give me exactly what I just described. He said the STR was slightly higher; the stall sopeed was a few hundred RPM more, and that it didn't need an external cooler.
I thought he was joking at first; but he had done this about 5 times before for people that were concerned about high stall converters, and that every one of them just loved this TC. We discussed prices and he said if I didn't like it that he would switch back to my original converter ay his expense. How could I turn this down ???
The next day I was taking the '02 home... it was a cold evening and I had the top on and the windows closed. I couldn't notice any difference in the way the car drove with normal driving... ZERO difference. The next day was warm and sunny, so out again for some street testing. From a stop, I could spin the tires a lot easier than before (remember that I'm still running the original factory GY EMT's) and I got a much more meatier chirp with the 1-2 WOT shift. Heck, I even got a little 1-2 chirp during moderate acceleration The car was definityely pulling harder (due to the higher STR).
But today I thought I was noticing a small difference in the normal driving feel. It was so slight that I could of just been imagining it. What I discovered is that the exhaust note during acceleration had changed just slightly enough for me to notice something was different. Keep in mind that the day earlier (when I had the car all shut up due to the cold) the actual "feel" of the car was unchanged.. but the next day my ears were able to detect a difference.
Long story short, there is a slight stall speed change during normal driving.. but soooo slight that only my ears could detect it. Yvonne drove the car yesterday and she said she couldn't notice any difference in normal driving. She questioned if anything had really been done (she wasn't up to doing any spirited driving
).
Then last Thursday I went to the track. My previous best with my 2002 was 12.93 with a 1.96 60'. And this was during super-ideal conditions... (perfect track prep and 60 degree air temps). That was a fluke run, but one that made my day because it was finally under that 13 second mark. Since that run, I have never been able to get into the 12's again ... mainly because of either the heat or poor track conditions. But I could consistently cut 2.00 60' times and 13.0x 1/4 times even during the bad days.
Air temp was 85 degrees, and the track had a lot of rubber pieces laying around. I ran 7 times total. 4 times within 10 minutes ... then I took a break - hoping that the air temp would drop (which it only did to 81 degrees) and ran 3 more times.
I could now powerbrake to 1900 RPM; 2000 if I pumped up the brakes right before staging. Of the 7 runs, I blew the launch twice
... which was interesting because I was never before able to "blow the launch" at the track. Of the 5 runs that the launch went fine, all runs were in the 12's :horray:
Here's my best run of the evening:
I truly believe that when another ideal track day comes along, I can get in the low 12.8's or even 12.7
Here's my original list again:
a. prices of aftermarket stall converters are rediculous.
the GM part number for this converter is #24208645; you can find it online for under $200; and this is for a brand new unit... not rebuilt.
b. I don't want to add an external cooler.
With constant highway driving @ 70mph on an 80 degree day, tranny temps never got above 180.
Of my 4 dragstrip runs within 10 minutes, the temp climbed to 199 degrees. I am satisfied that an external cooler is not needed
c. I don't like the feel of a high stall converter during normal driving.
could not feel any difference with normal driving
d. Since I personally will always have run-flat type tires on this car, I didn't want to lose all
hopes of usuable traction. I like my Corvette to be a no-brainer to drive.
car is still controllable, but just over the edge of being a no-brainer with factory tires. I can get the tires in full spin mode... but you have to try to do it - by smashing the pedal down at a stop.
e. Presently, I could only powerbrake up to 1400rpm; that I would like to increase that.. but no more than a couple hundred RPM increase (because of requirement "c").
I can now controllably powerbrake to 1900rpm
Am I happy with this new converter... you're damn right I am. Nothing like making a goal, and reaching all aspects of it. IMO; this GM #24208645 converter is a good comprimise TC. Hard-core dragstrip guru's may think it doesn't far enough; but for non dragstrip types... it just may be what the doctor ordered.
An example; when I upgraded to the 3.42 ratio from the 3.15; many will say it's too small a jump (and they are correct in that is is a small change). But I had a goal, and the 3.42's took me exactly where I wanted to be. It didn't matter how far away or how close I was to the goal; I zero'd in on the goal because I knew exactly where I want to end up at.
My 2002 LS1 A4 developed a transmission seal leak, so rear transaxle would need to be dropped for the repair. I've already done the carrier swap myself, but didn't want to do it again (gettin' old...
) and a trusted Corvette mechanic had recently opened up a local shop. With the car up on his rack, he asked me if I had even considered a higher stal converter... especially since he would be in that area of the car anyways (it would make sense to do the converter upgrade at the same time).I said no... that I was not interested in ah high stall converter. He asked me why, and I gave him the list:
a. prices of aftermarket stall converters are rediculous.
b. I don't want to add an external cooler.
c. I don't like the feel of a high stall converter during normal driving.
d. Since I personally will always have run-flat type tires on this car, I didn't want to lose all
hopes of usuable traction. I like my Corvette to be a no-brainer to drive.
e. Presently, I could only powerbrake up to 1400rpm; that I would like to increase that.. but no more than a couple hundred RPM increase (because of requirement "c").
I knew this would stop my mechanic dead in his tracks... as I was being too picky, and that there was no way in hell he'd be able to sell me anything.
But he threw me a curve ball; he said there was a GM converter used in their truck line that would give me exactly what I just described. He said the STR was slightly higher; the stall sopeed was a few hundred RPM more, and that it didn't need an external cooler.
I thought he was joking at first; but he had done this about 5 times before for people that were concerned about high stall converters, and that every one of them just loved this TC. We discussed prices and he said if I didn't like it that he would switch back to my original converter ay his expense. How could I turn this down ???
The next day I was taking the '02 home... it was a cold evening and I had the top on and the windows closed. I couldn't notice any difference in the way the car drove with normal driving... ZERO difference. The next day was warm and sunny, so out again for some street testing. From a stop, I could spin the tires a lot easier than before (remember that I'm still running the original factory GY EMT's) and I got a much more meatier chirp with the 1-2 WOT shift. Heck, I even got a little 1-2 chirp during moderate acceleration
The car was definityely pulling harder (due to the higher STR).But today I thought I was noticing a small difference in the normal driving feel. It was so slight that I could of just been imagining it. What I discovered is that the exhaust note during acceleration had changed just slightly enough for me to notice something was different. Keep in mind that the day earlier (when I had the car all shut up due to the cold) the actual "feel" of the car was unchanged.. but the next day my ears were able to detect a difference.
Long story short, there is a slight stall speed change during normal driving.. but soooo slight that only my ears could detect it. Yvonne drove the car yesterday and she said she couldn't notice any difference in normal driving. She questioned if anything had really been done (she wasn't up to doing any spirited driving
).Then last Thursday I went to the track. My previous best with my 2002 was 12.93 with a 1.96 60'. And this was during super-ideal conditions... (perfect track prep and 60 degree air temps). That was a fluke run, but one that made my day because it was finally under that 13 second mark. Since that run, I have never been able to get into the 12's again ... mainly because of either the heat or poor track conditions. But I could consistently cut 2.00 60' times and 13.0x 1/4 times even during the bad days.
Air temp was 85 degrees, and the track had a lot of rubber pieces laying around. I ran 7 times total. 4 times within 10 minutes ... then I took a break - hoping that the air temp would drop (which it only did to 81 degrees) and ran 3 more times.
I could now powerbrake to 1900 RPM; 2000 if I pumped up the brakes right before staging. Of the 7 runs, I blew the launch twice
... which was interesting because I was never before able to "blow the launch" at the track. Of the 5 runs that the launch went fine, all runs were in the 12's :horray:Here's my best run of the evening:
I truly believe that when another ideal track day comes along, I can get in the low 12.8's or even 12.7
Here's my original list again:
a. prices of aftermarket stall converters are rediculous.
the GM part number for this converter is #24208645; you can find it online for under $200; and this is for a brand new unit... not rebuilt.
b. I don't want to add an external cooler.
With constant highway driving @ 70mph on an 80 degree day, tranny temps never got above 180.
Of my 4 dragstrip runs within 10 minutes, the temp climbed to 199 degrees. I am satisfied that an external cooler is not needed
c. I don't like the feel of a high stall converter during normal driving.
could not feel any difference with normal driving
d. Since I personally will always have run-flat type tires on this car, I didn't want to lose all
hopes of usuable traction. I like my Corvette to be a no-brainer to drive.
car is still controllable, but just over the edge of being a no-brainer with factory tires. I can get the tires in full spin mode... but you have to try to do it - by smashing the pedal down at a stop.
e. Presently, I could only powerbrake up to 1400rpm; that I would like to increase that.. but no more than a couple hundred RPM increase (because of requirement "c").
I can now controllably powerbrake to 1900rpm
Am I happy with this new converter... you're damn right I am. Nothing like making a goal, and reaching all aspects of it. IMO; this GM #24208645 converter is a good comprimise TC. Hard-core dragstrip guru's may think it doesn't far enough; but for non dragstrip types... it just may be what the doctor ordered.
Last edited by Mike Mercury; May 27, 2007 at 04:00 PM.
