My converter? TH400 & Chance
06-07-2010, 06:40 PM
#1
My converter? TH400 & Chance I have a TH400 in my 99' camaro with a Neal Chance 9" converter. The converter was spec'd by Marty and is suppose to be in the 5500 range and be for all motor.
I have a 370CI made 494RWHP and 467RWTQ through a Moser 9" with 4.33 gears and a 4L60E
The car feels like it "yanks" for a split second, falls on it's face, and then out around 300ft it starts pulling good. I used to get high 1.4x 60fts with the 4.11's and 4L60E and now I can't seem to get any better than a 1.58 60ft with the TH400 and Chance converter.
I understand that I will lose power going to the TH400, but the car has lost around 300 to 350lbs since I went with the TH400. I'm also trapping 100-101MPH through the 1/8th and only running an average of low 7.0's.
It's shifting at 7300 and falling back to 5328 in 1st and then shifting at 6464 and falling to 5308 in 2nd gear.
Is the converter too tight? It works GREAT with a 150 shot though. I went from a 1.57 60' to a 1.32 60' just from a 150 hit.
If it's too tight, would going back to my 4.11's or a 3.90 gear help or hurt the shift extension? Trying to stay away without pulling the converter at the moment.
http://blip.tv/file/3524574/
^^Maybe the video will show a little what I'm talking about. It yanks, falls on it's face then comes alive around 300ft.
I called Marty earlier and we may be looking at going to around a 6500-6800 stall. Does that not sound too far fetched? I wouldn't imagine this little of a motor needing that much converter, or would it?
I'm at lost when it comes to this converter stuff.
I have a 370CI made 494RWHP and 467RWTQ through a Moser 9" with 4.33 gears and a 4L60E
The car feels like it "yanks" for a split second, falls on it's face, and then out around 300ft it starts pulling good. I used to get high 1.4x 60fts with the 4.11's and 4L60E and now I can't seem to get any better than a 1.58 60ft with the TH400 and Chance converter.
I understand that I will lose power going to the TH400, but the car has lost around 300 to 350lbs since I went with the TH400. I'm also trapping 100-101MPH through the 1/8th and only running an average of low 7.0's.
It's shifting at 7300 and falling back to 5328 in 1st and then shifting at 6464 and falling to 5308 in 2nd gear.
Is the converter too tight? It works GREAT with a 150 shot though. I went from a 1.57 60' to a 1.32 60' just from a 150 hit.
If it's too tight, would going back to my 4.11's or a 3.90 gear help or hurt the shift extension? Trying to stay away without pulling the converter at the moment.
http://blip.tv/file/3524574/
^^Maybe the video will show a little what I'm talking about. It yanks, falls on it's face then comes alive around 300ft.
I called Marty earlier and we may be looking at going to around a 6500-6800 stall. Does that not sound too far fetched? I wouldn't imagine this little of a motor needing that much converter, or would it?
I'm at lost when it comes to this converter stuff.
06-07-2010, 10:30 PM
#4
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The first gear ratio is whats hurting you. The 4L60 has a 3.06 first gear compared to the TH400s 2.48. I swapped out my 4L60 this winter for a TH400 and i suffered a little on my short times. I stayed with the same size converter that I had in the 4L60. I would consistently pull 1.42-1.43 60' with the 4L60 and now with the TH400 im only getting 1.47-1.49 as of right now. But on a side note I picked up 2 tenths and 3 mph with the TH400. Hope this helps.
06-07-2010, 11:05 PM
#5
gonna need a lot of steam to stall a 9" converter up to 5500... When I was converter shopping every company said I needed an 8" if I was trying to get 5200 out of a 650 hp small block, it would kill the efficiency of a 9" converter trying to get it up that high.
06-07-2010, 11:09 PM
#6
The first gear ratio is whats hurting you. The 4L60 has a 3.06 first gear compared to the TH400s 2.48. I swapped out my 4L60 this winter for a TH400 and i suffered a little on my short times. I stayed with the same size converter that I had in the 4L60. I would consistently pull 1.42-1.43 60' with the 4L60 and now with the TH400 im only getting 1.47-1.49 as of right now. But on a side note I picked up 2 tenths and 3 mph with the TH400. Hope this helps.
I haven't picked up anything from this swap, I've actually lost about a tenth or more.
With the 4L60E, 4.11's, Circle D 5C, and at 3,612lbs I ran a 6.96 at 96mph footbraking.
With the TH400, 4.33's, Chance 5500, at 3,488lbs the best I've ran is a 6.95 at 101mph
I gained mph but no better ET's at all. Yes the DA was about the same.
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06-14-2010, 12:38 AM
#8
I narrowed down and fixed the shifting problem, kinda.
Come to find out, the shifter is shifting on time but the transmission is dragging it out to 7200-7500 before it shifts? I broke my flexplate this weekend so I pulled it all out today. Any idea on why the transmission would drag out a shift like this? Maybe the bands in it?
I bought the transmission used and it only had about 10 or 20 passes on it and then sat in a shop for a long time.
Come to find out, the shifter is shifting on time but the transmission is dragging it out to 7200-7500 before it shifts? I broke my flexplate this weekend so I pulled it all out today. Any idea on why the transmission would drag out a shift like this? Maybe the bands in it?
I bought the transmission used and it only had about 10 or 20 passes on it and then sat in a shop for a long time.
