Tranny Swap ... but what to?
07-22-2007, 10:56 AM
#1
Tranny Swap ... but what to? What should I trade my FLT 4L65E transmission for ... to get better 14-miule times? This A4 has a 1st gear that is a disadvantage because I can't get good enough traction. I'm thinkin' an A3 would allow me to get off the line quicker and save the PCM a gear change for not having that extra gear.
07-22-2007, 12:20 PM
#3
th300 and th400 were switch pitch with 12"/13" converters mostly in the older Buick and Pontiacs. Wasn't the 300 a 2-speed and the 400 a 3-speed? Anybody know how much more advantageous each of these would be over the 4L56E level5 I have in the car now?
07-22-2007, 02:50 PM
#4
On The Tree
Join Date: Jun 2007
Location: haltom city/DFW, Texas
Posts: 165
Likes: 0
Received 0 Likes
on
0 Posts
The ST300 was a 2 spd transmission only available in a BPO bolt pattern not a Chevrolet , and all were not variable pitch converters . The THM 400 was available in either bell housing pattern but only the very earliest units were variable pitch ! These were not very durable converters and probably would not hold up to a lot of hp and torque !! I would question your traction issue because there are too many out there doing it with your type combo!!!
John
John
07-22-2007, 03:30 PM
#5
Sorry Wally, I should have been more specific. I was speaking to traction on the street with the Nitto's. I've been through a couple pair of MT Street Drag Radials and they're flat-out too dangerous to use in the rain over 25 mhp. At the dragstrip I'll be using different wheels/tire combo but our local dragstrip doesn't prep their track unless there's a really big event coming up. It's nickname locally is Orlando Spin World instead of Orlando Speed World.
Sorry I did not clarify these factors.
Sorry I did not clarify these factors.
07-22-2007, 05:24 PM
#6
Originally Posted by JEB99TA
Sorry Wally, I should have been more specific. I was speaking to traction on the street with the Nitto's. I've been through a couple pair of MT Street Drag Radials and they're flat-out too dangerous to use in the rain over 25 mhp. At the dragstrip I'll be using different wheels/tire combo but our local dragstrip doesn't prep their track unless there's a really big event coming up. It's nickname locally is Orlando Spin World instead of Orlando Speed World.
Sorry I did not clarify these factors.
Sorry I did not clarify these factors.
It is not the transmission. The problem is in your tire / suspension combination.
g
07-22-2007, 06:23 PM
#7
What tires other than my current Nitto 555r DR's do you recommend for the street? ... other than the MT Street Drag Radials?
On the second note you mentioned, the guy that tore down and inspected my 12-bolt stated he was really impressed by how nice it launches on the street and said that out of several thousand F-Body's he's driven/worked on, he thought my car was in the top 3 of all he's test-driven.
He said it goes straight-line perfectly without any over steering or correcting and he's a pretty serious racer, as well. I think my suspension is set up well, and this guy was extremely impressed with it ... said whoever did my suspension work was very talented at it. My BMR adjustable torque arm is set at -1.5 pinion angle and I've got all the aftermarket stuff except for the lighter K-member up front.
The statement I made about traction was my mindset of less gears 9and the gearing itself) making the car run faster down the 1/4 mile when I take it to the dragstrip, but, more about making it faster on the street, as well, by giving me more traction down low. My current gear range in 1st (A4) is 0-30 at nearly 7000 rpm. I'm thinking different gearing of an A3 would put the 1st gear at around 45-50 mph and 2nd gear change wouldn't spin halfway through 2nd ... like it does now. with my A4. I'm thinking an A3 would hit 2nd at about 45-50 and chirp the tires, get traction and go. I'm just overpowering my tires in 1st and 2nd right now ... I'm thinking becauase the A4's are just too tight of gears at low ranges. My torque converter shreds the tires ...figuratively speaking, of course. Maybe I should go with a 3.42 gear or lesser torque converter?
This being said, do you think my ideology is about on the mark?
On the second note you mentioned, the guy that tore down and inspected my 12-bolt stated he was really impressed by how nice it launches on the street and said that out of several thousand F-Body's he's driven/worked on, he thought my car was in the top 3 of all he's test-driven.
He said it goes straight-line perfectly without any over steering or correcting and he's a pretty serious racer, as well. I think my suspension is set up well, and this guy was extremely impressed with it ... said whoever did my suspension work was very talented at it. My BMR adjustable torque arm is set at -1.5 pinion angle and I've got all the aftermarket stuff except for the lighter K-member up front.
The statement I made about traction was my mindset of less gears 9and the gearing itself) making the car run faster down the 1/4 mile when I take it to the dragstrip, but, more about making it faster on the street, as well, by giving me more traction down low. My current gear range in 1st (A4) is 0-30 at nearly 7000 rpm. I'm thinking different gearing of an A3 would put the 1st gear at around 45-50 mph and 2nd gear change wouldn't spin halfway through 2nd ... like it does now. with my A4. I'm thinking an A3 would hit 2nd at about 45-50 and chirp the tires, get traction and go. I'm just overpowering my tires in 1st and 2nd right now ... I'm thinking becauase the A4's are just too tight of gears at low ranges. My torque converter shreds the tires ...figuratively speaking, of course. Maybe I should go with a 3.42 gear or lesser torque converter?
This being said, do you think my ideology is about on the mark?
Trending Topics
07-22-2007, 08:35 PM
#8
We see guys all the time who are after the same holy grail of racing..... digging hard on the street and at the track... it takes a seasoned guy to set a car up for that. Ask around in your area, look for the guys doing both well. Ordinarilly a car is not set up for both the track and the street. Some are though.
I would not change my 1st gear ratio simply because I wanted better traction on the street. But that's me.
g
I would not change my 1st gear ratio simply because I wanted better traction on the street. But that's me.
g
07-23-2007, 10:28 AM
#10
vps l must have installed 100 plus vp converters in real big motor home and had not one failure. the units are now chicken teeth. the vp was the very best tc ever make with the falcon a very close second
