I searched lots, but still have several TH400 questions (auto valve body?)
04-26-2005, 03:02 PM
#1
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I searched lots, but still have several TH400 questions (auto valve body?) Post totally changed after talking to larry at ls1 speed:
Car Background/plans: '98 Z28 with most bolt-ons including TCI SSF3500 and TSP MS3 (can check sig). Mistake by going with such a large cam with a 3500 stall converter and stock 3.23's, I know. Car is daily driver but will transition to nice day car/weekend warrior over time. The plan is to build it up for heads/cam/nitrous with some forged internals and haul *** as a street/strip car. I'd like to avoid doing anything over again down the road. Currently I daily drive with nittos and run 26x10.5x16 ET streets at the track. I am on stock ten bolt and 3.23's and can't afford a new rear until at least next year, at which point i'd go with something like 3.73's.
Why I need a decision: My tranny lost the 2-3 shift at WOT and I *think* it is slipping more. I'm taking this as a sign that it is not long for this world and trying to decide what to replace it with. I got it down to rebuilding the 4L60E and either having the SSF restalled or going with a whole new converter, or going ***** out with a "bulletproof" TH400.
I had decided on the TH400 for peace of mind that I can beat on it without worry of breakage or reduced performance. I contacted numerous people, including calling larry at speed inc as they are local and have done work on my car before. He said that he would only do a manual valve body in a TH400 and would not want to daily drive it. Given that he recommended I rebuild the 4L60E. I had previously contacted FLP and was told that their level four should hold up, and that they have numerous current customers who run 10's with h/c/power adder. Searching revealed a lot of satisfied customers but there were a few who roasted theirs and many, many who just don't like the 4L60E one bit and will never trust one to hold big power.
Questions
1): Should I get a TH400 or rebuilt 4L60E? I'd be looking at either the FLP level 4 or one of speed's Dr. Evil series. Would go with vacuum modulation either way. Any input on what it takes for a 4L60E to survive the kind of power I'll be looking for? Both at the track with the nitrous and on the street with WOT 3-1 and 4-2 downshifts.
2) If I went with a TH400 what stall speed and valve body should I go with?
3) If I go with a rebuilt trans what should I do for a converter? My 3500 stalls too low for the track and I could live with something a little looser on the street. Compared to a TH400 just having lockup and overdrive would seem like heaven, lol. PI's and Yank's prices are scary but they are the best, right? Would a PT4000 work well both now and when I am h/c/n2o? Approx how much would I give up at the track if I went something like a SS3600 or 4000 instead to tighten it up on the street?
Nathan
Car Background/plans: '98 Z28 with most bolt-ons including TCI SSF3500 and TSP MS3 (can check sig). Mistake by going with such a large cam with a 3500 stall converter and stock 3.23's, I know. Car is daily driver but will transition to nice day car/weekend warrior over time. The plan is to build it up for heads/cam/nitrous with some forged internals and haul *** as a street/strip car. I'd like to avoid doing anything over again down the road. Currently I daily drive with nittos and run 26x10.5x16 ET streets at the track. I am on stock ten bolt and 3.23's and can't afford a new rear until at least next year, at which point i'd go with something like 3.73's.
Why I need a decision: My tranny lost the 2-3 shift at WOT and I *think* it is slipping more. I'm taking this as a sign that it is not long for this world and trying to decide what to replace it with. I got it down to rebuilding the 4L60E and either having the SSF restalled or going with a whole new converter, or going ***** out with a "bulletproof" TH400.
I had decided on the TH400 for peace of mind that I can beat on it without worry of breakage or reduced performance. I contacted numerous people, including calling larry at speed inc as they are local and have done work on my car before. He said that he would only do a manual valve body in a TH400 and would not want to daily drive it. Given that he recommended I rebuild the 4L60E. I had previously contacted FLP and was told that their level four should hold up, and that they have numerous current customers who run 10's with h/c/power adder. Searching revealed a lot of satisfied customers but there were a few who roasted theirs and many, many who just don't like the 4L60E one bit and will never trust one to hold big power.
Questions
1): Should I get a TH400 or rebuilt 4L60E? I'd be looking at either the FLP level 4 or one of speed's Dr. Evil series. Would go with vacuum modulation either way. Any input on what it takes for a 4L60E to survive the kind of power I'll be looking for? Both at the track with the nitrous and on the street with WOT 3-1 and 4-2 downshifts.
2) If I went with a TH400 what stall speed and valve body should I go with?
3) If I go with a rebuilt trans what should I do for a converter? My 3500 stalls too low for the track and I could live with something a little looser on the street. Compared to a TH400 just having lockup and overdrive would seem like heaven, lol. PI's and Yank's prices are scary but they are the best, right? Would a PT4000 work well both now and when I am h/c/n2o? Approx how much would I give up at the track if I went something like a SS3600 or 4000 instead to tighten it up on the street?
Nathan
Last edited by blkZ28spt; 04-26-2005 at 06:11 PM.
04-26-2005, 06:30 PM
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No need for a RMVB. You can run a auto valve body or a forward manual.
I am using a forward manual valve body I built myself with no kit. It shifts super fast with no delay. I'll take the forward manual with band apply any day over a RMVB for any street duty. Just my preference.
Auto is nice for a daily driver. You'll give up a little shift quickness and control over a full manual. But nothing major if it's built right.
There is a lot more to the power capacity of the trans and also how well it will shift besides what valve body is in it.The th400 is a beefy sucker and doesn't need to many mods for your power goals.
You do not need a lift. Just a good jack, a set of jack stands and maybe a trans adapter for the floor jack to make it easier.
It's a very simple swap if your good with a wrench.
Steve
I am using a forward manual valve body I built myself with no kit. It shifts super fast with no delay. I'll take the forward manual with band apply any day over a RMVB for any street duty. Just my preference.
Auto is nice for a daily driver. You'll give up a little shift quickness and control over a full manual. But nothing major if it's built right.
There is a lot more to the power capacity of the trans and also how well it will shift besides what valve body is in it.The th400 is a beefy sucker and doesn't need to many mods for your power goals.
You do not need a lift. Just a good jack, a set of jack stands and maybe a trans adapter for the floor jack to make it easier.
It's a very simple swap if your good with a wrench.
Steve
04-26-2005, 07:53 PM
#3
11 Second Club
Thread Starter
Originally Posted by S_J_H
No need for a RMVB. You can run a auto valve body or a forward manual.
I am using a forward manual valve body I built myself with no kit. It shifts super fast with no delay. I'll take the forward manual with band apply any day over a RMVB for any street duty. Just my preference.
Auto is nice for a daily driver. You'll give up a little shift quickness and control over a full manual. But nothing major if it's built right.
There is a lot more to the power capacity of the trans and also how well it will shift besides what valve body is in it.The th400 is a beefy sucker and doesn't need to many mods for your power goals.
You do not need a lift. Just a good jack, a set of jack stands and maybe a trans adapter for the floor jack to make it easier.
It's a very simple swap if your good with a wrench.
Steve
I am using a forward manual valve body I built myself with no kit. It shifts super fast with no delay. I'll take the forward manual with band apply any day over a RMVB for any street duty. Just my preference.
Auto is nice for a daily driver. You'll give up a little shift quickness and control over a full manual. But nothing major if it's built right.
There is a lot more to the power capacity of the trans and also how well it will shift besides what valve body is in it.The th400 is a beefy sucker and doesn't need to many mods for your power goals.
You do not need a lift. Just a good jack, a set of jack stands and maybe a trans adapter for the floor jack to make it easier.
It's a very simple swap if your good with a wrench.
Steve
04-27-2005, 09:34 AM
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Forward manual patterns retain engine braking where as reverse don't. At least all the RMVB's I have seen. You can safely down shift with a forward manual without over running the direct drum.
If your worried about down shifting at an improper speed to avoid over revving the motor, then stick with a full auto. It has safe guards to prevent that.
Steve
If your worried about down shifting at an improper speed to avoid over revving the motor, then stick with a full auto. It has safe guards to prevent that.
Steve
