Transmission Opinions and Ideas

[v6buicks]

Sup TCG,

The ever revolving debate in my 3800 Camaro is what transmission I'm going to swap in. The only things I know is that the T5 is screaming for mercy, and I want to swap it to a strong automatic before I get it tuned. The car has a 3.42:1 final drive, I drive it mostly on the street (rarely on the interstate though), and I'm not interested in pricey electronic controllers or TV cables.

My latest idea was doing a full manual 4l80e so that I would have overdrive. There's a little diode box you can buy that just runs off a switched 12V and a ground switch for converter lock-up. It sounds like a cheap way to get old school simplicity and beef along with modern overdrive. However, fully manual function sounds like it could be a nuisance. Are there any sprags you can explode in a 4L80e if you forget to up shift or neutral before slowing down? Is full line pressure all the time going to make me hate driving it?

How about a TH400 or 350? Those are simple too. I've heard that there are some fairly simple mods you can do to convert them for boost and fully automatic function, but I've also heard that it might require conversion to a TV cable. That's not happening because I have an electric throttle. Of course neither one have over drive, but maybe I'll be okay when cruising since my commutes have a speed limit of 60mph anyway?

I don't know! What have you guys driven?

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[Yaj Yak]

this is going to be behind a 3800, right?

might wanna mention that as well.

 

[v6buicks]

this is going to be behind a 3800, right?

might wanna mention that as well.

Yes! I fixed it. I'm prepared to get bombed by the LS swap club now.

 

[daturbosix]

Carl@Redline

 

[Gone_2022]

I run a th400 behind my boosted LS. Cheap trans that can be built to handle most anything. If it was a daily type vehicle I might stay away from it simply because no OD for gas mileage etc.

I realize you are running a 3800 so I’m not exactly sure on what would be needed to make it work, but mine was simple. Th400, custom converter of my choosing. Driveshaft. Done

 

[v6buicks]

I run a th400 behind my boosted LS. Cheap trans that can be built to handle most anything. If it was a daily type vehicle I might stay away from it simply because no OD for gas mileage etc.

I realize you are running a 3800 so I’m not exactly sure on what would be needed to make it work, but mine was simple. Th400, custom converter of my choosing. Driveshaft. Done

There's a nice adapter kit that allows you to run SBC transmissions and off the shelf converters, so any trans with that bolt pattern is my limitation. I'm glad to hear from somebody with a boosted car. I can't seem to get the word straight on what 400s have as far as controls. Do they have both a kick down cable and a vacuum modulator? How do you set them up for boost? Do you use any cables? Thanks

 

[1quick]

almost anybody running a th400 with much power is going to be running a manual valvebody, I was building a turbo 3800 camaro used the adapter to bolt it to a th400 and had a custom converter made for it, I never ended up finishing the car and sold it off but it bolted together nicely

 

[v6buicks]

almost anybody running a th400 with much power is going to be running a manual valvebody, I was building a turbo 3800 camaro used the adapter to bolt it to a th400 and had a custom converter made for it, I never ended up finishing the car and sold it off but it bolted together nicely

Which kit did you use? I have the Speedway adapter, but it's so thin and I've heard it doesn't hold up well to abuse.

 

[v6buicks]

GMC V6 Engine to Chevy Automatic Transmission Adapter Kit.

Adapter Kit for a GMC 3800 Series V6 Engine to a Chevy Automatic Transmission. Number GM401.

transmissioncenter.net

This looks like a kit I can trust.

 

[1quick]

GMC V6 Engine to Chevy Automatic Transmission Adapter Kit.

Adapter Kit for a GMC 3800 Series V6 Engine to a Chevy Automatic Transmission. Number GM401.

transmissioncenter.net

This looks like a kit I can trust.

I used that one

 

[Gone_2022]

almost anybody running a th400 with much power is going to be running a manual valvebody, I was building a turbo 3800 camaro used the adapter to bolt it to a th400 and had a custom converter made for it, I never ended up finishing the car and sold it off but it bolted together nicely

^this mine is a reverse manual valve body with a T brake.

 

[v6buicks]

But what is it like to drive with a manual VB on the street? I'm going to be driving my car to and from work a lot more than I race it. I might hit up a test and tune twice a year if I have time.

 

[Gone_2022]

Also what is the goal? Is this just to make it driveable daily or is this to build something to make power/race?

Different trans builds for those. If the goal is to drive this quite often I would say stay away from a higher HP built th400. While my trans is stout, it’s also made for racing. It shifts hard, it hits hard going into reverse etc. not really daily driver type conditions.

 

[Gone_2022]

Ah we were posting at the same time. It’s easy to drive, I literally move my shifter down each time I need another gear. 1-2-3.

But as I said above my trans is setup for racing. It has race type shifts etc. my car may drive 800 miles a season where you may do that in a month.

I would suggest a very mild built trans if you go the th400 route. That way it’s more geared for the street vs the strip

 

[v6buicks]

Yeah, I don't really race which makes it hard to describe what I want. lol

Basically, I bought my Grand National which is nice to boost my way to and from the car shows every now and then. However, I want more. I have the speed bug. Even though my GN has potential, its too nice to bastardize! It's super quiet, comfy, low miles, and even has working AC. It's not a garage queen, but I like it the way it is. I think that's a rare feeling for a car guy to have, so I'm just going to hold onto that for as long as I can!

I got the Camaro to fill the voids. I can blow it up and not feel too bad. I can also drive it to work, get dented by some selfish asshole, and still not feel bad. Not that I street race either, but I want a fun commuter car. It can be a little obnoxious, but it still needs to be a reliable and comfortable enough car to get me home through traffic after working ten hours. I know that can be a tall order, but it's still only making maybe 300whp. The future holds more though.

After some further research it seems that transmission controllers have gone down in price! I should be able to tap into my electric throttle wiring and get the signal I need fairly easily. It's only about $400 over the little diode box, so that's kind of a no brainer IMO.

 

[LikeABauce302]

I don't drive it a ton on the street, but my '90 Mustang with a manual valve body isn't bad at all to drive with when I want to take it out for a cruise.

 

[Bob Kazamakis]

IceCreamAssassin has a 4l80e in his truck with a controller that wasn’t super pricey. He can probably speak to how it drives and how easy it was to set up.

 

[v6buicks]

IceCreamAssassin has a 4l80e in his truck with a controller that wasn’t super pricey. He can probably speak to how it drives and how easy it was to set up.

I'm leaning really hard toward this direction now. The TH400 would probably be a bit cheaper to get going, but not worth the lack of OD in the long run.

 

[Gone_2022]

The th400 is truly a great trans. It’s obviously able to be daily driven as cars used to come with it from the factory. Might want to change your rear end gear if you go that route. Maybe a 3.23 or less for better cruising rpms. But if you have a 3.42 now which is what I have it’s fine. At 60 I’m about 2600 rpm I think. It’s been a while since I drove it.

 

[Yaj Yak]

i mean, of course depends on tire size though too...

 

[v6buicks]

The th400 is truly a great trans. It’s obviously able to be daily driven as cars used to come with it from the factory. Might want to change your rear end gear if you go that route. Maybe a 3.23 or less for better cruising rpms. But if you have a 3.42 now which is what I have it’s fine. At 60 I’m about 2600 rpm I think. It’s been a while since I drove it.

Right, but I don't have the big block torque to blow past a low numerical gear ratio like the OG TH400 cars. haha That cruising rpm with 3.42s is not as bad as I thought. Going down the interstate at 75 sounds like it would be a miserable time in my buzzy 6 though. The rear end of course brings up the other issue. I'm still on an open 10 bolt. I know it won't last long the more I keep throwing power at it, but the T5 is the weaker link.

i mean, of course depends on tire size though too...

True. I try to plan ahead though. I have stock wheels and junky street tires on it right now, but I will definitely upgrade in the future. The speed bug really is a slippery slope....

 

[Yaj Yak]

Right, but I don't have the big block torque to blow past a low numerical gear ratio like the OG TH400 cars. haha That cruising rpm with 3.42s is not as bad as I thought. Going down the interstate at 75 sounds like it would be a miserable time in my buzzy 6 though. The rear end of course brings up the other issue. I'm still on an open 10 bolt. I know it won't last long the more I keep throwing power at it, but the T5 is the weaker link.


True. I try to plan ahead though. I have stock wheels and junky street tires on it right now, but I will definitely upgrade in the future. The speed bug really is a slippery slope....

but like, tire height is the factor, not how good of tires.

 

[v6buicks]

I realize that. By stock wheel I meant tire size too. I know that would aggravate the no OD situation, but I don't plan on keeping the wheels this way for too long. In fact, it might get bigger tires before I swap transmissions. I hate the way it looks right now.

 

[1quick]

Go baller and adapt it to a 10speed they have trans controllers for the hot rod swaps that thing would freight train with a 10 speed trans

 

[v6buicks]

Haha that would be really cool. Aren't the newer bell patterns quite a bit different from the original Chevy pattern though? I don't know if the guys making those adapters would be able to tweak it a little for me, but it could be worth a shot.