Opel GT Forum banner

1 - 20 of 28 Posts

·
Member
Joined
·
135 Posts
Discussion Starter · #1 ·
Has anyone out there seen or tried wringing performance out of automatic transmission Opels? I am very intrigued by this since most Opels that are modified are not automatics. I have heard that these automatics can handle 200 hp, and even though this would slow an Opel compared with the manual trans, it does offer performance and convenience.(I'd like to drive and drink my big gulp throughout the gears!
 

·
Old Opeler
Joined
·
5,564 Posts
Performance - Automatically!

Joe,

My GT is factory auto - it is a TH 180 box. A similar bos was used in Australian Holdens and known as the "Trimatic" and is regarded as one of the better three-speed autos. It has elements of Powerglide and Torqueflight design in it so is quite strong. The Rover V8 used it too in the 1980's.
Holden 5-litre V8s had uprated versions with five clutches in the 1st gear clutch pack and they handled 250HP successfully.

I have not pulled mine apart yet to rebuild it but kits are available for the trans - known as the "Strasbourg" as the Opel and Rover ones were built in that town in Germany. The holden ones were made in Australia.

For round town cars an auto cannot be beat!
 

·
Super Moderator
Joined
·
13,812 Posts
I've had numerous automatic Opels with modified engines. They were not as fast as manual trans versions, and the mileage was a lot worse, but with a high-stall torque converter (3000 rpms usually, stock Opel is 2200-2400), the performance was still MUCH better than stock.

If you go with a high-stall converter though, you MUST install a separate tranny oil cooler, or the fluid will fry (I found this out the hard way).
 

·
Super Moderator
Joined
·
13,812 Posts
Not an off-the-shelf item for sure, but any good hi-po tranny shop can rebuild them. Opel torque converters have been used for 30+ years in drag racing applications for small block and big block Chevys and such...since the smaller the converter the higher the stall speed. They can reconfigure the stock Opel converter without any expensive parts up to about 3000 rpms as stated earlier.

To go higher rpms, it climbs exponentially. I had one converter made for 4500 rpms, it cost almost $500.

I previously used Dynamic Racing Transmission, they were in New Haven, CT until a few years ago, then they moved further south, I think Maryland or DC?
 

·
Member
Joined
·
299 Posts
well i am alone on this but for drag racing the best bet is an automatic but you should not use a 180 they just wont last no matter what use a th200 they only have one weakness and even a 400 hp v8 doesnt break them so there np
you have to use a 200 out of a pre 1977 chevette and you will have to modify the top bell bolt holes
you can use v8 internals
it uses a tv cable like a 700r4 and 2004r and you will have to modify either the crankfor the pilot on the converter or the converter itself which isnt much i am going to build one for my gt with a engine built for nitrous
 

·
Über Genius
Joined
·
9,354 Posts
Might be the right place to check.

Is there an easy swap auto trans out there. I have a Manual trans and my daughter can't handle the clutch. Is there a trans out there that would just bolt up to the Opel engine. I had an auto a long time ago and I think it performed OK but I wasn't racing it either.

Thanks
 

·
Old Opeler
Joined
·
5,564 Posts
Auto - Manual Swap

First Opel 1981,

You may be able to find someone over there making the auto to manual swap who could do a deal with you to swap parts as the original GT auto is the easiest to fit. You would need everything between the back of the motor to the front of the diff.

The driveshafts are different lengths but the diff ratios are the same. Would also need the shifter and console bits too.

Most any other auto would need adapting and not just bolt straight in.
 

·
Member
Joined
·
240 Posts
Is there an easy swap auto trans out there. I have a Manual trans and my daughter can't handle the clutch. Is there a trans out there that would just bolt up to the Opel engine.
Ask around, you may find someone (near you) who wants to get rid of an auto. I have an auto from a 75 wagon collecting dust.

Garry
 

·
Über Genius
Joined
·
9,354 Posts
Garry,

Where are you located. I honestly forgot about gutting an old wagon or Manta. Stupid me. I have taken several motors from wagons and 1 from a manta and put them in GT's. The Manta even had the auto trans in it when I sent it to Opel heaven.
 

·
Super Moderator
Joined
·
13,812 Posts
Just be aware that the Manta/Ascona automatic shift lever location is opposite that of a GT, so the trannys are different.
 

·
Member
Joined
·
96 Posts
I thought i read that the trans. was the same,but, the shifter was just bolted on other side and could be switched to the same side because the hole was there with a bolt or plate blocking it off. is this true??


:)
 

·
tomking
Joined
·
2,484 Posts
I was told the same thing from the fellow I bought two auto trannys from. One is set up for GT the other for Manta. And yes there is a bolt on plate on the opposite side so it looks very doable to me.
 

·
Registered
Joined
·
11,747 Posts
I need a backup plan for the stock 4 speed trans.
Running the 1/8th whats the best final gear ratio? I'm thinking about a auto with a 5 grand stall speed hitting the line in second gear @ 7500 rpm.
I've been bitten by the drag racing bug.
 

·
Registered
Joined
·
69 Posts
After having my 72 Gt engine rebuilt, I am looking to change out the auto transmission that it is currently in it for an automatic tranny that will maybe take a little more power at lower rpms. If anyone has any suggestions for a good 4 or 5 speed autmatic that can easily be put in a Gt, could you please let me know. Also the three speed auto transmission that was stock, how many hp is that rated for? Thanks for all of the info.
Sterling
 

·
1000 Post Club
Joined
·
1,247 Posts
After having my 72 Gt engine rebuilt, I am looking to change out the auto transmission that it is currently in it for an automatic tranny that will maybe take a little more power at lower rpms. If anyone has any suggestions for a good 4 or 5 speed autmatic that can easily be put in a Gt, could you please let me know. Also the three speed auto transmission that was stock, how many hp is that rated for? Thanks for all of the info.
Sterling
There is always the highly sought after Getrag 5-Speed with an S10 clutch. And mentioned above, the stock 3-Speed automatic can handle around 200 HP, but let me look and see if I can find an exact number.

What 5-Speeds really work?
 

·
Registered
Joined
·
69 Posts
Thanks for the info. I do have a question though, can i put the 5 spees getrag with an s-10 clu5tch in an automatic, or is that to conver the car to a manual?
 

·
Super Moderator
Joined
·
13,812 Posts
Thanks for the info. I do have a question though, can i put the 5 spees getrag with an s-10 clu5tch in an automatic, or is that to conver the car to a manual?
Nope. Options include:

>Stock Opel 4-speed manual.
>Stock Opel (TH-180) 3-speed automatic.

These are the only two choices that are readily available in North America. However, if you order stuff from overseas or from one of our US Opel parts distributors, you can have:

>Getrag 240 5-speed manual.
>Getrag 265 5-speed manual.
>Opel ZF 5-speed manual (rare and expensive however)
>Opel R25 5-speed manual.
>Opel R28 5-speed manual.
>And I believe there was a derivative of the Opel 3-speed automatic that had an overdrive (making it a 4-speed), but I think it was ECU-controlled. In other words not readily adaptable to a carbureted US model.

Other options:

>Adapt a Borg-Warner T5 from a Chevette or S-10 truck. Ratios are not so hot and they are not that common anymore, but they are out there if you look.
>Make your own adapters and adapt whatever you can dig out of a junkyard!
For example I still have it in mind to adapt a TH-700R4 4-speed auto into an Opel. But it requires machining and welding, so it's not your average weekend garage swap. But it's possible.

HTH,
Bob
 

·
Supercharged 2.4
Joined
·
625 Posts
Nope. Options include:

>Stock Opel 4-speed manual.
>Stock Opel (TH-180) 3-speed automatic.

These are the only two choices that are readily available in North America. However, if you order stuff from overseas or from one of our US Opel parts distributors, you can have:

>Getrag 240 5-speed manual.
>Getrag 265 5-speed manual.
>Opel ZF 5-speed manual (rare and expensive however)
>Opel R25 5-speed manual.
>Opel R28 5-speed manual.
>And I believe there was a derivative of the Opel 3-speed automatic that had an overdrive (making it a 4-speed), but I think it was ECU-controlled. In other words not readily adaptable to a carbureted US model.

Other options:

>Adapt a Borg-Warner T5 from a Chevette or S-10 truck. Ratios are not so hot and they are not that common anymore, but they are out there if you look.
>Make your own adapters and adapt whatever you can dig out of a junkyard!
For example I still have it in mind to adapt a TH-700R4 4-speed auto into an Opel. But it requires machining and welding, so it's not your average weekend garage swap. But it's possible.

HTH,
Bob
What exactly are the Opel R25 and R28? Strength? How strong is the ZF 5 speed? I see the close ratio ZF units on eBay.de on occasion. They seem to fetch a good amount but if it is a strong unit and a "bolt in" replace of the stock 4 speed it might be worth it.
 
1 - 20 of 28 Posts
Top