SS/GT classes transmission?
 

In the GT classes do u have the option to run either an auto or manual trans, for any engine combination? Example can u run an auto behind a 302 Chevy. Just not clear in the rule book


Thank You

Re: SS/GT classes transmission?
 

No...

Re: SS/GT classes transmission?
 

Mark is correct.
The transmission had to be available with the engine combination.

Other examples are the Ford Boss 302 and Boss 351; they were manual trans only.

Re: SS/GT classes transmission?
 

Also, number of gears has to match, 5 speeds only if combo originally came that way.

Re: SS/GT classes transmission?
 

If it came with a 3 speed you are allowed to run a 4 speed.

Re: SS/GT classes transmission?
 

I guess I should have clarified that, but no 5 speed in an original 4 speed combo. Also, you can run a 4 speed in an orig 5 speed combo if you wish.

Re: SS/GT classes transmission?
 

Yes...

Re: SS/GT classes transmission?
 

Thank you for the quick responses.

Re: SS/GT classes transmission?
 

You can count on this group in a clutch.

Re: SS/GT classes transmission?
 

The way I read the rule book it says, " any model transmission, same make as car, with a maximum of three forward speeds". To me this means you could have or a 283" Chevy in a 98 Camaro SS /GT with a 200 metric or turbo or .....

Re: SS/GT classes transmission?
 

I'm not sure about this. In GT weight is linked to the transmission you want to run but I'm not sure a factory match is required in the finished car.



The rules state weight is determined using the heaviest weight gas engine with appropriate transmission available. So to find the shipping weight of a car for stick or auto application, find that car's heaviest weight in either stick or auto for the weight factor.
There is no transmission section in the GT section, just shield requirements. That means you look back to SS which reads any model trans same make as body with forward gear limits. Nowhere does it state stick must be stick or auto must be auto for any flavor of SS. Adapter plates are allowed. You can bolt up a trans that's not designed for your bellhousing.


If you are allowed to drop a motor from a '60s station wagon into the "trunk" of a Cobalt, why can't you bolt an auto to a stick only engine like a '70 BOSS 302 Mustang? In one, you rebuild the entire car. In the second you change the trans/bellhousing.

Re: SS/GT classes transmission?
 

Uhm, is that the regular SS classes as well?

Re: SS/GT classes transmission?
 

Yes

Ernie Neal
SS 354

Re: SS/GT classes transmission?
 

Except when you try to put that Boss 302 in a different body to run GT, it only gives you stick class
Stick only engine combos are only allowed to run in a stick class. Same goes for the 85 mustang carb 302.

Duane

Re: SS/GT classes transmission?
 

I have heard this numerous times on Class Racer but I can't find anything in the rules to support it. I simply can't find any rule restricting stick only showroom motors from being used with auto trans cars in GT.

Re: SS/GT classes transmission?
 

The reference at the beginning of the Super Stock section:

"Reserved for foreign and domestic factory-produced automobiles and sports cars. Classified per NHRA performance rating as listed in the Official NHRA Stock Car Classification Guide. Only those cars listed in the guide are eligible."

The reference at the beginning of the Super Stock GT section:

"Reserved for foreign and domestic factory-production two-door coupes, two-door sedans, sports cars, convertibles, or station wagons with any production V-8 engine of the same make. Year of engine optional. Only those engines and/or bodies listed in the Official NHRA Stock Car Classification Guide are eligible
for competition."

You can view the class guide on NHRAracer.com for the 1970 Ford as an example. The GT section references both manual and automatic transmissions. Look under the 302 column and you will see only HP factors for the manual referenced and none for the automatic for OEM heads or replacement heads.

Which means the manual transmission is the only one in the guide and eligible for competition. There is no factor if you wanted to run an automatic so it wouldn't be eligible.

Re: SS/GT classes transmission?
 

There a few of us that run those combinations that state STICK only in the guide, so they do exist.



Sean

Re: SS/GT classes transmission?
 

Sean, so u r running an automatic in a stick only GT combo?


Thank You

Re: SS/GT classes transmission?
 

In my signature it states I run in SS/N, it is a traditional stick car. I was clarifying that there are a few combos in the guide that are stick only. Hope that makes sense?

Sean

Re: SS/GT classes transmission?
 

[QUOTE=KRatcliff;616929]The reference at the beginning of the Super Stock section:

"Reserved for foreign and domestic factory-produced automobiles and sports cars. Classified per NHRA performance rating as listed in the Official NHRA Stock Car Classification Guide. Only those cars listed in the guide are eligible."

The reference at the beginning of the Super Stock GT section:

"Reserved for foreign and domestic factory-production two-door coupes, two-door sedans, sports cars, convertibles, or station wagons with any production V-8 engine of the same make. Year of engine optional. Only those engines and/or bodies listed in the Official NHRA Stock Car Classification Guide are eligible
for competition."

You can view the class guide on NHRAracer.com for the 1970 Ford as an example. The GT section references both manual and automatic transmissions. Look under the 302 column and you will see only HP factors for the manual referenced and none for the automatic for OEM heads or replacement heads.

This is a good reply and I thank you for your time, but those opening paragraphs refer to engines and bodies, not transmissions. The 69 BOSS 392 is not listed as a stick or auto motor, just 392/290. I looked up the 69 Mustang Fastback and it isnt listed as a stick or auto car. Just 302/290 with a BOSS footnote. Note that I am referring to the Official NHRA Rules and Guides only.
Im not trying to be difficult, just looking for a bulletproof answer to the trans question in GT.

Re: SS/GT classes transmission?
 

Maybe this will help. Wesley explained to me that the NHRA rule book is written in a positive manner. In other words, you can’t do it unless it says you can do it. You can’t run an automatic in a stick only original combination that is in the guide because the rule book doesn’t say you can do it.

You are looking for a nuanced reason to be able to run one because you cannot find a direct reference as to it being illegal. There are some references as to prohibited items such as aluminum driveshafts unless originally equipped.

I think it would help you understand the rule book better if you read it in the manner it was written.

Re: SS/GT classes transmission?
 

Thank you. This is the best take on reading the rulebook I have come across. I'm too analytical for my own good sometimes. Reading between the lines just won't work here.
Thanks again.

Re: SS/GT classes transmission?
 

Thank you and you are welcome. I didn’t realize that was the way we were to read the rulebook until I started hammering Wesley with questions. That was when he had me back up and read it again with the mindset it was written in a positive manner.

I can see your original point and I had similar questions, but after he schooled me as he often does it became clearer. He got tired of me asking if the medical grade nitrous would break down Royal Purple 10 wt before the end of Indy. With class and all we make a lot of passes.

Re: SS/GT classes transmission?
 

A way to cross reference engine-transmission application is to look at the Tech Bulletin for the engine in question. The carburetor list will show OEM carburetors and their usage with the engine. If it only lists "SM" application ("sychromesh" or "standard manual") the engine was only available with a manual transmission. In the case of the 1969 Ford 302-290hp, the 1969 Ford tech bulletin lists "Holl C9ZF-J/SM ONLY,(3069)" as the legal carb selection. Since it says "SM ONLY", the engine was available with a manual transmission only. In the same way, on the same bulletin the carb for the 429-320hp engine shows "Ford C9AF-J/AUTO ONLY", which means that engine was only available with an automatic transmission. The other engines on the 1969 Ford tech bulletin have both SM and Auto carburetors listed so they can be considered to be able to use either type of transmission. That determines classification whether or not the class guide indicates manual or automatic.

Maybe this will help some with those determinations.