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Can I use an automatic transmission donor car for a SM build?

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#1
Abhi

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My question has to do with whether I can use an automatic transmission car as a legal donor for a SM build.

 

I have a 2002 donor car that was originally an automatic transmission car. My friend wants to use it for a SM build.

 

When I read 9.1.7.C in the GCR, it says updating or backdating is not allowed.

 

Does changing the automatic transmission to a 5 speed count as updating assuming I use a NB transmission?

Also I assume I will have to use a VVT motor given that the 2002 originally came with that motor?

 

I think we will need to change the harness, ECU and diff also. Do any of these violate the GCR if I stay within the correct model year for those items?

 

Thanks in advance

Abhi Ghatak

 

 



#2
Johnny D

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You can do all you said and it should be legal but I think most here would say it’s a whole lot easier and cost less to start with a 5 speed, federal and maybe a sport model with torsen.

I’d sell your car and then go shopping.

J~
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#3
Abhi

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I agree.

But this one is a 20K mile very straight car.

And I have most of that stuff left over from building a 2002 ITS Miata last year, including a Torsen

 

Thanks for the response



#4
Johnny D

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Ok. You just need all OEM stuff.
Search upper right for automatic, your not the 1st to ask. There should be more threads on it like adding a clutch etc.

J~
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We have a Winnah! - Won their 1st race... Congratulations! Beta-Tester - Assisted us with beta testing the website. Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver Novel Approach - When a paragraph simply won't do... Survive the 25, NASA Thunderhill - Survive the 25, NASA Thunderhill Instigator - Made a topic or post that inspired other Make it Rain - Made Paypal donation of $100+

#5
Dave D.

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The wire harness is a little different due to the auto trans control module and the wire colors and pins for the VSS to the IPC are different. Not sure if it makes a difference, but I just swapped a harness with the IPC and ECU from a 5sp donor. Then as I'm sure you know get the pedal assembly as well. My last build was with an auto trans donor as it was just too clean,perfect and cheap not to use. 



#6
tylerbrown

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I feel if is that low of mileage you could sell it for a good amount and then buy a clean rust free donor car with a manual and torsen already. Yes it is nice that it is a very straight car, but figure in the extra work you will have to do along with the fact that it IS going to be a racecar, and after three weekends it very well might be not so straight anymore anyways. 


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#7
Johnny D

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Funny how it seems so easy to pressure someone with a clean car for the spot (regionally) and its more difficult with the beater.   :lol: 

 

J~


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#8
Dave D.

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I don't know of the original poster's situation, but for me I bought a very clean rolling shell for sub $1k. When building, it's going to be stripped bare with the harness and pedals out anyway, so just dive into crates of spares from previous parts outs to convert it. If I am going to spend the time, effort, materials and money building a fresh car, I really want to find the nicest one  I can. I agree that it will get scuffed up, but it's not something that can't be fixed later. 


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