hi i have a 87 gt with speed density and i wanted to know how to or who tunes the car? if i wanted a bigger tb or injectors what kind of tuning would i need?

 

You can change the throttle body and the S.D. won't care. Intake and exhaust mod's it won't care and shouldn't require a tune.

 

so when do i need to tune my car?

 

if you are gonna mod that thing past whats been said like heads,cam,intake,injectors and such you will need to swap it over to mass air flow so that you can tune the thing as sd hates anything other than simple bolons...

 

cant a dfi solve the problem?

 

actually you dont need to put on MAF, you can get MANY different SD systems, one ive been looking at is Holley Commander 950 its simple and can accept any modifications, also if your not on a budget a AEM fully programmable 5.0 computer may be more your style, they plug right into your factory harness, and eaisly adjust every aspect of the car with the click of a mouse, it even has datalogging capabillity, and you can tune on the fly, its a awesome system it sells for about 1500. if you have a laptop. and it can support up to around 2000hp