Changing 3 speed to 4 speed

[George Daina]

What we have here is a........

SHIFT KIT. Yes to answer your question. The norm for a shift kit installed is hard crisp shifts, and actually is better for the trans than the smooth shifts w/out the kit.

You probably have a 3:70 or possibly a 4:11 gear. That's why the high R's at cruising speed. You can change out the third member and put in a higher gear. This will drop down your R's considerably. Consider a 3:08 or a 3:36

[George Daina]

What we have here is a........

SHIFT KIT. Yes to answer your question. The norm for a shift kit installed is hard crisp shifts, and actually is better for the trans than the smooth shifts w/out the kit.

You probably have a 3:70 or possibly a 4:11 gear. That's why the high R's at cruising speed. You can change out the third member and put in a higher gear. This will drop down your R's considerably. Consider a 3:08 or a 3:36

[Patrick H.]

Yep, he's right

K,

George is right, it sounds like a shift kit was installed. I suggest calling Summit Racing (1800 230 3030) and ask about kits that can be installed to bring back your kindler, gentler shift if thats what you want. They can also give you the # of manufacturers and you can call them directly too for input. Or, if you like firm, you can leave it.

Yes, its normal for the rear to "drop" like that (I think its kinda cool).

As 3000 rpm is about 72 to 73 mph with my 3.36 rear, you likely have a 3.55 or 3.70 rear end ratio. I know 4.11 will bring about 3500 at 65mph. Your car likely had a 3.08 stock ratio which was good for highway cruising as well as CAFE fuel economy numbers for the government. You can check by looking at the numbers/code stamped on the undersurface of the differential and decoding them. The "higher" gear like yours is great for acceleration but does wind 'em of the highway. Swapping to a 4 speed manual won't change this, but with a 4 speed auto you would at least gain the 0.70 overdrive to help highway cruising and keep your acceleration. Likely cheaper to change you rear end ratio than swap trans units.

Hope this helps

Patrick

[Patrick H.]

Yep, he's right

K,

George is right, it sounds like a shift kit was installed. I suggest calling Summit Racing (1800 230 3030) and ask about kits that can be installed to bring back your kindler, gentler shift if thats what you want. They can also give you the # of manufacturers and you can call them directly too for input. Or, if you like firm, you can leave it.

Yes, its normal for the rear to "drop" like that (I think its kinda cool).

As 3000 rpm is about 72 to 73 mph with my 3.36 rear, you likely have a 3.55 or 3.70 rear end ratio. I know 4.11 will bring about 3500 at 65mph. Your car likely had a 3.08 stock ratio which was good for highway cruising as well as CAFE fuel economy numbers for the government. You can check by looking at the numbers/code stamped on the undersurface of the differential and decoding them. The "higher" gear like yours is great for acceleration but does wind 'em of the highway. Swapping to a 4 speed manual won't change this, but with a 4 speed auto you would at least gain the 0.70 overdrive to help highway cruising and keep your acceleration. Likely cheaper to change you rear end ratio than swap trans units.

Hope this helps

Patrick