Got a 3.9 to throw in the *** end of my car after I went turbo. However, I'm changing my mind on the turbo and now I wonder if this 3.9 will be a dog with my 5 spd and no Turbo

 

Is your car a dog with the stock 4.1? If so, it will be 11% more of a dog with the 3.9. Now you can answer your own question.

 

I have the 4.3 and it's not too bad. I guess I'm going to have to try and trade someone for a 4.3 since I flip flopped on my turbo.

 

I do know a guy that put a 3.63 in a 1.6 stock Miata. He was interstate commuting 50 miles each way. Said it was ****-slow but it did boost his MPG to the 35 range.

 

I currently have the 3.9 in my 99 n/a with a 5 speed, actually swapped out a 4.3. I like it a lot for daily driving but I couldn't stand the 4.3. IMO, it's just right.

 

How much was your acceleration affected? I don't hate the 4.3, cruising at 3.5k is fine by me as I have ear plugs.

 

To be honest it didn't really seem to be much of a change off the line, it may be slower but not enough to really cause me to care. I just wanted the cruising RPMs down.

 

Currently have the 3.9 with the 5sp in my 01.
Love it for daily driver duty.
Haven't even floored it yet and don't plan to cause I know it will be slow as crap

Are you trying to make it as quick as possible n/a or is it just a daily?
Cause if its a daily I'd probably keep the 3.9

 

It's primary use is for the track going forward. I intended to go Turbo it, but a deal on a RX-7 came up that I couldn't refuse. So, I have to force myself to get over being slow as ---- on the straights.

I guess I can throw it in and see how bad it does. Worse case, it forces me to brake even less than I already do eh?

 

I'll trade you my 4.30 torsen from my 99.