LX vs. SI/EX transmission...

[SlowEG9]

hey guys

I have a 95 civic lx (4 door) and right now its my DD. The car has high ass mileage but has sentimental value so i want to get it where it eventually needs to be.

I just had a swap done from the stock d15 to a jdm zc vtec. The power difference feels night and day and actually gets surprisingly only 2-3 mpg difference having vtec now. I eventually am either going to go turbo D once I paint the car and get the rest where i want it or do a bigger swap.

my question is though, until i do my swap its still just going to be used as a daily but i want a little more pep. Is there a huge difference in the SI/EX tranny vs the LX I have in it now or is it just remedial to even worry about it? If its going to rape my gas mileage since 90% of my driving is highway, i probably wont go that route but my gearing now just seems incredibly tall (used to my 2000 SI I've driven the last two years which is for sure night and day gearing wise).

[blaknoize]

All I know is the gear ratios will be shorter and while crusing at say 70mph, u will be running at or near 3200rpm or more. I would only assume (since I've never owned a LX) that the cruising rpm is lower. But other than that, I am not well versed on the transmission differences.

[SlowEG9]

im about 2500rpm at 65 roughly...i just dont really see much point in switching out if its going to not improve relatively decently..thats not much difference up top though at cruising speed

[solblu]

It's night and day. The si tranny has a 4.2 final where the dx has a 3.72. That alone makes acceleration completely different. Add the shorter gears and it's alot quicker on acceleration. As to the gas mileage question. Mr bone did a comparison a few years back and found a negligible difference in the DX 5th verses the Si 5th. I have personally compared the 771 from a zc to the 702 and not noticed a change in mileage.

[SlowEG9]

It's night and day. The si tranny has a 4.2 final where the dx has a 3.72. That alone makes acceleration completely different. Add the shorter gears and it's alot quicker on acceleration. As to the gas mileage question. Mr bone did a comparison a few years back and found a negligible difference in the DX 5th verses the Si 5th. I have personally compared the 771 from a zc to the 702 and not noticed a change in mileage.

so the final drive must be the big difference then...all the gearing charts i saw just had 1-5 on there and i couldnt really see a big enough difference...Thanks for the info :)

[preferredduck]

it may change your rpm on the highway some, i know if i put an integra ls tranny on my si i would be at lower rpm but could possibly go 160mph, i dunno i have a friend who tried this.