You guys were helpful with my previous question so here's another. We are running a
90 CRX SI (5-speed) in SCCA autocross and constantly run up against the rev limiter. I happen to also have a 91 civic DX hatch with a 4 speed. So here's the question: Can I swap the 5-speed in the CRX for the 4 speed in the civic DX? I think the 4 speed will have a taller 2nd hear which is what I need for autocross. And the 5 speed will help the fuel mileage in the DX.

So is this possible? Again, thanks in advance for your advice and comments.

Ya just gotta luv dem Honda's.

 

try finding an hf transmission. i don't see why the 4spd won't work.

 

for any racing application the four speed isn't a good choice, the gears are too tall, it's made for fuel mileage thats it, redlind in 1st is about 30 mph, second is around 60,
face it, it's not geared for high perfornace

 

They will swap. And sorry your car is not a dx if its a 4 speed it is the "std" modle unless some one swaped out the trans. And as previously stated the 4 speed will not be a good one for auto cross as 2nd gear is about 60ish. A dx Might be good but I'm not sure about the gear ratio in that.

 

lol, heres an example of how tall the 4spd gears are.

http://www.youtube.com/watch?v=ULKJUKeq-X0

 

Their second is like my 4th, lol.

 

if anything swap a to a taller final drive and you can use 3rd instead of second in the auto-x

 

lol..i have a 4speed ( not sure if it has locks or if its LSD) on my 88dx dd..it feels string but the gears are Looooooooooooong...lol

 

Ok to the people saying your dx's came with 4 speeds. No they did not, do you have a rear wiper? If you don't then you have a "std" hince the 4 speed. If you have a rear wiper then you have a "dx" and some dumb *** put in a std trans in your car and you got screwed when you bought it. End rant.

 

And no lsd in a "std" trans keep dreaming.

 

^^moron, i have a z6 swap in my rex, i have no idea what tranny i have, it peels with both tires ALL the time! that's why i put IDK...

 

I'm not a moron. I'm saying you dont have a lsd. Your 4 speed trans was designed for 60 hp. Your z6 has like 110 so think about it 2 times the hp. And you probably bounce it off rev limiter like every other ricer and then drop the clutch and then both would spin. Your car don't weigh all that much so double the horse power and torque and it will spin the tire's, and you probably have bald street tires which is why both spin. And all 4 speeds are "std" trans which never came with lsd or anything they are cheap pos's not even good for gear swaping. Best bet for you is to take it out get a dx or si and use your std trans as a fishing weight.

 

1) Raise wheel off the ground.

2) rotate wheel

3) find out whether your car has an LSD.

 

^^ doing that tomorrow morning..

 

when evaluating the various transmissions, you need to also consider the Final Drive (differential) gears, not just the 2nd gear ratios - here are the final gear ratios for 2nd gear for the various transmissions (the bigger the number, the shorter the gear):

STD 4 speed - Final drive = 3.88
2nd gear = 1.65
final 2nd gear = 3.88 x 1.65 = 6.40

Si 5 speed - Final drive = 4.25
2nd gear = 1.894
final 2nd gear = 4.25 x 1.894 = 8.05

DX 5 speed - Final drive = 3.88
2nd gear = 1.894
final 2nd gear = 3.88 x 1.894 = 7.35

ZC 5 speed - Final drive = 3.88
2nd gear = 1.944
final 2nd gear = 3.88 x 1.944 = 7.54

swapping the Si 5 speed in place of the 4 speed will not give you better fuel mileage - the Si final 5th gear is shorter than the 4 speed final 4th gear
Si final 5th = 4.25 x .771 = 3.28
4 speed final 4th = 3.88 x .823 = 3.19

 

i can tell you this much, a high compression d series at 12 to 1 with my 4 speed i used to own was one hell of a thrasher ride. i could hang with ls swapped hatches all day. as long as you have a clutch that will hold up to the abuse, and the 4 speed is in good condition, i say use it!!! i loved mine to death. i had a 5 speed in it before and i broke it with the same engine. i got consistent 28-29 mpg with the 4 speed as well with city driving and about 35 mpg on highway trips. i dont care what any of you say here.

 

^^ lol..4sppeds for life ftw!

 

really??? hill climb with no cage or fire suit????

 

he like to live on the edge! literately