DX tranny on SI motor

[jpoenitsch]

OK, I read that the overall ratios are different, 3.88 to 4.25 for the SI. But I only use the car for circle track racing and I am only using 1st 2nd and 3rd gear. I notice that there is a difference in the third gear ratio, 1.864 for the DX and 1.894 for the SI. What is this going to do to my RPM's for each tranny. Will I have higher RR's in third with the DX or SI, and will I really notice? Anyone who knows I would really appreciate it.


Thanks!


Please pm me if you can

 

[jlicrx]

Originally posted by jpoenitsch@Aug 9 2004, 10:03 AM
OK, I read that the overall ratios are different, 3.88 to 4.25 for the SI. But I only use the car for circle track racing and I am only using 1st 2nd and 3rd gear. I notice that there is a difference in the third gear ratio, 1.864 for the DX and 1.894 for the SI. What is this going to do to my RPM's for each tranny. Will I have higher RR's in third with the DX or SI, and will I really notice? Anyone who knows I would really appreciate it.


Thanks!


Please pm me if you can

[post=374326]Quoted post[/post]​

must be typo in where you saw the ratios - DX and Si have all the same gears, except for final drive

 

[Jeef]

The si tranny will be better for acceleration.

Please do not put the pm me with the info. Let people respond on the board so others can chime in and others can learn.

 

[jpoenitsch]

Why would I have better acceleration with the SI tranny over the DX tranny if they are geared the same in first, through third?

Here's another thing, the reason I am taking out my SI tranny, which I should have mentioned in the beginning, is that last week I was pushed into the wall in a race bending my lower control arm back 3 inches.

Since straightning the control arm, I have, at times, not all the time, but at times I have a hard time shifting and she won't even go into reverse, ever.

Swapped shift linkage from another CRX and it shifted better at first but then the same problem with shifting hard happened in the middle of the race. So I wonder if when I hit the wall my wheel locked up and caused damage in the tranny??? I have a DX to swap but I don't want to slow my car down.

SO JEEF especially, or anyone, if you could give me a bit more insight on the reason I would have better acceleration it would save me the mistake of putting in the DX tranny.

 

[jpoenitsch]

Just found out tranny has to be shot. I manually tried to shift, under the car, into reverse and it won't slide in like any of the other 5 trannies I have laying around.

So now I really need to know more about the gears one the DX and SI tranny.

ARE THEY THE SAME 1st through 3rd?? One says yes and one vote for it will make my car slower.

Need to know if I should look for a SI tranny to be faster on the track.

Anyone else have any input??
Much appreciated if you do!

 

[Jeef]

The dx will not make your car that much slower. The ratios are the same but the final drive is different. The final drive in the si is geared more for acceleration. Thats why with the si tranny you will be at 4,000 rpm at 80mph and 3600 rpm at 80 mph with the dx. (I don't know if those are the actual numbers but its pretty close, I haven't driven my rex in 3 months ) I had a 91 dx sedan and switch to a crx si tranny. So I have first hand experience that the si tranny is better for acceleration. It makes some difference but its not going to be night and day.