13 replies to this topic

[kyller]

I've been doing a lot of research lately, trying to find certain gear ratios. And I came across a few websites (unrelated to each other), that mention that the '85 CRX SI came with the same ratio 2nd/3rd gears that the integra did. 1.99/1.35 vs the 1.76/1.19 that the rest of the civics came with in that generation. The owners manuals that I've cone across don't mention the 85 SI specifically, so I can't find anything to prove it, or prove otherwise.

I remember when we first started racing our current car, we were turning about 8400rpms in second gear. That transmission is long gone, and I have no idea what year it was from. Now, with the shortest final drive available (4.40), we're still a lot of rpm's lower. So I'm wondering if maybe we did have the shorter second gear back then, and just didnt know it.

Anyone know 100% for sure that the 85 SI did/did not have the shorter 2nd/3rd gears?

[jsgprod]

Anyone know 100% for sure that the 85 SI did/did not have the shorter 2nd/3rd gears?

There were differences in some of the gear ratios in the 85 Si box, I just don't think 2nd & 3rd were the ones. I'm positive that 4th & 5th were slightly different from the later ones along with a slightly shorter 4.428:1 FD. I can pretty much guarantee that the 2/3 gears were not 1.99/1.35 though.

I made a post on here years ago listing the actual gear ratio differences between the 85 Si gear ratios and the 86/87s. I haven't searched for it in quite a while.

You could always try to find one of the VERY hard to find 4.06:1 final drives. Honda put them in both the early (short) and later (slightly longer) gearboxes, I recently found another one in an old early box I didn't know I had.

Jay

[kyller]

I've seen the posts in the past...but Just never really needed to know the gear ratios. They were all so similiar it didnt matter. But when you start mixing and matching final drives, you can make some big rpm increases/decreases, which is what I need right now. Problem is, and I may just be blind, but since they forum changed, I can't find all those really old posts.

We've been researching these cars for years now, and when it comes to the engine, I can tell you everything available, from every year and every model. The transmission on the other hand, I'm just getting seriously into now.

[jsgprod]

OK, I searched for the old posts and found em, I was 'almost' correct. Third gear is just a little different also.
http://www.redpepper...h=1

Go to posts 11 & 12. Ballade Sports corrected my error.

I just thought of something. I don't think Honda sold the HF models of these up in Canada did they? Well,If you’re interested, I have an old HF gearset that I just happened to uncover this past weekend (I was cleaning the garage). I don’t remember if it’s the longer or shorter version (easy to check) and it doesn’t have the fifth gear with it but a DX or Si gear should fit it. The HF gear ratios are supposed to be 3.27/1.666/1.041/0.807/0.607?

Put those gears in a box with the Si final drive and 2^nd gear at 70 mph will give about 7600 rpm with a 23” tire.

Jay

[kyller]

The HF's are up here, but I think they have the common transmissions up here.

I would definately be interested, you wouldn't happen to know what the final drive is?

I have lots of parts laying around, finding a spare 5th gear isn't an issue.

[kyller]

The problem is, like I said in the other post, is if we run fuel injected, we're fighting with the rev limiter at 7200 give or take. So basically I need 70mph to be around 6900rpms to give me a little breathing room to be able to go faster.

If I run carb'd, I want to turn as many RPM's as possible, so I would want the 1.92 second gear with the 4.40 final and be pushing 9000. The canadian carbs been solid power all the way up to at least 8500 and don't die off. But...the extra HP from the FI would be better I would think, but I can't confirm that (for our application) until I get the gearing right,

[kyller]

I just found a transmission out of an 86 with a 3.87 final drive. It's out of an HF, not sure which version though.

[jsgprod]

I just found a transmission out of an 86 with a 3.87 final drive. It's out of an HF, not sure which version though.

That's an oddity to me. I've heard one or two people mention that FD ratio before buy I don't ever recall seeing it listed in any Honda FSMs.
In regards to your question the other day about the FD ratio of the one I mentioned (not that it looks like you need it now), it was 2.95:1. I seriously doubt that it would have done you any good.

BTW, you have any Canadian DX camshafts you aren't using? I need a good one.

Jay

[kyller]

I probably have 5 ot 6 laying around. But honestly I don't know what imakes it a DX? I just sort by carb/FI. Is it just a candian carb'd cam you need, or does have it have to be a DX? I'll gladly check for you if you let me know how to recognize it as a DX. (I have never owned any HF or anything like that, but I have had a lot of regular civics as well as CRX's if they are different)

And, that transmission ended up having a 4.06 final drive in it. Puts up closer, but still going to rev too high to make it worth while. The 2.95 ratio puts us in decent shape though for 1st gear. IT's definately making me think about that one. For now though, looks like we're gonna go carb'd and just turn some really high rpms in 2nd gear.

Edited by kyller, 31 May 2012 - 10:52 AM.

[jsgprod]

The Canadian carbed car is what I was referring to as a DX. As far as I know it's (essentially) the same as the US DX camshaft it just doesn't have the extra lobes for the CVCC valves. It'll be easy to tell the difference between that and the Si cam. The Si Cam is about three inches shorter than the carbed cam!

As for that 4.06 you found... How long is it? I (or Greg) might be able to use it.

[kyller]

Yes, the camshafts I have from the carb'd cars don't have the extra lobes for the cvcc valves, just the 12 valves. And they have the fuel pump drive lobe as well.

The FI's also have a noticably taller lift, and are missing the fuel pump drive. I'm at work right now, but I will check when I get home to make sure I have some that are still in good shape. We've converted to a FI distributor and prefer the SI cams much more. So if I have some laying around, you can have it, you'd just have to pay for shipping. And I could even send it from NY so there's no cahnce for border issues.

And if you want, I can check the lift for you to make sure it's the same as the US version.

[kyller]

2 parts cars just came up for sale around me at decent prices. There's a '86 SI for $600, and an '85 dx for $250. The one for $250 is worth it for weight/cores alone, and the other one being an SI is worth every penny as well. Running or not.So I'll have lots of parts available, but the cars will be crushed very quickly. Anything else you, or anyone might need from a canadian car, now would be a good time to make a request!

[rallyxcrx]

I just put an SI tranny in my car, seems to have slightly closer gearing. Kyller, what kind of racing are you doing? Dave

[PHAT87CRX]

Unaware if 1985 and 1987 are the same,
this info is from the 1987 CRX Service Manual

1987 CRX Final Drive Ratios

2.954 = HF Calif
3.578 = HF Hi Alt
3.933 = Automatic
4.066 = HF Std
4.250 = 5sp DX
4.400 = 5sp Si

Model GW-020 5 Speed Manual Transmission Ratios

...... 5MT .... HF 49st . HF CA/HA
1st . 2.916 ... 3.272 ... 2.916
2nd . 1.764 ... 1.666 ... 1.526
3rd . 1.192 ... 1.041 ... 0.960
4th . 0.866 ... 0.807 ... 0.750
5th . 0.712 ... 0.655 ... 0.655
Rev . 2.916 ... 2.916 ... 2.916

22.6 sq. in. Clutch Lining Area

Edited by PHAT87CRX, 29 August 2012 - 10:43 AM.