I have a 1991 civic dx with the d15b2 motor and I'm looking to do some semi-budget upgrades. Its my daily driver but wantt a little more get up and go. I did an obd0 mpfi swap over the summer. Now im thinking about rebuilding the motor. I was gonna upgrade the valve train with a d16a6 camshaft and a supertech valve train kit. I was also thinking about putting in some better piston rods and possibly oversized pistons maybe but I'm not really sure if thats worth the investment or not? If i were to do all that would i need to upgrade to obd1 or 2. And which ecu would i use?

 

Piston/rod upgrades are not worth it unless you're going forced induction or nitrous. If you're just looking to make your daily feel more peppy, the first thing I'd do is get an L3 Si transmission if you don't already have one. You could also try to find a D16A6 or a SOHC non-VTEC ZC engine and rebuild that, then swap it in. The 1.6L non-VTEC with the L3 Si transmission in the EF chassis is a joy to drive. You do not need to upgrade to OBD1 unless you are going forced induction, and even then you technically COULD stay OBD0.

 

Thanks for the advice. I don't have the Si transmission in it. I'll start looking for one. My other thought was possibly just doing an a6 mini-me. I can get ta rebuilt a6 head for about $400-$500.

 

You can get a fully refurbished L3 Si transmission from Synchrotech for $600. If you can find a used one, you should be able to get it for less than half that. The transmission will probably be a better bang for the buck in how fast it feels, IMO.

 

Thanks. I've already looked at the site. Had no idea that it existed. I'll definitely be swapping the trans.

 

Where are you located? I've got a spare L3 Si transmission I'd be wiling to part with.

 

Gordonsville VA

 

Yeah, I'm about 7.5 hours away in TN. Probably not worth the drive.

 

Probably not but thanks for the offer. Then again, they're a little hard to find around here and im always up for an adventure.

 

If you decide you're interested, just shoot me a message and we can discuss.

 

how would the si trans pair with a y8 mini me im building? also im concerned about the rpms on the highway going 75 with the si trans. But its something ive been considering, and would be a definite upgrade over my 4 speed.

 

I've been told that all d-series trans will bolt up to any d-series block but I've also been told that if your using a 92-00 d-series motor than you have to use a 92-00 d-series trans and convert to a hydraulic clutch if you have an 88-91 chasis. So honestly im not really sure. Sorry. If anyone knows for sure, please set us straight, lol.

 

Yes, it would pair fine. RPMs are higher than the more common DX transmissions, but you get used to it. I had the Si gearbox in my EF for 10 years / 137,000 miles and didn't regret it. Many many road trips in that thing. You can compare speeds/gear here: https://www.zealautowerks.com/transcalc.php

You do not need to use a hydro transmission in an EF with a 92+ swap - the cable transmission works fine.

All D-series transmissions will bolt to all D-series blocks, with the D17's being the exception. 88-91 transmissions (and chassis) are cable, while 92-00 transmisisons (and chassis) are hydraulic. You can put a cable trans in a hydro chassis and vice versa with conversion kits that are sold. The DOHC ZC transmissions come in both hydro and cable and will bolt up to the D-series blocks, but this transmission uses a special half-shaft and takes B-series axles (27 spline vs. the normal D-series which takes 25 spline axles). 1988 cable transmissions used a different input shaft size than the 89-91 transmissions - you can use either, just match the clutch to the transmission.

 

not quite. the 1st gen CRX and 3rd gen Civic D15A3 engines along with the 86-89 Integra D16A1 engine will not bolt to the 88 and up D-series transmissions.

 

Haha, I was nervous typing that out, because I knew there was probably something I wasn't mentioning. Thanks for following up with the clarification.

 

no problem - i wasn't calling you out, i just didn't want anybody trying to use one of those other transmissions

 

Agreed - I'm all for getting the right info out there.