How likely and difficult would it be to put a D15Z1 and transmission into a Honda Accord from 1987-1989? What about reducing the weight of a Honda Accord 1987-89 to that of a 1992-1995 Honda Civic? I was thinking of swapping in a D15 engine and transmission and was wondering, what would be the reason for this car weighing more than the Civic? I see that it is longer but I was also thinking that if it had the same engine and transmission, you'd be able to save weight but aside from that, I can't think of anything else you could do to reduce weight of the vehicle.

 

The only thing to save weight really is to gut the whole car, cut out the bumper supports, etc. One guy on 3geez has his hatch down to like 2050lbs. But the car is completely gutted. As in no carpets, door panels, rear seat, heater core, stereo, or even a dash... I don't know why you'd want to swap a D15Z1 in. I doubt it makes as much power as the A20A3. It won't have nearly the torque and won't be worth all the effort at all. The engine won't save enough weight to offset the power difference.

If you're looking to make a gas-saving commuter, best off putting that engine in the car for which it was designed. The Accord is just too heavy and big, its quite bigger than the 92-95 Civic. The aerodynamics probably aren't as good, and the engine will spend all it's time working trying to get the heavier car up to speed. Sure you could gut it as discussed, but to get the car down as light as you need it, you'll be hating your daily commute.

 

It won't make as much power but that's ok, because apparently the 1988 Accord DX/LX makes 98HP while the D15Z1 makes 92HP, and since the D15Z1 has Vtec-E, it should have a LOT more low end torque. I was wondering what are the differences beween the DX and LX Accord and how it compares to the DX, LX and EX Civics. Did anybody ever compile a list of differences in the Civics and Accords through the various trims?

 

The D15 makes 95ish lb-ft at 3800RPM. That's a very peaky power band compared to the A20. The A20 makes almost 120lb-ft nearly all the way across the power band. It's got a very flat torque curve, and I can guarantee that the D15 will work waay too hard to get you any sort of gas mileage. VTEC-E doesn't do anything except save fuel at low RPMs by running the engine on 12 valves and opening the last 4 at higher RPMS. And I bet money it makes its peak torque AFTER the VTEC system has switched to the higher RPM operation.

Also, I don't know if you have read up on any swaps, but you will be making full custom mounts for the D-series in the Accord chassis. You'll be scavenging all the parts from fuel injected Accords, doing all sorts of custom wiring, etc. Also the D15, I'm pretty sure doesn't have the same axle splines in the transmission, so you'll be looking to make custom axles... It will be the furthest thing from a drop in swap ever.

 

THIS is what I was wondering and am thankful that you posted that gem.

 

I'm willing to bet that the d15 would weight, at best, 100 pounds less than the a20 and make 6 HP and around 30 TQ less. A bunch of the carbed guys make 35-40 MPG Highway all the time. A few of the EFI guys too.

 

I'm still super skeptical of the 35-40mpg claim in the 3gee. People say it all the time, but I really have a hard time believing they're doing accurate measurements if they're getting figures like that. I could see 33-34mpg TOPS at 55-60mph. I don't see how people are besting the EPA figures by over 30% unless they're extreme hypermilers. I mean, it's a heavier car, with a dated EFI system, let alone the complicated stock carbureted models...

 

my old 3g got 42mpg on the highway and 35 in town when it was running right lol

but no the D will not just swap in it will be a huge pia! i reccomend converting the the 3g to EFI from a 88-89 accord, that will give you 122hp and still have tq and get good mpg.. and if you do want to swap b-series mounts will be for sale shortly

 

42mpg? Now you're getting near CRX HF territory there. A car that weighed like 1800lbs, and had every possible friction reduction done to the engine.

 

Dude, you can get like 50mpg in a VX and that thing weighed at least 2100lbs.. Really light weight vehicles help the most with city mileage and aren't as important for highway mileage.

 

Eh i dunno 2ndGen, Those EPA estimates were a bit lower in the 80's than they are now. I get 32 mpg consistently on all highway, and I'm driving a stock EFI autotragic 3g. Im willing to bet with a slightly leaned out carb, and a carbed tranny (taller gears), i can see probably 37-38. 42, eh i dunno.

 

32 is totally reasonable. The automatic doesn't hurt highway mileage all that much, especially with the lock-up torque converter. Leaning out the A20 without other tweaks probably won't improve mileage. Just ruin its efficiency. 37-38 might be possible, but I can't see it on a regular basis without some serious fine tuning. And it's not the kind tuning that anybody on 3geez has ever done.

That might be true that it's more of a factor around town, but it's still a huge factor on the highway. The Accord weighs nearly 2600lbs if not more. That's like adding another 1/4 of a VX on top of it. That's going to make quite a difference. And why is it so important around town? Acceleration, which is directly tied to torque/weight.

 

lol word on that one.