Thread: Another Civic
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Old 02-19-2017, 09:44 PM   #5 (permalink)
EF Civic
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Join Date: May 2016
Location: FL
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So like most of my projects, this a slow moving one. I need to finish making the 1991 shell usable, as it has water leaks, and who knows what condition the gas tank is in after sitting for 5 or so years.

I ended up getting a 1988 CRX HF swap, and a 1990-1991 DX transmission. The HF engine & trans were sitting outside, so I wanted to get that trans rebuilt before using it. The engine I may rebuild someday, but for now it's sitting in my garage safe from mole crickets (one of which was found inside the HF trans ). Under the valve cover, that D15B6 looks fine. It was sitting under a cover, but the trans was not.

The 1988 Civic transmissions aren't so great because they used that-year-specific clutch & flywheel (input shaft splines are different than the 1989-2000 D series). So I picked up the 90-91 DX trans to have a hybrid one made up: DX 1st thru 4th gear, HF 5th gear & 2.95 final drive, DX casing (better condition), DX input shaft (can use newer/better clutches & flywheels). The DX gears will shorten up driving around town a little bit. The 5th gear will be fantastic at higher speeds on the highways -- about 80 MPH at 2400 RPMs.

I ended up swapping the D15Z1 engine & trans into one of my other cars, a del Sol. Since I didn't have the OEM wideband O2 or EGR wiring, I just used a California spec D15Z1 fuel map from and put that on a chipped ECU. I'm sure it's mostly due to my driving style, but I'm getting 34 MPG at best. I do have a lot of highway driving in the 70-80 mph range. I get the VTEC-induced 16 valve mode at 2700 RPMs.

I just ordered my GT2554 turbo, finally, and I now have the fuel map the previous owner of the engine had used. I can't wait to get it set up the way he had it and see what improvements there are in mileage. The Sol is heavier than the 91 Civic, but I should be able to get the engine set up & running properly before the 91 shell is ready.

More to come in the coming months.
1991 Civic DX hatchback, D15Z1 with turbo (in progress)
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