My new 91 HF, project econo box.

[MQTGSR]

Hello!

You may recognize me from the Teg section, I have a 94 GSR. I recently acquired a 91 CRX HF that needs quite a bit of TLC.

Well, seeing as I have had the car for a while now, and now have an engine, the project is about to start.

The car used to belong to a member in here, some of you may remember 91rexsi??, but he sold it to me this summer. The car has a shot D16a6 (bad rings most likely) and some electrical issues mainly. The shell is pretty solid, not a lot of Honda rot, tho I plan on getting it fixed next year. I bought the car for cheap insurance and awesome gas millage, I'm expecting at least 40+mpg highway and it runs on 87 octane, which will be very nice. I plan on keeping the car through college, then I dont know what I'll do with it.


Lets start with the basics tho. The car is a 1991 Honda CRX HF shell with 1991 CRX Si engine, trans, suspension, front brakes and some interior parts dropped into it. The car has a (for the most part) stripped interior other than the dash, seats and door panels.

The car needs....
-New Engine (Just bought a new D15 for it, should be here sunday)
-New Hood
-New alternator
-New Wiper swich
-New door locks
-prob. some electrical fidgeting

That should get it running and through the winter, but after that I plan to install:

-New front brakes
-New ball joints
-Get some body work done

I planned on investing some in the car, because it needs a decent bit of TLC, but I really want to learn more about how to work on cars, and well, I certainly got a lot on my plate here to do, should keep me busy for a while. I plan on just making the car a year round, cheap to drive DD. So please dont tell me about how "Fast" this car would be with a B swap or turbo, I know, I'm not new to Honda's I'm very aware these cars can be quick, but I'm NOT interested in go fast. I'm excited to get it going tho, from the few times I have driven the car, its been a blast. I see why many people say these are there favorite Honda's its a go kart! haha. I'll keep posting updates through out the motor swap and work phase here in the next couple of months.

Here are a few pics of the car how it sits. or did a few months ago when adam still had it:






I also just picked up a D15b2 out of a 91 civic 4dr. I have one question tho, I'm pretty sure it will be fine, but can I use the intake manifold on the D16a6? I assume it will bolt right up, and I already have the si ECU and wires injectors everything, I can't see that putting the manifold on essentially the same motor, just 100cc's smaller, would cause an issue, I was just curious because I believe that motor has tb injection, and not dpfi.

Anyways, I start the swap tomorrow or possibly tonight, so wish me luck!!

[drummingpariah]

I'm confused. You have a d16a6. That's about as good as CRX engines get. Just to set the record straight:
dpfi = dual point fuel injection (two injectors, crappy system found on the d15b2 in the CRX DX + Civic STD)
mpfi = multi-point fuel injection (proper setup with 4 injectors, the d16a6 is the CRX Si + Civic Si engine... just rebuild it and call it a day)

[MQTGSR]

Originally Posted by drummingpariah

I'm confused. You have a d16a6. That's about as good as CRX engines get. Just to set the record straight:
dpfi = dual point fuel injection (two injectors, crappy system found on the d15b2 in the CRX DX + Civic STD)
mpfi = multi-point fuel injection (proper setup with 4 injectors, the d16a6 is the CRX Si + Civic Si engine... just rebuild it and call it a day)

Eventually I'll re-build the D16, but for now, and where I live, its far cheaper to just swap a whole new engine in, not to mention, takes less time. Like I say, I dont need it to be fast either, I know the A6 is the more powerful motor, but I just need something in it for now thats basic and will work and is solid. The donor motor only has 90k on it and the harness and some other goodies.

Yes, this motor has DPFI manifold currently, but I want to swap the MPFI manifold from the a6 onto the D15, thats what I'm asking.

[EnJoiThaRex]

Thats what your supposed to do to swap it..there are a couple of threads around on this..

But the basics you need from an Si
-Dizzy
-ECU
-Intake Manifold
-Resistor box + injectors
-Engine harness (Si is the easiest to work with)

But if you want good gas milage DONT do the swap and use a 1.5 ECU..but i doubt youll get 40mpg...more like 30..

I have a 1.5 with MPFI and thats ALMOST what i get...then again i have a few issues...

[MQTGSR]

Originally Posted by EnJoiThaRex

Thats what your supposed to do to swap it..there are a couple of threads around on this..

But the basics you need from an Si
-Dizzy
-ECU
-Intake Manifold
-Resistor box + injectors
-Engine harness (Si is the easiest to work with)

But if you want good gas milage DONT do the swap and use a 1.5 ECU..but i doubt youll get 40mpg...more like 30..

I have a 1.5 with MPFI and thats ALMOST what i get...then again i have a few issues...

Have all that stuff, and I dont even have the 1.5 ecu, so that wont be an issue. I wasnt forecasting a problem, unless for some reason the manifold physically did not bolt up to the block.

Thanks for the info.

[MQTGSR]

UPDATE:

So its been a while since I posted on here, but I've made some headway on the project. Ends up the D15b2 was bad, seized valve-train

So, I ended up through a long complicated story, a D15b6 (the HF motor) instead, this one turns over and the valve train works! YAY!

So more or less, I am resoreing the car to its former self. I just picked up some things I'd need for the HF re-conversion. Since the car had si everything, I had to make a few changes.

Bought this PM8 ECU


Getting the Si wiring harness re-built by Wicked Innovations to accept the HF EGR plug ins so I can use the b6.

So the car will def. be an econo box now with this monster motor under the hood. Waiting now on some motor mounts and hopefully over x-mas break from school can try to drop the motor back in.

Here is how she sits currently:


Here's a few more shots of the car:
Pass. side rot:


Drivers side rot:




Interior

[jordan_myers]

Good luck, I wondered what Bam did with that one....The rims are def unique as hell too.

[MQTGSR]

Originally Posted by jordan_myers

Good luck, I wondered what Bam did with that one....The rims are def unique as hell too.

lol, you call him bam too? hahah.

Yeah, thats where the car went, didnt really travel very far,

I do like the wheels. I am for sure going to stick with the white on black look, tho, the hood I'll leave white once I get a new one.

[drummingpariah]

Get those harnesses mounted properly. Right now they're a death trap.

If this is going to be a gas sipper, your engine choice is the least important decision to make. You're pretty light right now, but you have a ton of air collecting under the car and creating both lift and drag. You want to minimize your drag as much as possible.
So:

• lower it as much as you safely can (make sure it clears the snow that collects at the end of your driveway)
• Tape off the openings that air could get through on the front. Only allow enough air through to keep your radiator cool. You don't want excess air going into your engine bay.
• Get a front bumper lip to keep air from getting under the car. You could always make one out of garden edging from home depot.
• Seal off the undercarriage. Get some aluminum or thin-gauge steel and screw plates under the car to keep air from collecting and swirling around under there. This will increase your aero SIGNIFICANTLY.
• When you replace your hood, get one with a slight cowl on the rear. That will relieve the positive pressure area on the front of your windshield, and put air where it belongs: your intake
• A cold air intake will improve the efficiency of your engine, as will deleting unnecessary accessories. If you can get an alternator with less draw and a smaller pulley, that'll help too.
• Lighter wheels will definitely improve your mileage and response, as will lighter tires.
• Higher compression equates to more efficiency, and e85 is cheap and readily available, and can handle much higher compression rates than standard gasoline. If you have a local supplier of e85, it might be a good idea to run a thinner head gasket and possibly get the head shaved slightly. I believe the d16a6 head is shorter than the d15 you have, so mixing the two could net a higher compression ratio (and probably better quench), but won't want to run on regular unleaded. e85, Premium, or Plus should be just fine though.

[jordan_myers]

Originally Posted by MQTGSR

lol, you call him bam too? hahah.

Yeah, thats where the car went, didnt really travel very far,

I do like the wheels. I am for sure going to stick with the white on black look, tho, the hood I'll leave white once I get a new one.

I love the panda look that's why mine was left white and black with a black hood...If I decide not to sell it for a greater cause I'm going to get it re-painted the stock two tone with a cf hood and lip.....I just love the black on white CRX.

[drummingpariah]

Mine was an uber-panda rex. I was mistaken for a really really low cop until i got close several times.



I miss it. I'd have another panda rex, if mine hadn't been red when I bought it. I'm currently planning to make it a track-only car, but a MPGmod might be a good idea too. I might even be able to squeeze 60mpg out of the zc with the right tune.

[EnJoiThaRex]

Originally Posted by drummingpariah

• lower it as much as you safely can (make sure it clears the snow that collects at the end of your driveway)
• Tape off the openings that air could get through on the front. Only allow enough air through to keep your radiator cool. You don't want excess air going into your engine bay.
• Get a front bumper lip to keep air from getting under the car. You could always make one out of garden edging from home depot.
• Seal off the undercarriage. Get some aluminum or thin-gauge steel and screw plates under the car to keep air from collecting and swirling around under there. This will increase your aero SIGNIFICANTLY.
• When you replace your hood, get one with a slight cowl on the rear. That will relieve the positive pressure area on the front of your windshield, and put air where it belongs: your intake
• A cold air intake will improve the efficiency of your engine, as will deleting unnecessary accessories. If you can get an alternator with less draw and a smaller pulley, that'll help too.
• Lighter wheels will definitely improve your mileage and response, as will lighter tires.
• Higher compression equates to more efficiency, and e85 is cheap and readily available, and can handle much higher compression rates than standard gasoline. If you have a local supplier of e85, it might be a good idea to run a thinner head gasket and possibly get the head shaved slightly. I believe the d16a6 head is shorter than the d15 you have, so mixing the two could net a higher compression ratio (and probably better quench), but won't want to run on regular unleaded. e85, Premium, or Plus should be just fine though.

Most thing are good in this list..
Just wanted to clear a few things up

Are you sure about the CAI? I dont know if he is really drawing that much air to make a big difference. I mean like people say mfg specs work best. Especially when your not really alterting componenets to flow more air. There is a chance he could benefit from it though, but w/e. Its like a $30 ebay mod, no big deal.

Be careful with the alternator part. Smaller pulley equals less output voltage as well. But since this is for MPGs i am suspecting you arent going to add many electronics to it.

I HEAR that 1 gallon of reg gas, mm 87?, will last as long or take you as far as 1 1/2 gallons of E85. So though it may be more economical is it really worth it?

Other wise good list with good ideas. Many of these things i didnt know. Id like to do this rather than sell my CRX but maybe i will in the later years. Or just make a sick track car.

[drummingpariah]

Originally Posted by EnJoiThaRex

Most thing are good in this list..
Just wanted to clear a few things up

Are you sure about the CAI? I dont know if he is really drawing that much air to make a big difference. I mean like people say mfg specs work best. Especially when your not really alterting componenets to flow more air. There is a chance he could benefit from it though, but w/e. Its like a $30 ebay mod, no big deal.

Be careful with the alternator part. Smaller pulley equals less output voltage as well. But since this is for MPGs i am suspecting you arent going to add many electronics to it.

I HEAR that 1 gallon of reg gas, mm 87?, will last as long or take you as far as 1 1/2 gallons of E85. So though it may be more economical is it really worth it?

Other wise good list with good ideas. Many of these things i didnt know. Id like to do this rather than sell my CRX but maybe i will in the later years. Or just make a sick track car.

e85 is only worthwhile if you up your compression. Comparing a 9.5:1 ratio to a 15:1 ratio, your e85 is going to be burned off as efficiently as possible, while your Unleaded gasoline would be burned off at ~60% efficiency. Combine that with having power lower in the revband, you'll be able to drive more efficiently, have fewer revs/mile which equates to mpg.

And as far as the CAI goes, colder air is more efficiently burned than hotter air. Especially when combined with a high compression ratio, it's the most efficient way to run a combustion engine.

The biggest gains will be seen from weight-decreases and aerodynamic improvements.

[MQTGSR]

Def. Planning on getting a lip, and tightening everything up, sealing some holes and what not.

As for a CAI, IDK if they make one for the HF, the intake tube is so small, but I could do a Homemade job, I have a K&N filter off a GSR that I think with some adaptations I can make work. The car already has a header and exhaust, and your right, its certainly lighter.

Also, the car has no. PS, AC ect. Just running an alt, and its a brand new one at that. The car had a minimum of accessories to begin with, so I don't think I'm going to be impacting my MPG that much in that regard.

As for the harnesses, yeah, I kinda wondered about that, the previous owner did them. I need to find a pic or article on how to install them properly. Thanks for letting me know for sure.

[EnJoiThaRex]

Originally Posted by drummingpariah

e85 is only worthwhile if you up your compression. Comparing a 9.5:1 ratio to a 15:1 ratio, your e85 is going to be burned off as efficiently as possible, while your Unleaded gasoline would be burned off at ~60% efficiency. Combine that with having power lower in the revband, you'll be able to drive more efficiently, have fewer revs/mile which equates to mpg.

And as far as the CAI goes, colder air is more efficiently burned than hotter air. Especially when combined with a high compression ratio, it's the most efficient way to run a combustion engine.
.

Wow, dont hit the valves.

Yes, with high compression combined with the CAI i can see you getting a few more mpgs.