Crx Hf Vs. Civic Vx
 

Hi,

Just wondering what car you guys would rather have? and of course your reasons why.

CRX has better mileage, slightly lower insurance premiums. VX can hold more cargo.

CRX with a VTEC engine from a VX gets best mileage.

thats what I would really want a crx hf with the d15z1 the hf tranny and vx wheels.

I wonder how many mpg you could get with that setup?

Hey guys, I'll let you know shortly. I have an 1985 CRX HF, the lightest of all HFs. They are rated at curb weight 1713. I have found this means that this build has no options. The acutal weight of my car which has factory air was 1780. After I am done with the conversion, I'll weigh again and let all know. The VX engine is now in and running. I am finishing the wrapping of the newly constructed harnesses at this time. The next phase of the project is to build a custom dash to house the VX instrument cluster, HF heater and ac control unit, and HF headlight dimmer switch. This conversion of a first gen CRX to a third gen engine has been more extreme than I ever imagined. I went from a three barrel carburetor and no computer to a SFI injection system in its entirety. I'm very pleased to announce that all applicable circuits work. Ie.: seatbelt warning light and buzzer, key in ignition buzzer, clutch override switch, air conditioning controls, heater controls, dimmer circuit, window washer/wipers including intermittent, and all other applicable systems required on factory original '95 VX cars. This is because I could not just plug in a few wires to make it work. I replaced the existing '85 fuse box and all of its satellite control boxes with the '95 integrated control fuse box and harness, under hood fuse relay box with electronic load detection (operable). Also reconfigured the '95 VX system to recognize all of the '85 controls (such as the combination switch). As for the transmission, the VX has taller gearing than the HF, therefore, I found it not to be desirable to stick with the HF tranny, and since they now sell a cable to hydraulic conversion clutch master cylinder, which is on its way, I used a '94 CX tranny which has the same gearing as the VX. Also, the '85 CRX HF axles slip right into the CX tranny. No modifications required. Do know that custom motor mounts are a must.
I manufactured my own to connect to the ' 85 CRX factory location to allow the use of '85 CRX rubber mounts for ease of future replacement. For you, a fair warning (not listed to brag). I do have a very extensive background in automotive (engines, transmissions, differential, electrical systems, suspension systems, structural alteration, paint and body, and exhaust system design/fabrication), machining, blacksmithing, welding, sheetmetal fabrication and with all that I still consider this to be an extreme challenge. If anybody is still interested in attempting this, I am very willing to help with as much information as I can. Good luck!!!!!

WOW cool I would be interested in the results. I thought 2nd Gen CRX HF's had the highest geared tranny's of all the hondas, yes including the cx and vx.

also vx has more room inside, car is rounder (not a box) and seats 4 people, 5 if you add a seat belt in the middle of the rear seat.

The gearing varried by state, Californa and High altitude models had lower gearing in the CRX.
I also have a 1985 crx hf, and a civic vx, and I like the crx for it's light weight and quickness, the engine is mostly shot in it (new one sitting in the garage) and it's still really fun to drive, but I've had 3 and 4 people in it befor, and having people laying in the back hatch area is not fun for very long (had a passenger back there for 700 miles once), it's also harder to find information on repairing it, and finding some minor parts, mostly due to it's age, and it's been a really cheap car to own.
I like my vx because it has more space in the back, front seats and head room are pretty close, altho the crx has slightly more space up front, the vx has that back seat for more passengers, and it folds, half at a time so you can have large cargo and someone in the back seat, it's great, the lack of 56 vacuum hoses is also nice for when you have to work on something or truble shoot it.
If you are commuting alone, I don't see anything wrong with a CRX, passengers are the main reason for liking the larger vehicle.

i would rather have the vx, since it has airbags for safety, can seat 4 people, haul stuff, looks nicer

Forgot about the airbags if that makes a difference - some people that is a plus.

Soletek - PLEASE start a thread about your build because people are dying to see it.

Please post actual numbers with the gearing in your tranny because all VXs and CRX HFs are NOT the same WRT transmission and ECU, namely the CA versions. A non-CA CX may have a taller tranny than a CA HF, but check both gearing and final drive on your tranny to be sure. The HF should have the tallest gearing - have checked many sites on its gearing to be sure.

I want a clean CRX HF as well....I have been on the prowl for one for a while but moneys a bit tight for now. I am sure I will come across a nice hf but I will probably buy it and toss it on ebay and then cry and wish I had the cash to keep it...

Not to take anything away from Soletek (because I think his setup sounds fantastic), but wasn't there a guy on this board who had a 2nd gen CRX HF (88-91) with the Civic VX engine & HF trans? I still remember pictures of it with the front of the car sitting an extra 1-2 inches higher due to the supposed weight difference with the (lighter?) VX engine. Was I hallucinating? Where did that car go? I was dying to hear the final curb weight of it, as well as how much more MPG it would get. If anyone knows who that car belonged to, please drop a name. I hate when these projects just disappear.

Upon your request I went over my notes and did a little research on gear ratios and did find that the '88 to '91 CRX HF had two different final drive ratio sets: 2.95:1 federal and 3.25:1 CA. The '85 CRX HF tranny that I took out had a final drive ration of 3.25:1 which is the same ratio as the '92 to '95 CX-VX. The information stated that the '88 to '91 CRX HF had 3.25 first, 1.65 second, 1.033 third, .823 fourth and .694 fifth. The '92 to '95 CX-VX had the same first gear ratio 3.25, second is 1.761, third is 1.066, fourth is .853 and fifth is .702. As the ratios are so close and with the added torque and horsepower that will come from the VX over the HF, if I feel, in the end that I can use taller gears, I will just change to larger diameter tires and because the car weighs so much less than the VX it probably won't bog down while starting off. I chose the CX tranny over the HF because it allowed me to use the vehicle speed sensor and all connections that come on the VX platform. This car is going to be driven on the street so I want to be able to trust my speedometer. My HF tranny had a cable driven speedo and no check engine light in the cluster.
As I do with all of my cars, this one will get some track time and the CX tranny is a heavier duty unit than the '85 HF.

I'm sure you will notice a difference there. I currently have lightweight Nokian tires on my car (supposed to be FE friendly), running 50psi., mounted on the superlight Mazda Miata BBS wheels...a very light combination. However, I did actually notice a LOSS in MPG when I swapped to this setup from my previous set of heavier 13 inch Mitsubishi Mirage rims with big fat 185/80-13 no-name overinflated tires. Yes, those big, ugly, bulky tires still helped me net a +3MPG effective increase. Which reminds me -to those of you who go with a larger overall diameter, remember, you have to figure an 'effective' MPG, since your speedometer will be inaccurate.

Not to overwhelm, but I am something of a math nut. Just figured out that the 165/75/13 that came on the VX as original stock, had a calculated diameter of 22.74409 inches. Multiplying that number by the final drive ratio of the federal version of the HF which equals 1.026 taller gears than the VX, equals a tire diameter of 23.33544, subtracting this diameter from the previous equals a difference of .59135, so taking it a step further, the calculated diameter of a 175/75/13 (the tires that are now on the car)equaled 23.3346. taller than the original VX tire by .59055 almost exactly the same final drive ratio as the HF. Now my head's tired -- I'm going to bed.

wasnt there a 1983 crx hf? i'd would think that would be the lightest. i'd rather have a crx :p

In the US the first year of the CRX was 1984, and in 1984 they didn't have an HF in the US insted they had a 1.3L engine EPA was high 50's low 60's, but then in 1985 the EPA changed how they mesure gas mileage and that year honda came out with the HF modle, either way the 1.3L engine was higher reving and put out nearly the same power as it's slightly larger but lower reving 1.5L HF engine.
Of course this is just US modles, if you lived in Japan or a few other countries you could get a CRX in 1983.

@ Soletek: what did you do with the HF engine? Hope that can be put to a good use as well.

I actually have my eye on a pretty nice 1986 Civic hatchback Si and if I am not mistaken putting the HF engine and tranny in there should be 'plug and play' right?

i wonder what kind of gas mileage that 1.3l would get now, if you could find one.

https://www.motorbase.com/shop/profiles/by-id/241/
Includes, Si, 1.5, 1.6, Coup, Spyder. 100 pages, 200 illus, SB. a spyder crx?!

McPatrick, I still have the HF engine/tranny. Why I pulled it was because the head gasket had blown and it was burning 1 qt oil per 1000 miles. When I got the car it had 320,000 miles on it. I wanted to get a realworld baseline on what that HF engine would do for fuel comparison purposes against the VX, so I had the head rebuilt and they didn't even replace the valves when they replaced the valve guides so I bought brand new valves and replaced them myself. I also replaced the bearings on the crank and rods. The engine got a best average of 51.7 mpg. Once the headgasket blew I decided to go ahead and switch to the VX since that was the reason for purchasing the car in the first place. As for plug and play I don't have a complete answer, but the HF CA version (at least this CA version) has a 3 bbl carb and I was under the impression that the Si was fuel injected. Please correct me if I am wrong.
I have been contemplating the idea of rebuilding the HF engine in its entirety for resale purpose and/or selling it as is or for parts. No decision yet.

Honestly, people, this is too coincidental:

Ebay item: 1.3L CRX HF '84...see for yourselves
Item #250220047445

Link: (copy & paste) https://cgi.ebay.com/ebaymotors/Honda...QQcmdZViewItem

Thanks for your answer Soletek. Yes you are right, the Si is fuel injected so it may take a bit of work. Right now it still get close to 40 mpg according to the owner.

I made a deal with the owner of the 1986 Si, so I am going to pick that up next week or so. You just don't see them anymore so I couldn't resist :)

https://www.fuelly.com/attachments/fo...812c49c6ac.jpg

the early SI civic had a decent 1.5L engine, not sure what the exact number is, but simaler to what the later fuel injected 1.5L civics had, it wasn't tuned purely for power, just more power then what else was avalible at the time, from what I hear 40+mpg is pretty standard with a mid 80's SI civic.

Sweet little ride can I ask what you paid for it?

McPatrick,
Congratulations on the purchase, it looks like a nice little car.

I have been keeping a log plus photos of most of the steps I've taken to do this swap. I will share once I figure out how to use this site. I don't know how many photos are possible here, or if there is another way. At this time I am awaiting a 5-wire lean-burn setup. The car is now running on a 4-wire setup. My extra time has been spent on the car so I haven't had time to post a thread on this site. I do intend to do so. Even though it has been a very difficult process I've been having a lot of fun!

@ panamacolin: Sure. I paid $900 for it. And it has 4 brand new tires, a new battery, new brakes all around, new muffler, new radiator and a new timing belt. It also has a new head gasket and valve seals. So even though I really don't need it, when I saw it advertised on Craigslist I couldn't resist. Craigslist can be pretty addictive that way :)

Anyways, to ad something to the subject. I sold the VX and now have a 1991 CRX HF so I can compare the both. I'd say the VX is definitely more practical because it has the back seat, but the CRX is more fun to drive. So i guess the choice depends on wether you drive alone a lot and obviously also on what is offered. Either car is not offered that often anymore, because owners are holding on to it with the gas prices the way theya re going and I would jump on either if you see a good condition Civic VX or CRX HF.

That was probably my car. 88 HF with a VX engine and HF trans. The weight difference was because the car is STRIPPED. The last time I corner weighted it, it came in at about 1480 lbs with 1/2 tank of gas. I have the car on "lowering" springs now and it sits at about stock ride height. My MPG has been holding in the mid 70's. On thing I have noticed, is that I've had the same tires for about 3 years now, put over 20k miles of them, and have only lost 1-2 32nds of tread depth. Gotta love light cars!

Does the VX engine bolt right up to the HF tranny?
 

Does the VX engine bolt right up to the HF tranny?
Did you have to do massive rewiring to make it work?

Thanks