Which CRX? - Fuel Economy, Hypermiling, EcoModding News and Forum

seanof30306 · 06-01-2008, 08:58 PM

If you were of a mind to buy a CRX for a hypermiler project, which would be best?

Obviously, an HF comes immediately to mind, but, EVERYONE claims their CRX is an HF; a guy on cars.com lists his as both an HF and an SI. Guess he wants the best of both worlds.

How do you tell if it's an HF or not? Will it show up in a CarFax report?

Let's assume you can't find an HF, what would the next-best choice be?

Would an HF engine and transmission swap into other CRX models?

What about the pcms? Is there software available to be able to do your own tuning?

Also, I have my preferences set to "instant email notification", but I'm not getting notified to replies to any of my subscribed threads. Does anyone have any idea why?

Thanks,

Sean

SVOboy · 06-01-2008, 09:13 PM

The crx is definitely a great car for an ecomodder (I have one!!!)

Check the engine for a d15b6 stamp, that's the HF engine. I can grab a picture if you need to know where to find that.

But yeah, the drivetrain will swap into any crx from 88-91. Same is true of an D series engine from 92-00 (including the VX engine), as long as you have a 88-91 cable tranny.

ebacherville · 06-01-2008, 09:32 PM

My 87 hf says HF on the rear passenger corner on the hatch and on the title.. if the motors been swapped, you will need to ID the motor too.. I believe my title says CHF as the model of car.

seanof30306 · 06-01-2008, 10:38 PM

How about this?

http://cgi.ebay.com/ebaymotors/Parts...m260244724927&

What's the big deal with ZCs anyway?

I assume, for a hypermiler, SOHC is preferable to DOHC?

ebacherville · 06-02-2008, 01:58 AM

Also look up curb weights of the car your looking at usually the older the lighter the car.. depends on what your going for.. also I don't know if your stuck on a CRX, but another contender when I was looking for a donor car for my areo mods projects was the Mazda MX3, its areo is pretty sweet to start out.. probably better than the CRX. CRx tapers to fast on the rear and is very boxy up front.. but that an be changed if your up for it

SVOboy · 06-02-2008, 02:27 AM

Tapers to fast...I wonder about that. You'd think it wouldn't have clocked in at .29 cd if the flow wasn't attached.

seanof30306 · 06-02-2008, 10:39 AM

Quote:

Originally Posted by ebacherville

Also look up curb weights of the car your looking at usually the older the lighter the car.. depends on what your going for.. also I don't know if your stuck on a CRX, but another contender when I was looking for a donor car for my areo mods projects was the Mazda MX3, its areo is pretty sweet to start out.. probably better than the CRX. CRx tapers to fast on the rear and is very boxy up front.. but that an be changed if your up for it

From what I've been able to find, the MK1s came in at around 1815-1936 lbs, and the MK2s came in at around 1980-2222 lbs. Pretty sure the HFs were lighter

I've thought about the MX3, I really like the way they look, but the I4 models are pretty hard to find, they weigh 2400 lbs, and the mileage posted on fueleconomy.gov for MX-3's is nowhere near the CRX's.

PS I'm still not getting my notifications. Can anyone help?

seanof30306 · 02-10-2009, 03:18 AM

Quote:

Originally Posted by SVOboy

The crx is definitely a great car for an ecomodder (I have one!!!)

Check the engine for a d15b6 stamp, that's the HF engine. I can grab a picture if you need to know where to find that.

But yeah, the drivetrain will swap into any crx from 88-91. Same is true of an D series engine from 92-00 (including the VX engine), as long as you have a 88-91 cable tranny.

What is the VX engine? Is that the lean-burn engine?

Also, were the '96 and later D-series engines OBDII? Would you just use the PCM from the later engine?

some_other_dave · 02-10-2009, 05:52 PM

The VIN will tell you if the shell was originally an HF or not. I don't remember the details, but you can find them in one of the FAQs on The CRX Community Forum :: Index .

All of the D-series motors from 1988+ Civics and CRXes will swap into an 88-91 CRX shell. The 83-87 CRXes are not as easy to swap, because the HF and DX ("standard") models used a carburetor and had a different fuel system from the injected cars as a result. The 1st-generation Integra motor will swap into a fuel -injected 1st-gen CRX pretty easily, but not into the 88+ ones.

The HF models were the lightest, the DX (or standard) the next, and the Si cars were the heaviest. The later cars are heavier than the earlier ones, as well. The 1991 Si weighed in at just over 2100 lbs, while the 1st-gen HF was around 1650 lbs I think. (Less than 1800, I am sure.)

The HF transmission is one of the keys to getting good fuel economy. It is geared very tall indeed, with tall gears and a tall final drive. They are getting harder to find because people with other Civic-based cars like to swap in the tall CRX 5th gear for their shorter ones.

The ZC motor is one of the more powerful early D-series motors. The DOHC ones made 130 HP, as opposed to the 105-108 HP in the most powerful US-market CRX and Civic. It's a drop-in for a 2nd-gen HF or Si, and makes MOAR POWWAH! That's why it's a big deal.

To convert to OBD2, you generally need a motor from a 96+ car, complete with engine management system. The extra hassle of adding the sensors and making them talk to the OBD system is generally not worth it, because you'll be adapting the sensors to the motor, hooking them up to the EMS, and adapting that to the car. Much easier to leave out one of those steps, plus the easiest way to get all of the OBD2 sensors and such is to get them off of a 96+ Civic. Easy enough to get the motor as well.

There are cable-to-hydro kits for the clutch linkage, so you can use the later hydraulic-clutch manual transmissions if you desire. It is more expense and complexity, of course.

Using the VX engine might give you some really stellar numbers, especially if you can find an HF transmission to hook it up to.

-soD