100+ MPG CRX HF VREX - help needed!
 

I'm starting initial work on my 100+ MPG CRX with a VX engine swap. My mechanic has asked for a detailed list of what I need to start. First - I appreciate any help. Second - if anyone has parts they wish to donate, I will gladly accept anything including backups.

Here is the initial list - which I will modify over time.

* Need a clean 1988 CRX HF shell with zero rust. MUST be the early 1988 HF with pillar mounted seatbelts, sometimes referred to as the 1988 1/2 even though it's the first half.
* Civic VX D15Z1 engine and transmission with exhaust manifold, downpipe & catalytic converter included
* VX engine mounts
* VX Shift linkage
* VX engine harness
* Non-California P07 ECU with lean burn
* VX CV shafts (may be different if I use the Wagovan transmission - I need help with this)
* New 5-wire O2 sensor
* VX EGR control box
* CRX Si suspension. I know this will add weight but I would like the added stability without starting with an Si shell. The Si has steel bars in the doors which add weight, moonroof which adds weight and can increase drag, and door-mounted seatbelts.
* Oil cooler
* 195 degree thermostat. If I'm going to do all of this, running hotter means needing the system ready to handle heat demands.
* K&N air filter setup
* Remote oil filter setup. I'd like to run Amsoil in the engine with a dual filter remote system. I'd also like to run Amsoil lubricating products in every single spot I can - wheel bearings, transmission, etc.
* Roller Wave pistons from TheOldOne.com. These give more swirl and better mileage. Not cheap, but I'll get there eventually.
* Honda Insight or VX wheels with moon discs
* LRR tires - need recommendations
* Full spoilers all the way around
* Belly pan (will be custom)
* Carbon fiber hood or aluminum?
* Quick-release passenger seat
* Racing seats for lighter weight
* VX wheels or lighter
* LRR tires
* Helium filled tires
* Antenna delete
* Rear wiper delete
* SuperMID
* Plastic or composite fuel tank like the Insight. May use an Insight fuel tank if possible

* Honda Civic Wagovan transmission. I need to find out if the Wagovan transmission is hydraulic or not. What I want is the 6-speed (5-speed plus granny gear) out of the Wagovan so I can get the best gearing. Wagovan was manufactured 1988-1991, so it should be similar to the CRX transmission. Apparently I need a 1989 or later - have seen reports that the 1988 is not the same as the 1989.
* Custom gearing for transmission

* HF transmisson from 1989 or later apparently. Need the gears out of it especially including final drive.

* Conversion harness - buy one from Rywire?

* Lightweight racing seats, which I really have no idea about. I'm very open to suggestion. I'm 6'3" and all upper body so they must be as tall as possible.

* New carpet kit for the floor. Let's face it, 20+ year old carpet in a vehicle that's likely going to have seen 100,000+ miles is not going to be pretty. Plus I should be able to save a few pounds when I put in new carpet and peel out all the junk underneath that's accumulated. Suggestions welcomed, especially from racers - need carpet but want to save weight.

* New fuel tank system. Anyone know a custom tank fabricator out there? Stock is 10-12 gallons on CRXs. I'd like to get 15-30 gallons and do not really want to use fuel cells - want to have a single tank period. Likely will involve losing the current spare tire holder.

* The best head gasket I can find. I appreciate recommendations here. I don't intend on needing a new one for a long time.

The vehicle will likely be stripped down to the frame, wiring completely redone, etc. Should I have the monocoque frame stripped and powder-coated, or does anyone have other ideas for the finish? I'm thinking of a red, white & blue paint scheme, complete with stars. Think Bicentennial.



What else do I need to get started? And again - donations to this project are sincerely welcome. I can use ANY parts you might want to donate. Right now my funds are virtually nonexistent for this project and I'm looking to scavenge anything I can.

Sounds like a great build!!! I will start looking through all my supplies to see what I can donate to a awesome cause.:thumbup:

Sounds very interesting.

Why put carpet in the whole thing? Why not just mats or partial carpet in the front seat? You're planning some extra weight from the Si suspension, might as well start to make it up there.

The car comes originally carpeted. The CRX has some fairly loud road noise already, so I'm going to replace existing, but get it back to original condition or better.

I have a not so secret goal of trying to make it cross-country on a 30 gallon tank of gas. Basically I want to show the world that 100 MPG vehicles are not only easily possible, but possible with stock, off-the-shelf parts. We have had this technology since the 70s, much of it actually since the 60s. The Detroit automakers did not put things into production that they could have.

The 1989 Pontiac Firebird Trans Am actually has the same coefficient of drag as a Honda CRX HF, yet it's a muscle car weighing nearly double the weight - and got over 34 MPG highway. I want to prove to the world that a production vehicle COULD be made that gets 100 MPG.

Plus it will be my daily driver when finished. I am figuring it will cost me nearly $20,000 to complete, but I hope to offset that with donations and sponsorships. I am 6'3" and about 220 - so this isn't something I take lightly as a daily driver. I just can't take it without the carpet. =)

I was under the impression that you were removing the padding/soundproofing stuff from under the carpet.

I think you will be able to do it. If I can pull off 75mpg on the freeway, with a 60mph avg. with even less aero then yours.

Good Luck on your build!

Great plan!

Are you planning on using an automatic transmission from the wagovan and swapping in the HF or VX final drive?

I would think that the VX 5 speed tranny will offer the best gearing (and weight savings since the wagovan tranny also serves as a transfer case for 4WD). Even though the wagon tranny has granny + 5 speeds, the top gear set is likely lower (less overdrive) than the VX 5th gear set so even with the vx final drive, it would be revving higher than the VX in top gear.

great start, I would recommend:

-vx wheels with moon discs (lightweight and aerodymanic
- keep the 12 gal gas tank, a bigger tank would be more weight
- I think there is 1.3 liter honda civic engines for the 92-95 in europe/japan? that might be better for FE if you can get your hands on one.
-get LRR tires with a very high psi rating for less rolling reisitance


100+ mpg will be very hard to attain, but it might work.

An oil cooler other than the factory oil warmer?
Get a fully programmable ECU vs. the factory P07

Good luck! :thumbup:

The car IS going to be manual. This vehicle will run HOT so I want all the cooling I can get. Oil cooler FOR CERTAIN. When I do my cross-country trip I'll hit a lot of mountains. Belly pan will be used - have to make sure I've got enough cooling.

Will be adding Honda Insight type tires with LRR to my list - thanks for the reminder. Any specific recommendations? Not sure what's out there right now but I'm interested in any specifics you might want to let me know about.

Adding moon discs to my potential checklist.

Honda Insight or VX rims? Benefits to each? Remember I can borrow from the VX as well as the Insight when needed.

Will likely put skirt spoilers on the vehicle as well for aero. Best ones you can think of let me know. Adding the above items to the beginning checklist.