How did I get here? Ex-drag racer turned mpg freak

[Jacktuned]

Hey guys,
First off I have to thank all the members on here because I was able to get a lot of good ideas and techniques from this site before I registered as a user.

History- I am 26 years old. I've been a certified mechanic since 2008. I graduated from universal technical institute and have worked for honda and ford up until 2.5 years ago when I decided to open my own shop.
My roots are deep in 92-95 civics. 3 years ago before I started my shop I had a prelude engine swap in my 1992 cx hatchback with a 61mm turbo on it pushing 18psi on pump gas. The car went 10.81 @ 137mph in the 1/4 mile! I tuned it myself on the highway with a wideband and egt gauge. I will attach a picture of that car in here for your viewing pleasure, it's pretty cool!

Anyways, on to the reason I'm here.
About 4 months ago I picked up a 1992 dx hatchback 5 speed for $300 on craiglist. The car was not running, all it ended up needing was the main relay for the fuel pump! After getting the car I updated all the past due maintenance.
Timing belt & water pump, bushings, tires, exhaust, oil pan etc etc.

About 2 weeks ago I decided I was going to drive to Indiana in March. This is were the wheels really started turning and I started trying to come up with ways to improve mileage, my goal is 50mpg on the highway for this trip. The drive will be around 2,300 miles round trip. Realizing that any small gain will pay off pretty big on this trip, I went crazy and took 2-3 days off and did a bunch of mods to the car at once. I really wish I could have done some A-B-A testing, but the gains are there and they're great!

I was getting 30-33mpg before these mods for several tanks. It is cold this time of year in Maine, so the numbers reflect that.

Mods so far:
Warm air intake made from aluminum ducting
Full front air dam- plastic
Passenger mirror delete-factory
Slim Drivers mirror-ebay
Front tire spats made from rear Subaru mudflats
Exhaust manifold flange air deflector
Rear lower control arm air deflectors
Rear civic Vx air diffuser
eBay exhaust manifold 4-2-1 style
Home brew Map sensor enhancer
Aem uego wideband air/fuel sensor
Air intake temperature gauge
A/c system delete
Engine kill switch for coasting

The best 3 mods so far if you ask me are
1. wideband o2, which makes adjusting the map enhancer super easy.
2. Map sensor enhancer (potentiometer to tell the Ecu different inputs for leaner air/fuel ratios.
3. Warm air intake. It's 0-20 degrees Fahrenheit here this time of year, so this helps big time.

Future mods:
Vx aluminum wheels will be here Friday. The steelies and studded snow tires gotta go!
Belly aero
Maybe a cx/vx transmission
Remove unneeded weight
Rear wheel skirts
Small kammback

I have not been on the highway for any testing before or after the mods, but just driving the same roads around town I'm getting 41.5mpg (this number doesn't include the tire spats or air deflectors as I have just added them). The driving mostly consists of 35-50mph roads, hills and traffic. I'm really excited to see what it does on the highway! I keep air fuels around 16.5:1 cruising.

Another wrench in my averages is I found my fuel supply line was rusted and actually dripping fuel when pressurized! I found that this morning and repaired it. I had been smelling fuel for months and just thought it was the 24 year old Evaporative system failing..oops

Thanks for reading, sorry for being long winded! If you have any further ideas for me please comment!

-jack

[Jacktuned]

I can't post pictures yet

edit
Pics are up

[user removed]

Welcome aboard.

regards
mech

[Fat Charlie]

Welcome- I know how you got here.

Performance driving is performance driving, and dragging kind of gets old after a few seconds- there's only so long you can continually accelerate and then it's over. It also gets frowned upon on most stretches of road and in most situations.

You can hypermile anywhere, for as long as you want and in any conditions. Mods can be as easy or elaborate as you want, as redneck or polished as you want, visible or stealth. It's all you.

It's hard to do up in our neck of the woods this time of year, though. But wait until summer- you're going to get disappointed with "only" 50 mpg, especially in 35-50 mph with hills. That's MPG City!

[elhigh]

Racer guys know what's up. Go fast vs. go far, the goals are different but the techniques draw on similar knowledge.

If you were to add some kind of cowling, maybe just a sheet of aluminum, to shroud the intake at the exhaust header a little more, I think you would see an improvement on your intake temps.

Absolutely start a garage page for your ride. It's too bad we don't have numbers for what you were getting at the start, but pushing from low 30s to low 40s is huge.

For some inspiration, take a look at The Donkey CRX. He's got a ride similar to yours and has pushed it to cartoonishly high fuel efficiency records. I think he has the better engine for it but if you're as good at wrenching as all that, that shouldn't be a big problem for you.

Is anyone besides me a little sad the new tire spats don't say "Outfront?"

[Daox]

Welcome to the site. Nice mods list.

[Jacktuned]

Originally Posted by elhigh

Racer guys know what's up. Go fast vs. go far, the goals are different but the techniques draw on similar knowledge.

If you were to add some kind of cowling, maybe just a sheet of aluminum, to shroud the intake at the exhaust header a little more, I think you would see an improvement on your intake temps.

Absolutely start a garage page for your ride. It's too bad we don't have numbers for what you were getting at the start, but pushing from low 30s to low 40s is huge.

For some inspiration, take a look at The Donkey CRX. He's got a ride similar to yours and has pushed it to cartoonishly high fuel efficiency records. I think he has the better engine for it but if you're as good at wrenching as all that, that shouldn't be a big problem for you.

Is anyone besides me a little sad the new tire spats don't say "Outfront?"

I got up to 120-130 degrees Fahrenheit intake air temps when ambient temperature was around 30 degrees! I'm going to have to remove some of the aluminum ducting when it starts to warm up around here or I'll have the engine gasping for air haha

I'll check out the Crx, thanks!

Also, if anyone wants to chime in on this idea-
I have an LED that flashes when the radiator fan comes on, it's a lot more frequent that it's on than I would have thought. I was thinking about putting a full size radiator in it from an Acura Integra with twin fans. It won't take a lot of modification to do. The question I have is-
Will the added weight and draw of 2 fans and a larger radiator equal the same loss as making a vent in the front air dam for cool air?

[user removed]

If the fan is running too much be careful about just replacing the radiator with anything oversized.

The fan should not run at all if you're moving at any decent speed.

Your old radiator may be clogged up to the point where some of it's cooling capacity is not there. This can make the fan run more and more unitil it can't cool the engine. In colder weather you should easily feel a difference between top and bottom hoses, indicating the radiator is removing enough heat for the engine to run cool enough.

If you decide to replace the radiator understand it COULD hurt your mileage. I would just put in what it called for as you are going to get more distance for the same fuel it stands to reason you need less cooling system, thus less heat escaping to the atmosphere.

I would remove some grille block most of my cooling fans rarely run unless I'm stuck in traffic crawling along and it's hot outside.

regards
mech

[Fat Charlie]

Like Old Mechanic says, maybe it's time for maintenance instead of modification. A brand new OE-sized radiator will probably have more flow than one with 24 years of crud in it. Going new and oversized may be too much cooling.

I wouldn't worry about the fan draw, because you shouldn't need much fan. Weight hurts on starts and uphills and helps on the glide and the downhill, but a hole in the air dam catches air whether you need it at the time or not.

[mcrews]

short story on radiators. my 02 Q45 was over heating. changed the thermostat, changed coolant etc. THe manual said 1. check for blockage. I didn't "see' any so I moved on.
When I finally replaced the radiator, I dropped it out and about 8 oz of dust/dirt fell out....and that's not counting what was wedged in!!!!

I drove on ranch roads to visit a bubby in texas. The dust and dirt built up and blocked the air from flowing thru.
THe stock replacement worked great!!!