FE not so good for Civic

[kamesama980]

The easiest way to check for a LSD is to jack both drive wheels off the ground with the tranny in gear and try to turn one wheel. with an open differential, it'll be easy as pie. with a LSD, it'll range from difficult to impossible by hand.

The fun way is to do a burnout...2 tire tracks=LSD. 1 tire track=open diff

+1 keep the engine close to the peak torque when accelerating or fighting wind etc for best FE, lowest rpm without lugging to cruise

[GasSavers_broadwayline]

Originally Posted by kamesama980

The fun way is to do a burnout...2 tire tracks=LSD. 1 tire track=open diff

This is extremly inaccurate with most honda trannys, my open diff will leave 2 marks 98% of the time doing a burnout on pavement.

[maxxgraphix]

I got a tach now. In 5th at 60mph my RPM is about 2600. Sounds about right for this motor to me.

Today I changed the O2 1 wire to a Bosch 4 wire Universal. The heater circuit is wired to be just ON when the key is ON.

Overall it runs better. I'll post back on MPG after a 100 miles (typically 1 day).

Also it's NOT a LSD. The snow and ice this weekend proved that.

[VetteOwner]

maybe the new O2 sensor was the culpret OBD1 cars use it as a primary scource to conrol fuel air mix, when it doesnt work right it goes into default mode which is usually richer than leaner

[kamesama980]

Originally Posted by broadwayline

This is extremly inaccurate with most honda trannys, my open diff will leave 2 marks 98% of the time doing a burnout on pavement.

*shrug* touche. I'm used to RWD.

[GasSavers_Ryland]

the CX and VX tranny are the same so your engine speed at 60mph should be less then 2,000 you shouldn't see 2,600rpm in 5th gear untill you reach about 85mph, also your tires are almost 1.5 inches wider then is recomended, if you look at that in terms of weight, a quick search on tirerack.com shows that "light weight" 17" rims weigh around 20 pounds each and tires are 19-21 pounds each as well, so 40 pounds per wheel/tire combo, lets now compare the stock VX rims, 11pounds each with a 14 pound tire comes to 25 pounds total, 15 pounds less per wheel/tire, 60 pounds less total rotating weight on your vehicle, and people who race anything will tell you that a pound of ratotaing weight saved is like 3 pounds of body weight saved, now add to that the lower rolling resistance that is gained with narrower tires, and sudenly your mileage makes a big jump, when I switched from 175/70-13" tires to 165/70-13" tires, the handling improved, acceleration improved, the car just felt lighter and more nimble, so unless you spend alot of time going a consistant speed around a race track, I don't see a need for such wide tires, I've never had a problem with cornering or traction.
I also wonder what modle of D15B you have, as there were atleast 3 differnt ones sold, one was a non-vtec, one was a single stage vtec, and one was a duel stage vtec, and from what I've read, it can take a little bit of skill to wire them up properly and that it was often left undone.

[maxxgraphix]

At those RPM's I have the VTi trans (original D15B 5speed). The D15B's only came in 2 flavors.
http://asia.vtec.net/article/d15b/

2 stage Vtec - most common (what I have)
and
3 stage Vtec - hard to find and later years. Has 2 Vtec solenoids.

I'm trying to trade the rims and tires for some 15's or 16's. Rides too rough.

I changed the O2 to a 4 wire Bosch and plugs to NGK V-Power. FE jumped to 39.5mpg
I used key on power for the O2 heater since the P08 doesn't support it.

The Vtec is wired right. Works well. I got a schematic and since I have a VX chasis, very simple. Check out http://www.hondahookup.com/manuals/

[civic94]

maxxgraphix, i think you have an ex tranny just like mines, 60mph is at 2600, 70 is at 3100, 80 is at 3500. in other words, if you floor your 1st gear and it hauls *** for a 1.5 liter engine, you pretty much have a ex tranny.

i thought i had a dx tranny, but i found out after i sat in a friends ex that the rpms were that high, which sucks.

[maxxgraphix]

I'm sure that the trans came with the D15B. It sounds like the same as the EX tranny you have. It will smoke the front tires until you let off. That was with 205/40/17's. Reminds me of my Civic CRX Si.

Is that your MPG? 29.33? I only got the 39.5 once. Today, I calculated at 18. But I filled up on unlevel ground. I'll test again. I really want 40mpg. Many others with D16Z's and turbos say they get 36mpg. What engine do you have?

I sold the Motegi MR7 17" rims and tires today. I'm getting a set of Honda Del Sol 15" Fat Fives next week. I'll order a set of new tires from TireRack and might step it up an inch to drop the R's.

Almost all our highways around here are 65-70, but we drive 75-80. Even my back country roads are 55. I'd rather be in 4th at 55-60.

I had a Saleen Mustang with a 355 gear and 90% of the time I had to stay in 3rd and 4th to keep under 60. I ran it up one time and shifted out of 4th to 5th @ 120. Nothing like American V8 muscle.

[maxxgraphix]

Here's a link to Honda gear ratios
http://www.knology.net/~jediklc/gearratiosdseries.htm

It looks like the final drive is 4.25 EX/SI, 4.05 DX, 3.25 VX / CX

Might explain the 7300 rpm red line on the tach.