The 300hp 240z Eco results

[Meph]

Hey guys, update on my 1JZ (Toyota 2.5L turbo) powered Datsun. These are my results after my aero modifications and fuel/ign tuning.

These numbers are rough, speedo was in miles, and reading 7% slow according to needle position vs gps (hopefully the trip counter is pretty accurate to the needle) thanks to differential and transmission changes. The fuel cell was filled up to the "that looks about as full as it was before" point.

After crunching the numbers, 33.5 MPG, 14.1km per liter. Im shocked, I may not have filed up quite to the same level ( I put in 30L from gas cans I filled at pump)

I hope to keep improving this number with tuning, I've since pulled the A/F from 15.3:1 to 15.6:1 and ive noticed my injection times coming down noticeably. All driving was 90km/h and under, no P&G or anything, fair amount of steady crusing, few instances of positive atmosphere too

This is better than my DD, more excuses to drive the 300+HP classic

[MetroMPG]

Looks great!

I guess you don't have to e-test that puppy, eh? (Thinking about A/F ratios affecting nitrogen oxide output.)

Any more aero mods planned? The most obvious one that comes to my mind is the sculpted headlight covers I've seen on some of these cars.

[Frank Lee]

I've always liked that body style ( at uncle for selling his without telling me)

[theycallmeebryan]

Nice car! And thats a nice Grand National in the 2nd pic.

[EdKiefer]

I take it your running in open loop (no O2 sensor feedback ) to get those lean A/F at cruising speeds (low rpm) ?

[Meph]

hey guys, the wind tunnel tests show a very small cd reduction from headlight buckets, somewhere int he .00x range so i think ill leave it for now, I checked my trip coutner vs googe maps and my trip counter reads 6.75 miles for a 7.5mile actual so an 11% under, using this conversion I was actually above 35MPG!!

I run an aftermarket ECU and wide band sensor, the wide band allows me to set a cross over point of its Narrow Band mimic output. So all i need to do to change the a/f is adjust 1 setting my fuel maps are all around 14.7-15 and the ECU will pull fuel when crusing to get the desired a/f.

Im considering swapping the 3.54 diff for a 3.03 LSD at some point, that will drop revs even lower, a lot of my cursing is at -18 to -20 In-hg, so a little more load and lower RPM maybe help out even more.

[EdKiefer]

Originally Posted by Meph

hey guys, the wind tunnel tests show a very small cd reduction from headlight buckets, somewhere int he .00x range so i think ill leave it for now, I checked my trip coutner vs googe maps and my trip counter reads 6.75 miles for a 7.5mile actual so an 11% under, using this conversion I was actually above 35MPG!!

I run an aftermarket ECU and wide band sensor, the wide band allows me to set a cross over point of its Narrow Band mimic output. So all i need to do to change the a/f is adjust 1 setting my fuel maps are all around 14.7-15 and the ECU will pull fuel when crusing to get the desired a/f.

Im considering swapping the 3.54 diff for a 3.03 LSD at some point, that will drop revs even lower, a lot of my cursing is at -18 to -20 In-hg, so a little more load and lower RPM maybe help out even more.

Ok, So your able to set a offset voltage to lambda to trick it from normal 14.7 .
If my memory is right you said your using haltech stand alone ECU ?

[Daox]

Congrats. Thats some pretty decent mileage for a huge amount of power (and a beautiful car).

[Meph]

Originally Posted by EdKiefer

Ok, So your able to set a offset voltage to lambda to trick it from normal 14.7 .
If my memory is right you said your using haltech stand alone ECU ?

The haltech works off a cross over voltage, 500mv right now. The wide band has an output that mimics narrowband cross over voltage, I have set the wide band to cross over (500mv ) at 15.6:1. The control unit of the wide band will produce a voltage signal mimicking a narrow band but tuned to the a/f ratio you desire. Hook it up to the ecu and your golden

[EdKiefer]

Originally Posted by Daox

Congrats. Thats some pretty decent mileage for a huge amount of power (and a beautiful car).

One big advantage If that is based off 240/260Z , there weight was pretty light at around 2400-2600lb and with new motor its probably even lighter as those were long L6's (cast iron blocks ).