Civic EG

hi all i have been searching everywhere and find little to no info on what i am looking for.
so i guess i will post here to get some help as this looks like the best site
i have a 93 hatchback. i am looking to turbo and get the best possible mpg while shooting for 200-250hp, hp is not a factor really but it would be very nice. i have a d15y7 as of now and auto dx trans. i was thinking of turboing it and swaping the auto trans for a cx-vx 5spd with the longer gears.
so my question's are has anyone turbo'd a stock cx or vx? did you get better mpg's? i would assume with less than 100hp the turbo also boosted the mpg of the car, but i cant find any info anywhere on it.
can i do a mini me swap (just the head swap) of a d15z1 vtec-e engine on my bottom end. or a d16 bottom (so i can ger forged rods)? i know how to do a d16 head swap already
i have read my bottom end is good for up to 200hp +or- but the rods are small. are the rods on a d15z1 the same or smaller? i have heard there pencil thin.
i am really stuck on what i want to do. i know the civic vx is good for about 45mpg city and 55 hwy, it has the vtec-e engine and the long gear trans.
if i could get theese mpg numbers with a turbo installed i would be happy even tho it would be a real shame to have the slow cx-vx trans.
i get an average of 35mpg now on my completly stock dx hatchback. so turboed and way better mpg's is the way i want to go. and i am sure if i have 250hp on a cx-vx 5spd i would spank the motor and auto trans i have now.
so please please any info you can toss in here will help me out.
thanks alot for the suggestions and info

i should also add that i am not sure about the d15z1 head and a turbocharger. i heard the valves are only finger wide so i am not sure about how good this will work. i should however mention that the head will be ported and polished before installed.
any help on this too?

Im not a fan of the d15z1, However I do like the D16y5 which is also a SOHC VTEC-E Engine.

VTEC-E gives you good low end torque, Adding a Turbo Charger will give you power in the higher revs.

One of the builds i have always wanted to do was a Turbo Vtec-E Build. I might do it one day for a Daily Driver.

However I wouldn't use the D15z1, I would use the D16y5. Better torque and much funner stock. The d15z1 uses lean burn to get its crazy high mpg. Running super lean and turbos dont go hand in hand. The D16y5 isn't as finky when it comes to running lean but still gets awesome MPGs.

Btw in my EG DX Sedan powered by a BONE STOCK D16z6 and a Rebuilt Civic HX(vtec-e tranny from 96-00) Transmission I get 50+mpg on the freeway, 30's in town. With the D16z6 it gives you enough torque and power to pass people on the freeway and have fun. Much peppier then the d15b7/dx tranny the car had in it before.

cool thanks for the info. i am not a fan of the d15z1 ether. i saw somewhere that the hx trans is bigger and may have issues fitting in.
was the motor from a civic hx too?

chrono404 wrote:The d15z1 uses lean burn to get its crazy high mpg. Running super lean and turbos dont go hand in hand.

No fuel calibration is always lean. The VX is like every other Honda in that the ECU will dump the maximum fuel the injectors are capable of when you have the throttle down all the way. It only burns lean on very light loads at cruising. It is not lean when leaving from a stop. It will not be lean when your turbo spools.

The Y5 is capable of running leaner because the OBD2 system brought a crank sensor that is actually on the crank. This signal is compared with the signal from the distributor to check for lean misfires. The ECU will push it as lean as it can go.

People have turbo'd the Z1, but the Y5 is definitely the better choice. It is the same as the Y8 in all ways except for the EGR on the intake manifold, the cam, and the roller rockers.

The turbo will improve mpg as long as the calibration is tuned properly. You wont achieve boost except when you're really pushing it, and the added power gets you up to cruising speed faster. Turbos + small displacement motors were a popular choice among German manufacturers during the fuel crisis.

i think it's definitely a good plan to use the Y5, as forementioned.

i would recommend a smaller t25 turbo. it's a smaller turbo, but that's basically a little more ease of mind while daily driving your car. getting forged rods, like you said, wouldn't be a bad idea. i'd also recommend ARP head studs. they've always kind of been called "turbo insurance" haha

good luck! i'm excited to see your work!

What about the complexity of running an OBD2 motor in an OBD1 car? The D16y5 motor is going to need to be run by its ecu in order to have the proper fuel curves & lean burn, right? I'd say you could use the ecu from the D15z1 but I don't know if it will work on the D16y5. The d16y5 has a distributor that is different from every other D series engine. (I'm still not sure exactly why, I believe it's the electronics inside) And the D16y5 has an EGR valve. Plus the other things that suspendedHatch mentioned (roller rockers, crank position sensor, cam)

I was thinking run a chipped P28 with a P07 (d15z1) ecu basemap and maybe you could bypass the EGR valve and tune to compensate for the roller rockers & cam differences. Converting the car to OBD2 would be too much work.

i'll just leave this right here:
http://www.d-series.org/forums/engine-m ... ntrol.html

its the saga of a guy who 'turboed' his y5 head d15.

cliffs:
tried a chipped obd1 ecu then used hondata s300
or AEM stand alone

you would have to drive it a long time to get the return

wow thanks for all the info guys. ceep it comming

so now i guess the question is will the d16y5 fit in my 93 civic hatch? i would think so but someone said the trans is longer. i have a auto trans right now. i want a 5spd but wouldent mind the cvt auto trans i guess. i prob can get this cheep at a junkyard. so i can get forged rods cheep for this motor right?
i know i got alot to do but i want to know what motor so i can buy it and get started.