hybrid d15, why gas mileage so terrible??
 

Alright, I made a d series motor. Block is from an d15b6(crx hf) internals are from a d15b2(crx dx), head is from a d16a6(crx si). Block has been bored 40 over, block has been milled, lightened and balanced, head has been shaved, ported and polished, 3-angle valve job. Still using stock pm5 ecu(crx dx) and still have the dpfi injection. Timing is right, and to my knowledge it seems the timing with the dizzy is right too. Evere since i put the new motor in, i have had crap for mileage, like 18-20 mpg. Also using the crx si tranny from a 91 si, 82xxx miles. My peformance has been complete crap, i ran like a 11.1 1/8th mile on stock tires, and i shifted about 6500 to 7000rpm. Any help would be appreciated. Also i never did the dpfi swap, so i realize it would help with power but is there any way i can get decent performance with this combo?

Thanks,
Matt

Re:hybrid d15, why gas mileage so terrible??
 

You getting an 02 code. Also the dpfi is complete garbage. Just convert to mpfi

Re:hybrid d15, why gas mileage so terrible??
 

ya mang. why go through all that trouble and stay with the dpfi?? oh ya btw i got a z6 mani with ls throttle body if your interested.......

Re:hybrid d15, why gas mileage so terrible??
 

not recieving any codes at all. Runs and drives like a normal rex, has a little more torque but not much, car comes a live once revved high but thats about it, still seems to just fall on its face. I have a d16y8 manifold that has been port matched with my head, but not installed, had the throttle body part matched with the h22 60mm throttle body, but sold the throttle body. I beleive the ls is the same size as the h22. I would like to do the swap but i dont feel like really making another harness. I checked all the wires with an ohmeter and everything checks out just fine, i was just kinda worried something would happen since it was not built onto the car stock. Anyone with a dpfi mpfi harness??

Thanks,
Matt

Re:hybrid d15, why gas mileage so terrible??
 

Lol...your intake mani is killing you.
The DPFI is robbing all the power.
And the MPFI conversion is easy...you just need to add some wires and lenghten some wires and put a resistor box and change the dizzy and connector

Re:hybrid d15, why gas mileage so terrible??
 

How many tanks of gas have you been through? What are you driving habits? obviously you go to the track so you must beat the ---- out of it once in awhile. I would say 21mpg is that bad, but it should get a little bit better than that. The DPFI-MPFI swap is really easy and you dont need to make a harness you simply add about 6 wires to the original harness, there are tons of write ups. If you already have a pm6 and intake mani, along with distributor this swap is cake!

Re:hybrid d15, why gas mileage so terrible??
 

Well there is about 9xxx miles on the new motor, so like 180tanks of gas. Ive hardly ever exceded 200 miles on one tank of gas. If i drive it nice, like granny style, the mileage still sucks, if i run the piss out of it, it sucks a little more but not by much. I just put a new throttle body and stuff on there i got from a friend. It is actually new, maybe had 1000 miles on it. But after the powerband this car comes a live, but is still slow. Really makes me sad after spending all my dough.

I do realize that the swap is very easy, it is more i have had to mess with this car so much, it drives me nuts to mess with it anymore. Yes i would like it done but i dont really want to be the one to do it. Also it is not the most reliable thing at the moment, probably every week something pops up that needs attention. I have fixed all of the main stuff, alternator, dizzy, started, fuel pump, throttle body, all that kind of crap, then swapped the motor. Have replaced all the front suspension pieces not with new stuff, but had some tein on there for quite a while, sold it though. Had some sways, waiting on the money for those. Waiting on the money for my ecus that i sold, both pm6's one is chipped with 8200 rpm redline, and the other is just a stock one. But i can obtain another pm6 anytime i want.

Matt