Honda D Series Forum banner

1 - 18 of 18 Posts
N

·
Guest
Joined
·
0 Posts
Discussion Starter #1
ok, i have a 1990 crx hf, it has a "d15b" no numbers after the d,ie.d15b6, i dont know how to check if its the jdm d15b or what, it has american parts so it can pass smog but i have no idea if its the jdm (sohc vtec) block or not,
it has a 16 valve head, i see no vtec solinoid, the ecu is still the hf one, and if it is i want to put a vtec head and all the other good stuff. can n e 1 tell me how to check if its the vtec block?

thx :wtf:
 

·
Registered
Joined
·
934 Posts
well the block doesnt contain v-tec the head does. It might be a jdm engine but with us smog parts. you can use a z6 head on that block if you want to go v-tec. there are serveral minime writeups on this forum, check them out. You might want to consider a d16z6(v-tec) from a 92-95 civic. Swap tech guides are here too. "if you search....you will find...." :)
 
C

·
Guest
Joined
·
0 Posts
Discussion Starter #3
there is a d15b non vtec motor...and that is what you probably have.

from what i can recall it's either the same as a b2 or weaker...

so dont get excited...
 
N

·
Guest
Joined
·
0 Posts
Discussion Starter #4
its not weak, my friend has a 95 hatch cx and i take him like nothing, but... when i start to feel power its already time to shift (stupid hf ecu). the motor has less then 30k miles on it and the head seems to be new, silver valves & springs, also the motor is a 93, so u could be right, but then... maby not
 

·
Registered
Joined
·
934 Posts
sounds like that little motor has some work done to it or at least a jdm cam. change out the ecu if you can its to econo. :)
 
N

·
Guest
Joined
·
0 Posts
Discussion Starter #6
hmmm.......the po8, or .... what? 95ex? i have no idea
 
D

·
Guest
Joined
·
0 Posts
Discussion Starter #7
The diference between the CX and your CRX is not insignificant. you have a D15b7 with tbi and a short geared transmission. He has essentially the same engine with mpfi but with a much taller geared transmission. Also, you have sixteen valves to his eight. That basically means that for the same 70 flywheel horses, you get a quicker throtle response and a higher top speed which is achieved earlier. So, of course you take him every time; even though the weights are comparable as are the thrusts, the final drive in yours gives you just that little extra bit that it takes to edge him. Unless your car has had an engine transplant, to the best of my knowledge it would be next to imposible for a USDM crx hf (which was designed specifically to post high epa milage numbers) to have a JDM engine. An easy check is that almost all (all 4 cyl) JDM engines have a higher static cr than USDM equivalent models. IF you dyno it, anything above 50hp at the wheels does not come from a USDM HF engine.
Regardless of the block, D is D (except for the D17 until someone solves the mounting problem and the rest of us can snag that block and mate it to a hot Z6 head) What you need is a harness conversion and the ecu from a EG civic EX. You dont say if yours is a stick or a CVT (if it is a cvt you are screwed) but the ecu must be from a stick. I think hondata or hasport make the harnesses. you might even consider a Mugen, Spoon, or Hondata tweaked ecu which would make your crx (and your buddy's cx) seriously hot. Incidently, not every JDM piece is going to give you better performance and those that do are well known and ourageously expensive. watch the cash and good luck.
 
D

·
Guest
Joined
·
0 Posts
Discussion Starter #8
notthepoopf said:
its not weak, my friend has a 95 hatch cx and i take him like nothing, but... when i start to feel power its already time to shift (stupid hf ecu). the motor has less then 30k miles on it and the head seems to be new, silver valves & springs, also the motor is a 93, so u could be right, but then... maby not
Ok, I didn't quite catch this. A 93 engine with 16 valves and an econo ecu (no ecu transplant was needed) so...that must be a D15b8 from a DX and your 103 flywheel hp are clearly puting his 70 to shame. The fact that he is still able to compete (he shouldn't) suggests that your tranny is fairly tall geared. Given that, Id strip it out in a garage, get the harness in and drop an exospeed tunned engine into that crx and put it all back together INCLUDING THE HF BADGES!! before you know it, you will be spanking cocky B turnkey swapers who know next to nothing about their engines.
I'd also would rebuild the tranny with an lsd and a real short final drive (i'll get back to you on a number but there are others that know more about this) You will know exactly when to shift to stay in the sweet spot AFTER the shift and with over 160 on tap and a car that is at least 400 lb lighter than any civic.....well, you get the picture.
 
C

·
Guest
Joined
·
0 Posts
Discussion Starter #9
whats the code on your ecu?

how you know it's an hf ecu?
 
D

·
Guest
Joined
·
0 Posts
Discussion Starter #10
calboi510 said:
whats the code on your ecu?

how you know it's an hf ecu?
regardless of the code, it is simple. first, no vtec is present (hx had vtec-e) second, the shift points (first up beyond 20, 2nd to about 55, 3d and 4th top speed, and fifth never redlines on a flat) third, you have 16 valves but no ecu change was needed from original engine. Therefore, you have either a DX ecu or a HF ecu. given that choice, the fact that the hf ecu would operate with the stock tranny and the engine without much change suggests that it is unlikely that anyone changed it (waste of money) Hence, HF CRX is almost certain to retain that ecu.
anything other than a P28 (ex ecu or above) is imo a why bother. hence my suggestion of dumping the current set up and getting a D16Z6. alternatively, switch the tranny -I believe the EX tranny will mate but ask others- then get a chiped ecu or a hondata box and turbocharge it for some very satisfying horses.
 

·
Registered
Joined
·
2,075 Posts
well first off the hf comes with a d15b6 and mpfi.....you probablly have a jdm d15b non vtec, mpfi......now are your gears real long if so its still prolly the hf tranny but the best ecu to swap in i sway would be a pm6 from a crx si or pg7 just to see if that thing will make power up high....the si and pg7 ecu will be easy to swap in just plug right in....btw i have a reprogrammed pm6 ecu if you want for $80.
 

·
Registered
Joined
·
137 Posts
i may be wrong but wouldnt the shift points be determined by the tranny's gearing and not the ecu? and why in gods name would he want a p28 from an ex when he doesnt have vtec?
 
D

·
Guest
Joined
·
0 Posts
Discussion Starter #15
freeturkeys said:
i may be wrong but wouldnt the shift points be determined by the tranny's gearing and not the ecu? and why in gods name would he want a p28 from an ex when he doesnt have vtec?
The Tranny gears are often pushed only to about 80% of where they could be for various reasons that include but are not limited to longevity. You certainly are correct that not having vtec, he will only use one fuel map on that ecu but the EX/SI tranny does as far as I know need an EX/SI ecu. To tell you the truth, I am not certain that the 92-95 SI hatches all had the same tranny or that it is even the same as the one on the ex's but the idea has merit nonetheless as it allows him to upgrade just the head in the future and add 25 horses and hook up a hondata box for a few more and the power shifts.

ZC-crx49, I do not believe all CRX's came with cable tranny's as the one's that I have driven had hydro's. Granted, one was a 92 si and admitedly was loaded. However, it was brand new-if I new then what I know now :( - so I am certain it did not have a heart transplant.
Hondadog, I wouldn't have thought you'd be a hot head but I do have a question: what plausible combination would satisfy the conditions of same ecu and same tranny with 16 valves and no vtec.
 

·
Registered
Joined
·
3,414 Posts
:cockbloc:
Hondadog, I wouldn't have thought you'd be a hot head but I do have a question: what plausible combination would satisfy the conditions of same ecu and same tranny with 16 valves and no vtec.[/QUOTE]

Hmmmmmm. How to approach you on this. :???: My hotheadedness could be due to the fact that there is one whole page on this post without any concrete information about what he is asking. The relevance of the guesswork going on here is not answering his/her? post.

Now if you have any other names or accusations for me. Please PM me with them. I will be more than glad to argue with you privately so no one else has to listen to us. My main post was to get to the bottom of what is originally being asked. Dont like the way I speak? I dont really give a shit!
 
1 - 18 of 18 Posts
Top