Finally my D15 motor is on its way!!!

[SSJSubgeta]

Whats up fellas,

I just got my motor ordered a D15 single cam V-tec.
I will put this in my HF, now i have a hand full of questions....please help.....


1. How hard is it to do this swap, I know how to put the motor in im talking about the wiring? is it hard? how long would it take?

2. Will my HF axles fit with this motor or will i have to get new ones?

3. Will i need a ECU to be compatible with the D15? or can i use the one in there already?

4. I know this is a drop in motor, so i figure will i need new motor mounts or could i just use the old ones?

Well there you go i will have pics of my CRX up soon Its currently being stripped off paint and it will look ugly...i got it for $400, but it looking good everyday.....

[civicdemon91]

ok well im no mechanic but if its a vtec ur best bet is to get a p28 ecu an get a conversion harness obd1 to obd0 an as far as motor mounts?i don't think u will need new ones if its a d series motor should line up an drop in perfect

[travagliante]

are you using your hf transmission?
Then use all your stock axles and transmission

Motor Mounts:
Old ones can be reused. Do you have a/c. Most likely when you take that mount out it will need to be replaced.

Ecu:
For the easy route id say go with a pm6 and a vtec controller, or a chipped pm6 with p28 maps.

If you dont convert to obd1 you will need a obd0 distributor, because a sohc vtec d15b is obd1.

The best ecu would be do what he said. Convert to obd1 and use a p28.

The quickest and easiest way (half ass though) is to use you hf distributor and stock ecu. Swap harness, make it plug and play. Bad bec. no vtec, crappy ecu, etc.



If it were me id convert to obd1 with a p28, not really that hard, but just time consuming with the wiring.

[turtlecrxsi]

pm6 ecu and si dizzy with vafc for vtec... (if I ever get a y8 head that's what I'll probably do)

Is your d15 vtec coming with the Intake Manifold? I'd swap out the hf manifold cuz it's smaller...

[civicdemon91]

yes like he said did a swap on mine did a d16y5 motor don't laugh yall but the mounts were the same lining up yes use ur hf tranny but check ur clutch before puttin it back together since u got the tranny off just replace it an use ur old intake mani an ur exhuast mani will bolt up the same but i would really recoment doin the p28ecu an obd1 obd0 conversion harness did mine didn't take long at all plugs right into ur ol plugs an there will be a couple extra wires hangin off so u can wring in vtec like ur vtec solinoid an pressure switch good luck with the swap ooo by the way don't get a chipped ecu if u go the route get a virgin not chipped trust me do some mods before chippin

[SSJSubgeta]

ok ok let me get this straight....

the motor im getting is a jdm d15b sohc vtec.
Longblock, comes with the complete intake manifold, and exhaust manifold. I doubt i will be using my HF tranny since it was made for an economic mileage set up. I want a perfomance one Si or DX around that.

so i will use my stock axles (HF axles are 23 spline).

As for the obd0/1? I know the HF models have MPFI. So do i need to wire it to obd1, or is it obd1 already? D15b vtec sohc is obd1.

The ECU PM6 or P28? which one is better? or does it matter, i might get a Spoon chip on it, but i dont know yet.

I basicly want to swap the motor, make it run with vtec, after that i will upgrade with a air intake, exhaust....and so on.

[Hybrid1990crx]

If you want to use a si or dx tranny, you will have to change axles si and dx are 26 splines. you'll also need si hubs. A dx tranny is basically a HF tranny but without a 5th gear, so you dont want that for performance. Spend the money for a Si tranny you'll thank yourself for not skimping out in the long run. you can use your stock mounts, but they might be a little beat after years and use, so new oem mounts will probably help, or get engery inserts a shop will press them in for fairly cheap. I'd also get a obd1 ecu and get a conversion harness to run it, but you could also do what turtle said and run a pm6 with a vafc, or if you are on a budget get a rpm activated switch.

[SSJSubgeta]

sorry for the late update but its here and i will take pics of it over the week when i get a chance...keep posted...

[Scott82]

Hey SSJ, I am about to put a D16Z6 in my 89 HF, i am going to convert to OBD1, traviglante knows whats up with that. Get the P28 ECU, if you don't you wont have the fuel curve for Vtec. I am going to use my HF Tranny, but i am not building a race car yet, i am just wanting a daily driver and still get bad ass gas milage on the interstate, but i am putting a stage 2 clutch in for the 92-95 civic si, and the D16Z6 flywheel so i can have some good grab in 1st, 2nd, and 3rd, after that i am going fast enough for a daily driver, i am thinking with the HF tranny once you get to about 35-40 mph 2nd and 3rd gear will be fun, at least a little more fun that the tired 62 hp if ya know what i mean. Well, keep in touch and maybe we can help each other with wiring and what not, PM me and we'll swap email and phone if ya want so we can try and help each other through the swap. Good luck man

[SSJSubgeta]

yea thats what i was thinking too scott, but i heard if we rebuild the HF tranny and mix some components from an Si it would purely make a nice tranny both for performance and milage. I read of it being done with some little mods ill look up tons of info on it and i found a nice disc brake set up for a 4th gen civic and a 2nd Gen CRX, ill post later on in like 1 hour or so...

[Scott82]

Yea i eventually want to go 4 whl disk brakes but that another project after the motor and body work. The HF Tranny is not geared all that bad, it's just had 62 HP turning it over in my opinion. Has anyone seen the web site where you can calculate you RPM and get your speed and Vise versa, well, i ran across it one time and entered in all the numbers and heres what i got

Vtec Starts
1st@22mph
2nd@43mph
3rd@68mph
4th@86mph
5th@103mph

ok here is something that i doubt would be fitting in fith gear, but i calculated the redline with the HF Gearing too
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]

Now i doubt 4th and fifth gears will ever wind all the way out, but i have hit 120mph going down hill in my HF and with this swap i will be close to doubling my HP and have quiet a bit more low end torque so i figure that it will be a big difference that the 62 hp stock. and plus i don't want to go over 120mph untill i get better susp. cause is shakes like crazy when ya get that fast, so i definatly need some work done before i try and tackle anything faster than that.

[Ones&zeros]

i agree w/ the motor mount put energy suspensions, and as for the db15 vtec sound cool.

[SSJSubgeta]

i got a quick q? for scott as well as everyone here? whats the difference in performance/quality between Exedy and ACT clutch systems.

From what i can tell if you want some race performance/quality and hard durabily, its ACT all the way.
Price range: $120-$450

But for a person on a budget and for performance/quality, upgrade i think Exedy is the way to go...
Price range $80-$300

what do you guys think?

[Ones&zeros]

I Went W/ A Center Force Stage 2, I Should Have Coughed Up The Other Hunderd For An Act Tho.

[Scott82]

I myself am getting an exedy clutch kit, however i have never had the experince of an exedy clutch kit so we'll see how it goes, and i have heard good things about center force also. As far as i can tell, as long as you are getting a racing clutch, sure certain ones are better for racing, but perform the same as a daily driver. I have heard if you get a really good racing clutch that you have a really stiff pedal, so i guess it just depends on what your going for, a race car or daily driver.