'91 Civic LX

Hey guys, i have some questions. they are sort of newbie questions, but i'm a noob to this part of the forum. i am upon purchase of a 1991 civic lx 4 door. i was just wondering, what engine does this car come with? would it make any difference if i swapped in a D15b SOHC VTEC engine? if i were to do this swap, what axles would go this engine, since the does not come with axles. also, could i use my stock ecu on this swap? thanks for the info.

projectsilvia97

:feedback:

it come with a d15b2 non vtec engine with dual point fuel injection. you would have to convert the car to multi point fuel injection for the vtec swap. you would need a new ecu for that too. the axles will work since you need to use your stock tranny, which will bolt up to that engine.

so if i got the D15b from hmotorsonline, i wouldn't have to buy there tranny because it would bolt up to my tranny? same with the axles right? where would i get this new ecu, from hondata or something? thanks for info GTA

Ummm...yes. Your tranny & axles will work if you get the SOHC VTEC D15. You should be able to get the ECU from the same place you get the motor. Or you can keep the ECU you already have & hook up an RPM activated switch for the VTEC.

A buddy of mine swapped the VTEC D15 into his CRX & he used the stock ECU with a toggle switch for the VTEC (NOT recommended). A RPM activated switch can be bought from MSD for about $30.

*Edit* My bad, the friend of mine that did the swap was starting with a Si platform. Greg's correct in that you have to convert (the wiring) to MPFI. That should be pretty easy. You could always get an Si wiring harness & ECU off eBay for less than $200 (total for both).

the one on hmotorsonline is just the long block though. do they sell ecu's there? or should i go hondata or somethin?

yes, they sell ECU's there. And the 'long block' just means that it doesn't include the tranny - which you don't need anyway.

If I were you I'd just find a CRX (or Civic Si) ECU - I think it's the PM6, but I could be wrong. Then just do the MSD RPM activated switch. It would probably be cheaper than the ECU from Hmotorsonline...

you can find ecu's anywhere on the net for civics..you just gotta look harder..ebay, thepartstrader.com, they all got it ..

-meng

what is the ecu called again? could i find this on hondata?

I'm sure you could find a Hondata that would work, but it probably won't be cheap... You could find a CRX/Civic Si ECU for about $50 (maybe even less), and do the RPM activated switch for about $30. Why spend more on just the ECU?

Ummm...yes. Your tranny & axles will work if you get the SOHC VTEC D15. You should be able to get the ECU from the same place you get the motor. Or you can keep the ECU you already have & hook up an RPM activated switch for the VTEC.

A buddy of mine swapped the VTEC D15 into his CRX & he used the stock ECU with a toggle switch for the VTEC (NOT recommended). A RPM activated switch can be bought from MSD for about $30.

*Edit* My bad, the friend of mine that did the swap was starting with a Si platform. Greg's correct in that you have to convert (the wiring) to MPFI. That should be pretty easy. You could always get an Si wiring harness & ECU off eBay for less than $200 (total for both).


ya I believe it would work with an activated switch. I believe however, that the JDM D15B VTEC is the one with the 3 stage VTEC, I think you could run it with an RPM switch however, but I don't know if it would work properly (all 3 stages). I am not sure but I would think that you would need the correct ECU to run that (so you couldn't use one from a D16z6 or y8)....I think atleast, never had one.....

what exactly is the RPM activated switch?

do all the '91 civic sedan models come with the same engine?

what exactly is the RPM activated switch?

I've never personally used one, but I know people who have & they liked them. Go here (http://crx.honda-perf.org/articles/z6swap/z6swap.html) for more info.

do all the '91 civic sedan models come with the same engine?

No, the EX has the D16A6. All the others have the D15B2 or D15B1.

wouldn't it just be easier to buy a vtec controller? what rpm does the vtec kick in at on the D15b

Um a vtec controller is the same as a rpm activated switch. A vtec contoller is an electronic device. and a rpm activated switch is a dial the you turn till the rpm that u want vtec to kick in. You can make vtec kick in whenever you want but its best to have it kick in over 4500.

oh and the crx hf engine is a d15b3 not a d15b1 or d15b2

I was just going by my Helm's manual. Personally I've never heard of a D15B3, but that doesn't mean they don't exist. And the Helm's I have doesn't list an HF, but that may be because it's for the Civic...

You're right about the VTEC controller, but those are usually pretty costly (at least the ones that I've seen). I was just trying to suggest an inexpensive alternative if this guy can't get the ECU he needs.

thanks for all your help CZ-R

would the p28 ecu work for this swap? if so, where can i find it?

a pm6, pm7 will work with a vtec controller or rpm switch. Any ecu from a 92-00 vtec ecu will work but u will have to convert over from obd0 to obd1 or 2. You could use the ecu, p30, pwo, and dohc vtec engine, but has to be chipper for sohc. Many choices.

and about the d15b3 thats my fault te d15b3 is a single carburated engine. My fault. Sorry again.

ya I believe it would work with an activated switch. I believe however, that the JDM D15B VTEC is the one with the 3 stage VTEC

No, it's not... singled stage VTEC engagement, just like the D16Z6.

Si/EX ECU and RPM switch will work just fine, as long as you tune your ECU for the extra air intake at higher RPM VTEC activation.

Although, the P28 is what I used for my swap.

No, it's not... singled stage VTEC engagement, just like the D16Z6.

Si/EX ECU and RPM switch will work just fine, as long as you tune your ECU for the extra air intake at higher RPM VTEC activation.

Although, the P28 is what I used for my swap.


it says here its 3 stage....but your right, I would imagine the Si ECU and RPM switch would work.....
http://www.leecao.com/honda/vtec/3stagevtec.html

I know what that says... but that's not the motor that hmotorsonline is selling.

If you pull one apart and want to prove me wrong that way, that's fine. But otherwise, from talking to the tech person at hmotorsonline, the D15B they are selling is almost the same as the D16Z6, except for the smaller displacement.

I'm sure you can call them and ask them about it, they were quite friendly over the phone.

I know what that says... but that's not the motor that hmotorsonline is selling.

If you pull one apart and want to prove me wrong that way, that's fine. But otherwise, from talking to the tech person at hmotorsonline, the D15B they are selling is almost the same as the D16Z6, except for the smaller displacement.

I'm sure you can call them and ask them about it, they were quite friendly over the phone.

I am sure your are right about the hmotorsonline thing. I was just not aware that there were two d15b vtec motors.......

I am sure your are right about the hmotorsonline thing. I was just not aware that there were two d15b vtec motors.......

And I've yet to come across an actual "3 stage vtec" engine anywhere. And I've yet to see any REAL information proving that there is a D15B with 3 stage vtec system, and am starting to think it's bullshit/hype to sell a slow selling product... I haven't seen any dyno results... I've met pleanty of people with the D15B, including myself, but never anyone with 3stage vtec D15B.

I bought it cause it seemed like a good engine, mine was blown, and it was cheap... not for "3 stage vtec"

And I've yet to come across an actual "3 stage vtec" engine anywhere. And I've yet to see any REAL information proving that there is a D15B with 3 stage vtec system, and am starting to think it's bullshit/hype to sell a slow selling product... I haven't seen any dyno results... I've met pleanty of people with the D15B, including myself, but never anyone with 3stage vtec D15B.

I bought it cause it seemed like a good engine, mine was blown, and it was cheap... not for "3 stage vtec"


what kind of dyno results are the D15Bs (that you have) that everybody has putting out?, similiar to the D16z6, with a little less torque?..so in the 130 HP range?

what kind of dyno results are the D15Bs (that you have) that everybody has putting out?, similiar to the D16z6, with a little less torque?..so in the 130 HP range?

Haven't dyno'd it yet... probably wont be until April.

i'm pretty sure that the D15b has 130 hp at the crank. not sure about the torque though, maybe around 110 lb/ft.


so the vtec controller and the RPM activated switch are the same thing, except that rpm is a dial and cheaper, where as teh vtec controller is more costly and is electronic?

The VTEC-D15B engine is a 16-valve SOHC design with a displacement of 1493cc and uses the PGM-Fi fuel injection system. It develops a high 130ps at 6800rpm with max torque of 14.1kgm at 5200rpm. With the manual transmission, the VTEC-D15B uses a 4.25 final drive ratio with 1st and 2nd gear ratios of 3.25 and 1.9 respectively. These are actually very high gear ratios and helps give manual EG4 & EG8 a preppy performance.

http://asia.vtec.net/article/d15b/


at the end of that page, they explain the 3-stage vtec, and in which car it comes in. IT'S REAL!!!!! :evillol:

http://asia.vtec.net/article/d15b/


at the end of that page, they explain the 3-stage vtec, and in which car it comes in. IT'S REAL!!!!! :evillol:

Don't put all your faith in that website... and a little FYI... SiR-II engine is supposed to be 3stage vtec (OBD1)... 94-97 Del Sol models with B16A's are supposed to be 3stage vtec (OBD1)... D16Y8 is supposed to be 3stage vtec (OBD2a)... 6th gen Si B16A is supposed to be 3 stage vtec (OBD2a)... and the 7th gen EX engines are supposed to be 3stage vtec (OBD2b).

I know I've left off a few, but I think you get the point.

Killa_CRX, ok. i just thought that that website may clear up a few things, also thought that maybe it would be real.


Would a chipped P28 ecu like this one work?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2460268608&category=33596


i am not going to purchase this actual ecu, just wondering if something like this would work. i think the rpms are a litte too high for the d-series. tell me what you thank.

Would a chipped P28 ecu like this one work?


Yeah, it would work.

Only thing I don't like about those chipped ECU's are that they are usually programmed to run too rich for my preference at lower RPM's and run 'just right' at higher RPM's (reason for the 9k rev limit)... and that also makes for bad gas milage. And since I'm not building a 'race car' I'm building a 'reliable get me where I need to go with some speed' car, I opt'd for an unchipped ECU.

I was getting between 40 and 45mpg on every day highway driving with my DX engine, I'm hoping for somewhere around the same or better with this new engine. (yes, still using the DX transmission)