honda swap, need help - Gas Savers

crazymechanic · 10-06-2006, 08:33 PM

I've got a 95 del sol s, d15b7. I'm wanting to drop a jdm d15z1 vtec-e motor in. the d15b7 gets 30 in the city as is, but I want that lean burn motor because my job is getting ready to move 30 miles away and I want some better fuel economy for my longer commute. the d15b7 is also a little tired. I was thinking of just freshening it up, but decided a swap would be better for the same money. I know I need the motor and ECU, what do I need to do about wiring? since the vtec-e motor is obd1, and my current motor is obd1, would I only need to add the wiring for the vtec solenoid? or is there more to it than that. my goal is to have all the information ahead of time so I can accomplish my swap in one weekend (I have access to lifts and many air tools, and a bunch of friends will join in for free beer!). I'm planning the swap for next month, or the month after depending on how the bills work out, but I need to know everything I can so I can plan accordingly. I know a few of you have done the vtec-e swaps into your own cars, I just need a little guidance so I don't screw things up too bad. thanks...

mike

thisisntjared · 10-06-2006, 08:56 PM

you will have to run vtec wire(s) and the necissary wires for the 5 wire o2 sensor and egr valve.

the del sol can be quite a challenge because of the aerodynamics, but if you keep your speeds low you will be alright. another member on this board used to have a del sol and did fairly well with it.

out of curiosity, is the majority of your driving city or highway?

Matt Timion · 10-06-2006, 09:09 PM

I'll post more about htis later, but you probably want to find a Civic VX or Civic VX transmission as well.

Diemaster · 10-06-2006, 09:14 PM

first of all there is no such thing as a jdm d15z1. jdm dosent have the number at the end so it's be a d15b. also try to get the 3stage vtec.

Matt Timion · 10-07-2006, 01:33 AM

Quote:

Originally Posted by Diemaster

first of all there is no such thing as a jdm d15z1. jdm dosent have the number at the end so it's be a d15b. also try to get the 3stage vtec.

3 stage vtec is a waste if all you care about is fuel economy. Not only is it expensive, but wiring it is a PITA and getting all of the right parts for it is impossible (or at least difficult)

and when people say JDM d15z1 I can assume they mean the JDM d15b vtec-e engine.

crazymechanic · 10-07-2006, 07:00 AM

that is the engine I mean, I just wasn't sure how familiar you guys were with the JDM nomenclature, so I referenced the us designation for the same motor. I thought about the 3 stage, and would prefer it, but that's going to be more wiring than I really want to do. I want some performance out of the car, but my main concern is gas mileage. at the moment, most of my driving is city, but that's about to change because my boss is moving the business.

now what would be the advantage of getting the VX transmission? I was thinking about just reusing my factory transmission, after a quick freshen up, of course. the car gets between 30 and 40 mpg on the hiway as it is, and that's at 70mph, pulling about 2750 rpms or so in fifth gear. I'm trying to do as little as possible in this swap, so I still want a hydraulic clutch engagement, not cable engagement, and I don't want to have to change the cable shifter. I just want to put a new engine with better economy with a new clutch and call it a day. thanks for the quick response too. over on hondaswap, I asked almost the same question a few days ago and have yet to get a reply...

krousdb · 10-07-2006, 07:07 AM

You don't need a Z1 swap to get good FE in the Del Sol D15B7. See "Quench" in the Gaslog.

crazymechanic · 10-07-2006, 08:33 AM

how fast did you drive to get those numbers? the motor is tired anyway, which is why I was going to go for the vtec-e. it doesn't appear too difficult as far as swaps go, and it'll be more efficient so I don't have to change my driving style too drastically to get better mileage

Matt Timion · 10-07-2006, 11:17 AM

Quote:

Originally Posted by crazymechanic

that is the engine I mean, I just wasn't sure how familiar you guys were with the JDM nomenclature, so I referenced the us designation for the same motor. I thought about the 3 stage, and would prefer it, but that's going to be more wiring than I really want to do. I want some performance out of the car, but my main concern is gas mileage. at the moment, most of my driving is city, but that's about to change because my boss is moving the business.

now what would be the advantage of getting the VX transmission? I was thinking about just reusing my factory transmission, after a quick freshen up, of course. the car gets between 30 and 40 mpg on the hiway as it is, and that's at 70mph, pulling about 2750 rpms or so in fifth gear. I'm trying to do as little as possible in this swap, so I still want a hydraulic clutch engagement, not cable engagement, and I don't want to have to change the cable shifter. I just want to put a new engine with better economy with a new clutch and call it a day. thanks for the quick response too. over on hondaswap, I asked almost the same question a few days ago and have yet to get a reply...

Honestly, a VX/CX transmission is going to give you the most FE gains. The reasons for this is that the transmission is longer geared. You'd probably lose about 500RPM for each gear/speed, which could put you up to 50mpg at highway speeds. The VX and CX transmissions are identical, and have a hydrolic engagement. Cable stopped on the Hondas in 1991.

I put a JDM vtec-e engine into my 89 civic a few months ago. I also used a 1991 CRX HF transmission. I have no idea what is going on with it though, as I'm averaging around 27mpg. I'm VERY certain it's the oxygen sensor. I made the mistake of ordering one through oxygensensor.net. I've yet to receive it so now I have to contact paypal to get my money back, blah blah blah.

Anyway, the easiest way to get a boost in FE is just by a transmission swap. It is going to yield the best gain for the least amount of work and the least cost.

But then again if you are still wanting to do the swap, I'd be more than happy to help. The last thing i want to do is tell you what to do on your own car.

thisisntjared · 10-07-2006, 01:15 PM

the tranny is the best feul economy upgrade and the worst performance downgrade. its not just the final+top gear combo its all the gears that give it better fuel economy its all the gears that are longer in between. that also is what murders the performance.

for the time being, some freshening of the b7 should prove useful even if the motor is tired. pluges/wires/filters/fluids/timing/alignment and tire pressure can go a long way.

crazymechanic · 10-07-2006, 04:56 PM

when I speak of freshening, I meant a rering and bearing job. the motor is REALLY tired. I've got a rear main seal that leaks about 1.5 qts every oil change, it's got 145k miles, just had its first timing belt change, still on the original clutch, before the timing belt it was pinging like crazy. I'm the third owner and I've babied it as much as I can. I don't mind the longer gears from the different transmission, especially if it means less money per month at the pump. I've found a number of places I can source the engine from, but where can I source the trans? haven't really found anywhere for one yet. also, does the JDM computer plug right into my obd1 harness? or do I need an adapter, and if so, where can I get one? thanks again

Matt Timion · 10-07-2006, 06:42 PM

Quote:

Originally Posted by crazymechanic

when I speak of freshening, I meant a rering and bearing job. the motor is REALLY tired. I've got a rear main seal that leaks about 1.5 qts every oil change, it's got 145k miles, just had its first timing belt change, still on the original clutch, before the timing belt it was pinging like crazy. I'm the third owner and I've babied it as much as I can. I don't mind the longer gears from the different transmission, especially if it means less money per month at the pump. I've found a number of places I can source the engine from, but where can I source the trans? haven't really found anywhere for one yet. also, does the JDM computer plug right into my obd1 harness? or do I need an adapter, and if so, where can I get one? thanks again

Transmission: You can get one from various honda websites, like Honda-Tech. A lot of people buy Civic VXs and put in differnet engines and transmissions. I'm certain that you can find one for $50+shipping if you ask around enough.

Engine harness: You won't need a harness, but you will need to run a few wires to the ECU. One for the EGR Control Box, one for the vtec solenoid, and one for the vtec oil pressure sensor. You'll also need to run an extra wire for the 5th oxygen sensor wire (the d15b7 has 4 wires), unless you get an ECU from a California VX, which only used a 4 wire o2 sensor.

I would recommend against using a JDM ECU, and that's only b/c no one will be able to help you with any issues. Everyone who has done this swap got their ECU from someone who swapped out their d15z1 for another engine. I also have no idea if the JDM ECU uses the same plugs as the USDM ECU or not. Your current plugs will fit the d15z1 ecu with no problems at all. As I mentioned you will just have to add a few wires, which is easy as pie.

I bought my JDM vtec-e engine from nippon-motors.com, and it was cheap and in great shape. It even came with the flywheel and clutch.

crazymechanic · 10-09-2006, 06:55 AM

I'll see if I can find a US ecu then, and get the ball rolling on this. thanks a lot for your help. I'll keep you guys updated when I get the engine and start the project.

DaX · 10-09-2006, 07:24 AM

Check out my gaslog...the jump in FE a few months ago is solely due to an HF transmission swap. I have a DIY on here about doing the swap. A VX tranny swap (hydro, not cable) would be nearly exactly the same.