tahleel

So I'm looking to drop in a motor into a DC-chassis. My goals are to get the best fuel economy as possible. I would sacrifice a few mpg for better performance. I plan on using the CX trans, as it has the lower final drive ratio. Now as far as engines, I am undecided what I want to do. First of all, I do not want to deal with the hassles of opening an engine (i.e. "mini-me swaps", and etc). I want an engine that I can just drop in. From my research, I found the following:

With all controls being the same, the D15Z1 gets 48/55 fuel economy, where as the D15B gets 42/46. Both have the same bore and stroke, and both have the same transmissions with the same final gear ratios. The difference between D15B and D15Z1 would be the heads. The D15Z1 has a VTEC head, where as the D15B does not.

Now, I'd like to compare the D15Z1 with the D16Z6. Both are similar sized, besides the D16Z6 having a slightly longer stroke (which makes the extra .1L, but it does not play a huge factor in the power, IMHO). The main difference in between the two engines is VTEC RPM changeover, which on the D15Z1 head occurs at 2500rpm. As for the D16Z6 head, the VTEC RPM chaneover happens at 4800rpm.

From what I've read, the D16Z6 and D15Z1 have the same head castings, but I've come to the conclusion that they must have different cam-timings to take into account of the different VTEC changeover times. The D15Z1 makes 92 hp @ 5500 rpm & 97 ft·lbf @ 4500 rpm, where as the D16Z6 makes 125 hp @ 6500 rpm & 106 ft·lbf @ 5200 rpm. My conclusion, yes the Z6 makes more power, but the maximum power is also a full 1000rpm over the D15Z1. (Sidenote: Does anyone have stock dyno graphs of both a D15Z1, D15B8 and D15Z6?).

With that being said, I pose the following questions:

Will a D16Z6 have similar fuel economy as the D15Z1 with both having the CX trans?
Is there a way to optimize VTEC for better fuel economy (i.e. lowering the VTEC changeover point)? I'm assuming that this would entail swapping the cam from the D15Z1 to the D16Z6 head, unless there were some other way.

Thanks a lot, and feel free to critique and correct what I've mentioned.

-Tahleel

Aquafina

iTrader: (3)

You won't have any performance in a stock'ish D powered Integra using a CX trans.

tahleel

Bump.

-Tahleel

Phil M

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">You won't have any performance in a stock'ish D powered Integra using a CX trans.</TD></TR></TABLE>

night

damn, is it april fools again already?

Salsa

the D15Z1 is the 3 stage vtec head, right? if so, Honda specifically designed this motor for gas mileage.... where as the Z6 was made more for power...another one of the main reasons the Z6 gas mileage is lower is because of the shorter Final Drive.... but i dont think a z6 will touch 50 mpg with a cx tranny (40 maybe)

U said that u would sacrifice a few Mpg for better performance, but would u really??? cx tranny and performance shouldn't be mentioned in the same sentence. gearing is very important when it comes to torqueless, peaky motors (honda) as it keeps them in their narrow "powerband"..... i went from a 15.4 to a 14.8 just changing from an LS (4.2) to a GSR tranny (4.4)...


lowering vtec would not help gas mileage, it switches to the big lobe, which flows more air, which in turn needs more fuel.... Think about it

my advice to u would be, either pick gas mileage or performance.... its a trade off, ur not goin to have a fast 40 mpg D-series integra, unless the bitch is electric

ShaunRR

Your MPG will be better in a lighter Civic chassis than in a Teg.

LSVTEC 91 Civic

Change your driving habits.

InJ3cted

If you want the best fuel economy go with the z1 if you are prepared to do all the wiring to adapt it to a non vx chassis

d15z1 vtec-e with 2 lobe vtec. It only runs on 8 valves until vtec-e then it runs on all 16. The intake manifold and intake are tiny.

- you must use the p07 (i think its the p07 or p08) ecu
- has a 5 wire wideband o2
- EGR
- Must use the z1 exhaust manifold.
My buddy swapped one into his cx hatch and he said he would never do it again because of the wiring. A brand new vx o2 sensor is 180 bucks.

Go with the d15b and dont worry about the couple mpg it will save you headaches in wiring.

tahleel

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by InJ3cted &raquo;</TD></TR><TR><TD CLASS="quote">If you want the best fuel economy go with the z1 if you are prepared to do all the wiring to adapt it to a non vx chassis

d15z1 vtec-e with 2 lobe vtec. It only runs on 8 valves until vtec-e then it runs on all 16. The intake manifold and intake are tiny.

- you must use the p07 (i think its the p07 or p08) ecu
- has a 5 wire wideband o2
- EGR
- Must use the z1 exhaust manifold.
My buddy swapped one into his cx hatch and he said he would never do it again because of the wiring. A brand new vx o2 sensor is 180 bucks.

Go with the d15b and dont worry about the couple mpg it will save you headaches in wiring. </TD></TR></TABLE>

Is it possible to start with a D16Z6 head/block, and then swap the cam from the D15Z1. While using the D16Z6 wiring harness, axles, and the CX trans. Then, using the P28 ECU w/Crome to tune for what the D15Z1 would do (i.e. a lean tune with a lower VTEC changeover)?
I'd figure with this way, I would be able to use my current wiring harness, without adding the 5-O2 sensors. I would also be able to have a little more power increase, while still keeping it economical.

I figure the cam swap should be more pretty straight forward, since the Z1 and Z6 uses the same head casting. All I would need to swap over would be the cam and rockers. Has anyone done this before? As far as the ECU, I would be able to use a chipped P28.

I know that fuel economy would suffer because of the larger intake runners, and throttle body, but I guess thats the price I'm going to have to pay.

This seems like an in between in regards to ease of the swap, performance, and fuel economy.

-Tahleel

EDIT: This is an interesting read. Conclusion, the D15B uses the same cam as the D16Z6:
https://honda-tech.com/zero...43787




Modified by tahleel at 4:38 PM 5/20/2007

Aquafina

iTrader: (3)

Quit wasting your time. You'll be slow and mileage won't differ much from a stock Civic.

tahleel

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">Quit wasting your time. You'll be slow and mileage won't differ much from a stock Civic.</TD></TR></TABLE>

I will answer this, so I won't have to answer it to the million other people who think they are automotive gurus. Yes, I know it will be slow. Yes, I know the mileage would be the same as a Civic.

Detroit has a high theft rate for Integras, I find shells here ranging from $500-$1000 all the time. I find D15Bs/D16Z6s/D15Z1s (engine, tranny, axles, wiring harness and ECU) anywhere from $150 to $500.

Now, I challenge YOU, to go find me a Civic, that has nice creature comforts, a decent interior, a good dashboard design, and looks nice like an Acura, for less than $1500.

I wouldn't build a Honda for speed, thats why I have my turbo AWD DSM. I would build it for a cheap daily driver, that I'd be happy to drive from point A to point B, without being in a rediculous Geo Metro/Suzuki Swift, or any other econobox.

Thank you for wasting your time, my time, and HT's bandwidth.

-Tahleel

LSVTEC 91 Civic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tahleel &raquo;</TD></TR><TR><TD CLASS="quote">

I will answer this, so I won't have to answer it to the million other people who think they are automotive gurus. Yes, I know it will be slow. Yes, I know the mileage would be the same as a Civic.

Detroit has a high theft rate for Integras, I find shells here ranging from $500-$1000 all the time. I find D15Bs/D16Z6s/D15Z1s (engine, tranny, axles, wiring harness and ECU) anywhere from $150 to $500.

Now, I challenge YOU, to go find me a Civic, that has nice creature comforts, a decent interior, a good dashboard design, and looks nice like an Acura, for less than $1500.

I wouldn't build a Honda for speed, thats why I have my turbo AWD DSM. I would build it for a cheap daily driver, that I'd be happy to drive from point A to point B, without being in a rediculous Geo Metro/Suzuki Swift, or any other econobox.

Thank you for wasting your time, my time, and HT's bandwidth.

-Tahleel</TD></TR></TABLE>

What he was trying to say, was... The D15 is built for a 2000 pound car, It will not move an Integra. Your gas mileage may even be worse off.. because you'll have to run that little torqueless motor hard just to move an Integra.

Just run an LS motor, drive it like a grandma, and you will have great gas mileage. Simple as that.

kismysushi

I understand what you're trying to make... I find myself in the same boat. I'm finding it nearly impossible to put down money quickly enough for a CX, VX, or HX in the SF bay area, and I wouldn't mind a better looking car, interior, ABS, etc. I have another car for performance duty, so this one is for gas mileage. The car I just sold was an Insight, which was great, and I couldn't imagine its performance being any better than a D15 series integra. Oh, and reason for selling the Insight was to cash out.

I can't help you much with tech. info. Something I ran across, however, was another thread where someone with a CX swapped in a D15B and proceeded to add a hot air intake, aerodynamic mods, etc. He's apparently taken the 46 on the highway up to 70. So, I would say don't worry about the D15B not being fully optimized as it is-- there are plenty of ways to make up for the lack of a lean burn mode. And, as mentioned before, you can avoid costly replacement O2 sensors and other things like hesitation and plugged up EGR valves common to the Honda car lean burn modes.

http://www.gassavers.org/showthread.php?t=774

If you find out any more info, please share.


Modified by kismysushi at 12:27 AM 5/22/2007


Modified by kismysushi at 12:28 AM 5/22/2007

Aquafina

iTrader: (3)

Why don't you just spend $2,500 on a nice 92-95 EX and be done with it? You're putting way too much work into this just for a Civic that looks like an Integra and drives like a paperweight. If you think I'm an idiot, take a look at my 1/4 mile gearing comparison thread. My 2,340 pound car with a stock Y7 felt like a slug even with a stock Y8 transmission. I'd never drive a car that weighs 300 pounds more with longer gearing. I got better mileage going from the stock 3.722 final drive to the SRR 4.71.

Relic1

The D15Z1 is a good setup for mpg, but with the additional weight of the DC chassis you're going to need to push a lot harder to get the car to move when you want it to. (killing the mpg figures)
The D15Z1 uses the P07 ECU and a 5-wire O2 sensor (NGK L1H1 wideband)
the VX also uses the same trans as the CX, so if you can pick up a VX swap with trans it will save you some work.

IMO, for cheap mpg figures with the additional weight, go with a D16Z6 and keep your foot out of it.

Best would be a three stage JDM D15b but that would defeat the idea of avalability.

s_18

Listen to the guys advising against this. Otherwise, why ask at all if you're going to do it anyway.
The D15Z1, with it's incredibly long gearing, is slow even in the light EG chassis.

How do you think it will perform in the heavy Integra? I guarantee you that milage will be worse off, as the engine will struggle a lot more to get the car going.
Up hill will probably be a nightmare.

If you're going to do this no matter, I would use the D16, as it has a bit more torque.
But a B18 would definitly be a better choice in my mind for the Integra.