new owner of a 88 crx si
 

Hello fellow gas savers. Ahh... finally a website i can relate to. i'm tired of those other boy-racer sites telling me that it's "gay" to think about mpg and so on. My name is Alex and i live in Los Angeles, CA. I would like to start my post by wishing all of you a happy new year ;) ! I celebrated my new year by purchasing an 88 CRX si; a clean title car with everything in tact (with Si transmission and ecu, but no engine), no rust at all, and it includes sunroof. This car officially weighs in at 1843 pounds (weighed in at an auto-cross event) due to minor weight reduction performed by the previous owner.

Future mods will include:

EXTERIOR: more weight reduction (1500-1600 lbs), carbon fiber hood/fenders, paint because it's really in bad condition cosmetic-wise, light weight rims (hx, or spoon rims), no A/C.

Engine: OBD1 conversion harness, P07 ecu, D15Z1 engine with transmission, intake, possible mild headers, and a mild/light weight exhaust.

I'm in a mission to achieve 60-70mpg or even more if possible in my crx. If anyone has any advice, wisdom, comments, a how-to guide, know an even better engine/transmission/ecu combo, weight reduction methods and ideas for optimal mpg, feel free to leave me a message.

Welcome to Gas Saver's. So your minus an engine? What are you using currently to ramble around, until you get the CRX set up the way you'd like?

If your going to go for mileage, your going to need to either get an HX transmission, or make the modifications to put a CX transmission in, to replace the one already in the car. The HF is a cable unit, the CX has a hydraulic clutch, instead of a cable. The HF should bolt in, as is, the CX requires some adaptation, I believe. Good Luck.

I have yet to see someone put a hydro d tranny in a crx. I've heard a lot of talk, and maybe it's happened, but it's a pain, so go with the HF tranny.

Also, your best bet with the d15z1 is to go with the stock exhaust manifold. It is designed for the car very specifically and there's no sense messing with it.

Anyway, the z1 and hf combo is the best choice, and will give you the ability to make big numbers, but then it's a matter of how you drive and what your commute is.

Good luck and welcome.

yeah... the commute here is awful sometimes (L.A. traffic sucks, but it's not as bad as N.Y.). I presently drive an 06 matrix xr auto. i bought the crx just to get my hands dirty, and the matrix is so heavy, it's not giving me the mpg i want. I've seen many crx's with hydro trannys (b16a, b18c, etc), but yes.. it is costly and difficult to wire i've heard. It might not be worth it in my case unless it gets more gas mileage than the HF, i just might consider it :).

Also, i was considering swapping a JDM D15b 3 stage vtec (92-95 obd1 i believe). It's supposedly the steroid twin of the D15Z1, but i don't know the accurate fuel mileage for this engine since it's rated at 127HP/102Tq. Many of the boy racers in some sites recommended the engine to me since i'm concerned about mpg, but i was thinking if the D15b 3 stg vtec engine has more hp and tq, wouldn't it reduce the FE level? Many said it was capable of getting 55mpg hwy if driven right. Would anyone recommend this engine for fuel efficiency?

The 3 stage will not be as good as the z1, but it will approach it. Because it does endeavour to make power it is not a 100% FE machine like the z1 is.

The comment I made about the hydro transmissions was based on the fact that I don't think they make mounts for D series hydro trannies in CRXs. It's not bad with B, H, K, blah blah, but I don't think anyone makes a mount kit for D series. Not sure if thats changed in the last few months though.

Thanks. I might as well get the bracket from a vx, weld it on the CRX, and somehow accommodate it. Luckily i know a certified welder. I'd just rather prefer the smoothness of a cx/vx hydro transmission. That, and it's also made for that engine. LOL. I don't know how i'm going to get away with this car when i'm finished. CA. DMV laws are such totalitarian dictators.

I'm pretty sure this swap has been done before with an HF transmission. i wonder how it shifts. FYI :

L3 88-91 HF 3.250 1.650 1.033 0.823 0.694 2.954 (3.250 Cali) 3.880

L3 88-91 Si 3.250 1.894 1.259 0.937 0.771 3.153 4.25

P20/A000 92-95 Civic CX/VX D15B8/D15Z1 3.250 1.761 1.066 0.853 0.702 3.153 3.250

hmmm.... 3 trannys to chose from...

oh... lol... it's obvious why i can't chose the L3 Si tranny... so two trans. to chose from.... L3 Hf, or the P20/A000. anyone know which one will give me a better FE level with these specs posted?

Go with the HF, I like mine, :p

I just don't think the VX tranny is worth the money, and you'll be revving higher anyway.

I second what SVOBoy said. Putting a VX Transmission in there will cost loads of money, time, and will actually give you worse MPG in the end compared to a CA version CRX HF.

BTW, you can get a JDM D15b (d15z1 equivilant) delievered to your door for $350 in SoCal. www.nippon-motors.com.

Weird... how can the P20/A000 tranny (92-95) made for the D15z1 engine (92-95vx) give you worse mpg than the Hf tranny (L3) made for the D15z? Beats me, but yes. What i do agree is that it will take much more time and money to install the P20 hydro vx tranny. thanks for snapping me out of my dream.

The D15b.... is that the j-spec stg 3 engine, or is that the 62 hp engine?

The VX got worse FE than the CRX HF. They moved began moving away from FE with the VX, hence the shorter gearing than the hf.

So i shouldn't trust edmunds and sites like that... right? it' reads that the hf gets 49 city/52 hwy... then again that's with its stock HF engine. With a 92-95 vx D15z1 engine (48 city-55hwy rating)/L3 hf transmission... i'm guessing i will see a difference in FE. That, and everything just gets heavy after 1990.

I'm still confused in what engine i should get now... lol.

okokokok.... should i just get a d15z1, obd1 conversion for the p07 ecu, and an HF transmission?

oh... lol.. thanks SVOboy. I just read your 1st post in his thread. lol.. thanks. i wonder if the D15z1 is a direct bolt-on to a crx... anyone know?

it's a d series engine, it should just bolt up.

What about the crx si axels. Would they bolt up nicely on a HF transmission?

Direct bolt in, less wiring. Axels will work with the transmission, they're all the same on the tranny side, but the HF are smaller on the brake side, which doesnt matter in this case.

The d15b, as it is known in japan, is actually 3 different engines.

1) d15b vtec - regular vtec, 120hp-ish
2) d15b vtec-e - our little friend, 62hp w/o vtec. 92 with
3) d15b 3 stage vtec

When you buy it, you have to specify that you want the d15z1. They should do you well.

The SI axles will bolt right up. The HF transmission will bolt right up too. These engines usually come with exhaust and intake manifolds. Mine came with a clutch and flywheel. It'll also come with a bunch of sensors and probably most of your pigtails for your new harness.

You can get a custom obd0->obd1 conversion harness at www.rywire.com for around $130. Be sure to tell them what you're doing. In your case, you're going from pm6 to p07. If you have the money, I'd actually recommend you acquire a civic VX wiring harness somewhere and just send in your two harnesses. For a bit more money they'll send you back a plug-n-play harness. No wiring headache.

Don't forget that you'll also need the EGR Control box, which is unique to the Civic VX. You should be able to get those cheap on honda tuner sites from people who got rid of their d15z1.

Thanks everyone for your input. i just downloaded the honda 92-95 manual from hondahookup.com and the crx repair manual as well just for a piece of mind. Matt, so i can actually send in a vx and my 88 crx si harness so i can avoid a nightmare and directly plug it in a p07.... wow.. sounds nice.

Also, how does $50 for a P07 ecu sound? is it a good bargain, or can i find the cheaper?

You can find cheaper for a p07, I;d shoot for around 30 shipped.

I guess i'll keep looking around. i really don't trust ebay that much anyways. $350 is also too much for a d15z1. maybe i can find it cheaper elsewhere. how much do hf transmissions run for? lol... i might be able to get it for free some where or just trade in my si's for an hf tranny. hmmm... i might be able to trade in my ecu for a p07... double hmmm... then again, i'm better off selling them.

from what I can tell, the D15B 3 stage V-tec, is the first two stages of a D15Z1, and then a 3rd stage that kicks in at around 5,000 or 5,500rpm (if you have the computer) other then that it's pretty much the same block, altho the intake is larger to alow for the higher revs, and I suspect the exaust is a little larger as well.

You can get good coin for the si tranny, and my hf tranny was free, so look to pay at most 50 bucks for one.

i think it also has an si head with a wild-cam (aka the hot cam) available only in japan, but i'd rather sacrifice the extra 36 hp just to get more mpg. the swap sounds tempting, but i know i'll be punching it left and right. To me, those days are over with. i'm getting old and i need something more mellow, more frugal in FE to move me around. having that power at my disposal will just be a waste of gas. it's time for me to step down and actually care about the environment and driving habits. after all... driving habits are contagious ;)

a free hf tranny? you're so lucky. nothing is for free now-a-days. then again it's also not impossible since racers swap them out left and right.

How much money do you think i can get for my si tranny/ecu?

Yeah, I think the d15b 3 stage has the y8/y5 head casting. Not 100% sure, but probably.

I'm somewhat known around here for getting everything for free. I'm very patient and jump on opportunities when I see them.

Anyway, si tranny might be worth 100-200, depending on mileage/condition. ECU prolly only 30 bucks or so. OBD0 boo, :p

place an ad on craigs list and so on, maybe with an offer of trade or sell/buy for parts you are looking for.
I found my hf engine bolted to a hf tranny thru an ad on Redpepperracing.com, the engine was free, the tranny was $40, and they came with boxes full of all those little emision parts and so on, it was great.

hmmm.. not even half of what a D15z1 is going for. i guess patience will be a virtue when it comes to this swap. i live in L.A. and nippon motors may be kind enough to reduce the price for a z1 if i negotiate and pick it up myself (fingers crossed.

A z1 may just pop up, but the good thing about nippon is you're getting a low mileage engine with all the stuff attached to it, including sensors and manifolds and such.

mmm... yes. so i might as well spend the extra money for a low-mileage engine. it sounds like cheap insurance and it will save me headaches. thanks SVOboy.

exactly, all those sensors add up, you might pay $300 for an engine, but if it comes with $1000 worth of sensors that all fit that engine, then is it worth it? I meen, o2 sensors are $200-300, throttle body with tps and map sensor is $450, and then you get a catolitic converter, fly wheel, clutch? it almost seems like getting a z1 and parting it out could nearly pay for it's self.

hmmm... can i use my stock cat, or will i have to purchase the vx cat?

You will need the downpipe/cat from a vx/cx/hf/std

The cat on the HF/VX/CX/STD are all the same. You can usually find people willing to sell you one. Bunger found me one from his friend. Just had to pay the price of shipping :)

FYI, I can get you a TPS sensor for $20. They usually are damaged on import engines.

Quote:
Originally Posted by Matt Timion
FYI, I can get you a TPS sensor for $20. They usually are damaged on import engines.


hmmmm... i'll hold you to that thought.

also, will i be able to swap in a 92-95 gauge instrument panel? my gauges don't work.

Pyramid Head is my favorite Silent Hill character. He's just so cute wielding that big blade you just want to hug him!

You can if you use an electronic VSS. I have a 97 teg cluster in my car.

Quote:
Originally Posted by The Toecutter
Pyramid Head is my favorite Silent Hill character. He's just so cute wielding that big blade you just want to hug him!

LOL.. thanks. I've liked that game since the demo came out (1998 i believe). I havent played 3 and 4 though but i'm getting too old for games. I also don't have any more time :(

And as for the gauges, if i'm going to use a VSS, then is it possible to use a 99-00 civic si cluster? I like the way they glow :p

Yes, you can use that cluster.