Honda and Acura Car Forums banner
1 - 20 of 21 Posts

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #1 ·
In the next few months, I will be ordering a whole crap-load of parts for my 1991 CRX Si. It is currently stock, and I am dead-set on keeping it that way until I'm ready to do all the work needed to make her what I want at once.

First off, I'm rebuilding the block and keeping it. I have it, I like the idea of having a fast D-series, and parts are readily available. Also, that way I know what has been done already, and it definitely needs it. Bad rings, burning oil, not a good scene in general. I'm expecting to spend around $1500 on this part, read on and find out why.

Secondly, I'm going to be installing a D16y8 head on it, and making my D16a6 engine into a mini-me. I don't want to go completely crazy on this, but I do plan on doing a rebuild on the head too.

Thirdly, I have a Garrett T25 turbo sitting on my kitchen table, begging to be installed. This would be my reason for rebuilding the block thoroughly, I want it as reliable as possible, it will still be my daily driver. I have a Starion intercooler (already tested for leaks) ready to be installed, no BOV yet, and all the tubing I will need. I'm planning on OBX turbo headers because they're affordable, high-temp-paintable, and available.

Fourth, I have a set of shocks and springs ready to go on, along with a set of rims and tires. 205/16/45 should be the end result, with 1-1.5 inches of drop.

Fifth, if all goes to plan, all bushings in the car will be replaced with polyurethane bushings. If there is an issue with any (other than squeaking, which doesn't really even bother me), what is it and which bushings would cause problems? I've read several articles on this, and people get pretty heated, I'm looking for facts: What works, and what does not.

Finally, there is a 6pc Wings West body kit in my van, ready to be installed, and a friend's paint shop ready to paint the whole car when it's ready.

Now that all my plans are out of the bag, I'm looking for recommendations on several things, most importantly the engine rebuild.
Is there enough advantage to forged pistons to make it worthwhile?
Who makes high quality pistons/rings/sleeves?
What blow-off valve is the most effective? (sound isn't too important, but the Neon SRT-4 sounds pretty nice)
Exactly what will I need to mini-me my engine? (Head, head gasket, intake manifold, headers [and will the obx headers fit on the d16y8 atop the d16a6 correctly?], ?ecu? (or can I just chip mine, or do I need to replace it at all?)... does the list go on?
Will my 450cc DSM injectors fit right onto the fuel rail, or do I need an aftermarket fuel rail?
Do I need a larger fuel pump?
How aggressive are the D16y8 cams and is it worth replacing them in a daily driver?
What's the deal with Exedy? Why are they so inexpensive?
What pieces am I missing?

Essentially, I'm of the belief that swapping the engine would be great, but the engine that's in there would be fine if it were performing at its best. Right now it's peppy, quick, and fun. I want to be truly impressed with my car when I pull past s2000's, SVT focus', and Neon SRT-4's. And I want to have done it all myself. I have plenty of help around here, a few mechanics who are willing to put in some time and help me out with my projects, but I want to know what your experiences have taught you. I want to make sure I do this correctly.

I'm looking forward to your suggestions, and will keep everyone posted on the project as it moves along over the spring.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #2 ·
just as a post-script...

I realize I'm spending as much as I would on a B16 or B18 swap, and I quite frankly don't care. So far, half the fun of this car has been tearing parts apart and making them better, not doing the craziest, most obscene changes I can. If anybody has done anything with a D-series like this, let me know. I have a few leads, but nothing definitive.

http://crx.honda-perf.org/articles/z6swap/z6swap.html
http://www.crxresource.org/modules.php?name=News&file=article&sid=143
http://www.homemadeturbo.com

There is the information that has been truly helpful to me so far.
 

·
Registered
Joined
·
39 Posts
All I can say is paint with the engine out of the car so you can paint the engine compartment with ease. Go with forged internals, especially connecting rods if you want a long lasting and strong engine since you're going turbo. Also, I can't recommend specific fuel system upgrades since I have no idea what kind of boost pressures you're going to be running, but I will say that if you're like most speed freaks, create a system with a wide range of adjustability because as time goes on you're going to find yourself raising boost more and more. This addiction is why there are street legal Supras with 900 horses to the wheels out on the roads. Lastly, the cams you have should be fine but you might want to have some valve and port work done. And adjustable cam gears are never a bad idea on a turbo car.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #6 ·
Adjustability will be killer, but for right now I want to get the system together so that it works as reliably as possible. That's primary concern, as this is my daily driver. Second consideration is performance. Tertiary consideration is cost. Last comes comfort/sound. The biggest problem I'm finding is a decent turbo header for the d-series. Everybody seems happy enough with the HF manifold and adapter, but I really want to go tubular, and don't trust my engineering and planning skills enough to make a header from scratch even if I do have the tools on hand. I've been looking at the OBX turbo header that I keep seeing, but apparantly the D16y8 head is taller than the D16a6 head, so I'm wondering if it'll fit my mini-me without modification. It'll be an interesting project. This week I should be relocating the battery into the rear cargo area and possibly ordering a bushing kit. I've had some pretty good experiences so far with Energy Suspension, and I need new bushings pretty much all around. I think I just might order the kit tonight, and install the shift bushings for now, and the others as I take each individual piece of (motor mounts when I rebuild the block, suspension bushings when I replace my suspension, etc). That way I don't have to remove everything twice, just take care of each piece in one fell swoop. I'm on a 10k budget for the car, and that's the max. I don't need to go completely overboard on any one part, but I want everything done as well as possible overall. Basically looking to bulletproof my engine, put out 250-300hp and 125-175tq and be able to corner like nobody's business. Enjoying my car is the name of the game, and everything's been a blast so far.
 

·
Registered
Joined
·
39 Posts
Corner like nobody's business? Comfort comes last? This is sounding less and less like a daily driven street car. Also, what is in your budget for brakes? If you can't afford a full front big brake kit you should at least consider swapping better brakes from another vehicle because I cannot think of any D powered car that's ever had a good set of brakes.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #9 ·
Hardedge said:
Corner like nobody's business? Comfort comes last? This is sounding less and less like a daily driven street car. Also, what is in your budget for brakes? If you can't afford a full front big brake kit you should at least consider swapping better brakes from another vehicle because I cannot think of any D powered car that's ever had a good set of brakes.
well, i did get the disk brakes in the front and rear, and have no problem locking up the tires right now. and my reasoning behind the priorities is that my daily driver has to be fun to be in first and foremost. if i was at all concerned with comfort, i wouldn't have even considered the crx. seats are terrible, no space for extra people, the si has fairly stiff suspension as it is... just not a very good comfy ride. but that's really not a concern. i love driving a quick little car. and i'm a little crazy.

i was considering integra/prelude discs/calipers/master cylinder, but haven't found any concrete reason to. maybe when these rotors really start showing their age, or i have enough power to warrant better brakes it'll be a concern but for right now, the stock system is working just fine for anything i need.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #10 ·
2highpsi said:
a 190 fuel pump and some injectors should be all you need fuel wise, fuel rail,injectors,fuel pump, and a fpr should cover you on the fuel side..and 450 injectors should be fine
So you're saying a fuel rail, pump, fuel pressure regulator (i'm assuming that's what you mean, but I don't even know what the purpose of regulating fuel pressure is), and my injectors are what I need to install in order for the fuel system to keep up? I can deal with that. Will I need to chip my ECU or have a standalone fuel management system for this, or how does it work? Sorry for my ignorance, but I'd rather ask dumb questions now than to screw this up.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #12 ·
link doesn't seem to be working for me. the website is only available in new zealand. any other ideas? I think I'm going to end up using a d16zc with the turbo setup for mild, with a bulletproof-built bottom end and a diy port and polish on the head. The big question now is headers and clutch. I'm keeping the d16a6 transmission, but I'm not sure which clutch will work best for 150-250 peak horsepower off a turbo d-series engine. I've heard great things about the Exedy and ACT clutches, but should I go "stage 1" or "stage 2", and is a lighter flywheel really worth it?
 

·
Registered
Joined
·
10,272 Posts
Sounds like you're really serious about this and I'm glad to see that you're thinking it out thoroughly....and it's awesome that you are sticking with your D-series.

First...if reliability is a concern stay clear of OBX or SSAUTOCHROME. Their turbo manifolds have quite a reputation for cracking. Your best bet would be to get a custom turbo manifold welded up for you. A simple tubular log manifold will do the trick and be reliable...but if you are willing to spend some more cash I suggest going for the mini-ram horn manifold. Click Here for a good source on custom manifolds. He does quality work and the manifolds make power.

As for the clutch...if you plan on building up the bottom end for boost...then you will probably want to make more power...so I suggest a Stage 2. Both ACT and Exedy are good companies....but I recommend ACT only because I have the stage 1 and am very happy, and it's the only one I've had direct experience with.

And no, don't bother purchasing a lighter flywheel. With your car boosted it will be fast as hell and you wouldn't notice anything from a lighter flywheel, and the engine would probably rev up too fast anyway, making it harder to drive. However I do recommend getting your OEM one resurfaced....just a good thing to do when you change out the clutch.

The most important thing in a forced induction setup is engine management. I suggest going with DSM 450cc injectors...if you are going to be running OBD-1 then you will need to run a resistor pack to increase the impedance otherwise your ECU will fry because OBD-1 and after ECU's are used to high impedance...but if you are sticking with OBD-0 then you are fine. And to get DSM injectors to fit in the Honda fuel rail you will need to bore the O-rings out a bit with a dremel. Other than that they fit right in.

And I suggest a Walbro 255lph fuel pump...they are about 100 dollars shipped. As for engine management I suggest getting Hondata s200 with boost and going to a reputable tuner and getting it dyno-tuned. However, if you are a DIY kinda guy and trust yourself then you can buy a wideband o2 sensor and use a free program like Crome, turboEdit, or Uberdata to tune your car.

Whatever you do, make sure you think long and hard about how you are going to set your engine management up and tune the car, as that's the most important part...a poorly tuned car will make shitty power, get bad gas mileage, and probably blow up.

As for a blow-off-valve...they are all pretty much the same....they are simple parts that don't require lots of engineering..you can cheap out on them...a lot of people just use DSM blow off valves....it's really about your preference to the sound. The only time blow off valves differ is if you are going to be running really high boost.

I actually have a knockoff Greddy Type-S adjustable BOV for sale if you are interested.

As for upgrading the cam...Zex/comp cams makes a decent turbo cam but IMO it's not really needed...if you want more HP then just up the boost..I mean you will have a built motor. :) You can upgrade the cam later on if you want but I suggest concentrating on the turbo build at the moment.

1 last kinda important thing....that turbo is a bit small. Many people use t25's on their d-series...but in my opinion it's way too small. It will spool up quickly but it won't make that much power and you will most likley have trouble reaching decent HP numbers with it.

I suggest selling and getting something bigger. In my opinion the perfect sized turbo for a mini-me setup is a .48/60 T3. Spool times will be acceptable and you will make tons of power with it.

And I suggest using a t3 with an internal wastegate to simplify things....or if you wanted to go external then I wouldn't get anything other than a Tial 35/38mm wastegate.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #14 ·
First off, thanks for the quick and informative response.
Those manifolds look like EXACTLY what I want. I'll probably go with the middle of the line with the $500 miniram. If I'm going to spend money on anything, it may as well be a manifold.
Upgrading the turbo is something I've considered a few times, but I figure if the turbo is already in my hand, I may as well use it. I can always swap it out and retune further down the road, but that's always an option.

As far as injectors, I actually already have a set of dsm 450cc. They're sitting in the box with the turbo, right next to the box of H&R springs. I'll need the fuel pump, and is there a concrete reason to replace my fuel rail? I see lots of show cars have them replaced, but is it necessary or just another part some people do?

On the lines of the ECU and tuning, I know of no shops in NH which have a dyno, so I'll probably do the tuning myself (we're getting a wideband o2 sensor anyway, so it only makes sense), but WHY would I want to upgrade to obd-1? What gains does it offer that obd-0 doesn't?

Do you have a recommendation on pistons and/or headgasket? Eagle has good reviews on their pistons, and I only know I want a slightly thicker metal headgasket to lower my compression (and further bulletproof the block).

Finally, I am interested in the BOV, but now is not the time. I need to get the ZC and manifold before I can even start doing my tubing, at which time I'll need an intercooler and the BOV. So, as much as I'd love to start stockpiling today, it's not going to work out that well. Ask again in a month :)

Thanks for every bit of help and insight you've given so far, I've done a fair amount of research so far, and I think I'm in the right direction, being here, and on homemadeturbo and such, but the personal insight means more than everything else combined in the end. Thank you.
 

·
Registered
Joined
·
10,272 Posts
drummingpariah said:
First off, thanks for the quick and informative response.
Those manifolds look like EXACTLY what I want. I'll probably go with the middle of the line with the $500 miniram. If I'm going to spend money on anything, it may as well be a manifold.
Upgrading the turbo is something I've considered a few times, but I figure if the turbo is already in my hand, I may as well use it. I can always swap it out and retune further down the road, but that's always an option.

As far as injectors, I actually already have a set of dsm 450cc. They're sitting in the box with the turbo, right next to the box of H&R springs. I'll need the fuel pump, and is there a concrete reason to replace my fuel rail? I see lots of show cars have them replaced, but is it necessary or just another part some people do?

On the lines of the ECU and tuning, I know of no shops in NH which have a dyno, so I'll probably do the tuning myself (we're getting a wideband o2 sensor anyway, so it only makes sense), but WHY would I want to upgrade to obd-1? What gains does it offer that obd-0 doesn't?

Do you have a recommendation on pistons and/or headgasket? Eagle has good reviews on their pistons, and I only know I want a slightly thicker metal headgasket to lower my compression (and further bulletproof the block).

Finally, I am interested in the BOV, but now is not the time. I need to get the ZC and manifold before I can even start doing my tubing, at which time I'll need an intercooler and the BOV. So, as much as I'd love to start stockpiling today, it's not going to work out that well. Ask again in a month :)

Thanks for every bit of help and insight you've given so far, I've done a fair amount of research so far, and I think I'm in the right direction, being here, and on homemadeturbo and such, but the personal insight means more than everything else combined in the end. Thank you.
The reason I suggested getting a larger turbo is because if you have a t25 then there's not really much point in building up the block. You won't be making enough HP to require it....and the T25 will die out up top...it will spool up quick but around 5800+rpm it will just be blowing hot air...pretty much just become a restriction in your intake path.

As for the fuel rail...nope no reason to upgrade...the OEM one is good for over 400whp...people upgrade them because they are misinformed, or ricers, or they like the looks. I have an aftermarket fuel rail only because I got a great deal on an AEM fuel pressure regulator and fuel rail combo for 80 bucks. If there's a great deal it's hard for me to turn it down. :)

And the OBD thing...there's no reason to upgrade to OBD-1. I only said that because you are doing a mini-me; your car is currently OBD-0...you are swapping an OBD-1 head on which means you need to convert to OBD-1 or change some crap on the head to OBD-0 which will be easier. (actually now that I think about it you just need to change in OBD-0 which you already have (dsm))

So I recommend going over to pgmfi.org and reading up on TurboEdit. That's the OBD-0 tuning program. Ask questions and get real familiar with it all, because like I said before, a tune can either make or break a turbo setup.

As for pistons...I suggest going with forged pistons (JG, Wiseco, Arias, they are all great) and aiming for a compression ratio anywhere from 9:1 to 9.5:1. A higher compression ratio will increase spool times and create more power with less boost...but it's far easier to detonate and harder to tune. Since this is your first custom turbo setup and you'll be tuning I suggest whatever piston closest to 9:1. Don't go under 9...some people run 8.5 or even 8:1 but IMO they are just tards.

And just get some eagle H beam rods. As for the head gasket...go with either OEM or a cometic turbo headgasket. You don't need a thicker one to lower compression if you are going to rebuild the engine. The pistons will be the main determining factor for your compression. Just go with OEM thickness....but a Cometic turbo headgasket might be a good choice for reliability.

Also one other thing....D-series heads are known to occasionally lift under boost...so a good thing would be ARP head studs. They have a higher torque rating to keep that head bolted down snug under all the boost.

And about the Type-S BOV...I'm moving to England in September so make sure to contact me before then. I'm charging 55 shipped for it. Not a bad price for a brand new aftermarket BOV. So the sooner the better for me. :)

Here's a little clip to give you an idea of the sound. It's adjustable so it sounds anywhere from a loose whoosh to a tight birdy chirpy thing...also depends on your turbo setup and amoutn of boost.

Here's a looser clip: Greddy Type-S --Celica Turbo

Harder Type-S Clip: Turbo Supra :)
 

·
Registered
Joined
·
10,272 Posts
BTW I was just browsing the HT classifieds and I came across a very good deal on the turbo i recommend. Trust me if you put that t25 on you might think it's ok at first...but I am willing to bet that after a few days you will be sick of it and want something bigger....but I can tell you that you WON'T regret buying this .48/.60.

IMO it's the PERFECT size for a d16 vtec. Here's the link....awesome price for a brand new turbo
 

·
Registered
Joined
·
7 Posts
Its late and I didnt read the whole post from the beginning, but just wanted to comment on sticking with the D16.

There are plenty of options to go with on a D16 setup, whether you go all motor or turbo. It has alot of potential either way, and turbo setups are actually pretty daym impressive with a good combination.

IF you have any questions on D16 setups/builds, feel free to email me. I'm a super D16 fan for more than 14 years. We've built different setups from crazy all motor to big hp turbo D16s
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #18 ·
if I can find someone who's interested in a garett t25 with no shaft play, I'll go bigger for the extra money, no problem. If not, I'll put in the t25 for now and upgrade and retune later.
 

·
Registered
Joined
·
2,722 Posts
Discussion Starter · #20 ·
It turns out I am going to sell it, but not because it's too small (at least not officially). I'm selling it because my d16a6 blew up (250 miles from home, and it was NOT a cheap towing bill), threw a rod right out of the block, and decided to sit still. At this point, I have it out of the car, and I have a b18a waiting to be installed (on Monday, keep your fingers crossed) and would rather have extra money as a buffer to spend on little extras (like new axles, shift linkage, etc) than have one more thing (a small turbo) waiting in line to eat up my money. Anyway, if you know anybody looking for a t25 with no shaft play, let me know!
 
1 - 20 of 21 Posts
Top