Ryan D15Z4

hey guys! just joined the site about 2 days ago. Already read alot of threads and some very good info. Im from south africa and civics here are soooo rare!! i drive a 97' civic hatch D15Z4.... motor still completely stock. Only modification is a SRI induction kit. Thinking of forced induction, and ive read up on some previous threads, wheter to do n B-series swap or just boost the current D15Z4 ive got in at the moment. I want to get about 160kw on the wheels, or 215whp in your terms. I read that thats more or less the limit on the stock rods and internals on the D15 motors. But dont know if i want to take a chance. Would rather go forged and spend the money and know my motor is reliable. My question actually is: Would it be possible to get so much power out of the little 150i motor and still use it as a day to day driving car?? Would appreciate any info alot! cause its hard to find good info and people who really know civics well in South Africa!

MPR

A great rule of thumb is that you can only pick two of the following: Cheap, reliable, fast.

That being said, stock D series engines can handle a respectable increase in power and still hold together for daily driving. It's longevity will ultimately depend on how hard you drive it and how well it is tuned. 200hp is probably the most I would recommend pushing on a stock D series engine if you still want some reliability. If you want to make more than that I would suggest upgraded internals.

Look into a "vitara" D series build. It's probably the least expensive routes to building a reliable 200whp+ D series.

Also, don't use an enormous turbo. Bigger is not better. Turbos need to be properly matched in relation to the size of your engine, how much power you want to make and at what rpm. Keep in mind, revving an engine higher than necessary will actually put more stress and force on engine internals than forced induction alone. So keeping the rpms down below 7000-7500 will significantly help the longevity of the engine. A great turbo for your setup would be a TD04-13T from a stock subaru WRX (not the STi). It'll give you full boost down around 3000rpm and hold it all the way past 7500rpm for a huge wide power band. If you're afraid of it trying to "boost" all the time while cruising with the engine above 3000 (in the turbo's efficiency range), just use a synchronic blow-off valve. It stays open all the time even with low throttle inputs (while cruising), but as soon as you give more throttle and the turbo starts to make significant boost, it shuts tight and off you go! lol.

Keep us up to date and let us know what you end up building. Are you planning on building this setup yourself, or having a shop do most of the work for you?

Ryan D15Z4

Makes sense, I think I'd rather upgrade the internals just to be on the safe side. What brand pistons and rods should I look at? Or is it just the rods that needs to be changed to handle the power? Also do the stock pistons provide the right compression for boost? Otherwise I'll change those as well, seeing that I'm gonna do the rods in anyway?

MPR

You only really need to decrease compression when you're going for huge power increase (like over 250-300whp+). Otherwise, keep the compression up at stock spec as it will help with drive-ability when not in boost.

Look into the vitara d-series build. The pistons will take most of the abuse as it is the heat produced from the more powerful combustion that is most damaging. As long as you don't rev it higher than needed, (no higher than stock, or even a bit lower) the rods should be fine at those power levels (200-220hp). The vitara setup uses pistons that are much stronger than the stock d-series pistons and yet much less expensive than aftermarket forged pistons. If you go aftermarket forged pistons, JE and Arias are good brands. Try to choose the set that retains the stock compression ratio for reasons I mentioned above. You'll want to examine your engine block for cracks and any other damage that may make it unsuitable for boost. If it all checks out, check the cylinders for the "cross-hatch". If they are in good shape, a quick hone is always a good idea. They may need to be bored out 0.5mm or so depending on the condition. So don't order pistons until you know what work needs to be done to your block. You will also need to have the block resurfaced as well as the head. The head should have new valve seals/guides installed and possibly new valves depending on their current condition. Porting is not necessary neither is changing the cam. You'll want a complete engine gasket set as well. For a head gasket, get a metal layer gasket, meant for forced induction. Use ARP fasteners (head bolts/studs etc.) for extra strength.

Ryan D15Z4

thanks MPR!! The WRX TD04-13T turbo sounds like a really good setup! Im busy researching and trying to see where i can get hold of one. Dont think it should be to hard. Lots of guys driving Subaru's in SA... But im going to have a work shop do every thing for me. So the car will probably be standing for a couple of weeks. And another question,
seeing that there will be alot more HP and Torque, shouldnt i change the stock CV's ? Or only the clutch?

devingodard

Love the cheap, reliable, fast!!! And mpr is great lol. And from what ive read/seen cvs should be ok up to around 250? depending on the launch of course lol.

The other thing i have read when looking into boosting my car, is to boost it to the 200hp and if its not enough for you then build you internals because 200hp is quite a bit in our little cars

D.T.P

Here's a question, where are you going to get a tune? Doubt there are many Honda tuners down there...no offense.

MPR

Stock axles and CV's should be fine.

Clutch will definitely need to be upgraded. Go with a ceramic puck clutch that has a SPRUNG disc. Unsprung is too harsh and unnecessary for that power range. You may also want a stiffer clutch pressure plate, but the stock pressure plate with a ceramic puck disc should hold fine.

I should also mention that the way you treat the car and drive it can and will have a profound effect on how long the setup lasts and how often parts will break. There is no need to dump the clutch at the limiter in a fwd car with this kind of power. All it will do is spin the wheels and or break something. Also, don't run in boost at WOT(wide open throttle) for significantly long periods of time. It's ok if your doing a drag run or the straight on a road course race track. However, a full 1 minute long WOT pull on the highway is not advisable. The heat will build in the head and pistons and you'll either melt or break a piston doing that.

200-250whp in a light weight fwd car is plenty to have tons of fun. Drive it smart. Constantly banging through the gears, dumping the clutch hard and bouncing of the limiter is just asking for destruction and doesn't make you go any faster. The power can be used effectively without going mental...lol. The reason I'm saying all this is because there are people out there who built cars like this, drive the absolute snot out of it and wonder why it blew up so soon and didn't last.

The engine from our turbo MR2 race car is currently being rebuilt. It is, however, a race car and all we did with it is drive the snot out of it. lol. So it just proves my point. You can built a fast car, make it last and have fun with it. Just don't abuse it. If you abuse it, you'll lose it.

Ryan D15Z4

hey DTP no offense taken lol... But South Africa isnt that bad when it comes to tuning shops. Actually there is alot of guys doing that here. Ive had a 5th generation honda ballade 160i before. A couple of years ago... Found a good workshop when i wanted to do some tuning. But funds was a bit rough at the time. anyway.... Took my current Civic ( D15Z4) to the guy last week and had the piggy back Dastek Q-Version Unichip installed. Think MPR might remember what Im talking about now? I spoke to him about the unichip. So I didnt want to get my hopes up, so I didnt expect a really HUGE gain from just the Unichip... after all the only mods on my motor so far is a SRI kit. So got it on the dyno. Did a before Run... installed the chip... played around, got a good tune and map sorted out. Did the after run on the dyno again and gained 8 BHP on the wheels :-D .... dont think thats to bad on a D15 motor? still got the dyno sheets in my car lol... I love the map he programmed. its tuned so that on PARTIAL throttle, I get as good as possible fuel economy. And on Full throttle MAX power... and I must say, did some nice calm driving and the car is most definitely more economical on petrol. NO JOKES. On full throttle the power delivery is a LOT smoother and a LOT more consistent right through to 7400Rpm... I rarely drive the car that harsh, but just checked to see the difference. But like a said, not a MASSIVE increase in power, but really not bad for the money spent.

MPR

^Yeah, considering the window of error and other various factors that can effect the numbers during dyno runs, 8bhp increase is a respectable gain, considering your engine is still stock.

The manufacturers must tune their cars from the factory to incorporate a very wide range of operating conditions all over the world. Air temp, humidity, etc. it all effects how much power the car makes, but they must tune so the engine runs safely in all possible conditions. While they do do a good job of this, in some conditions it is a compromise and not completely optimized for any specific conditions.

When you gain the ability to tune your own engine, you can fine-tune it to your climate conditions and there is almost always gains to be had, though they won't be too significant on a bone stock engine.

D.T.P

^^and meet emissions requirement.

And OP good luck on the build post pics as you go along.

Ryan D15Z4

so i thought while im saving up for the build i want to do, I would just do a couple of small mods on the motor just to play around. I had a 57mm free-flow exhaust installed the weekend, and just got my 4-1 cowley header now. Gonna start taking of the old manifold now! I'll post some pics after im done.... think the motor should breath alot better now and perform good with all the small mods combined by now. Will take it to the dyno again in a couple of weeks to remap the Unichip after the header & free flow.

MPR

Cool, post up the results.

When you go turbo you won't be able to use that header, but I'm sure you realize that.

Ryan D15Z4

yes I know the header will be useless when i go turbo. I'll give it to my little brother. He's got the same D15 motor in his 97 sedan. I got the old ugly cast iron header and on with the new one ... started the motor and let it idle for a while so it can burn in. Always alot of smoke from a new header. Got out on the road and it goes very well. Can feel the motor breathes alot better now. Ive uploaded a couple of attachments.

MPR

Looks good!

devingodard

I know this is an older thread but i was doing a bunch of reading bored in the winter no heated garage lol. And i figured if you hadnt started your build this is possibly helpful. I read somewhere d series.org. that you can use b series ls rod in the bottom end of your d series blcok if you had access to a machine shop and could get some ls rods on the cheap it would cheap and b series rods can holld correct me if im wrong somwhere in the neighbourhood of 275-300hp? I looked in to this beause my ex gfs dad was a machinist no didnt do boaring or honing of blocks or decking prob could have talked him into it lol but anyway here it is if it helps great if not some cool info lol.
from d series.org:
The piston end bore needs to be bushed to match the D16 piston's smaller pin size. The pin on the LS pistons is 0.826" (21mm), the pin on the D16 pistons is 0.748" (19mm). You need the custom made aluminum-bronze bushing with a width of 0.786, ID. 0.748, OD. 0.827 +(over) three thousands due to the bushing will be pressed in the small-end of the LS rods, so the bushing won't come out of the hole. Crower sells these for around $40 a set"