courtney42

I was just wondering cause i have read from several posts that bolt ons will not increase HP worth the money on a D engine ? Is this true? Intake exhaust all useless? I don't believe it. Any one car to comment on this?
Or is this only applying to the D15b7? I have a JDM D15B. Is it worth the time and money to bold on some HP?

trustdestruction

That's just the man tryin' to keep you down.
Don't listen to the DOHC fanbois.

The D15B7 is for the most part a piece of junk, performance wise at least.

Your JDM D15B however, is pretty much the best D-series engine (opinion) from the factory. It is totally worth modding. It's comparable to a D16Z6 or a D16Y8, but of course has some substantial differences, with it being a 1.5L and all. It is essentially (not literally) a D15Z1 block with a D16Z6 head and a unique cam. There are some other differences, but I can't think of them off the top of my head.


Choosing your Long-Term Goals
N/A will be hard to make power on any D-series though, and you'll max out N/A around 160-170WHP on a D-series. So, if you're looking for big power you want to look into turbocharging it. D-series engines respond extremely well to boost, and they are cheap to do so on, since the motor is cheap to obtain and usually you already have it. Exhaust is definitely worth it (not much power but a little), mostly because of the tone quality. Also, if you turbocharge it, the exhaust will definitely help that a lot, because a turbocharged engine won't breathe well at all on that puny stock diameter piping. If you're going to turbocharge it, you can skip the header and intake, because charge piping and the turbo manifold will replace these parts anyway.

If you just want a little more pep and not huge power, intake/header/exhaust is definitely worth it.



Intake
For the intake, an eBay intake will work, but stick a name brand (AEM, K&N, etc.) filter on it. eBay filters are restrictive and don't filter well. You can find name brand filters separately on ProCivic.com, for example. They have a nice selection of filters.

Although, if you're going to do that, you might as well just get an AEM short ram intake. I found mine new on eBay for ~$100 shipped.


Header
For the header, a quality budget header is Megan Racing for ~$160 shipped on eBay. If you get it, when you put it together be sure to coat the midway flange gasket in Copper RTV to prevent it from blowing out. Also, torque down all the bolts properly and retorque the bolts after the engine cools down from the first quick run on the new header. Then after a couple days, check the bolts again. You don't want those bolts coming loose, because if they do, it will cause problems with repeatedly blowing midway flange gaskets. If you take the proper steps to avoid this, this is a great header.


Exhaust
For the exhaust, that is where you want to spend the extra cash you save from buying budger intake and header. The more you spend (as long as you're not getting ripped off, literally), the better the exhaust will sound (generally).

You'll probably want to get an oval canister muffler. Typically, the round fart cans are the loud obnoxious ones, and the oval mufflers are the ones with nice tone quality. Also, with the round fart cans, you add 10 points to the rice factor on your car. lol.

Relatively quiet exhausts include the Apex-i WS2, the GReddy SP2, and the RS*R Exmag. Another is the Tanabe HyperMedallion (or something like that). I recommend the WS2. It is quiet while cruising (so you can hear what you want to hear... the radio!), but when you get on the gas real heavy, it screams like a race car (and not in a ricerish uber loud fart can kind of way), especially while VTEC is engaged.
The RS*R Exmag sounds a little bit better, but is discontinued and harder to find, and more expensive (~$100-200 more). It is definitely worth the extra cash though.
If you decide on the WS2, let me know. I know a website where you can get it for like $420 shipped, and i'll dig up the link for you.


Catalytic Converter
Also, to gain an extra 1-2HP, look into a Magnaflow Direct Fit High Flow Catalytic Converter. If you have a 93-95 del Sol, you can get one at summitracing.com for $100. If you have 96-97, it'll run you ~$150, because of the O2 bung. The 93-95 version has a spin flange on it, which greatly aids the installation of your header and exhaust, especially if your header or midpipe flange doesn't line up perfectly.

More importantly though than HP with this catalytic converter is that it should help your gas mileage a small bit, since your ~15 year old cat is probably pretty clogged and beat up.


Further Thoughts
I own the AEM short ram intake, Megan Racing header, the Apex-i WS2 exhaust, and the Magnaflow Catalytic Converter. I recommend all of those for quality and value reasons.

I hope this information helps you with your decisions.

LUiS010606

i've heard exactly what u've been hearing about the d series and bolt ons and i have the jdm d15b and i just went back to stock for smog purposes and its killing me. yes on the dyno u'll pull max 5 more whp but its a noticable 5. ofcourse its nothin compared to blowing but not every one has that kinda money and u could find a cheap intake header set up on CL. and i kno people are gonna be lik boogga booga.but it doesnt matter this as all imo so i hope it helps.

trustdestruction

I LOL'd.

halfkoreanboy

I have a 92 hatch with a jdm d15b i drove it bone stock for 6 months,then i put a aem short ram intake,dc headers,e bay catback with some square shiney muffler welded on the back lol my hommade catback(the ebay n1 replica muffler it came with felt realy restriced it just didnt feel right like it had no power ....lol)and then i put on a magnaflow highflow catalytic converter(not a test pipe)after i put all that on i felt a big difference,the jdm d15b seems to love the mods and in high rpms it hauls a$$ im trying to figure out what other bolt ons to put, but i think i/h/e will make a big noticable difference not just one or the other,and its worth it i bought all my stuff gently used lol..... but my almost 40 mpg went to crap because im ******* on it 24/7....i thought id just add my 2 cents since im sporting a jdm d15b...some cars ive seen in modified mag when on the dyno with intake/header/and exhaust get like 15-35 whp but all cars are different....mod mag did a stock 240sx and it got like 10 or 12 whp and a base model automatic acura rsx got like 30 whp

95vxtealhatch

Ive got a d15b vtec block and a d16z6 head w/y7 cam gear. I pull REALLY hard from 6000 -7500 rpms. Maybe its just the d15b vtec block that likes to make power up high, because i know for a fact i have a d16z6 cam. I even have a stock header and exhaust.

SOHCinWA

There is quite a bit of hp to be had from the d15's.... Twin cam people just dont know what they are talking about most of the time.

halfkoreanboy

i read somewhere just now a guy ran his d15b on the dyno with intake only 110whp----so if you were to put a good cat back it should give you 7-10 hp average----then like a greddy header 8-10 hp-----sometimes i/h/e work even better together and give good results-----you could put a skunk2 intake manifold thats got to be like 10 hp-----bigger throttle body ???not not sure maybe 2-5 hp----lighter flywheel you get some hp back that you loose through the tranny-----since somtimes power is lost through high rpms you could put an msd ignition get some hp back------lighter crank pulley get power you loose back-------catco,or magnaflow catalytic converter like the guy above a few stated 1-2 hp----and sometimes if you put all that stuff on and go get it tuned it will produce more power----and if you got money you could get port and polished head thats 10 hp i hear----and if you got a light car like a hatch or somthing that would be one fast ***** i wish my 92 civic 2300 lb hatch si was the vx 2100 lbs---i only got the i/h/e magnaflow cat and its a fun thing to drive around town and putting highr hp engines to shame lol

sergiolib

Save the SOHC!!! There are many guys who turn D15's and D16's into decent machines with simple upgrades. I/H/E and a GOOD tune can go a long way. Check out d-series.org . There are guys on there making close to 160hp out of their D15's with simple Mods. The D15 is pretty similar to the D16Z6. Finding mods and possibilities for your engine are vast. I run a D15B too and ive seen pretty good gains through simple mods and a tune. Good luck with your project and keep everyone posted on goals and gains. Cheers

courtney42

This is all good news. I have a del sol si and the jdm D15 pulls hard. It was surprising to me. I used to have a 98 Civic ex and it didn't even pull this hard. Could help that this car is way lighter. lol
I already have an AEM intake, but the suggestions here leave a good taste in my mouth. Looks like i will eventually boost it. thanks you guys.

halfkoreanboy

oh i forgot that i also read somewhere in mod mag that they changed the ground wire or somthing to do with the engine ground wire and gained like 4 hp its minimal lol.....but its power when you add little things up it makes abig diference lol good luck

courtney42

What? i dont know abut that. Changing a ground would not effect HP. Where did you read this?

V8 Eater

you will relatively see the same gains in % which is what matters when upgrading most parts on honda engines unless its an already upgraded engine from factory like the itr, take example an intake,its a mod that probably will add a good 5-8 hp on a k20 and 3-5 on a d16z giving out a very close gain in %. and it is how much you have gained in % that matters not hp, think about it adding 20hp to a 400hp monster might not even be noticable but give 20 hp to a 90 hp d15 ef an you should be able to tell quite a bit of a difference! in other words the fact that you cant gain power off a d is bullshit, tell those guys to stop looking at plain numbers and start looking at real performance like 1/4,0-60,top speed, I would rather have a 150 hp x that pulls 10 secs slips and 300mph than a 500hp no go! numbers mean nothing!
but in reality with all the money needed to make a d get good numbers down the track you really are better off starting with a B series, just IMO though fella's!

think about it an d16z equiped si hb needs 16.5 for the 1/4 while an heavy *** gsr only takes 15.5 (both stock) with a full second difference and that with much more wieght(probably 1.2-1.5 difference for an si hb gsr swap) the best reference would be the delsol its a car that had both,both the d16z and the b16a3, it too has a full second difference and thats only a shity b16, dont believe me?
http://www.albeedigital.com/supercou...0-60times.html

a second down the 1/4 is hard to get and considering you can get b16 swaps for less than 2 grand these days I think its a better idea just to swap than too waste time on the D! besides you resale with the moded D wont be any higher than a regular d powered civic vs a b swaped civic always go's for alot more, so you actually win most of that 2 grand back. IMO best mod ever in the name of performance!

halfkoreanboy

b series swaps get kinda expensive its like 2200 average just for a b16a plus shipping plus install plus bolt ons and if theres anything bad on it like alternator,starter,sensors etc...and the good parts everyone wants,like totaly gets more expensive for some reason,ive checked this all out i was about to do a b16a....lol just something to consider imo only,lets keep the sohc alive like the other guy said above.lol.....im not a b series hater i love them its just pricey imo....and the d15b engines are pretty cool they can hang with some b series i raced a gsr swapped hatch its not that far off and my tranny grinds in every gear i had to drop rpms and shift and still was not that for off....but dont just listen to me im sure other d series owners can vouch

halfkoreanboy

i read it in modified mag,they did a dyno pull on some car and it got like 4 or 5 hp they say when you get a better ground every thing runs smoother and throttle response is better but im still looking into where and what to use ive found a ground wire set it claims like 7 hp or so but i need to fully check it out like to see if any one did it

V8 Eater

well yeah you do have a point it can get expensive, actually it really depends when compared, take for expample a guy who has an ef and wants a jdm b18c(itr) the motor alone go's for over 4 grand then mounts that are needed and a hydro conversion and most of all labour if he isnt mech inclined can all add up to over 6 grand and thats before any mods, but on the other hand if one is capable of doing a swap, which in this case for an eg it is extremely easy, one that plays it smart and looks out for an wrecked,salvaged gsr for the swap can sometimes get his hands on a clean swap for less than 2 grand as I mentioned, an intake and catback is more than enough for a gsr to pull very hard on a d15b specially when droped in an eg! see this all matters to what you consider close? I pulled 2 cars length on a friend and he kept bragging about how close he was while 2 cars almost ment a full second in a 1/4 mile!

dividedas1

d-series are cool, and most b guys don't hate them, its just b-series respond better to simple upgrades. more power to be had easier. sure the initial cost of getting the motor is high, but with just the motor alone you are probably where you would be had you dropped all that cash on simple upgrades to the d. but you would have room to improve with i/h/e and so forth.

overall d's are fun. they are cheap, parts are cheap and they can make fun little go kart builds

V8 Eater

I recommend sohc fans to look out for 1/4 numbers listed for sohc builds located in the sohc drag times section listed in the old eg/dc faqs section, then compare them to dohc ones to have a better idea! read this aswell .http://importnut.net/theswap.htm

my friend runs 14.7-8 ish all day long in an eg dx gsr with just an intake and catback!
I ran 14.9 with an b20z nonvtec eg vx with very cheap and plain bolt-ons, both are only achieved in d series that have a very serious modification list and have a big price tag! and do remember the point of resale with a d vs b civic!

halfkoreanboy

no arguments there if i found a good deal on a b series im on it....lol i had a gsr 4 door tegi back in the day (rare)kinda heavy i guess not insane fast....fast enough to total it though.....and also im sometimes a redliner and if i blow my d15b engine i can get another for like 500 shipped lol and be back on the road i would not be able to afford not having a car while searching for another good deal on another b series...im a broke a$$ racer.......lol....i gots to make due with what i got but i got much love and would NEVER disrespect the b series......

halfkoreanboy

i belive nrg makes a ground wire kit they claim a few ponies...lol im gettin one to see if its noticable or not

SOHCinWA

I am having a few sets of d15 pistons made. Not just a d16 piston dropped into the d15. Wrist pin and deck height will be correct. PM me for more info.

ek's=deathandestruction

haha thats kinda like saying that a giant wing adds horsepower to!

sr20hardbody

milling the head, adjustable cam gear and a y8 headgasket on a jdm d15b should make comparable power to a stock b16 i hope lol and the d weighs about 90lbs less then a b swap from what i gathered.

im gonna give it a try soon already bought a set of r1 carbs to tune it should be here friday!

courtney42

y8 headgasket? Why is that gasket different from the one that belongs? Accommodate the port polish?

SOHCinWA

It is a thinner gasket allowing for a little more compression.