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exhaust piping

3K views 32 replies 14 participants last post by  Slow_Import 
#1 ·
hey guys.. i wanna ask.. for NA aplication like swap head with d15b or d16z6 head, with some port n polish, mill head
how many inch of piping exhaust after header till muffler for d series user usually used ? 2 inch maybe ?

oh yeah any body here used Gude bullfrog cam ? which is better if we compare with zex,crower etc
thx alot
 
#5 ·
2.25 is good for n/a applications, but you can go 2.5 and still be ok with your setup, dont forget to install a "cat" and a resonator.
I think crower will be the best cam selection you can make!! just my thought;)
 
#6 ·
I have always used 2 1/4 on all my D motors if its used for the street. Perfect back pressure. Just enough. Any bigger and it seems to lag on the bottum. Not good.
 
#7 ·
what modification all of u have aplicated ?

my own is stock vtec 115 hp engine d15 block with d16y5 / y8 ( i dont know exactly..) head

i want to know if i use 2 " or even 2.25 " are still ok with no lag on bottom rev

because now i only use 1.75" piping, resonator n muffler, and no cat
 
#8 ·
my own is stock vtec 115 hp engine d15 block with d16y5 / y8 ( i dont know exactly..) head

do you own an HX? or do you know if it has 3 stage vtec? if so its a y5.

normal vtec (EX) will be a y8. how is the throttle body located...on the side or vertically?
 
#10 · (Edited)
stick with 2.25" with a n/a application, 2.5" at the most. 2.5" will be on the loud side on a n/a, even with a cat and resonator.
 
#14 ·
Yes in most likelihood, your engine has a typical D15 whole block but the head will be the trick part. I am quite familiar with Citys coz we have lots of em here in asia.
Your head is the same one as for a Y8 being a P2J.
BUT, your valvetrain most likely has a 16-lobe cam (which runs on VTEC-E designs)
A typical Y8 engine has the same P2J head but with a 20-lobe cam much like the Z6.
Here's what I would do:
- First, look at the ecu. If it's a P2M then it's indeed a VTEC-E but because it has a P2J head, it would classify as a NEW VTEC because of the high swirl design of the ports.
- Next, we would like to know what pistons you have. I'm almost sure it has a P08 piston same as for a JDM D15B or something almost as close (compression height & dish volume-wise) Otherwise if the piston is a P07 (severely dished and is from a 92-95 D15 VTEC-E w/ 92hp) then it's impossible to have a 115hp advertisement.
- You would then need to use the 20-LOBE CAMSHAFT, ROCKER ARM SET (complete with lost motions,cam holders. etc), DISTRIBUTOR, P08 ECU , all from a JDM D15B or a Z6 and convert the whole pizza to OBD-1.
- Try not to get a Z6 head anymore coz yours will work and is more fresh, and not to mention,, offers higher compression due to the smaller 32.8cc combustion chambers. (it's a freebie already so why get rid of it?)
- From there you can do anything you want really like chip it, swap intake manifolds, pistons and all that's in the d-series.org menu you'll find here.
- Good luck.
 
#15 · (Edited)
whooooaaaaa... thx for your replies doc! its great n informative especially for me..

so ... from your information, my engine is mix between vtec -e which is from ECU, but use P2J that have a good port design ,right ?
how about D16y5 which is P2J code, Vtec-e and 115 hp ?

and from what i read above, i dont need change my head right ?just stick with my P2J head ..
and i can just change the internal like the cam with 20 lobe cam set ,ecu P08 which i can get from d15b or d16z6 right ? is it plug n play on my stock head, or need some modification ?, how bout P28 ECU ?

or.... what about changing my head with y8 that have 20 cam lobe ?
and i dont have to change my ECU which is OBD2
how about P28 ECU ?

which is more simple ?...
can u recomend what th best brand for intake,piston,cam,chip etc
 
#20 · (Edited)
The simplest would indeed be to swap to a Y8 head package. But you'll end up with another P2J head as your spare. (which is still good so you can practice porting on one and have a safe stock as backup in the event you overdo things hehe!)
Anyway the D16Y5 is a 1.6 version of your engine if im not mistaken. Except for the intake manifold which I reckon yours to have the down draft design.
My engine is a D16Y5 with a Y8 manifold (P2J)...all except that it is a 16-lobe valvetrain and im in the process of converting to 20-lobe like how I outlined to you previously. The problem is there arent Y8 engines to be found here coz theyre USDM so if Y8s are abundant in your country then go for the entire Y8 head conversion package.
I'd suggest port & mill that extra head for compression and flow, order a chip from one of the experienced guys here, buy a camgear, TB, and see if you'll be happy.
That way, you'll have converted to 20-lobe & OBD-1, have a spare head, ported it yourself, raised compression,got a tune and still have your original head & parts for keeps with enough beer money to celebrate LOL!
Then you can upgrade to cams, springs,retainers,pistons etc when you decide to go for more.

BTW, you cant run the 20-lobe well if you still use your original city ecu. Better to get a P08 (maps specific for 1.5 liter vtec engine) for this, chip it, then have the option to toggle switch from stock map to your new chip.
P28s are more specific for 1.6 liter displacement but will still work if that's the only kind available there.

Lastly, go with either 2" or 2.25" diameter on the exhaust, nothing bigger than that IMO.
 
#19 ·
I would also say 2 1/4" for all N/A d-series hondas. That what i am runnin' and am very pleased with it.
 
#22 ·
Thx doc for your info ...

btw.. where do u live bud ?im from indonesia ..
so i wanna search n buy Y8 head package to replace my stock head.. it has
P2J-# code right ?

something i wanna know is.. are the part like cam,valve spring,retainer of Y8 as same as Z6's ?

now about ECU,
are u sure that i must change my ECU to P08 which is OBD1.. but the Y8 is OBD2
P08 ecu is more rare than P28..

n about chipping, what is better between chipping or use piggiback like Dastek Unichip

can u recommend where i can get P08 or P28 ECU ?and if i want chip it,where?

thx alot
 
#23 · (Edited)
Im from the Philippines.
- Yes the Y8 package does have the P2J-# designation on the head & intake manifold.
- The valve springs & retainers are the same for Y8 & Z6. The cams are keyed differently between the two. Buy a Z6 cam,sprocket, cam holder, rocker arm assy. dizzy. You can use your valves,springs and retainers.
- DANG! I wish we could exchange problems coz vise versa, we have LOTS of (small case) P08s here and I have yet to see a P28 being sold.
(Large case) P28s are OBD1 as well and they come from the USDM D16Z6.
Though it's not a MUST that you use a P08. It will work, should even work fine IMO...hell you can even use a B16 P30 box if that's more common.
It's just that I thought you were going the route of chipping so it would be BEST to chip a P08 coz its for a 1.5 vtec motor which is what you have / will be building towards.
And when you dont want to use the modified chip (let's say you suddenly fancy economical easy driving on the Indonesian city traffic) you can conveniently switch maps by installing a toggle on J1 and PRESTO! - you're now running on stock P08 maps.
But dont get me wrong. This can also be done to a P28 and P30 so it's not a priority.
I havent used Dastek Unichip yet but we also have it here. Yes it's versatile with fuel & timing control but i know it's kinda expensive when I inquired. I decided to order a taylor-made chip from one of the gurus in this forum coz I feel it was the best to do given my limitations. I gave him (Ubertuned) all the details of my build and the settings I want so he'll use his experience in creating a good map.
You can go piggyback with Dastek if you want but tune on a dyno as everyone would advise.
- I dont know the honda surplus market there in your country so I cant recommend where to buy a P08 or P28. Though the P08s here should cost arnd $ 150.

Good Luck man!
 
#24 · (Edited)
thats great bro..
thx alot...

so i can use either P08 or P28 depend on what i got in here right..
can u tell me who's can map the chip if i buy a new one in this forum.. are u experience with him ?from what country and how about the budget for that?
and what chip that i must use

what the cons if i keep using my stock ECU with piggyback ? will i get something bad?

in ebay there're lot of P28 but not P08, have u bought sumthing from ebay bro ?
im not yet

err bro.. how about d15b head JDM 130 hp ? i wonder ift that will be better for my d15 engine .what about the compression, are the part same as d16z6/y8 like cam,retainer etc
 
#25 ·
If your piston is a P08, you'll get 9.6:1 c.r. if you put in the entire JDM D15B head package.
You'll hit around 10.0:1 if you use your Y8 head.
You have to use an OBD-1 ecu if you'll convert to the 20-lobe.
Take the whole JDM D15B package including ecu, dizzy, O2 sensor, I.M., fusebox with ELD (in case yours does not have ELD)
Sure, no problem if you use a unichip for this.

If you want to get a Cromed chip from the states, it's best to contact forum members who do it. Search the Engine Management threads and ask around.
 
#26 ·
i dont know what is my stock piston
so which head have the higher compresion ratio... from your info .. i gonna get 10:1 if i use y8.. so the y8 higher than d15b

d15b head code is P08 same as d16z6 right... ? i think they are same.. d15b JDM and d16z6 USDM
 
#28 · (Edited)
PJT... what kind of piston is that ?
what the.... half of my compression.. mine is 9.4 so if i use P08 head without change the piston..i get too low compresion i think..

what about i change my piston with P29 piston

so .. i must use Y8 / P2J head
 
#29 · (Edited)
I have no idea what PJTs look like. But I'm willing to bet they have a bigger dish volume than P08 pistons coz if you say your compression is at 9.4 and youre already using a P2J head, using a P08 piston from a JDM D15B with an advertised 9.6:1 c.r. on a P08 head, I would estimate your compression to reach 10.1:1 if you use P08 pistons and P2J head.
You want this to go up more? then you have the good option to shave off say, .020" , use a 2 layer headgasket and you'll be at around 11.++:1
(i hope you were able to follow)

Im not so sure about the P29s on your 84.5mm 1.5 liter crank. I dont know how it will sit on the deck to be honest. It's worth a try to find out coz it's a dome piston but I have a feeling it will set you at a very high c.r.

...and I'm not a dome fan LOL!
 
#30 ·
hey .. i just know what is my piston code.. from the local dealer that sell honda part, and i try to ask that he have honda city type z.. and i look for the code..

it is P3M and its Flat top

oh yeah i just look the stock head code of local Ferio 1.6 '97, its P2J-4 !.. hey that's code for d16y8 right ?and its sohc vtec.. not vtec -e... but why when i ask people about this ferio' shead.. they said its vtec-e
 
#32 ·
Hmm, I wonder if they meant to say PM3..not P3M..(coz PM3s are flat top 1.5liter pistons indeed)
BUT PM3s are non vtec pistons so P3M is probably what it really is.
Again I have no idea of the P3M but since you mentioned theyre flat top, and being VTEC pistons (as they should be) that yield you a 9.4:1 compression, they probably sit much lower down the bore.

Assuming that that ferio is indeed a vtec-e,then it's just a 1.6 version of your engine (same 16-lobe cam)...a D16Y5 from the USDM 96-00 Civic HX.
Same as my engine now.
Man, there are A LOT of mixed parts in the Asian market that it's not even funny! Hell, even bogus horsepower claims from Honda just for marketing lure...

Anyway, the P2J head is used for the USDM D16Y8,Y5, JDM D15B 3stage VTEC, Asian City 1.5 VTi, and some more.
 
#31 ·
try to figure out the City's piston compression height (from piston pin center to top of the piston, not including dish or dome)...
i have a D15Y2 which have "PLC" label pistons, Piston compression height is 27.0 mm with a (4-5 cc dish not sure)... it sits 4.2 mm below deck... it's on a 2001-2005 7th gen civic :)
 
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