question

ok i have a jdm d15b with si ecu, si tranny, vafc2, act stage3 clutch, shortram intake, headers and downpipe on my hatch
now my frined has a similar setup
he is si motor, std tranny, si ecu, act street disc , safc, cai, headers, 2.5 with muffler

specs to specs i should be the faster car right? well his car seems to pull much harder then mine, he pulls about a car length on me before i start catching up... is my exhaust holding me back? what could i do to add tourqe?

You should be much faster considering he has an std tranny!
Does your car run right? VTEC is working?

Really man, with a STD tranny that car should be a snail. Maybe he just seems to pull harder because he has to shift less? I know in second gear I could get my HF up to 65.

ok i have a jdm d15b with si ecu, si tranny, vafc2, act stage3 clutch, shortram intake, headers and downpipe on my hatch


So im guessing you have the imfamous V4, since you say you have headerS. :loser:

So im guessing you have the imfamous V4, since you say you have headerS. :loser:

took my line :iceslolan

Really man, with a STD tranny that car should be a snail. Maybe he just seems to pull harder because he has to shift less?

Less HP to pull him, and longer gears to climb? I doubt thats the reason.

could exhuast be holding me back that much? also i used the 88 si ecu, and the rev limiter cuts on around 6500-6800 and my motor is suppost to redline at 7200 i believe. could that also be the issue?

I definitely think your car isn't running right. Do you have any CELs on? My si cuts at 7500k. Maybe u have a poor A/F ratio and ur running rich. Who tuned ur VAFC?

the shop here, like it feels like it wants to go
but its being bogged down or something i think im running like +3% correction

its a 88si ecu and the rev limiter is like 6500-6800 somewhere in there

Have you checked your timing with a timing light?

So im guessing you have the imfamous V4, since you say you have headerS. :loser:

Yeop its the infamous Cube design...the 2 by 2 that has become ever so popular u know, lol.

If you know how, you should do a compression test.

we used a timing light and set the timing, its still pretty slow. how do i do a compression test?

get a compression guage. It screws into the spark plug thread. Just remove the plug wire from the valve cover, remove the spark plug, then screw in the guage. Start the car. It will show you what compression that cylinder has. Repeat for each individual cylinder. I've also never heard of the 88 si having any different rev limiter than the 89-91. I'm pretty sure that's wrong. It's still an si. I have an 88 dx. Before I did the si swap, my 88 dx motor and ecu cut at like 7200. I don't understand why the si of the same year would have a lower rev limiter.

your DX cut out at 6800 rpm. your tachometer was off. there is no variation in ROM programming in honda ECUs. it is hard coded as one variable and one variable only.

Also, on a compression test, to get more accurate results, remove the fuel pump fuse and hold the accelerator to the floor. this is so the throttle stays open and more air gets in so the test doesnt take as long and will be more accurate to real conditions. make sure the engine is warm also.

88-91DX
88-91LX D15B2 1493cc
4 cyl, 16valve
SOHC
9.2:1 c.r
92 bhp @ 6000
Redline: 6800 rpm
89 lb-ft @ 4500

88-91Si D16A6 1590cc
4 cyl, 16valve
SOHC
9.1:1 c.r.
108 bhp @ 6000
Redline: 7100 rpm
100 lb-ft @ 5000

That information was taken directly from 4thgenerationcivic.com.

There IS a difference between the si and the dx. Also, redline is different than the fuel cut off. My car redlines at 7100 and cuts off at 7500. My dx used to redline at 6800 and cut off at or around 7200.

again, you are wrong sir.

the DX ECU PM5 has a fuel cut set in the ECU's memory @ 6800 rpm. the "redline" is only the red line on the tach, which is 6500 for all models except for HF that have a factory tachometer.

the Si 90-91 PM6 ECU has a fuel cut @ 7414 rpm, but most often times is represented by 7200 rpm on the factory tachometer.

this was taken from the good folks @ pgmfi.org, reverse engineering honda ECU's tends to tell you the actual value, not something somebody heard or read on a website.

by saying there is no variation in honda rom's, i meant per ECU. all PM5 ECU's are identical etc.

so are u guys thinking its my ecu then? as for the compression, test what am i lookin for, and say its not right, what does that mean? thanks for all ur help guys!

If the tests were low, you would most likely benefit a lot from a set of piston rings and may even find out that you have a bad piston. Or you could do a leakdown test, It tells you a lot about your engine actually. Shows if you have bad valve seals, head gasket, and/or rings, look into it...

Yeop my car is one that cuts off at 7414...almost up to 7500.

well its a new motor, and they claimed a leakdown test was done. i believe i mean dont get me wrong the car is quick like once its going its fast it just seems to bog on on tourqe

has anyone else done this swap, what ecu did u go with and what do u think about this motor compared to an si motor

i thought the d15's were the 64 hp engines in the hfs im so confused now

d15b2 is the engine that is in dx and lx cars which is 92hp...and i think d15b1(???) is the one in the hf. If u check up under the frequently asked questions thread at the top i think it has all that stuff in there.

d15b is a jdm civic vti motor sohc vtec
i changed the fuel filter today since it been a while, but that didnt really do much. i was reading up on it and i think it may have 2 vtec switches... i have one hooked up to my vafc2, perhaps the 2nd isnt hookups up, yo kris where u at ur a pro with this swap

hasnt anyone on this forum ran this swap besides me???

What are the specs on the jdm d15b? Are they as good as the Si bottom end?? I'd almost say that's what's holding you back - the Si bottom end has more torque, - your both running intake header and exhaust with Si ECU. I don't know if the vtec head would give you that much more advantage on the 1.5l block compared to his 1.6l block. But I don't know the specs on the jdm d15b either - I'm prolly thinking the the stock d15b2 with 92 horse.

Looking at the 4th gen FAQ sticky thread it says the jdm d15 has 125-130hp.

where is kris @ he should know

bump

I think he's still fightin fires... :uhoh: but dont quote me on that, last I heard, thats where he was, but I dont keep up on him like others....

Wow Josh...first intelligent post i've heard from you in a while. Normally its just you whoring up threads like I am right now, lol.

I have no idea what youre talkin about, me whore threads? :22yikes:

Yeah, bitch...ahem sorry I mean Josh.

Whore...not bitch...bitch

bump cause no ones helped yet

The 4 speed tranny from my std. was used on a friends zc. he did 8.7 in the 1/8th. i don't know how bad it really is......... he likes it more than the zc and SI trannys.

actually he has an si tranny now i found that out, the only thing i can think is the exhuast, i have 1.5 inch banged up exhaust with a glaspak and he has 2.5 straight back with a catback muffler...

is there anyone on this peice that has done the same swap??