37 replies to this topic

[RexBoy21]

i have a d15a3. does the engine have a lot of potential? i was wondering because i dont hear too much about modding the engine out or anything. mostly talk about the d16a1 and stuff. i personally like the sound of the d15a3 when it hit like 4-6 grand on the tach.

Edited by RexBoy21, 12 April 2005 - 06:18 PM.

[cbstdscott]

RexBoy,

You are my homie! I too am a fan of the bastard step-child of the Honda family.

Long story short, the D15A3 has maybe the strongest bottom end of any Honda engine and an ideal rod ratio. It also is handicapped with a restrictive intake side of the head and a serious lack of aftermarket support.

But do not dispair! All you have to do is to think like a 1950's hot rodder to make some serious power in the beloved beast. I am making ~120hp at the crank (up from 91 stock) with a mostly stock bottom end and lot of mods to the top end.

It is possible to make ~200hp NA and if you are brave you can put the squeeze on the engine and make a good chunk more. But those configurations are not destined for a long life.

Here is your clue: Get more air and fuel into the cylinders IN THE CORRECT RATIO. Do not worry about the fuel delivery system or the ignition, they are fine in stock form. Concentrate on head, cam and throttlebody improvements.


Scott

[Omega Mugen]

Do not worry about the fuel delivery system or the ignition, they are fine in stock form.

Scott

<{POST_SNAPBACK}>

I have begun work in the CRX laboratory to prove this statement wrong. I need to compete against new cars and their new technology. That is what motivates me.

Your right about the bottom end. It is a one piece crank girdle. In 1988, Honda switched to a two piece in the new generation D's then back because the one piece was superior.

Edited by Omega Mugen, 12 April 2005 - 07:46 PM.

[Omega Mugen]

Long story short, the D15A3 has maybe the strongest bottom end of any Honda engine and an ideal rod ratio. It also is handicapped with a restrictive intake side of the head and a serious lack of aftermarket support.

<{POST_SNAPBACK}>

Scott,

Out of curiosity, what makes you say so?

[jsgprod]

Long story short, the D15A3 has maybe the strongest bottom end of any Honda engine and an ideal rod ratio.

Scott

<{POST_SNAPBACK}>

I wouldn't go so far as to say that it's ideal, CLOSE, but not quite. The rod/stroke ratio for these is less than 1.7:1. That, from what I've read, is what Honda themselves have figured is an ideal rod/stroke ratio. Which just happens to be what their 'Type R' motors have.

Of course, back when I was in high school the hot number was 1.9:1. A number that just happened to be what you'd get with stock Chevy small block rods and their 3" stroke crankshaft (283/302).

Jay

[xxine3dmon3yxx]

ummm.....what is a rod ratio? this is something that i have never heard about. what does it have to do with performance? sorry im ignorant...

[IfTakumiDroveACRX]

i personally like the sound of the d15a3 when it hit like 4-6 grand on the tach.

<{POST_SNAPBACK}>

I know the sound and the feeling man !!! that's why i still run the d15a3 !!!! i love getting the rpm to about 4 grand then punching it !!!! It feels like vtec without the whiny sound hahahahahahahahaha !!!!!

[eldo]

Definately stick with these EW motors until you learn all you can performance wise. (You can easily replace these motors for cheap) With only a cam change ,you can outrun stock 16a1's (1/2 hour to change a cam). Get some head porting, add a better induction and exhaust system, a way to map your fuel and timing curve, a bigger cam (Maybe even some nitrous or forced induction) and you will be seeing 13 second 1/4's.
I am jealous of the sound you guys still have- mine lost it with the turbo. (Turbo exhaust note sucks!)

[76kcfdeng]

Stick with the ew and learn how to make more power with it. If it doesn't satisfy your need for speed you will then have a better idea of how to do a swap and make it run. I am staying with the ew because of weight and the desire to see what I can get out of it.
Glen

[jsgprod]

Well it looks like I wasn’t exactly right about the R/S ratio in the Type-R engine after all.
I knew that there was an engine Honda had made with a R/S ratio of around 1.7:1. Turns out it was the B16A3, which was the 160 hp version of the Del-Sol Si from 93-97. It has a 1.74:1 ratio, the Type-R has a 1.58:1 ratio, which, as it turns out, is the same as what the D15A3 engines R/S ratio is.

Jay

[3gencivic]

cool info.
im also one that is staying with the ew engines im working with the carberater ones. the ew2, d15a1
with the mod to the carb that eldo didi i was able to get a highest highway run aobut 300k on the trip got 52 miles to a gallon so its a good highway engine now im tring to see what setup to do a tthe strip.
doing a staged cam webber carb 12lb f wheel.

[RexBoy21]

Definately stick with these EW motors until you learn all you can performance wise. (You can easily replace these motors for cheap) With only a cam change ,you can outrun stock 16a1's (1/2 hour to change a cam). Get some head porting, add a better induction and exhaust system, a way to map your fuel and timing curve, a bigger cam (Maybe even some nitrous or forced induction) and you will be seeing 13 second 1/4's.
I am jealous of the sound you guys still have- mine lost it with the turbo. (Turbo exhaust note sucks!)

<{POST_SNAPBACK}>

Stick with the ew and learn how to make more power with it. If it doesn't satisfy your need for speed you will then have a better idea of how to do a swap and make it run. I am staying with the ew because of weight and the desire to see what I can get out of it.
Glen

<{POST_SNAPBACK}>

wow thats some good advice. i never thought of it that way. i think i will stick with it. right now i have over 205,000 miles on it. what should i do? u can get ur valves cleaned or somthin right? although when my friend rebuilt his mustang engine he talked about replacing all the parts like valve springs, pistons etc. or shouldi just buy and swap a d15a3?

Edited by RexBoy21, 13 April 2005 - 07:36 PM.

[Omega Mugen]

wow thats some good advice. i never thought of it that way. i think i will stick with it. right now i have over 205,000 miles on it. what should i do? u can get ur valves cleaned or somthin right? although when my friend rebuilt his mustang engine he talked about  replacing all the parts like valve springs, pistons etc. or shouldi just buy and swap a d15a3?

<{POST_SNAPBACK}>

Well, you don't exactly clean the valves you can have the faces re-cut and lapped. That helps you power by getting rid of the leaks and so you'll have better compression and combustion. Then you have the valve to rocker arm clearances adjusted. That helps your valve timing for the same reason that a cam does. Also, when you get that high milage, it's good to get new piston rings and hone the cylinders wall if needed for the same reason, better compression and combusion.

[RexBoy21]

Well, you don't exactly clean the valves you can have the faces re-cut and lapped.  That helps you power by getting rid of the leaks and so you'll have better compression and combustion.  Then you have the valve to rocker arm clearances adjusted.  That helps your valve timing for the same reason that a cam does.  Also, when you get that high milage, it's good to get new piston rings and hone the cylinders wall if needed for the same reason, better compression and combusion.

<{POST_SNAPBACK}>

what else do i need to get the engine to run like new? i would like to do that first and then mod the engine. or should i just buy a one.

by the way, at precisionengine.com they sell d15a3/ew3. there are two types of this engine. the "premium longblock" and the "economy longblock". whats the difference?

[87MugenProCR-X]

Economy isprobably referring to the Hf motor the other is probably referring to the Dx and Si motors.

Julian