11 replies to this topic

[87civDX]

hey everyone im taking my 3g hatch to the fontana speedway on the 26th of this month and i was wondering if there was any quick modifications that i could do to make a little more power by the way it has a stock carbed 1.5ltr d15a2.

im trying to see what it will run without any major mods and then build the engine up and turbo it and spray it mabie but im just thinking out loud


thanks in advance

[zakats]

So you don't want to open the engine up or you do?
Is this a USDM car or Canadian model?



Intake, header, exhaust/pull off your exhaust after the header. the DX header/cat isn't the best for performance but if you wanted to swap to an aftermarket or Si (doesn't have a cat built in) you'd have to swap oil pans to an Si unit.

If you're good at grinding and such you could port match your intake and maybe even pull off a ghetto port job with the head on the engine... but I wouldn't recommend it. A good home brew port job on the intake side of the head will help it out.

Cbstdscott ought to have a write up on lighter distributor springs to give the engine more advance at lower rpm's that tends to help give it a bit better powerband

Getting your hands on a set of Si inner valve springs to make a DX outter/Si inner valve spring combo on the intake and exhaust ports makes you a little more rev happy.

Be sure to adjust your valves even if you don't mess with your top end or the engine at all, they are supposed to be adjusted every 30k mi and people never do it- that'll cost you a little bit and you want every bit you can get with these cars.

A straight up swap to an Si engine with your carburetor/intake and a $20 aftermarket fuel pump will make you much, much faster IF you're running a USDM model.

You might focus on gutting your car. There is a good 100-200 lbs that you can shed if you don't care for your interior- I have a steering wheel, gauges, driver seat (sometimes a passenger seat), and carpet... I like having carpet weighs 1755 with 1/3 tank of gas.

Edit: Fontana... so you have a USDM car and CVCC. Get an Si engine if you can, otherwise stick with intake and open header

Edited by zakats, 05 June 2009 - 03:42 PM.

[rexsk8er]

royal purple will give you 3-5 hp.... (dyno proven)

Edited by rexsk8er, 05 June 2009 - 03:46 PM.

[87civDX]

thank you zakats a lot of good information i want to open up the engine after i see what it can do with just little modifications. does the si engine bolt to the stock engine mounts? if so i might go that route

i found that post on lightened springs but i dont know where the weights are are they under the electronic pickup on the distrubuter or is mine just weard and dosent have them

what about an aftermarket headder would that show any gains?

[zakats]

You might pick up a few hp from running a free flowing exhaust but that engine isn't worth much as it is.
the difference between the Si and your 1.5 DX is:
-dx has CVCC which is not good for performance and with its age tends to hurt more than anything else
-dx carbureted
-cam protrudes out the pass side of the head and has lobe that goes in the distributor to drive the fuel pump- when you go with the Si cam on any motor you then have to use an electric fuel pump
-oil pan not compatible with Si header or aftermarket

-Si has oil cooler
-Si slightly less compression but only because the Si head doesn't have any quench pad aka larger volume
-bigger cam and no lobe for a DX distributor/fuel pump, must use Si distributor and aftermarket low psi (~3psi) fuel pump for carbureted engines
-Si oil pan, compatible with aftermarket headers


A well running Si engine in a DX is said to be good for a low 15 second quarter mile according rfl85crxsi and that's with the stock carburetor I believe.

if you bought a Si head(home brew port job), integra p29 pistons, and minor rebuild items you could have a pretty strong 14 second motor for pretty cheap and you end up with a new motor.

I took the time to run down the cost of doing a rebuild with the specs I mentioned. With the exception of the break in oil change, gas spent breaking in, and the ~$30-80 machine work; $198.37 Shipped with all good quality/name brand parts, possibly cheaper for you being on the west coast or even cheaper if you don't mind using different brands- on that quote, I had only Fel Pro, Clevite, and Gates parts: Water pump/gasket, Head gasket set, timing belt/tensioner, all bearings, and thrust washer. I forgot to add the oil pan gasket so add another ~$15

Cyl Head $50-100 and grinding stones $~5, $20 for a drill at harbor freight if you don't have one or ~$12 for a die grinder if you have access to an air compressor.

Later you can change oil pans or at the same time if you have the money. You can port match the stock header and just leave it open before it gets to the cat for track use- not ideal but functional.

You could do it for a LOT less if you don't want a new engine but that's not bad for less than $400 and being faster than a D16a1. Add ARP rod bolts and valve springs for a combo good for 8krpm though the cam will run out of breath at 7

[cbstdscott]

Fontana Speedway? Is that the California Speedway, now called the Auto Club Speedway?

They have a bunch of tracks at that facility, which one are you going to? The drag track?

So from what I can gather, you will use this session as a "baseline" for all your future modifications. It would be more accurate to spend the money for a baseline dyno pull.

Scott

[87civDX]

zakats wow i didnt know that the si was that powerfull i am defanatly going to go that route then thank you for all your information

cbstdscott yes the autoclub speedway and yes the drag track
exactly i want to see what it can run now and then see where i came from after it has the si engine in it. i would take it to a dyno but i cant find any up here and its only $20 to race all day at the speedway

[zakats]

I wouldn't say its powerful... Keep in mind, that was a crx which is lighter by at least a hundred pounds and that was on the opposite side of the country, your results will vary. Engine condition plays a major role on performance. You'll have to straighten things out, maybe change a lot of stuff over to CDM spec in appearance to get it to pass smog since you're in California... right?

[1styearSI]

it kinda sucks i just replaced my head on my si with a reman i see now that i should of or could have used a brown top head or had the reman shaved.i don't feel like pulling the head now it run's great but like anyone i would like MORE POWER.i'm considering sending my cam to delta for a regrind maybe i'll pull the head this winter.i just did the water pump idler pulley timing belt thermostat cv's clutch new head and exhaust.now i can get a brown top swap(complete 1g teg whole car)for 250 it has 140k on it my civic has 123k on it and 800 miles on the new parts.i'm kinda torn if i should sell the ew and go brown top it would be kinda like starting over plus adding weight for only a small hp increase if left stock.i apparently could easily make the same amount of power with the ew and save alot of weight.sorry i didn't mean to jack the thread.i'll start a new one

[87civDX]

zakats ya i forgot about the weight difference between the civic and crx but i could loose 100lbs really easy and ya i would have to change the way the new engine would look so it would pass smog but all of that is cosmetics not a big deal
and again i never figured in the altitude difference and everything between here and where the crx was

1styearSI no wories atleast you jacked it while still talking about performance insted of somthing compleatly random

[cbstdscott]

i would take it to a dyno but i cant find any up here and its only $20 to race all day at the speedway

Where is here?

[87civDX]

im sorry i forgot that i dont have any of that information filled out
im in lucerne valley california its about 20 miles SE of apple valley and about 40 miles NW form yucca valley