34 replies to this topic

[CSPCRX]

actually you can but its like not within 1/2in of the valves. Really doesnt do much but when your trying to get every last bit of hp out of it you have to take advantage of every rule. Yes at the motor. This was messured at Tri Point when they tuned the Electromotive.

[CRXdan]

PS, With my SI Motor, with; header, open Exhuast, Mild P&P head, Stock cam, i'm making 100hp at the wheels. So 113hp.......so 113-91=22hp gain. Not bad.

Thats interesting. I have a d15a3 with header, a cone air filter, and free flowing 2 1/4" exhasut with magnaflow muffler. Do you guys think that with a high flow cat and a cam regrind and lightened flywheel my car would make 100hp+ at the wheels? If this is possible Im wondering whether its even worth it to swap in a d16a1....

[d15a3power]

I have an 85 Si with basically the same mods as above, but I have a Bullfrog cam.
The cam gives you a surge of power from 3500-4000 on up. It idles in & around 750. I remember driving it home it was like getting Frankenstein's brain installed. It was one of my 1st mods, so as I added I/H/E one at a time, it seemed like my cam got happier and happier!

[CRXdan]

Ok guys so is the extra weight of the d16a1 worth the trouble here, or just spend the money on a cam/lightened flywheel instead???
I woudl think the car woudl be faster, as the engine would be lighter and the cam/flywheel would make it round out to 120hp at the crank (im hoping)

Id rebuild it with new rings and seals too.

then again thikning abou it a d16a1 with intake, header, exhaust woudl be making 120-125hp....

Whats ur opinion???

d15a3 power, have u dyoned ur car, done any 1/4 mile or 0-60mph tests???

Edited by CRXdan, 13 November 2003 - 12:49 AM.

[d15a3power]

Nope, haven't dyno'd or done any time trials.

It just *seemed* like a whole new brain was installed when I got the cam. It felt like VTEC above 3500 mpg due to the power surge.

[cbstdscott]

The stock throttlebody and intake plenum are relatively tiny and act as a limit to potential power, a better breathing induction system is the path to power.

As long as you are going to fabricate a mounting for a larger TB you might as well skip the relatively wimpy Integra's 55mm TB for a later model 60mm TB. On my car, I have a 62mm RC engineering TB on the stock head and cam and that is a definite improvement. As soon as I get the time, I will slap on the head that was P&P'ed by Don Paramour Racing and add the Webcam cam. Once everything is together, I will dyno it and get some hard numbers.

As for cost and trouble, if you have a good tranny and bottom end, the only part of the engine that needs attention is the head and induction. A junkyard TB can not cost too much and the fabrication to make it fit is figured in the value of your time. A webcam regrind is about $200 and a head job can be as cheap as $200 to as much as you want to spend. Do not forget to exhude the intake manifold and do some port matching. Figure maybe $600+ to make an engine that potentially can make up to 120hp at the crank and weighs 100lbs less than a D16A1 swap.

Disclaimer!!! The head modifications I am making are not CSP legal. Do I care? Heck no. I run in SM2 which means I get my butt kicked in my class, but I have a CRX that is street legal and has the performance to make believers out of yuppies in their expensive "sports cars."

So if you see me at the next autocross and I try to slip into CSP, flag me for the Integra front brakes, the Mugen LSD, the RC Engineering TB and the trick head. 99% of my drving in my CRX is on lonely country roads, I would rather build a car for those conditions than for a couple of runs once a month.

Scott

[CRXdan]

cbstdscott: doesnt installign ahuge throttle body liek the Integra rob the engine of low end torque???
I am thinking of doing the following upgrades to the engine:
Rebuild with new rings
Shave cylinder head
4-1 header
Cam regrind (3500 up)
Extrude hone intake manifold
Polish stock throttle body
Lighten flywheel
Adjustable Cam gear
2 1/4" exhaust
High flow catalyic converter
K&N filter
Integra injectors
Integra ECU

Now can anyone tell me what upgrades not to do, what upgrades are a waste of time, what upgrades to do first, etc...
And about how much hp, and what kind of 1/4 mile times woudl you predict...

[LEW]

i think everyone who has an adjustable cam gear has it set on 0, so maybe save the 100 bucks, if you've messed with your's speak up please!!

is there any other tb that has a vac port for the idle advance other than a stock, 86-87 teg or 85 lude? how could u use a newer tb with out? could your do it external with hoses or something.... or just do away with it and use the ac idle booster manualy boost rpm's for a minute or two...the idle booster trick works good for launches, you can set the rpm at the tb. all this only if you had ac and cut the belt or removed it

i'm buildin by baby too!

this winter comes the p&p head w/bullfrog cam, gear, ported intake and tb is already done, lightspead header, mugen cat replacement and 2" with a 18" or 24" or 2x18" inline out the pass side.

and winter is here, 27f outside right now (night time)

[cbstdscott]

I have not noticed any lack of low end torque with the bigger TB, but I am still using the the stock plenum (modified to take the larger TB).

The RC Engineering TB does not have the vaccum ports for cold start fast idle and the engine does not like to idle with the A/C on. But I am willing to live with that for the extra power.

I have the adjustable Cam gear, and yes it is set at 0 degrees. When I get the shaved head on the engine I will experiment with putting a small amount of advance in.

Scott

[LEW]

humm, that makes things easier.....

cbstn, you can alter the amount of fast idle when the compressor is on.. try upping the smaller secondary dashpot (not the actual dashpot) on the tb.

Edited by LEW, 14 November 2003 - 09:10 PM.

[1985crxsi]

someone asked about the cam gear. i have mine advanced 6 degrees. it idles up and down but i have more power. im wondering if any of you know any little tricks or anything at all how i can get more HP. so far i have intake,P&P head, B20 injectors,B&M fuel pressure regulator,cam gear,MSD coil,ACT clutch,DC short shifter,NGK plugs and 8mm wires,headers and muffler are on their way, going to do 2.5 straight pip no cat no res. any ideas let me know. email me if ya can.

[CRXdan]

a cam regrind....thats everyones recomendation

[d15vtec]

Who makes a good cam regrind?gude is good,but to expensive.

[jsgprod]

What's too expensive? I think Web Cams is around $200, not sure though. I have a regrind from Colt cams that was less than $180 plus shipping.

[cbstdscott]

Web cams is about $200 with shipping. They offer 3 or 4 different grinds.

Scott