Making HP...
VPT
Band Wagon
Picked up the rt4wd a couple months ago and have been tinkering here and there to get a little more out of it. I did all the usual stuff right off the bat, exhaust, intake, advanced the cam, timing, etc. But I have questions now. Is the cam in the RT a6 motor the same as the CRX SI a6 cam? I went to check the ecu and I see a pm6 which is typical to the crx SI's. I can't seem to find any info on the crx cam being different than the RT cam but this a6 just doesn't put out like the SI a6's I am used to. I know the car is 600 pounds+ heavier than a crx, turning a 4x4 drivetrain and all that but still it just doesn't have the spunk a SI a6 has. What is the deal with the RT a6? Is it completely identical to the crx si a6?
I think I posted a pic of it before.
I think I posted a pic of it before.
Comments
Weight does make a HUGE difference.
I know weight can make a difference, but not this big of difference. Not sure if it is well known but just the sound of the intake isn't the same as a regular SI. That is what got me to thinking the cam may be different (less overlap or lift). Every other SI I put a intake on would "bark" pretty good at WOT threw the rpm range. Even with the cam advanced this one just doesn't have the bark of a normal SI motor. When at WOT the RT a6 sounds more like a DX D15.
As far as weight being an issue, it doesn't seem right. I have taken 500 pounds + out of crx's/civic before and the gain in those is no where near the ratio of loss in the RT.
Intake manifolds, throttle bodies, injectors, exhaust mani's, everything is the same as the SI? Its to hard for me to believe. lol
And just so people know I'm not pulling chains I got a few pics of the crx's and stuff that I owned/worked with.
Gutted (1600 pounds) crx.
These two full interior crx's perform better than the RT.
That brown thing in the first post is also stripped and I believe was down to 1900 when I sold it.
Even this full interior pile performed better before I stripped it and sent it to the smelter.
Now I don't expect the RT to be as fast as the civics or crx's, I just expect the motor to perform like it should. Compression is even and good all accost the board, everything is maintained and up and up. It just baffles me. :hopelessness:
I originally thought about putting a supercharger on the D when I got the RT but don't want the bad mileage. If I can't relatively cheaply get this little D to perform at least a bit better I think I will start gathering parts for a B series to mate to the D trans. I love the EF chassis with a B in it!
-Transmission gearing
-Transfercase power loss
These two things alone will rob power compared to your crx, even though they're the same exact motor.
Me too! Is that a loft above the lift? I would KILL for that!
I was wondering about that today while driving around. I was curious if even though still turning if the case was disengaged would it make a difference. I won't do it now because winter is right around the corner but in the spring I will give it a try. Thanks!
Others: no loft above the shop, just parts storage
I did pick up a dohc zc a couple weeks ago. It will be my winter project to make the head flow and maybe do some lower end "something". I would really like b16 power out of it.
What B16 are you trying to match the power from though? I'd think that would be a hard target to match the 170 horsepower without having the vtec to broaden that powerband, though if you were going for the ones that are closer to 150 that could be possible.
I think the torque is near enough to that that if you did manage to bump up the horsepower you'd have a sight more torque than the B16 has anyway, so that could be cool.
If you have easy access to E85 I'd absolutely bump up the compression on it and run some of that through it. Definitely take some pics of any tear down you're doing.
From what I read the stock compression on the dohc zc is 9.2:1, I would like to bring that up to around 10:1ish and still run pump gas (91-92oct). We do have some e85 pumps around but honestly I hate the stuff and I don't want to be reliant on a fuel I might not be able to find when traveling around. My kids will one day be driving this car as well so I don't want them to have to worry about what gas they are putting in.
I will most definitely take pics of everything as it goes along.
I did have a thought yesterday when I was thinking about the build. I am almost certain of the answer but does anyone know if dohc LS cams fit the ZC head?
Regarding the Ethanol though I think some of the chipped ECUs allow for timing adjustment, and I know they have ethanol sensors. Might be something to look in to, advance the hell out of the timing when it's running E85 and retard it back when it senses it's not.
This motor will run on 91-93 pump gas, will have 10+:1CR and will take all the timing I will throw at it and like it! lol
I mean if my B16 crx with a supercharger at 9.5 psi running on 16 degrees base timing with 91-93 octane pump gas can do it there is no reason this NA zc can't.
That way I don't have to worry about the rubber fuel lines, the fuel pump, o-rings, injectors, fpr, or a crappy idle.