No Difference With The J Spec Cams

No Difference With The J Spec Cams

I recently purchased from Mazdaspeed the sport 20 intake and exhaust cams. I had them installed by a buddy of mine who is a Acura mechanic. I don't know what is the problem but there is no difference in power it feels exactly the same. When I compared the parts with the original cams they looked the same and I just thought that the difference did not have to be noticeable to make a difference in the power output. Is there anyone out there who can give me some info that would help me make some sence of this.

DOGG.....

Unless you know what to look for, they look a lot alike. If you hold them endwise, you'll notice the tips of the cam lobes are fatter on the Mazdaspeed cam. Other than that, the exhaust cam has about .020 extra lift that you won't be able to see, and it also has a couple dayglo stripes on it at about the midpoint.

As far as performance, they added 5-6HP on my car with the stock intake and exhaust. They really don't come completely to life until you open up the exhaust and put a better intake on though. With the right cam timing (adjustable gears) and some adjustment of the ignition timing and fuel at WOT, I think you could probably pull 12HP out of the cams realistically.

Traveler said:

.......I think you could probably pull 12HP out of the cams realistically........

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Everyone on this board has been waiting for someone to pull those kind of gains with just the cams alone and after all this time, I'm beginning to believe that it won't be done.

hell i would love to do it. but i dont have the money right now.

B.E.G.I. turbo? Should I get one?

Seriously thinking about getting one. First off what am I looking at price wise I'm in Canada so remember Canadian funds. Also how long is the installation process and what gains am I looking at in the acceleration and top end speed areas. I love this car and definitly need some power gains.

APEXistud said:

Everyone on this board has been waiting for someone to pull those kind of gains with just the cams alone and after all this time, I'm beginning to believe that it won't be done.

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You'll notice that I said with the right cam gears, ignition and fuel. The problem we have is that the ECU is not optimized for these cams. But then it isn't optimized for the stockers either. I'm getting good fuel mileage with my setup right now and I'm a total of about 14HP and 11 lb/ft of torque over stock. If I could tune it I'm sure I'd get quite a bit more as the stock ignition map is WAY too slow and the fuel is WAY too rich at WOT.

If I end up retaining the stock ECU tuning, the only thing that I think would work better is to boost it and maybe add a little fuel to it. The ignition map on the stock ES/LX/P5 is perfect for boost. No need to run boost retard. It would still be nice to be able to tune a few degrees of advance in while not under boost though.

As for fuel, it would seem to be the easiest way to adjust that would be to get an adjustable fuel pressure regulator and adjust the pressure 3-4psi lower than stock. The computer will compensate by richening up the part throttle settings and the WOT settings will lean out some. I'm still looking for a good one. There was someone that had one on another site but they never told us where they got theirs.

best performance???

I've read a couple times the way to get the most from your cams is to open up your intake and exhaust for better breathing. So are we talking about a new intake manifold and cat back exhaust? Or will a good CAI and Mazdaspeed muffler open it up a little?

Re: best performance???

blue_hotty said:

I've read a couple times the way to get the most from your cams is to open up your intake and exhaust for better breathing. So are we talking about a new intake manifold and cat back exhaust? Or will a good CAI and Mazdaspeed muffler open it up a little?

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If you have an mp3, new exhaust w/o any other mods won't get you much. Intake may add a few hp.

Traveler: I have a fuel pressure regulator...its from Ractive. I think I have seen them on Nopi Online.

Question: 3-4 PSI lower? wouldn't increasing the pressure force more fuel through the injectors? more fuel with mods like an intake, exhaust work...wouldn't that make more sense? I'm looking for your input on this very much.

I've got a cat back with in intake and I have the regulator at about 5 psi above stock. I may be imagining things, but I am experiencing better acceleration with no real change in fuel economy.

I was thinking about the intake and exhaust cams.

Actually, the stock A/F ratio is fine except at WOT. Then it goes way too rich. The dyno shop and I were thinking that if you took out a few psi, then the computer would compensate at part throttle by increasing the injector pulse width. Then, at WOT, it would be leaner (it uses preset values from lookup tables depending on RPM and TPS value) due to the lower pressure available. If it worked, then it would be a cheap fix to the overrich condition.

Our ECUs tend to try to tune around any mods we make to the fuel curve.