Patio

yes, i did a search, the last reply to this post was in May? I think, anyway, it was like 5 months ago. So I figure someone might know something by now.



I found the specs to the cams, as posted above, from what I've been told, I can go wilder on the exhuast, and a lil bit wild on the intake. so here are the ?'s

What should i get to the specs reground to?

does anyone know the MS Exhuast CS Specs?

I want good power throughout the mid range, bottom end and top end arent too much of a concern for me, the way i see it, the engine already puts out good low end torque and the n2o helps out on the top end.



nah, im just kidding , i want the glug-glug sound , lol, no im serious, anyone have any new answers now that we know more about the motors?

Patio

??????????????

zeus

When you say you want that glug-glug sound what do you mean, race cams? I see glug-glug as meaning valve timing that sacrifices all bottom end and a good bit of mid range for pure top end out put. And there lies the dilemma; the stock ECU will not support that state of tune, or anything close to it. So you’re stuck with relatively mild cams until you buy into a tunable ECU at the very least.

My long range plan is to do just that and run the stock bottom end at a rev limit of 8K rpm, with head work and a C/R of 10.3:1. I have cam blanks and plan to have them cut to the following specs when I’m ready to do it all at once. Here’s what I decided on:

Intake – .352 @ 226 deg. op @ 10 BTDC, cl @ 36 ABDC, LC @ 108 deg
Exhaust - .336 @ 210deg. op @ 36 BBDC, cl @ 6 BTDC, LC @ 108 deg
Over lap 4 deg. for starters, 10-6 BTDC
LSA 216 deg.
All angles at crank

Of course this means the pesky cam angle sensor has to go and adjustable pulleys are installed. Also going to need new springs, unless I go with a very mild ramp rate and verify the stock springs won’t bind at those lifts. Closeing in on an LSA of 210 will be posible with better springs for sure. The intake manifold will need worked with the head and I have money down on two headers that are currently in work. I expect the stock injectors/pump/reg will work for at least the initial tuning. I wish I could say how well that set up works, but my development cycle is very long, and for now I’m happy to wait on an AEM controller for the FS-DE.

That should be close to glug-glug.

chooch

If you're talking about the blank cams from Mazda, I don't think there is enough meet on it to get 226 degrees on it if you want to use factory shims. Mazda doesn't make anything thick enough. You would have to go with aftermarket shims or valve lash caps.

If you are going to be spinning a 8k redline, IMO you should go with a bigger exhaust cam.

Nevermind ramp rates, the valve springs should be done just because of the 8k redline. And with that, you can probably go with a lot more lift with the proper spring.

Unfortunately, with our motors, it's going to be tough to have the best of both worlds naturally aspirated. To be able to make power to 8k without it dropping off a 7k, I think it's going to be tough to get a street friendly motor with power down low and mid range. No variable cam/valve timing.

Traveler

The SP 20 exhaust cam matches the J-spec intake cam for duration and lift.
It's basically the same cam lobes and seperation angles moved around the cam slightly for exhaust events instead of intake.

zeus

I decided on the short exhaust lobe to maintain a reasonable mid range, and don't expect the motor to pull all the way to 8k. Thats just where the rev limiter will hit. Always leave a little over run, to reduce risk I say. Running solid at 8k on the stock bottom end would probably snap a rod sooner than I care to.

Those numbers should pull well to 7400 before a drop off. That's if the head work is right. If the motor hits well at all down low, that long stroke will make it plenty streetable. Also, adjusting the overlap will allow the top end and low end output to be paired to my liking.

Reduced base circle and thicker shims are a given, unless I have the blanks hardfaced first $. New caps and retainers to reduce weight would be nice too $$. But not necessary. If I was to take that step, I'd go with new SS big dia valves too $$$. And if doing that, I'd have a slightly milder cam profiles picked out.

Before I can say anything about the springs I need to tear it down and measure the damn things. It would be nice if someone could throw out some numbers on the stock springs. Right now that's the biggest unknown.