mxt_77

I originally had a set of Toda SpecA v2 cams, and they "failed". However, before the failure they were making good power (the cams themselves were making about 5-8hp with stock intake/header/exhaust). So, after the failure, I decided that I wanted to get a new set. I acquired a new set, and installed them. Unfortunately, after the install, I went and got the car dyno'd and found that I'm actually making 5hp less than stock, and 15hp less than my previous setup with the original Toda cams.

So, my question to you guys is: "Looking at the dyno chart below, do the losses displayed look characteristic of any particular problem?" The red line shows my old dyno (original Toda SpecA v2 cams, Toda valvesprings, AEM CAI), and the blue line shows my new dyno (new Toda SpecA v2 cams, Toda valvesprings, AEM CAI). There is nothing different other than the cams (and the fact that I installed the cams myself instead of having someone knowledgeable do it)... but it just didn't seem like there was a lot to be screwed up in a cam install.
Does this dyno look characteristic of a particular mistake? For example, on my original install of the old cams, the valve clearances were off and this showed up in the dyno as huge losses on the low cam, but minimal losses on the high cam. However, with this dyno, there are huge losses across the board (and notice that there is hardly any increase in torque at the VTEC x-over). Would this be symptomatic of a timing issue? Would it possibly be due to having the Intake & Exhaust cam swapped? Or does it look like something else entirely?

Anyway, here's the dyno graph. Any input will be appreciated.

mxt_77

No one has anything?

Slows2k

Have you verified the cams are installed in the correct positions?

mxt_77

Reading xviper's "MAP Thwack" thread makes me wonder if this could be a MAP sensor problem. However, if the MAP sensor is having issues, I would expect that to affect the A/F ratio. Can anyone confirm this?

mxt_77

As well as I can. The instructions say that there are 3 degrees of play in the keyway, but there really isn't. It's a snug fit. There's not really any play anywhere. I pulled the cams out Saturday afternoon (after I dyno'd) to inspect them, and they looked fine. After re-installing them, I verified that the timing marks were aligned properly and that my valve clearances were good (I actually decided to go .001" tighter than the Toda spec on the intake side). The car feels slightly stronger after pulling the cams out and dropping them back in, but that could just be the placebo effect. I'm going for another dyno this week, just to see. I just want to see if anyone comes up with something I may have missed before trying the dyno again.

Slows2k

So we can assume the intake and exhaust cams are in there correct positions? I've never seen any play in the cam gear keyways, I'm puzzled why Toda's instructions would say there is.
Have you compared the coolant and IAT temps from your previous dyno? Without similar temps, comparing the 2 dyno sheets really doesn't tell you anything.

mxt_77

[QUOTE]Originally posted by Slows2k
So we can assume the intake and exhaust cams are in there correct positions? I've never seen any play in the cam gear keyways, I'm puzzled why Toda's instructions would say there is.

turbo_pwr

Toda is smoking crack if they think there is play in those cams. I've had mine out a few times when I had my CEL problems.

ultimate lurker

I've never been able to identify the "play" that Toda talks about either. But, I have seen issues like this when the cam timing is off. Usually the differential is bigger though. Are the sensor wheels for the cams installed correctly (on the right cams, etc.)? Its really hard to mess those up, so I doubt its the problem, but check everything.

UL

mxt_77

Yeah, I checked everything (twice actually). I'm sure the sensor wheels are on the right cams because I only disassembled one cam at a time (just to make sure that I didn't put the wrong cam on the wrong side! ).

While I couldn't ever identify any play by hand. I think I may have resolved the issue. Basically, what I ended up doing was loosening the end nut (on the cam gear end) while the cams were still installed in the car. I put the transmission in gear to effectively "lock" the engine (which prevented the cam gear from moving), then I tried to advance/retard the respective cam (retard for the intake, and advance for the exhaust cam), by pushing/pulling with a wrench on the camshaft. If there was any play in the cam keyway, this should take care of it. While I was applying pressure to the camshaft to advance/retard it, I re-tightened the end nut.

The car feels stronger after this procedure, but I'll wait until I get it re-dyno'd before I state for certain that it's resolved. I'll post back here once I've hit the dyno again (which should be soon, because I'm anxious to install my new Toda header).

Thanks for the input,
-Marcus.