Yep. Here's the unabridged version of the story:

The first set of Toda cams made good gains (5hp peak, 6-8hp midrange) when they were installed. Then I added an AEM CAI and picked up another 5hp peak. I had them in for about 2500 miles before the lobes sheared off of one of the camshafts. I removed them and re-installed the stock cams for a while (didn't dyno during this time, so I don't know if my power loss had already occurred). I then installed a new set of Toda camshafts. After installing the 2nd set, I dyno'd and found that I was making about 15hp less than I should've been.
So, I pull the cams out and re-install them. Toda's instructions says there are 3 degrees of play in the cam gear keyways... that's BS. There isn't any play anywhere. I put the cams back in, double checked everything and took the car back to the dyno. Still down about 12hp. I let the car cool off for quite a while and reset the ECU and picked up another 4hp... now I'm only down about 8hp from where I should've been.
In the meantime, I add a Toda header & Amuse R1000 exhaust. Back to the dyno. This time I find that my $3000 in exhaust upgrades netted me about 4hp. Now I'm only down 4hp below where I was when I only had the original Toda cams & AEM CAI. I tune the VAFC and pick up the better part of those extra 4 ponies, though I'm still 1-2hp down through most of the curve (compared to where I was when I just had the orig Toda cams & AEM CAI).
Obviously, I'm a bit pissed off at that point, so I drop the stock camshafts in, just to see what happens. I find that the stock cams make just as much as the new Todas on the high cam, and actually make more power below 5500RPM on the low cam!

Still... even on the stock cam (or the new Toda cams) with the VAFC tuned, AEM CAI, Toda header, and R1000 exhaust I'm barely making as much power as I was with just the original Toda cams & AEM CAI (no VAFC, stock header/exhaust).

I've thought all along that timing was an issue, but I was looking for play in the installation... something that I could've messed up and caused the timing to be off. But there's really nothing to mess up. I've re-installed the new cams 3 times, and always came out with basically the same results.

Also, marcucci pointed out that I should keep the Intake Air Temp in mind, as the ECU may pull timing if it's too warm. Since my dynos w/ the original Toda cams were done at 60-65 degree ambients and my dynos w/ the new Toda cams were done w/ 80 degree ambients, that's still a possibility, but I don't know if that would explain why the stock cams would make more power on the low-end than the new Todas, even under almost identical conditions. Also, I don't know if the ECU would pull enough timing to cost me an estimated 15-20hp on relatively cool days (80 degrees... that's considered cool in Texas).

I also checked compression, to see if that could be a cause of my problem, but that checked out OK. I just can't think of anything else that could lead to these symptoms, other than valve timing. That's why I'm chasing this cam chain issue.

 

Mxt, It sounds like you allready know about comparing dyno #'s without the same IAT and ECT values being pretty close is not accurate. I think I remember UL stating he like to have the Temps within 5deg for each run.

It's hard to say how much timing the PCM is pulling it hot weather without a datalog of 2 runs with different temp conditions. You can watch it on the Honda PGM-FI tester, The PCM is pulling ignition timing even at idle.

I'd be tempted to toss a bag of ice on the intake on a ncie cool day and run again.

I just don't see the likelyhood of a worn timing chain on your 03.

 

Was the PnP on the head done before or after the 1st set of cams?

 

P&P was done at the same time the 1st set of cams were installed.

I agree with your statement about the IATs & ECTs... but that still doesn't explain why the new Toda cams were making less power on the low-end than the stock cams - in nearly identical conditions (ambient temps within 2 degrees). I truly wish I had a datalogger, just so I could see what was really going on w/ the ECU.
Still, to me, the timing chain thing seems to make more sense (or not necessarily the timing chain, but at least something that would adjust they physical timing of the valves in relation to the pistons... not just the spark timing)... simply because it would impact the Todas more because they are a more aggressive cam profile. Therefore, they probably rely more on scavenging, etc.

I dunno... I don't have a good grasp of the physics of it all, but in my head it makes sense.

 

Since you don't have to touch the chain to swap cams, I think the Toda's are the power loss. Is it possible the cams were ground on slightly different centers? Does Toda reccomend degreeing the cams, or just installing them straight up with stock gears?

 

If it were only the cams, then why am I also not making more power with the stock cams? I made 201rwhp when fully stock. Then I added an AEM CAI, Toda header, and Amuse R1000 (header-back, i.e. straight pipe) exhaust, and now I only make 208rwhp? If it wasn't for the fact that I know that there are people locally that started with a similar baseline but are currently making nearly 215rwhp with "similar" setups, then I might believe that all of this is just due to the fact that the stock setup is very good and leaves little room for gains... but I'm certain (by looking at results for people with similar mods) that I should be making at least another 10hp... even with the stock cams.

Technically it's possible that the new Toda cams differ from the original Toda cams, but I think that's unlikely. Toda does not recommend degreeing the cams, and the original cams made power without any additional effort (plug & play). And even if I can't get the Toda cams to make power, I expect more from my stock cams considering my other supporting mods.

In addition to all this, the fact that I've already had to replace the autotensioner is suspicious. The car has less than 11K miles on it... I can't imagine why the autotensioner would go bad so quickly.

 

Doesn't somebody make an adjustable cam gear for the F20C?

 

Toda does... about $400 per set, and dyno time for tuning cam gears on the F20C would get very expensive very quickly.

 

Why not just tune them by the seat of your pants?!