A real back to back of the bc cams...
 

Long story short, I decided to try this as one of my first mods to the car, and then I could try to offer some real data for a back to back comparison. There don't seem to be many back to back tests, so I wanted to do it.

I had the car put on the dyno before the install, only mods at this time were Invidia Q300 dual exhaust and the Invidia 70 mm test pipe. Here is the graph from that session.

http://i291.photobucket.com/albums/l...IMAG2443-1.jpg
The engine was apparently not very warm when it was first put on the dyno and it made more power as it heated up. This is the only variable that I don't like about this test, but I was not there when the car was on the dyno so I had no control over it. Even still, with just exhaust and a test pipe, I don't see how the car could make much more. Possibly 208ish? idk. Final number on graph is 204.7

A few weeks later, I had installed the BC stage 2 n/a cams and Ferrea beehive springs and retainers. I then set up dyno time, this time on a saturday so I could be there.

http://i291.photobucket.com/albums/l...c/IMAG2487.jpg

The car was pretty warm, it had sat for maybe 15-20 mins after driving up to the shop, and the first pull it put down 217hp, if I remember correctly. Here is the final numbers from the after session, along with the graph from the before. Final number on graph is 223.6

http://i291.photobucket.com/albums/l...c/IMAG2492.jpg

The only other difference was I tried it with the airbox lid on and off, and with it off the car made another .5 hp and close to 1 lb/ft. minimal difference, but the car did richen up, which was good.

I should also mention that the afr readings may not be the most accurate as it was just a sniffer in the tailpipe.

However, I do believe this is solid evidence that the BC stage 2 cams DO in fact make more power, across the board. Let me know what you guys think, or if you would like any additional information.

Thats awesome. Glad you took the time and money to do this test. I would imagine a few more HP/TQ will be had once you get it tuned. Easy bolt on 20hp peak and 15ft/lbs of torque down low. :)

Is the ECU stock or do you have any sort of engine management?

Stock ecu for now. My next step will be the ems series 2. I believe there could be another 10 hp to be gained, and I will lower the vtec engagement to smooth out the powerband. Also will probably raise the rev limit to 8500

In that case, very impressive indeed! Would be curious to see results after a tune!

Keep in mind 4forall, this is on an ap2 which I believe has slightly less aggressive cams than the ap1. So gains on an ap1 main not be as great. But clearly they do make pure bolt in power.

Thanks for sharing, but the dyno plots seem a bit "off". I've never seen a breather mod that showed legitimate gains on a dyno without also showing a change in AFR. Basically, if you were using the stock tune for both tests, and the AFR didn't change, then I don't believe the power changed either.

I knew someone would not believe it lol. Unfortunately, I don't have a wideband installed on the car. So as I mentioned earlier, the afr readings are from a sensor stuck in the end of the tailpipe. Most likely not the most accurate way to get reliable readings. You can however see that at lower rpms, it did read richer.

Mine looked the same way as op for drop in (only other mod was hfc), except the dynapack's wideband was installed at the header and afr was definitely leaner on top end. I didn't even tell the dyno tech what I changed, what incentive would he have to skew the results?

I don't even bother posting the graphs. I believe everyone agrees that they don't lose power...question is how much it actually makes.

Perhaps the variability is coming from the need for cam gear tuning/timing.

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I have to agree with Gernby. I also have a hard time believing that the entire tested power-band has basically been bumped up. I would love to believe these cams produce more power from 3k+ but it just seems "off".

Well I don't claim to be any expert on this by any means so if you could go into further detail on why you don't believe this I would like to hear it.

I would think since the primary and secondary lobes are both indeed different than stock that its not that hard to believe. And I just looked at real street graph and it looks very similar

After a little calling around, it looks stonesilverap2's results are pretty close to what is expected for these cams. I guess people are seeing really good results without tuning, and even better with! Huh...

Tempting, if these actually made ~10-15wtq and 10-20whp across the entire band without tuning, and I would be able to pop these in my car that currently tuned makes 140wtq and 220whp and make those gains, I would drop the money on them instantly. But 160wtq and 240whp on an ap1 seem a bit of a stretch

Like I said before, I would imagine that gains on an ap1 would be a few ponies less, like real street made 13 whp. But every engine is different so ya never know I guess.

Is the op's car a DBW Ap2? If so, I wonder what kind of results it would get from a flash pro tune Vs Aem EMS 2 tune? Or would it matter?

No, my car is an 04 cable throttle. I would think gains from a tune would most greatly be affected by the tuners ability rather than the computer used.

True statement there. This goes for just about all tuning though imo

i've got those.
my engine is F20C2 with all possible bolt on mods and a tune (vtec at ~5600)
could drove only ~20 miles but the car definitely felt punchier at 4-4.5k and up in high gears.
3rd gear is strong all around.
the top end felt somewhat rough. maybe becuase quite significant increase in engine noise.

looking at logs and Gernby's soft dyno the top end looks not smooth:

https://sites.google.com/site/crocwe...res/edyno1.jpg

maybe after all keeping stock valve springs is not enough and valves float indeed....

It was my understanding that BC recommends springs on AP1s especially.

The increase in engine noise may also explain the rough top end if the knock sensor is pulling timing.

springs are springs.
i suspect they're the same for ap1 and ap2.
retainers are diffrent.
my enginne is F20C2 and comes with ap2 retainers.
so retiners wise the updgrade is not a must.
my tuner came back to me taday and says that he don;t see knoks.

I'm beginning to wonder if I should have placed this in the s2000 talk section or something also or instead of here.

So the BC cam's Do make power. Kool

Soft dyno plots naturally get less smooth as the RPMs rise, since the calculated engine RPM becomes less accurate. You should just adjust the smoothing settings on the spreadsheet to reduce the "noise" in the plot.

thanks for chiming in !!!!
what's the OK range of values?
with smoothing at 200 it looks pretty good.
with 250 it's almost perfect....

It's been so long since I've used the Excel based soft dyno that I don't even remember what smoothing values I used. One thing you can do to improve the smoothness is to choose a very smooth / flat road with some incline, and load up your trunk with a known amount of weight. This will increase the number of samples per pull by increasing the load time.

Anyone know where the redline on an ap1 would be after installing the bc stage 2 cams?

when i tested the bc2 vs stock my car had similar gains and the tune didnt change at all.

As long as the valves aren't floating, like one earlier poster may suspect, you *shouldn't* need to change your rev-limit. BC seems to consider these a "drop-in" upgrade. They *shouldn't* cause any kind of piston-valve contact on an internally stock motor.

Can I run Super Tech valve train with BC2 cams or does it need to be Brain Crower valve train?

I use the supertech beehive springs for all motor setups. You dont need 100lbs on the seat for NA.

My F20C2 motor is fine with stock 9000 redline (8900 actually).

ive never seen a cam change do anything like this.. it looks like the ballede header graph