That was the thought I have had, maybe off a tooth either way. Doesnt that throw a camshaft out of range code though even if its 1 tooth (about 3.5*)? P01171 or whatever it is? That was why I also mentioned the CAS as a possible explanation?

 

When looking at razorlabs dynos it doesn't appear that the Cossies have an advantage over the S1s even on the green. Are all those runs on crap gas? Do the cossies show better gains at higher boost?

 

one tooth is WAY more then 3.5*. if that were the case there would have to be over 100 teeth on each cam gear. there are only about 50 teeth, so each tooth off TDC the cam gear is is about 7.2 degrees (and thats cam angle degrees). because the crank spins two times for every one cam revolution, you need to double that to have the crank angle degrees. so every one tooth off your cam gear is from TDC, it is over 14 degrees off crank position. that can certainly make a difference of 1000rpm in spool.

 

when i did my swap from s1's to cosi, timing was checked before swapping as this is the first step to a cam install.... setting the car to TDC. Timing was dead on before and after. Both graphs were done on the same dyno, the same tune, the same boost controller settings, the same anything and everything i could think of to make this as accurate as possible. They were both done in the same gear and both times the rollers were synch'd before starting to log graphs.

I honestly dont know why the difference was that dramatic. All i know is my car is completely different from S1's to Cosi's. The car ran great with the S1's in it, dont get me wrong.... but that was also with my frame of mind that the 20G spooled the way it did because it was a bigger turbo and spooling by 41 was normal. My car was leak tested before JB tuned the S1's and it was fine, held 30 psi with a slight slight taper. It has always done that though, even now. Im totally confused as to why the results were like this as it was not what i expected either. The only reason i switched cams is because my 35 build was coming and the S1's wouldnt of done well. I only dyno'd the cosi's and my 20G because i installed meth and wanted to tune that after i got a base and i get damn near free use of our local dyno.

Maybe in the end, my car is just retarded lol. I dont know.

 

razorlab - that is really interesting info. Have you found in general that cosi's and S1's seem to be the same when compared on a similar setup or does one setup (big turbo or little turbo) seem to favor one cam over the other?

 

I dont really think in crank degress except when using the MIVEC map. I was also applying a rule from Hondas that one tooth is 5*. The only reason I question that is I have built 2.4 DSMs and without using adj cam gears (didnt have them at the time of the initial assembly, but thats another story) we would end up 1/2 tooth off. Putting the cam gears on to adjust for it I do not recall it being a total of 7.2* cam degrees though.

However all of that aside (believe it or not I am not trying to disagree here) it still would be a logical explanation for where the spool went or came from.

 

Yes they where all done on our wonderful California 91 octane.

To be honest, here in California I have not personally seen huge gains on Evo 9's with the typical bolt on and then adding cams. Here on evom people are touting 20+ whp gains with Mivec cams, but I do not see this whatsoever here in california. I do see torque increases and a little peak horsepower increase but nothing like what has been shown here on evom.

I've tried every single Mivec tuning variation under the sun with little to no power increase difference with the current Mivec cam offerings.

On 100 octane I do see good gains overall, but it's hard to know if it's just because it's better octane. I have not done a 100 octane stock mivec cams to aftermarket mivec cams test yet.

I have tuned a couple 9's with larger turbos than a FPgreen with Cossie cams. They have made great power so I do know the Cossies really wake up with more flow.

 

razorlab - thanks for the info. man I wish you guys had 93, I don't really know what to make of 91oct figures.

 

Tell me about it. 91 is a whole different world.

I run 100 octane 24/7 in my personal evo.

 

^^^ AMEN for the 100 24/7, I do the same.

I am very happy with the performance of my car but I would love to know if mivec cams would be worth it for me. When dyno'ing my car the boost and power curves indicate the turbo is out of breath. I'm not sure how adding more air flow via cams would help with that. The turbo is still out of breath.

At this point I think a green with stock cams would be a better option then stock turbo and cams especially when on 100 octane.

 

More data for you:

Evo 9 with stock cams, FPgreen, 91 octane:



Same Evo 9, 100 octane:



Same Evo 9, back with stock turbo, 91 octane (test run):



Evo 9 with Cosworth cams, FPgreen, 91 octane:



Same Evo 9, 91 octane + meth:



Evo 9, stock cams, stock turbo, 100 octane:



Evo 9, cosworth cams, stock ported turbo, exhaust cam gear, 100 octane: (this 9 has always been really strong)

 

^^^ LOL

That makes my observations even more sound especially since that was on a green.

Cams just do not seem to show major gains across the entire power band like this post seems to indicate:

https://www.evolutionm.net/forums/sh...d.php?t=302140

 

here is my stock to s1 comparison with just a baseflash for the cams

 

This thread just talked me out of cams.

 

Haha, thats how i feel now.