272/272 cam timing test and tune

[SILVER SURFER]

I did some test and tune on the street last night. Want stock idle, low end torque, and improved power with the 272/272?

Have you tried increasing the seperation? Say -3 or -4 on the intake and -2 or -1 on the exhaust? With all of the backpressure created by the stock turbo, the overlap of the 272/272 seems to be too much. I have had good results with these settings, and the idle and low RPM power improve dramatically.
I started out with 0/0 and then -3/-3, and that definiatly showed an improvement. I then started trying different combinations on the street doing timed acceleration runs (40-100). Starting with -3/-3 I was getting consistent 7.8 - 8 second times. I finally settled on -4/-1 and 40-100MPH runs dropped to 7 - 7.2 seconds, and the idle and low speed torque were greatly improved. The temp did not seem to change much during my test, but I even set them back to -3/-3 and did another acceleration run just to make sure, 7.8 40-100. I will try to get on the dyno soon to get a quantifiable number.

Each car may be a little different, timming belt stretch, component tolerances, tunning, etc, so YMMV. I found that retarding the intake seemed to have the biggest improvment with knock suppression, going positve with the intake or exhaust only made things worse.
In some configurations, good to garbage could be as little as a one degree change. If you have adjustable cam gears, why not use them?

With added fuel and 3-4 degrees of seperation, this thing idles as good or better than stock. If you can't tell I am thouroghly stoked about this!

Other than going to a cookie cutter -3/-3, -2/-2, or -5/-5 settings, I have not seen any postings about cam timming adjustments, so hopefully this will be helpful.

Regards,

Eric

[Hooptie157]

Silver Surfer you freaking ROCK!!! You just helped me make my mind up about straight 272 or the 264/272 combo. Well if you can get them idling stock, so can I and I will. Awesome results!!!

First the clutch line help, then I/C help, and now this!! I'm gonna call you the yoda of evo's

[evo542]

thanks for the info silversurfer

[EVOlunchbox]

Are you still running the Power FC?

[SILVER SURFER]

Yes, still using the Power FC, very happy with it.

Another interesting thing regarding the cams and adjustment. I have over 24K (still original stock clutch) and after the first 2-3K my car always used oil, especially after a track day I would need to add about 1/2 a quart. After installing the cams and running -3/-3 it did not use a drop of oil. Even after two track sessions and 3-4 weeks, didn't use a drop. Well after the cam timing test and tune and a lot of hard acceleration runs, I was down half a quart!

I have a theory: With these cam gear settings the idle improves and the idle vacum goes back up to stock values. With these new settings I am getting much greater vacum on the intake stroke (because of less overlap), this is sucking oil up past the rings.
I don't think this is a problem especially when your running synthetic oil (really small molecules). I would much rather have the car running sooo much better and have to check and top off the oil once and a while.
My EGT's also dropped quite a bit, I used to easily get into 900-950C, last night I never saw anything above 850C (peak hold gauge). I pulled the spark plugs and they looked great also. If anything, that little bit of oil may be helping to lubricate the combustion chamber?
Oil contamination also seemed a lot better with the cams for some reason, even with the new settings the level was low but it was not contaminated like I was used to seeing after so much hard driving.

[umiami80]

Yeah cams cool off the engine, more air, more cool.

I have 272's as well. They idle ok, never stall, but is lumpy with NO separation. Just brought it to Turbo Trixx, had them install and flash, works great, really gets up and goes, now when I race A-Holes, I can give them a head start, do a Mild launch, and have them by the top of 2nd, then let off at 70, its great.

[jj_008]

Good review of your findings. I am running my 272's at -3 and love the power. My idle is pretty close to stock after Vishnu did there reflash.

I do have a question that is off topic. Do your cams make a ticking sound in the 1500-4000 rpm range? At idle there is no ticking at all. Mine just started doing it after 2000 miles of no noise.

[Deceit]

I need to pick up a set of some gears.

Which are you using?

[evo542]

they could be of any kind, it doesn't really matter

[weightless]

Silver Surfer, you say your cams are idling like stock but does this happen: every once in a while the idle will rev up like 3-400rpm by itself w/o my foot touching the gas pedal at all and then the idle settles back down. Other than this my car idles close to stock. I have spoken to other people w/ cams and they also have this issue. I was wondering if your cam gear or fuel settings got rid of this problem or if you ever had this problem to begin with.

If you do get on the dyno to test your settings please do post the graphs thanks.

[BJai02]

Originally posted by jj_008

I do have a question that is off topic. Do your cams make a ticking sound in the 1500-4000 rpm range? At idle there is no ticking at all. Mine just started doing it after 2000 miles of no noise.

Not sure, may be you need to readjust the valves? But minor valve noise is common with high lift cams

[SILVER SURFER]

I am running my 272's at -3 and love the power. My idle is pretty close to stock after Vishnu did there reflash.

Ok, I don't think you guys are getting the full picture here. I was running -3/-3 for a while, I dyno tested and indeed picked up 25-30WHP, and yes by adding a bunch of fuel it will idle reasonably well. But the idle still wasn't quite as good as stock, and you could definiately feel that the low RPM was soft. I dynoed 310WHP (SAE) with the cams and a high flow CAT, more or less what everyone else is getting with similiar mods (what a suprise).
Now, with these new settings:

1. The idle is absolutely perfect, "not pretty good or ok", it purrs like a freakin kitten. Not as good as stock, I am talking better than stock! It still needs more fuel compared to stock, but the results are amazing.

2. The low end (1k - 3k) is much better than even the stock cams, and when the boost comes on it hits much harder.

3. Seat of the pants and my acceleration testing tell me it's making considerably more power across the RPM band. It feels amazing, and this is above and beyond the 310WHP I already measured on the dyno.

I am not selling anything here, and all of you with 272 cams/gears can easily try this and see for yourself. I am running a Power FC so YMMV, but the improvement was so drastic with my car that I would be very suprised if it doesn't work well for others. Any one in the D/FW area is more than welcome to drop me a PM, visit and see for yourself. I will get some dyno graphs ASAP, could be a week or two though.

do have a question that is off topic. Do your cams make a ticking sound in the 1500-4000 rpm range? At idle there is no ticking at all. Mine just started doing it after 2000 miles of no noise.

They are louder than stock, but nothing unusual as you have described.

Which are you using?

Any will due, but I am partial to the Unorthodox gears. They are expensive and probably overkill, but the design and quality is really really nice. For me it was worth it to spend a little extra for such a critical component. Between this and the crank pulley these guys should be giving me commission or somthing, but their not

Silver Surfer, you say your cams are idling like stock but does this happen: every once in a while the idle will rev up like 3-400rpm by itself w/o my foot touching the gas pedal at all and then the idle settles back down. Other than this my car idles close to stock. I have spoken to other people w/ cams and they also have this issue. I was wondering if your cam gear or fuel settings got rid of this problem or if you ever had this problem to begin with.

Maybe it fluctuates a little when the AC compressor comes on and off, but that's about it. I am also running a stand alone so....

Oh yea, this is my before and after with the 272/272 cams and gears (with no tunning before/after). Other mods were 3'RMR exhaust with Random high flow CAT, K&N drop in filter, Power FC, Unorthodox under drive crank pulley. I don't know what it's making now but based on seat of the pants and acceleration testing, it's significantly better.

[stvbreal]

Great information. I think I'll do some tweaking tomorrow morning.

[umiami80]

I see you retarding timing, and Yeah getting cam gears and retarding it a couple of degrees certainly help idle, that is fact, BUT you inhibit max performance.

I Made 330WHP and even more torque. Is my Idle perfect? No, does it stall? no... Is it as good as stock, no. I like having amazing power, put you in the seat and Hold you there power, so I am against retarding the cams a few degrees, although it is a viable option.'


Again if you are really afraid of teh Idle, get 264's, you won't notice a thing.

[Smogrunner]

Eric,
I have the 264/272 combo at -3/-3. Doesn't my less aggressive 264 intake make my "cookie cutter" -3,-3 really make sense because of the differing cams. Do you think your approach with -4i,-1e make sense for those of us with the 264,272?