It is actually cool when it does this due to a high overlap cam, like you see on Sprint Cup cars when they run their two solitary road courses per year.

NOT so much when it is due to a **** poor tune!

 

Glad the custom grind worked out well for you, although I believe when you ordered it I no longer worked at Tick.

Great videos on your other thread as well!

 

thanks, yeah we conversed right in the middle of the transition. just a couple days after i ordered the news hit.

Thanks! lots of folks seem to enjoy that thread.

 

Have you run this at any events yet? If yes, how does it feel? How does the fall off above 5800RPM feel? If not, when do you expect to attend your next event?

My dyno peaks around 5600 and sort of flat lines to 6400, and I've convinced myself it's the VE's picked by PatG back in 2010. Every dyno I go to the operator wants me to give them money in the future to diagnose the non-standard graph behavior. My piston CFM demand is only ~300...MAF & TB both easily flow that CFM, Rick's manifold is supposed to flow that above .600 valve lift, fuel pressure is fine, no exhaust back pressure problems; advance/VE/MAF was tuned on a Mustang dyno, and VE/MAF was touched up on the street; CylAir just stops increasing at peak HP. What I'd like to do is keep the HP curve climbing past it's current peak without affecting the curve below the current peak.

But everything I see says it will be a trade off. These numbers were pretty close to the Mustang dyno, ironically, not sure if one was calibrated to read like the other.

 

Your curve looks suspiciously like my very first cam-only dyno curve, peaking at 5500. In my case, the cam was way off on the grind - 9 degrees advanced! But the point is that the intake valve was closing too early and it simply would not support higher revving. On paper, that cam looks like a great truck/torque cam.

If its the cam in your signature, I think that the cam could be improved. Your IVC is early and your EVO is late. If you wanted to maintain the current drivability and torque, and yet rev higher, i'd suggest something like this - 228/232-114+3. That would move you IVC from 41 to 45 and your EVO from 49 to 53, both of which would support higher revving. You'd still have 2 degrees of overlap, so your idle quality would be about the same. If you don't want to give up too much torque, you could do a 4-degree advance and still have a IVC of 44 degrees, which would still make quite a difference. That cam would still be nice and torque, just rev higher.

An alternate option would be to run the same durations and a wider LSA, like 222/230-116+2. This would rev, but you would sacrifice torque to do it.

Your car looks like it wants to pull higher but something is holding it back. If you're positive the exhaust is not backing it up, then I'd look into cam options. Bottom line, you need to get the spent fuel out earlier and delay that IVC just a touch to support higher RPM -especially on a larger cube engine (>346, anyway)

 

So I am doing a similar thing,
Any estimates on how a 226/232 114+2 1/45/52/0 would behave from an RPM perspective?

LS1, ls6 intake, 241 heads, 1.75 longtubes no cats

 

your peak torque should be around 4800 rpm and peak HP around 6300. Those are pretty typical for a moderate cam and stock casting heads and stock runner length intake manifold.

It'll likely carry power to 6500 and drop off fast after that. If you plan to DD it, you'll feel the power kick in somewhere around 2500 rpm.

 

I have. you definatly feel it run out.
my old cam would just keep climbing (it was a typical peaky/dyno queen cam. 242ish 607/608 112?)
ie you could feel the car come alive about 5500 and continue to really make power the longer you held it. exhaust note would really come alive too. but it had to build, like a turbo car.

the new cam you really dont feel the lower power band power, its more sneaky/hidden. the upper end feels kinda weak.

 

Sooo... How often are you above 5800? Do you feel that you sacrificed too much upper RPM power for your application?

 

I may start using that....

 

with my 4.10s quite a bit.

if you were to ask me right now, having run the cam now in my car, yes i would probly move the power band up 500/800/1000ish rpm

you can really see, feel, hear it run out on the big end. passes are more difficult on the straights.

 

I wonder what Martin or Darth's feedback would be to either extend the current power band 500-1000RPM so it keeps climbing, or to shift the existing power band to the right by 500-1000RPM.

Your 227/235 @.050 112.5+3 cam is IVO 4, IVC 43, EVO 53, EVC 2, 6* of overlap @ .050 but overlap is biased toward the exhaust. I remember reading somewhere that having the overlap be intake biased helps the power carry as well. In post #34, Darth elaborated that an IVC of 43/44 corresponds to a 4800 peak torque and 6300 peak HP on a stock or Fast intake, yet your dyno clearly shows TQ is peaking near 4800 but HP is only peaking around 5800RPM. What type of intake manifold do you have? Did Patrick have any comments on the curve when he tuned it?

 

id love to hear that feedback too. to learn for the next one.
one thing i think i would do from the TINY bit of knowledge i have is have both the I & E duration in the 23x's ie I=low 23x E=high 23x
instead of the I in the 22x's. from what i understand that would move the powerband up.

im running a Fast 90 setup.
Patrick didnt have any comments, hes not a man of many words. but i trusted everyones recomendation for him, and would/will be going back to him for my new car.

 

A few things I've seen cause it to peak early, though if PatG did your tuning I'd be surprised if he didn't pick up on something and have any feedback:

A collapsing intake hose. Sounds weird, but if the tubing isn't rigid enough, I've seen the thing get sucked in and choke off the motor.

Spark plugs too hot, causing reduced spark at peak power. Possibly even some KR.

A less than optimal merge. This hit my car. The Y pipe merge was a dead-head instead of the two lines coming in parallel.

Plugged cats. Also hit mine really hard. Cost me 70 rwhp on the dyno.

Valve float either from a weak spring or pushrods flexing. I doubt this, but always good to include everything. Typically the tuner and/or dyno operator pick up on valve float.

Cam timing off - I don't think this is very likely, but if it's accidentally advanced a couple of degrees either from grind or installation, it'll peak early. However, you'd also have a weird torque curve too. So I really don't think this is it.

Some simple tricks to shift the power curve - x pipe and dual exhaust shifted my peak power north by 300 rpm. Simply retarding the cam a couple degrees will shift it, but you'll sacrifice torque - same is true if you move to a bigger cam. A shorter runner intake will shift peak power north.

 

On another forum it looks like he bought a '09 Z06 and was going to offer this car up for sale.

http://www.frrax.com/rrforum/index.p...ic=17639&st=60