Thought I'd chime in: FLAT torque curve

224/230 112* cam, Joe Prince Heads.

 

Thanks all for chiming in here. I'm getting more comfortable with narrowing down my cam selection.

Roman95z,
Do you have any dyno numbers on that cam?

Fastbird93,
I love the top end torque with that cam, but I'm worried a little about the low end. It might even be pushed a little too much to the highend for what I'm looking for. It looks like it starts to decline a decent amount in the low RPM. Does it fall below stock levels at 2500 rpm? I don't know if you have that information. Everywhere else it is making more than stock on your chart, so that is great. This car is still going to be my daily driver, 250+ miles per week to work and back, mostly 60+ MPH. I need some low end for cruising and just general driving. Does the TQ fall below 290 anywhere from 2000-3000? It looks like it only drops about 30 TQ from 4000-3000, so if kept that trend, it woud only drop to 290 TQ at 2000 which whould be GREAT! Oh yeah. I don't plan on doing heads, so that would probably drop the TQ curve a little lower in RPM. That cam may be a little too much duration for me.

By the way, I'm using 290 as what I believe our stock TQ numbers are with a M6.

Thanks,
Dan

 

I had taken the car to the dyno after the chart that I posted, but it was with a VERY rich problem that I'm still trying to sort out. We lost 10 HP and TQ, but started the pull at 2500 rpm too.

Basically what I'm saying is that the car wasn't performing up to the specs of the posted graph. At 2500, my TQ was still at about 315.

This setup isn't lacking, that's for sure.

 

Sounds great. 315 at 2500? WOW. Have you been able to run it at the track yet? I was on your site and was impressed with the numbers you put down before the cam.

Also, what to you think not having heads would do to that curve? I'm not planning on heads in the near future, just headers and exhaust, and maybe a TB.

Thanks,
Dan

 

Quote from Vetteman.org:
"However, if you re-gear the car so it is operating at the power peak (5000 rpm) *at the same car speed*, it will deliver more torque to the drive wheels, because you'll need to gear it up by nearly 39% (5000/3600), while engine torque has only dropped by a little over 7% (315/340). You'll net a 29% gain in drive wheel torque at the power peak vs the torque peak, at a given car speed. "

You win stereomandan, but I think I was looking at this aspect too, just failed to mention the torque multiplication importance of the higher rpms and gearing. Although, I have a hard time agreeing w/ the whole changing speed faster at a low rpm compared to a high rpm. Just from my own experience, there feels like more acceleration at the power peak rather than the torque peak...strange. If this is indeed correct...WHY would it feel like more acceleration at a higher speed than the lower speed when it's the same gear multiplier? Or am I just imagining it is pulling harder? I don't get it. But I do agree w/ the statement he says on there about the LT1 just pulling longer compared to the L98...

So anyway, now that you got your point across...good reference by the way.

See that 224/230 cam I was talking about has a nice flat tq curve, that's similar to the CC305 cam, w/ a little less top end. My car made 310 rwtq on shorty headers at 2100 rpm and didn't fall below 300 until 5500, w/ a max of 325 at about 4300 rpm. Those number should all increase about 15 rwtq w/ the additions of my LTs though.

 

Dyno Here

This is from a guy who used the 218/224 on stock heads. Granted, the numbers are STD, but that's still a very healthy output and power curve for the setup. I'd personally go with that cam unless you plan to port your heads sooner than later.

 

FastWhiteTA,

I didn't believe it at first either, until I did this: My engine is stock except for the K&N CAI, so I still have the major rolloff in torque after 4500 rpm. You might not notice this as much in your car because now your torque band is pretty flat. Anyways, this is what I did. First gear is where you have the most torque to the wheels, so you can feel the acceleration the most in 1st gear. So I took the car to about 1500 rpm in 1st, so I wasn't moving very fast. Then I gave it about 1/2 throttle and held it there. I could feel the strong acceleration, but as soon as it hit 4500, I could feel myself not being pushed back in the seat as much and it got much less by redline. That proved to me the concept that torque alone is where you get acceleration from. I think the psychological effect of your motor getting louder at high RPM makes it seem like it's accelerating more. That is what I used to "feel", but after my 1st gear experiment, I know better. For you, with a flat torque curve, you probably won't notice a difference in acceleration unless you start at a low rpm and feel the increase as the torque goes up.

Fastbird93,
I'd love to have the torque curve of your car, but I guess without heads, I'll have to stick with the 218/224(CC502) or the CC305.

Thanks for all the help. The 502 in that dyno chart does look like it would be very close to what I want.

Thanks,
Dan

 

Stereomandan, do a search on here for the 224/230. I know some guys were putting down pretty good numbers on stock heads with that. I just knew right where to find the 218/224 sheet easily. Good luck, let us know how it turns out.

 

Hmm I'll have to try it...except using full throttle...I think that partial throttle will choke the engine at the big end, after I'm done installing my headers I'll try the experiment

 

I tried to do it full throttle at first, but a) it ramped up so fast, I couldn't take the time to notice the drop off. b) It felt like my tires were braking loose when I punched it at 2000 rpm.

So I had to go partial throttle and just hold that throttle position.

Fastbird93,
Thanks, I'll make sure to keep that one in mind, especially since it would be a great cam to have in there if I ever do decide to do heads.

Dan

 

Oops, meant to say I'll try it in 2nd gear

 

Sorry I don't have any dyno #'s for the crane 210/224, as i'm still on the stock cam. However, I have heard that it makes killer fat torque on stock heads and a lot of imapla guys run it. I think there's a guy on the board (Frank) that traps 116 with it. Maybe he or some impala guys will post with some #'s. Seems like a good profile in terms of area under curve.

Cheers Roman

 

This is true. That cam is WELL matched to stock heads because of the greater exhaust duration and the much greater exhaust lift. Bearing in mind that the LT1 head flows weak in the exhaust area, and you've got a nice match there.

 

So what cam has the least overlap. The hotcam, the CC305 on a 112LSA or the CC502 on a 112LSA. The 502 is the XE grind correct? I don't think the CC305 is, but I could be wrong. Just wondering a little about fuel economy.

Thanks,
Dan

 

Honestly I'm not sure. I'm not a big cam expert, and LSA is where I go fuzzy. I'm thinking that the least overlap is going to be the hotcam on the 112 because it has the least amount of duration. DON'T quote me on that though.

On the fuel economy note, I got a shade over 300 miles out of a tank of gas, mostly highway miles. I think it was around 20-22 MPG if I remember, and that was WITH my rich condition.