Hello ,

what do you think of that cam :

duration at 0.050 : intake = 224 ; exh = 230
lift : intake = .606 exhaust = 603
LSA = 107

i'm using it in my car for one year and start to worry about his effect on my lost of torque at low RPM and low vacuum too, i have since i got it.

Thx

 

no opinion on this cam ?

i was surprised on the tight LSA

 

I used a very similar cam on my old setup, worked out quite well. (Lt1 350 LE2 heads)
I wouldn't worry too much about "lost" torque. Car was running 11.8s at full-weight with a 275lbs driver.
I DDed that setup for quite a while. 825 iodle speed, no bucking or funky idle.
Make sure you have a good tune, Ed Wright @ Fastchip.com did mine,
he does awesome work.

 

It's a spring eater and the loss of torque is needless, a competently spec'd cam of that duration will have plenty of lowend.

 

I'm not arguing a different cam might not preform better, but what exactly are you going by to say this cam is a spring eater? Thanks

 

Bah, certainly not a cam for stock springs, but a proper spring selected for the application would do just fine.
I ran 977s, but a set of K-800s or even the Patriot Gold dbl springs I run on my 383 would work great.

 

http://www.compcams.com/Technical/Ca...obeCatalog.pdf
look up lobe 3192, with cheap street springs it wont work long.

Compare the durations at different points to other popular lobes, this is a NASTY lobe. The chronic troubles controlling it are well documented.

 

in fact, i was quite happy with that cam until i convert to M6. car is bogging at 1500 rpm always in every gear and i was thinking the cam was the pb. I got a 33 code too sometimes

 

The 107 LSA produces a lot of overlap. That's what kills your intake manifold vacuum at low RPM. I'ts also likely the overlap is producing poor low RPM torque. Who tuned it for that cam? High overlap puts air into the exhaust, and screws up the A/F ratio - runs very rich (at least if you have a closed loop tune - do you?). Hopefully, you aren't trying to lug it in O/D gears at 1,500RPM. What rear axle ratio are you running?

 

thanks injuneer for opinion.

Ion tuned it and we discuss it the last days. He agrees with everything you are telling and beleive the only way i can get a "not so bad" drivability is to run a 4.10 ratio (i have a 3.42).

Also : yes i have a close loop tune. Yes it runs VERY rich. Idle vaccum is VERY low and cause lose of brake assistance sometimes.

Anyway, not to put a blame on this cam : it was a killer as soon as the engine go over the 3000 RPM but driving it in traffic is more than a pain in the *** with the M6. It was fine with the Auto trans.

I dont beleive it can run better than it is running now. I've just tried everything.

Just one thing to add : i put a LT4 knock module 2 days ago. It haven't solved my drivability problem but the engine is way more agressive to take RPM.

Also i have a RAM aluminium flywheel. I guess it dont help.

 

I think a 4.10 gear will help out a ton with driveability. Now that you went m6 you need rpms.

What kind of compression are you running?

I would also try to get it on a dyno/wideband to see whats really going on. you may find out a few things??

 

i was thinking about taking it on the dyno and make a scan record with datamaster.

Anyway i beleive i will never succeed having a good drivability with my cam and an M6 at the low RPM. the problem happen only around 1500 rpm, but this is the rpm band you use when you are in traffic jams and so what i have everyday going to office.

My solution = instead of trying again a new cam , I will probably go to forged 383 bottom end, make decent power with it, and probably add a 150 shot for the little times i will need more on track.

 

I am running an almost identical cam with 918's. Cam is a 224/230 .600/.600 108LSA.

Mine smells very rich at idle (haven't hooked my Wide Band up yet though). Keep it over 2000RPM's and it drives like a champ. Screams up past 6,000RPM's. But below 2,000RPM's all it does is buck and surge.

I just got TunerCAT and FreeScan so as soon as my new battery comes for my laptop I am hoping to do some logging and tuning to try to improve driveability.

I am afraid to **** with the A/F though as I feel it is not really running "rich" per say, but is just drawing the air/fuel mixture through the exhaust due to overlap. Thoughts?

Thanks,

Joe

 

i am running a very similar cam also 230/230 .600/.600 107 with 918's

it idles very rich but otherwise runs great. lacks some power below 2.000 but the top ends more than makes up for it

 

I can deal with lack of power, I just want to do some tuning to eliminate the bucking and surging at low RPM's (idle to say 1800 RPMs)