Stock CAM vs After Market - GN and T-Type Performance Enthusiasts (GNTTYPE) Forums

MCHdrivesan86GN · #1 12-27-2008, 12:14 AM

Happy Holidays to all.

I blew a head gasket this past October, since the head gasket was being replaced I went ahead and ordered ported heads and had my intake ported. As it turned out my fuel pump had a defective part on it, which may or may not of contributed to the blown head gasket. Anyway, the person doing the work on my engine didn't suggest that I get a different/better CAM. From the opinion of others on this forum, it seems that I'm wasting my money by not upgrading the CAM as well. So my question is, is this a definitive? Will I not see any improvement in performance? Absolutely no ponies added? Or if there is a performance increase how much more would I be missing out on by not upgrading the CAM? I realize this might be a tough question to answer. Also, does anyone have performance metrics for a case that I've posted? I've posed this question to the guy doing the work and his answer is that I will see performance improvement, but I never asked the question about what I would be missing out on by not upgrading the CAM too. As always any input is appreciated.

One other question I have, it is a bit embarrassing to ask, but what do the numbers represent with respect to a CAM? For instance, a 206/206. What does this mean, is it lift for intake/exhaust? I did some searching on the internet, albeit not a lot of searching, and I didn't find the explanation I was looking for.

Thanks.

Keller · #2 12-27-2008, 03:24 AM

Quote:

Originally Posted by MCHdrivesan86GN

From the opinion of others on this forum, it seems that I'm wasting my money by not upgrading the CAM as well. So my question is, is this a definitive? Will I not see any improvement in performance?

Will ported heads/intake give improvement on their own? Some. Will a cam added to the mix add to that? Quite a bit! It takes advantage of the added airflow benefit by more aggressively opening the intake and exhaust valves. If the heads and intake were unported, the more aggressive cam would be choked by the stock head and intake flow. The mix of components allows everything to sing in unison when selected properly.

Quote:

Originally Posted by MCHdrivesan86GN

One other question I have, it is a bit embarrassing to ask, but what do the numbers represent with respect to a CAM? For instance, a 206/206. What does this mean, is it lift for intake/exhaust?

Those two numbers are actually the duration numbers for both intake and exhaust. Note that they may be given at .050" lift, not the moment the lifter starts to move. Some companies give duration at .006", some at .050", and some offer total lift as well as one of the other numbers.

Some info on the topic:
http://www.racingheadservice.com/Inf...?ID=1775889296
http://www.popularhotrodding.com/eng...ecs/index.html
http://www.popularhotrodding.com/eng...ecs/index.html
http://www.hotrod.com/techarticles/1...aft/index.html

Supercomp729l · #3 12-27-2008, 12:29 PM

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PaCemkr86 · #4 12-27-2008, 02:13 PM

it also depends how fast ya wanna go..

kenmosher · #5 12-27-2008, 02:41 PM

11.9 is pretty much at the limits of a lot of the stock stuff (injectors, turbo) for most full weight cars. You can still squeeze a bit more out of it, but it gets harder and harder (and breaks more stuff!

)

If you are already doing the heads, then a nice conservative cam (Supercomp nailed it!). DON'T get a bunch of overlap or excessive duration/lift ...

Your head porter should be able to give you an idea of what will work well with your heads. Just remember these aren't rev happy motors and make all their power below 5500 RPM for the most part. If you are running a larger turbo, you can get away with a bit more exhaust duration on the cam (some of the bigger turbo guys get some good results with something in the 208/212 range). Normally you will get best street results with something around 206/206 or a split duration like 210/205.

If you go roller cam, due to the ramp profiles, you can actually go a bit larger and still get really good street-ability.

All that said, I've gotten 650+ HP out of ported heads, TA61 (modified), and a 208/208 cam (engine dyno).

MCHdrivesan86GN · #6 12-27-2008, 06:16 PM

Thanks for the input. Just keep in mind, my original question was with ported heads and intake is it a waste not to go ahead and get a "better"
CAM.

BTW, does anyone have the specs on the stock CAM? Just curious.

Thanks.

kenmosher · #7 12-27-2008, 06:44 PM

Short answer ... yes.

Stock cam specs here:

http://www.gnttype.org/maint/quickref.html

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MCHdrivesan86GN · #8 12-28-2008, 02:52 AM

Thanks for the input, I need it.

Sounds like a new CAM might be in order and the good thing I have sometime to think about it and research a little more due to the Great Michigan Winter.

I've had my TR about 7 months now and prior to this I have never really worked a vehicle in this capacity. It is all relatively new to me, so I apologize for any stupid questions and appreciate everyone's input and patience. I still have lots to learn and I'm trying to get a good solid foundation of knowledge. No better place to get it then here.