norog

Hi im looking for a good Street/Track Cam for my '02 LS1 Camaro.
I drive it on Street, Autocross and circle Tracks (Trackdays)...

The goals are:
1. California Emission legal (im in Switzerland, same SMOG rules & sniffer tests)
2. Mid & high RPM Power (like to rev it up to 6500rpm)
3. Reliable Engine/Valvetrain
4. good, stock like idle

i already found following cams

TexasSpeed 224 224/224 duration @0.050", .581/.581 lift 114 or 115 LSA
OR
TexasSpeed 224 220/220 duration @0.050", .581/.581 lift 114 or 115 LSA

Almost the same but less lift from
Thunder Racing TR224 224/224 /.551/.551 lift 114 LSA
OR the COMPCams
XR265HR 212/218 duration .522/.529 lift 114 LSA

which one is the best my project?

Stock Heads, stock headers, highflow cat, LS6 intake, lid, portet TB.

garygnu

from what I have read you at least -5* overlap for a cam to pass emissions.do you stock cast exhaust manifolds?Int + Exh duration at .05,divide by 4 ,- the cam lsa.

Darkman

iTrader: (2)

I recommend that you have PatrickG spec a cam for your application. I have a PatrickG spec'd EPS cam that reflects essentially the same requirements that you have (although mine did not need to be CA smog legal) and none of those cams you have listed come close.

Big&Tasty TA

Id give Texas Speed a call and see what they think the best cam for your application is, tell them your current mods and goals and they will spec a cam perfect for your car.

99Bluz28

iTrader: (35)

The unwritten rule is a -4* of overlap (example: 224/224 114lsa or EPS 218/226 113lsa), but you'll probably need around -8* of overlap for a more stock sounding cam. If time isn't a big issue EPS lobes are supposed to be very valve train friendly. You'll probably want a cam with traditional split pattern, like the EPS cam I listed, since the factory manifolds/cats are restrictive. TR has their CheaTR V.3 cam, which was designed for the purpose you had in mind.

99Bluz28

iTrader: (35)

You could run a custom cam from TSP, something along the lines of a 219(LSL lobe.607")/226(XER lobe.585") w/115 lsa, which would have -7.5* overlap.
FYI, it won't very take long at all to get just about any custom cam you want from TSP (LSA, ICL, and lobes).

norog

i read about the -4* overlap and that a 224 duration is the biggest to pass SMOG, i'd like to go for a -6* to -10* Cam just to be sure about emissions...

Time isn't an issue just want to buy the right cam, so i think will ask TSP or EPS for custom Cam.

The TR Cheater .v3 has a lift over .600" do the stock valve covers have enough clearance for that high lift?

@Darkman: what cam specs do you have? Just to get me in the right direction

norog

..ok did some further research and the 224R seems to be too hart at the emission limit, it will pass but only with "good" tune...
I just have a out of the Box Diablosport Predator tune and no good dyno tuner around here. So need something smaller i think a split pattern and a wide LSA would be good.
Still not sure if i should just take the comp XR265HR HighLift version w/115LSA. It runs even with stock tune but it's small 212/218 @0.050" almost GM LS6 spec's
If it would produce a gain of 30HP over stock LS1 i'd be happy...

What do you think about a 216/222 @0.50 with .55+".55+" lift and a 116LSA (emmision friendly -13* Overlap ) ?
should produce good mid & high-RPM power, good idle too, correct?

Any other suggestions for a small but better than LS6 cam, stock like idle and a powerband about 2000-6500RPM(or higher) ?

thank for your answers!

99Bluz28

iTrader: (35)

These EPS cams should be no problem:
-13* overlap
http://www.engpwrsys.com/index.php?a...od&productId=4
-11* overlap
http://www.engpwrsys.com/index.php?a...od&productId=9
Better yet, you can have them do a custom grind like a 218/226 115 or 116 lsa.
The 115lsa would have -8* overlap, and the 116lsa -10* overlap.
The 115lsa with -8* OL should be more than enough to easily pass emissions.
Also you could go with a custom TSP cam like a 220/226 116lsa on XER lobes (-9* overlap).
I'd still call EPS and/or TSP and see what they recommend.

Edrummr

iTrader: (1)

I designed my own baby cam (LSL lobes) and made 386 rwhp SAE. This is on a 2001 Camaro w/ completely stock intake except for a lid, bone stock 243's, stock manifolds and cats. 3" Borla XR1 cat-back. 99Blu is pointing you in the right direction.

IMHO, emissions are not going to be a problem if you are designing around the stock exhaust. The only problem I have is with speeding tickets.

norog

I mailed TSP and EPS already, waiting for answer.
Like to profit from your knowledge too

Edrummr: thanks for the dyno graph looks good. power up to 6500RPM, really need to know the specs of your cam, please!?


"The only problem I have is with speeding tickets" lol... same problem all around the world
...some unlimited pieces of german "Autobahn" are fun once i did 167mph (270km/h) there, and a average of 119mph for a distance of 150miles without any fear of speed cameras

Edrummr

iTrader: (1)

The cam spec is 215/227 115 +2 (installed with ICL @ 113).

The Autobahn must be nice... I've never had a chance to drive it. BTW, the last speeding ticket I got in Europe was in Zurich. I didn't know the box on the side of the road was taking my picture! Anyway, I guess the guy I borrowed the Volvo from got the ticket mailed to him...

norog

...seems to be right what im looking for. -9* (correct?) Overlap should pass emission.
do you drive it with the stock ecu or a dyno tune?
Where did you buy the cam?
What effect has the ICL?

Edrummr

iTrader: (1)

Yes... -9*
113 ICL just means the cam ground with +2* advance was installed "straight up"
The cam was made by CompCams using their LSL lobes.

.006" .050" .200" Max lift
Exhaust 277 227 151 0.614
Intake 265 215 139 0.604

LSA 115
Advance 2

ECL 117
ICL 113

EVO 50.5 BBDC
EVC -3.5 ATDC
IVO -5.5 BTDC
IVC 40.5 ABDC

Overlap -9
Split 12

Edrummr

iTrader: (1)

....The car was street and dyno tuned. However, I don't think it required significant modifications to the factory tune. Mike @ Vengeance dialed it in effortlessly. It runs via MAF from 400rpm up (all the time). It was put on the dyno to confirm A/F ratio and pulled over 380 whp the first time.

garygnu

maybe consider HP-tuners.

norog

got answers from TSP an EPS.

EPS recommended a 222/226 115+3 LSA, that should pass emmissions with a tune.

Matt from TSP said the 220R would work well with my diablo tuner and pass emmision tests. And that a 220/224 would also work well but make even a little bit more power.

I think i will order the 220/224 w115 LSA -> -8* Overlap

SNLPerformance

iTrader: (15)

Just to clarify it's (intake duration+exhaust duration)-(lsa*2) for overlap at .050"

Edrummr

iTrader: (1)

I'll take a quick stab at addressing the emissions concerns. The problem with LT headers combined with "higher" overlap causes the scavenging to pull some of the unburnt air/fuel from the intake charge into the exhaust port. Emissions sniffer will frown upon these unspent hydrocarbons.

With stock exhaust manifolds and cats, you really won't have effective scavenging. Additionally, you will risk reversion if you have much overlap and you're using the stock exhaust (due to higher backpressure). This is the main reason you're going to keep overlap down, and IMHO -4* might not be enough.

Furthermore, it could be argued that opening the exhaust valve earlier might release gases whose combustion is "less complete" than it would have been if they were left in the combustion stroke a bit longer. You want to rev the engine, but you also want to autocross. Opening the exhaust valve earlier will significantly help you maintain torque at higher rpms (power) with the stock exhaust - but, to some extent, you will sacrifice torque at lower rpms. You'll want that torque for autocross (4.10 gears may be implemented to eliminate concern about lower rpm torque - you're call).

Maybe EVC-IVO bias doesn't matter much, but it's interesting to look at the difference between the original cheaTR cam's bias vs. the cams you're looking at. The cheaTR was designed specifically for use with stock exhaust - and it makes power. Take a look at the overlap and split of the cheaTR. I approached EVC-IVO bias in the same way as the cheaTR. I did this to avoid reversion. I want to make sure that the cylinder is cleared out before the intake is opening much (I don't have any intake duration to waste).

The trend in these cams (and in the cams suggested in this thread) seems to be to open the exhaust valve earlier to use the additional cylinder pressure to clear the spent gasses. (For the record, I don’t see this as a significant risk to emission compliance. However, I prefer to use the cylinder pressure a bit more for the power stroke and a bit less for working against a restrictive exhaust at high rpms.) The higher pressure delta achieved by an early EVO allows the exhaust to escape the cylinder faster – which requires less exhaust duration. Now the exhaust valve can be closed a bit earlier (compared to my approach) - remember, we have to hit our overlap target. Now the intake valve can be opened earlier while still keeping that overlap low. I think everyone here will agree that to make power in the LS1, you're going to need some intake duration. Well, we can start opening that IV early this way. We can get a healthy intake duration (220+ for stock cubes & stock exhaust could be considered healthy) and still hit our IVC target of around 40 to 42 degrees. I'm the last person to argue with this approach. It works. My intake duration is a measly 215.
So in summary, we’ve opened the EV earlier to make the most of our EV duration, closed the EV earlier (to maintain our negative overlap) which allowed us to open the intake valve earlier. The split is now lower than the cheaTR and the EVC-IVO bias is the opposite of the cheaTR.

The cams you're considering will likely make more power than mine. I think mine will make more torque down low (pulls at 500 rpm and still makes over 385whp). This is a compromise I was willing to make. You can choose valve events that force air through an exhaust-choked system at high rpm or you can optimize for area under the torque curve from say 2500 to 5500 rpm. It completely depends on how you will use the car. Mine stays on the street where I like the broad torque curve. To me, forcing the car with stock exhaust to make big power made the VEs ugly.

I think my cam would be good for autocross. However, the other cams you're looking at are probably better for your mid and high rpm torque goals.

I am absolutely not an expert, just trying to help. Actually, I hope is that the experts will chime in and clear up any nonsense I'm inadvertently posting. Now please install your cam and post up a dyno graph!

norog

wow...thank you Edrummr, your last post is veeerrry helpful!
I begin to understand more and more how this cam tech works and your explanation for choosing your cam sounds completely logic to me.
There's more than duration and lift to look at when selecting a cam.

Just two last questions for better understanding...
If we take your cam, but install it instead of +2* advance with 0* advance, what would happen? from what i read the powerband should move a little up?

What springs do you use/recommend for the LSL lobe and how often do you have to change them?

It will take some time for the overseas shipping and install but i will for sure
let you know what cam i install and post some dyno graphs befor and after cam swap.