New engine build and I'm trying to decide on the cam. Its a California car so I'm trying to keep the overlap low and the idle chop to a minimum. What is the opinion of the stock 02-04 LS6 cam verses the older design Lingenfelter GT2-3 cam? I know they are very similar but I can see the lobes are more aggressive on the GT2-3 cam when comparing the advertised and @ .050 duration numbers.In addition, it does have a bit more lift. Is there a better/modern choice other than the GT2-3 cam?

Intake Duration at 050 inch Lift:
207
Exhaust Duration at 050 inch Lift:
220
Duration at 050 inch Lift:
207 int./220 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.571 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.578 in.
Valve Lift with Factory Rocker Arm Ratio:
0.571 int./0.578 exh.
Lobe Separation (degrees):
118.5

Build:
LS6 block
Mahle power pack pistons. .005 over
Compstar rods
Stock crank
CNC ported 243 heads
Manifolds to pass smog, then install headers
Possible blower in the future

 

I would have a serious look at the Summit Racing Ghost cam. It makes good power with a subtle idle.

https://www.summitracing.com/parts/s...lScbD1ncXvaW5d

 

I have looked at that cam and it seems big to me. Would I lose a lot of bottom end with the Ghost cam compared to the others?

 

While the @0.050 duration numbers are higher, the advertised duration is very similar to the stock '02+ LS6 cam, with about 10° more exhaust duration. This means the ramp rates are a little more aggressive and where the extra power comes from. The Ghost cam is also advanced 3° vs the LS6 cam which is retarded 2.5°. The 5.5° of total advance will help the cam come on sooner in the low end. It shouldnt sacrifice much if anything down low, and have a stronger top end.

 

I can see what you mean when looking at the advertised numbers for both cams. The Ghost lobe ramps are very much aggressive compared to the LS6 cam.

Will the -2* overlap be enough to pass the sniffer tests in CA?

 

I cant speak to the Cali rules unfortunately.

 

Lately smog checks here in Cali are-
1) Visual for missing/unauthorized parts
2) Plug in the OBDll scanner for any codes.
Your car might easily pass as long as you're using CARB legal VISUAL parts and there are no codes showing. That's literally all that goes on now.

 

I wasn't aware of that, good to know.

 

If Hib Halverson is on Tech, you might try PMing him. If he isnt, try him on Corvette Forum. He is VERY knowledgeable on California smog laws. It is my understanding that they can tell if the computers have ever been tuned. Apparently tuning leaves an electronic "fingerprint." They will know if the computer has any previous tunes, even if it has been returned to stock. If they find fingerprints, the car fails whether it passes the sniffer test, or not

 

Yeah, it’s my understanding that they plug in the OBD port and confirm tune hasn’t been messed with. If you can’t tune in Cali, you do not want to think about camshaft.

 

Not all vehicles show that it has been tuned and they don't have all the records on early vehicles...

Newer cars do have counters for that to show how many times an ECU has been flashed.

I can tell you my personal cam and heads tuned vehicle passes smog.

 

I’m boring, so I’d just run the LS6 cam. I’d rather give up 5-10 hp and have peace of mind that I’m running a cam that’s easy on the valve springs and I never need to worry about them. Don’t have worry about drivability, emission tests, etc.

 

My car had the stock cam and springs, broke a spring and dropped the valve. Luckily the valve got jammed in the seat area instead of windowing the block. I guess even stock deals can fail.

I guess I’m a hot fodder at heart and want that extra power if I can get away with it.

 

That’s nice to hear. I’m putting together an ‘89 MR2 for a friend in California. It has *very* mild cams and slightly raised compression… hopefully it will pass. Stock looking externally.

 

Engine swaps are different as the play by different rules and look at every little detail. I am not sure if your friend plans to get it legalized or not.

 

what cam and heads do you have? Will help us tell how small we should stay / how big we can go.

 

Ported 706 heads that were milled and the OG 212/218 comp cam. 54-412-11

But I am also Factory Flex Fuel. So if they question anything, I blame it on the Ethanol... Even If they were to Sniff it, E85 burns cleans...

All Stock appearing...

Only had 1 tech say it doesn't seem stock. But he couldn't figure it out.

 

This is just a rebuild and slight improvement on the stock engine

 

Are you rebuilding the stock MR2 engine or LS Swapping it?

 

Rebuilding the stock engine.