Project GatTagO

iTrader: (7)

Honestly, it sounds like you need a tune, badly. I have the ASA cam in my 5.3L and it does not stink much at all. Some, but not crazy. Then again, I have spent A LOT of time tuning my idle (I have a Holley Dominator). With the Dominator (and all Holley systems) you can specify the injector end angle. This determines when the injector pulse ends relative to the valve events. I have it programmed so that at low RPM the fuel is sprayed a little later, which helps cut down on raw fuel exiting through the exhaust valve during overlap. I don't know if the stock ECU can do that.

It also drives perfectly, even when lugged down, and I get 21mpg (I realize I have a smaller engine) with 4.33 gears and a T56.

Andrew

lees02WS6

iTrader: (5)

Not sure what can be achieved with an 02 f-body ecu and this cam. The smell is bad for sure, and related to the unburned fuel from having the lobe overlap. My biggest concern though is the belching out of CO and whatever else, not the smell, none of it (co or smell) gets in the cabin. The poor people aft, to the left, right, and especially directly behind are getting it though, if they sit too close. With the smell it's a big warning to hang way back, and they do.

Project GatTagO

iTrader: (7)

I'd be curious what the same CO test does with a different cam. And you are right, the tune may not be possible with the 02 ECU, but I don't know that for sure.

Andrew

rdymond

Very interesting post. I will do this measurement as well and post the results. I admit getting sucked into all the cam hype and so I bought the DR525 crate instead of the 430 or 480 to replace the broken 430. Learned much since then, and I admit getting the 525 was a waste of money. The car stinks. Its like driving with someone who has a body odor problem all the time. The 430 got 20-22 mpg on the highway, power delivery was smooth yet there was tons of it, and the car did not stink. The 525 lope sounds powerful, and I like it, but the drawbacks are plenty. I am not running CATs so that makes the smelly car problem worse.

We can try adjust injector angle, but I thought that would have been dialed in by GM.

Another key point is that the 430 on an engine dyno with the same accessories as the 525 actually puts out closer to 490, not 430. The 430 number is sand bagged, so GM can sell the 480 and the 525 for lots more profit with very similar manufacturing cost.

I had my 996 swap on the dyno twice. The first time the air at the intake was getting too hot so timing was retarded and car put out 290rwhp. After installing a fan in the deck lid temps came down and the engine produced 346rwhp on a clean pull. Since then we got the idle sorted so it doesn't hunt so much. The dyno was a Mustang, and the tuner knows his work. He tuned a Super light coupe with the same engine and transmission (manual 6 speed transaxle) though that car had a high end titanium exhaust. The SLC pulled 350, so basically extra 4 hp at the very top end revs. So my stock 911 cat delete exhaust is not the issue.

My conclusion at this time is the additional ~35hp of the 525 over the "430" is not worth the problems or the additional cost. GM's marketing is intentionally misleading. If you want more power, get a stock LS3 engine, reinforce the internals and add turbos as most modern engines do today. It won't improve the gas mileage but at least the fuel will actually be burnt, the car won't stink and it will have 600+ hp.... and lots more heat to deal with.

Project GatTagO

iTrader: (7)

For what it's worth, I bought a Summit "Ghost Cam" to eventually replace the ASA in my 5.3L.

Andrew

G Atsma

The manufacturing costs of the 430, 480,and 525 are IDENTICAL. The ONLY difference in the 3 engines is the cam. And all cams cost the same to make. Just different grind profiles.

rdymond

Cam costs are not identical since the manufacturer of the Cam will price it based on volume. Fewer 525 cams means higher cost per part. Also 525 has different valve springs. Likely also some changeover costs on the line. So costs a bit more, hard to guess, maybe $100 to $200? Not $2k though.

Also, is that the only point worth commenting on?

G Atsma

The 525 has the same lift as the 480 (.525) and a bit LESS on lift than the LS3 (.553). They all use the same springs.
And on the GM scale of things, the 480 and 525 cams are run on the same production machinery as the rest of them, so cost per unit might be a tiny bit more due to the smaller numbers.

rdymond

According to the GM website.
The ASA camshaft is a hydraulic roller with .525-inch lift on both sides, along with 226 degrees duration on the intake side and 236 degrees on the exhaust side. And for durability, we complement the cam with higher-rate valve springs.
https://www.chevrolet.com/performanc...ines/ls376-525
Same for the DR525.

G Atsma

OK thank you. I don't think that was always so, but I could be wrong. Even with the low lift, the ASA ramps aren't the smoothest. GM had the same problem with the LS2 cam. Same lift as the Hot Cam and ASA cams (.525) but it would float the valves before 6200 RPM. So yeah, the high rate springs are a must.

lees02WS6

iTrader: (5)

G Atsma, what would you recommend for a cam that is easy on the valve train, idles well, and will pass emissions (sniffer, not just obd-II), with a modest bump over stock ls3 power? Including GM cams, not just after market.

G Atsma

GM has the LS9, which is 211/230, .558/.562, 122.5 LSA that gets used a lot. With about a -25 degree overlap, it WILL pass smog. It normally goes on the LS9 supercharged engine.
Cam Motion's smallest LS3 cam is 212/222, .553/.553,116 LSA. Not positive it would pass smog, but with a pretty smooth idle it should. A -15 degree overlap SHOULD allow it to pass.

rdymond

How do you like it?

rdymond

PS. Thanks to all the contributors to this thread. Have learned quite a bit from everyone. Apologies for tone on some of my posts.

Heading back to the tuner to see of we can work with this cam to improve the emissions and the poor throttle modulation below 3k rpm. Running a stock GM 430 ECU, hopefully we' will have enough capability with it.

lees02WS6

iTrader: (5)

CSP recommended the LS9 cam, and I got the recommendation for that cam motion cam as well. I'm definitely going to check it out. Thanks for the help, it is appreciated.

KW Baraka

iTrader: (7)

The only difference between the three LS3 crate engines are the cams. If the springs are different, it's a VERY recent change.

GM is making consumers pay more.....for the horsepower.

Period....full stop.

KW

G Atsma

Thank you for this! I did not THINK the springs were different, but was in no position to argue. I agree with all you say here.

rdymond

Check out the link to the GM performance website that I posted above.

KW Baraka

iTrader: (7)

Like I said....it's a VERY recent change....like in the last 4 months.

That said, the price difference in the three crate motors is completely reflective of the HP of the engines.

It has nothing to do with higher rate springs and nothing to do with a higher cost cam.

BTW....the ASA cam costs LESS than the HOT cam.....and it always has.

https://www.gmperformancemotor.com/category/LS214.html

KW

G Atsma

You reinforce what I have always thought-
Within the same mfr., a cam is a cam, whether for an LM7 truck engine or an ASA cam.
Same for springs, within reason. Wire winding is the same process whether for the above-mentioned truck engine or an LS3.