Gundam

Right now, i have a set of used Dynatech LT headers sitting in my garage waiting to get installed on my 2006 A6. With a smog test coming in 2 years, I'm starting to get cold feet on getting them installed. I'm starting to consider getting a mild cam and selling the headers. However, I'm not sure if it'll be worth it without a free flowing full exhaust. I don't have the money for both, so it's going to be either or for the time being.

I've tried searching but I can't find any threads whatsoever that document power gains for LS2's with just a cam and no LT headers.

c6 batmobile

put the cam in and use the ZO6 manifolds and exhuast. They flow way better than your manifolds but still maintain that factory look and if the cam isnt too crazy you should be able to pass smog.

Jim_H

I agree on the Z06 manifolds, they do make more power, I think they would be good enough for milder engine builds. There is a bit more work to get the 3" over the axel pipes to fit on an A6 car but its been done. I have the full Z06 system and it only cost me $600. It looks totally stock and has no other issues that I tell can from the stock system.

There are a some posts on here and LS1tech about cams mild enough to pass CA sniffer tests and that make decent power with stock manifolds. The top tuners in this area use a 224/228 114lsa, this is supposed to be about the limit to pass CA smog tests. This is also a reported by many to be an excellent daily driver cam on an M6 car, no idea how it works for an A6 with a stock converter.

c6 batmobile

Youll need a converter as well. Probably only a 2600-2800 though.

Ragtop 99

The Z06 manifolds are a good way to better exhaust flow and keep a look that passes visual inspection.

I did a cam on stock manifolds with my LS1. I used a big split to give the exhaust extra help. The hot cam actually works and a variation would be 218/230 114 using XFI lobes on the intake and Xer or XFI on the exhaust. The comp lobes make a noticable improvement compared to the Hotcam lobes. Limit overlap to around -2 and you can pass smog. I've seen slightly more overlap pass, just depends on the tuner.

Jim_H

The hot cam I heard had a definite lopey idle, but it won't require new valve springs since the lift is about the same as stock.

Thunder Racing CheaTR cams are also big split with 117lsa, these are supposed to work well with stock manifolds and give a stock like idle, but they have really high lifts. Don't know anyone who's tried to get one past smog in CA.

66yellowstingray

My question would be.......is it worth it though? For stock manifolds....or even Z06 manifolds (I know they are stock but you know what I'm sayin) is it even worth to consider a cam vs. price? Cam install costs $1500 - $2000 right? If power gains are minimal why bother?

Seems like gears would be a better mod for the money. To the OP, maybe this tis the best way to go.

Jim_H

I don't think the power gains are minimal with a cam only, they might not be all you could get with headers. Certainly the more aggresive you go on the Cam you would yeild diminishing returns without headers, but aggressive won't smog here anyway.

I would agree just going to something like a 02-04 Z cam is not worth $2000 for the 10-15hp gain, but I doubt the lack of headers would be the limiting factor for the gain from that cam.

You're right though, it all depends on what you're trying to accomplish for the money available. I only have stock Z06 manifolds and I'm doing a cam and heads, the lack of headers has been predicted by a couple of tuners to be leaving only a max of 10-15hp on the table, if that. I can live with that, and the fact I saved over a $1000 on headers and I can still pass smog.

c6 batmobile

Youll probably leave approx. 30hp on the table without headers. The loss is not enough to give it up though. There are certainly options out there where you can still make power and use the Z manifolds. A cam install can be pricey but probably around the same possibly less than gears with close to the same results. I would personally do both but thats just me.

Ragtop 99

The cam I suggested will have some lope, but not as much as the Hotcam. It all depends on the idle speed as to how much you'll notice.

TR Cheater will easily pass CA emissions. LS1s with 224/224 114 have passed out there and the LS2 has a few more cubes and better tuning.

IMO, the TR cam leaves some power on the table, even for its goals. Tighten up the LSA to 114 and it makes a little more power and still behaves like a sweetheart.
Is 30 rwhp minimal? depends upon your goals and definition. Some would agree, for others it is a nice bump.

Definitely an emissions friendly option with proven results.

Jim_H

Thanks for the reply Joel.

What are the lifts on the Cam you suggested?

Ragtop 99

218 XFI intake = .605 lift
230 Xer = .592
230 XFI Exhaust = .604

Definitely need good springs, but the area under the curve difference for the intake valves of the XFI vs. hotcam is very significant at .200. The Xer is a faster ramp than the hotcam exhaust so it has less overlap below .05 which helps improve idle.

csun213

If you are worried about passing smog and want more power, I would recommend just get a vortech supercharger. You can get one installed for about $6500. You would get over 500 rwhp even without headers and it is smog legal.