mbowers13

Looking for advice. Currently have 07 A6 base coupe with 93k on the clock. Recently installed 1 7/8" long tubes with X pipe and Vararam CAI. Has a tune and sits at 370 rwhp now. I looking to see who has naturally aspirated power in the 500 area with a 6.0.

I don't want to use nitrous and I'm a little hesitant about forced induction due to longevity. I've seen stories about having to get a SC rebuilt and I'm not crazy about the idea.

Is there a H/C or H/C/I combo to get me there? Would a stroker be a better route? Budget is between $5k - $10k. Thanks in advance

timd38

I have a strocked LS3, CNC heads, 102TB, FAST and other goodies and have over 500 at the wheels. I also have a manual trans.

If I had it to do over again, I would buy an Edelbrock supercharger. Less money, similar performance.

Suns_PSD

Your best bet is to shop for a 416CI engine to swap out for about $6K. They are out there. Used, on the Internet, on ebay, etc...

GO4URS

stillspinnin

FI will be much easier on your engine than any cam. You can bolt on a supercharger and be at 500 rwhp easier with a better tq curve than any cam. Plus with a cam, you ll be changing springs every 15-20K. My turbo build has out performed and out last all of my h/c builds. Of course they were ls1s. I personally think fi is more reliable at that power level unless you go stroker.

damascus1986

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mbowers13

What kind of reliability can one reasonably expect, and which type? Centrifugal or PD?

stillspinnin

lol ever heard of zr1 or ctsv. Both make right around or more than what you're goals are and last to at least 100K miles unless neglected

Pitufina

That's not an apples to apples comparison. The ls2, 3 or 7 wasn't built with FI in mind. Can it last 100k? Possibly but not the norm. We're taking high compression vs low compression just to start.

stillspinnin

I ve got news for you, few modded motors last to 100k. At 500rwhp, compression has nothing to do with longevity in an fi app. However, Heavy spring pressures and aggressive cam lobes do play a huge part in engine longevity. Don't believe me go over to ls1tech and see what guys do with stock engines and turbos/blowers. Theirs a reason you don't see stock cubed 500rwhp ls2 n/a cars too often.


A fi ls2 should last a very long time at 500rwhp. When things do go wrong it's usually a rough time or someone getting greedy with boost or timing. Also if the op was going to do it right, he would stud the heads and swap head gaskets at which point he could throw on a pair of lq4 heads to drop compression. (The 72cc chamber heads) plus supporting mods obviously

Pitufina

I know there's a lot more than compression for reliability purposes. Like I said, just a start since you're comparing different engines that were built specifically with FI induction in mind from the very beginning and different tuning characteristics. Turbos dont put strain on the crankshaft like superchargers do. We can go and on and on.

Btw, I have an ls3 that is cammed and an ecs kit on top of it. Tuning and the parts you choose based on your desired outcome have more to do with reliability than FI or N/A.

stillspinnin

Lol I can tell by what you're saying you have more experience at a key board than with a wrench. The op has a simple goal and a good budget to achieve it with. At 500rwhp with a blower, crank strain and belt slippage isn't much of an issue. LS motors have proven themselves to be extremely durable, yes even under boost especially moderate levels (under 10psi). Drive train breaks before the engines break 9/10

OP go to the boosted section and do some research. Centri seems like it would be a good option but you can't go wrong either way. Maybe talk to some local guys that have the a&a kit. Talk to some shops and get some recommendations. I promise you, they ll all tell you n/a 500rwhp on an ls2 is tough to do without worrying about reliability

LEAVINU

I was able to crack 500rwhp with my LS2 before the stroker that's in it now.

Recipe for me was:
LWA 243 ported heads
mild cam (Comp)
methanol
1 3/4" headers
3" exhaust
Vararam intake
FAST 90 (ported)

With this is was 501rwhp. An EWP put me at 509rwhp but I yanked it because it shorted out in <1k miles. This was done on a manual car so you'd have to account some power lose for your A6.

Pitufina

I've been working on cars, mostly performance ford and chevy since I was 14 years old and now I'm 38. Went to college to be an auto technician but decided to join the military after I graduated. I do all the work myself and tune as well.

There's nothing that you can tell me and would change my point of view. Comparing an lsa and ls9 to an ls2 with supercharger for reliability makes me laugh. Any engine can be destroyed with the wrong parts and/or tune. Bone stock with stock tune lsa or ls9 will last as long as it was intended from factory.

To the OP, talk to someone with experience whose been there and done that.

Joe_G

My thread on the effect of various mods may be useful to you. 500 rwhp sounds good but there are other mods, such as a 3800 stall converter, that might be a lot more useful to you, depending upon what you want to do with the car (unless show a 500 rwhp dyno sheet on your windshield at a car show is precisely what you want to do, in which case, you can pay the dyno operator to use a blow dryer on his weather station to get that for much cheaper lol).

https://www.corvetteforum.com/forums...ast-heads.html

All that said, the tried and true way to 500 rwhp in a ls2 is big cam, FAST intake, and Trickflow 225 heads. The Trickflow heads are the secret to 500+ rwhp.


Oh, and I have 82,000 daily driver miles and 497 drag strip passes on my engine and original equipment clutch, so I'm here to tell you the LS engine in these cars is VERY reliable.

mbowers13

Do you know one or two people who have gone this route so I can research more on it?

I appreciate everyone's input. I plan on visiting a shop over the holiday next month and getting their feedback as well.

timd38

I got the 500+ number with CNC LSA heads, cost much less than TrickFlow heads, but you need an LS3 intake.

493lszosix

not an ls2 but my ls6 is making around 490 with the tfs 215 heads on 93 octane so it's definitely doable but I'm also a stick not an auto if I was doing mine again then I would bump my compression just a little more and run the lg pro headers instead of the streets I have now, would probably get me to or over 500

xBoostx

Op your na instincts will serve you well stick to em.

I love na power and love fI but a simple light uncomplicated engine compartment has it's merits in my book.
Making power na in just a blast and reliability is enhanced over force induction imo.

My ls3 only have Trick Flow heads low lash solid roller cam and headers makes 575 whp.

That's all the power I need them took off 230 lbs bring on any of those blower cars mention here and I I'll show em my handy cap licence plate and my four aluminum muffler tips sitting on my Kirkeys intermidiates.
Oh I forgot to mention it also makes 604 wtq at 3, 300 rpms @ only 91% volumetric efficiency soooo what's the blow for?

1FastAzzC6

Im not trying to be selfish by not posting my combo that got me INCREDIBLE NUMBERS. But if you really want the true combo send me a prvt msg and ill gv u my number. MyLS2 dyno'd at 490rwhp/474tq. 1FastAzzC6. Cheers