would an LS6 intake make that much of a difference in HP on my 2000 coupe? I figure it would cost me @ $650. buying, having it intalled & a tune. Maybe more $$. Just don't know if its worth it?

 

CRAP! You can get one used for cheep, Its actually a cinch to install and you really don't need a tune! Hook up with someone in your area who is mechanically inclined and have them help you install it.

On a stock C5 LS1, you will see approx 5-6 HP. On the other hand, that manifold is an EXCELLENT base for future mod build ups and responds well to deep breathing MODS.

You could add a ported Throttle Body, VARARAM and then get a tune and that would give you a nice seat of the pants improvement!

BC

 

What Bill said. If your car is currently stock you could do this without a tune. Used LS6 intakes go for $300-$350 in the C5 parts for sale section. I got mine new, in the box from a forum member for $350 with gaskets.

If you're stock I think you might want to go a different way. First take care of the exhaust system. A quality cat back and longtube headers with high flow cats. Then look at a cold air intake system. There are many to choose from and vary in price from $90.00 to $300.00+. After that look at the intake. Include a porting job on the intake and porting and polishing of the throttle body. The throttle body work won't add HP but most report a dramatic improvement in throttle response (mine did). After all that you will need a tune to maximize the mods. Have fun!

 

OK I already installed Kooks LT headers, X-pipe & cats. I replaced the stock exhaust w/a Zo6 Ti cat back. I have a Vararam intake. So I'm looking for the next cheap mod for more HP. I was told that along w/the LS6 I needed diff fuel rails?

 

WOW! Man,,,,you need to take a closer look at your performance up-grade recomendation providers.

I have a heads, cam, ported fast 90, 90mm TB, header, vararam 02 ZO6 that makes 450 RWHP on the stock fuel rails. Granted, I up-graded to 42lb/hr injectors but,,,the fuel rails are still stock. Im still running the stock fuel pump.

There NOT an issue until you go forced induction and make like 700 HP!

BC

 

I use stock rails on my 99 and dyno over 700 RWHP with over 800 RWT...(I have several power adders on built 402, plus A & A additional fuel system with 60 # injectors) agree with other member, would not buy land from the guy who told you about fuel rails.....your rails are just fine....if you need more fuel go with higher injectors but then you should also tune them in...

 

Had 600+ rwhp with the stock rails.

If you can't swap an intake using instructions readily available then you should seriously consider turning in your man card. Swapping an intake is slightly more difficult than changing a tire.

www.ls1howto.com has step by step instructions.

 

Here is a great read for the difference in manifolds, as well as HP and TQ #'s Enjoy!

http://www.tpis.com/index.php?module=2_17_06

Thanks,Matt

 

I went LS6 intake with a mild HC setup. Its a cost effective mod that- Like BC said- is a great base to help out future mods.

 

OK you guys talked me into the swap. And thanks. What parts do I need to purchase w/the LS6 to do the swap or is it a direct swap intake for intake?

 

The intake bolts right up but there are a couple things you can add. First, if you don't want to grind the bottom of your intake for clearance you will need to replace the coolant bypass pipe assembly. Order 2 covers, part # 12602540 and one pipe assembly, part # 12602544. I recommend Gene at gmpartshouse.com. You might also want to change to a LS6 style valley cover which has a better PCV system. If you haven't done the throttle body coolant bypass now would be a good time as well.

 

Thanks Mark. That's just what I needed to know.

 

FWIW I just did the swap I compared the grinding off one rib and tapping (knocking) off one rib procedure. The tapping off way was much easier and cleaner imo and is the way I did it. I just took a large screw driver and hammer and just tapped off the ribs it seemed like it only took about 10 minutes. I recommend this over grinding and the vapor bypass tubes it was very easy. The throttle body coolant bypass was simple also if you going to do that I replaced all 3 5/8 hose clamps and installed a barbed adapter. I thought about just replacing the bypass hose (less connections and cleaner look/ if your picky) with just a longer one but didn't just incase I ever want to undo the bypass for some reason but it is a option you might want to consider. I blew out around the intake before removal with compressed air to clean out the dirt so nothing gets in the heads once the intake is removed or you don't have compressed air use a vacuum. Once I removed the intake I used blue painter (or duck tape if you have) tape on the head ports and on the LS6 intake ports while working on the car and manifold and cleaning the motor up and around the motor. I would also blew out the LS6 intake with compressed air after you either grind or knock the ribs off just to make sure its clean inside just as a caution on install going back on the heads. If you can I also had a laptop setup in the garage with the LS1 how to page open ( for photos also) and also this ls1 page with a photo of the ribs removed pattern links below. You can get new LS6 (taken off a crate motor) intake manifols for $325shipped-$345shipped off Bay if you can't find a used one.


http://www.ls1tech.com/forums/genera...anifold-2.html


http://www.ls1howto.com/index.php?article=5

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Are there any issues with 78mm Ls1 throttle body on the LS6 intake , I was under the impression that 90MM throttle body was needed for the LS6 intake ?

 

No, the 78mm throttle body bolts right up. I think you are thinking of the LS2 intake.

 

I may have been asleep under a rock but aren't there two different TB diameters used on C5's I though the later cars had a 90 MM TB's already... What is the best way to tell.

Also when changing to the LS6 intake is it worth doing the oil pressure sender even if you've never had issues. Mine is orginal and I'm waiting for my oil pressure guage to pin itself one day based on what people on this board say.

Thanks

 

The 90MM wasn't used until the LS2 for the C6 came out.

I would definitely do the oil sender relocate while I had the intake off, bad or not, good catch.