Hey everyone,

I have a few questions for those of you who have taken your stock ls1 and swapped the heads for a set of ported/polished 243's and a '02+ z06 cam/springs.

I'm considering doing just that with my coupe, while leaving everything else stock (exhaust manifolds, catback, intake, etc etc.) with the exception of putting a stock z06 air lid on the intake.

I'm looking to get a setup that looks 100% stock, but offers the performance of a Z. I am not looking to do bolt ons, like I said, I'd like it to look and sound stock.

Were you happy with the results? How was the change in sound? too much?

What would you have done differently?

what did the setup end up costing you?

what were your final numbers? (please list final mods)

Are there any other considerations for modifications to handle the bit of extra power?

Any other input about the conversion?

Thanks folks!

 

anyone?

 

I did it & with a Z06 Cam & stage 1.5 heads cnc'd from Total Engine Airflow,milled to a true 11:1 compression ,B/W & Icebox,ported TB by New Era.I do have Kooks long tubes,so it does'nt look completely stock.I got about 385HP @ the wheels,which eqates to maybe 470 BHP.I was warned by TEA that the stock Z06 v/s were'nt reliable,at mid to high rpm,so take heed.The sock mufflers ,IMO, do not sound agressive enough so I went wth a Hooker CB.I did also go with a few other add ons like the VR Power Duct,Tr6 NGK plugs, MSD wires,& the all important ZO6 3:42 rear box.

I soon added a set of Yella Terra rockers,a catback, & have a LS3 TB,ready to go on.Just waiting for the phantom Street Warrior manifold,or I'll go with the Fast92.

Regrets;I kind of wish I went with a slightly more aggressive cam,but was told by tuner anything other than a Z06 cam would be noticably lopy.I deffinately don't like the "sewing machine" sound of a lot of aftermarket cams.So I was told that a Z06 ,vintage 03+ was the cam for me.

Just do it!Whats there not to like,other than a lighter pocket book?

I think with the LS3 TB & either the Fast 92 or the Street Warrior I can come close or get slighlty above my goal of 500 BHP,or fly wheel HP.

 

Thanks for the detailed response! I got a quote from my Speed shop of $3400 tax included to turn the key, parts/labor/full dyno tune. They do good work and don't cut corners. Only part I would have to provide is the camshaft. are all '02+ cams the same? you hinted at 03+, but for some reason I though 02 on were the same? Also the heads he has available are off of an '06 GTO, so no sodium filled valves. Think this is going to affect much?

I'm not sold on the idea of doing this yet.. though it's becoming more and more tempting!

 

Why the goal of 'looks stock'?

A good set of ported 243s will be a nice upgrade, but the z06 cam will not offer much. You will notice a good difference, but it may not be 'performance of a z'.

The Z06 has different gearing in the trans, and is a little lighter and has wider wheels. Also, depending on if your Vette is 2000 or earlier you will have the ls-1 intake which is not as great as the 2001+ ls-6 intake.

You may have to get some gearing to get what you want.

 

Well, the car is an '02, so I'm set with the LS6 intake manifold, larger MAF, etc.

I'd like to keep the car looking stock because as it sits, the car is a beautiful, un-molested example of a C5, and I'd like to keep it this way. I'm also planning on taking it to bloomington gold, and would like to be able to have it be capable of being certified.

 

Interesting. I would think you could do a gear change 3.73 or 3.90, but have no idea what the certification consists of... But, a gear change would get you more performance just about everywhere except top speed and still remain stock.

I can understand wanting to stay stock, they were great from the factory.

 

I would not go crazy on a set of ported heads-the reliability would suffer--I would rather see you go with a set of 243 LS6 STOCK head take-offs from a Z06 those can be found fairly cheap with low miles--
If you are dead set in something C/C'd or ported -I would do something like a stage 1 only---Patriot comes to mind--ALSO I would NOT go with a Stock Z06 cam--It is really a waste of your effort--Something with a stock sounding idle would be in the .218-.224 range @.50--lift i'd keep it less than .550 and the LSA no lower than a 114--
I would alsolutely NOT touch the stock MAF--It is good for 500 RWHP and would cause you nothing but headaches to change to something different--leave it alone--screen and all if it came with one--
LS6 manifold of course---depending on your budget a better set of rocker arms and pushrods and springs to handle your cam--Comp 918's are great--
Other than a better exhaust and a cold air intake--that would be it for the engine--But if you want it stock appearing then that is up to you--A "Zip-Tie mod" for the air intake is stock appearing and helps the airflow--
ALSO-- On an A4 trans I would seriously look into buying a Z06 3.42 rear axle--again take-offs can be found easily--I bought mine for $600--Really helps them "wake -up" off the line--and is un-noticeable-mileage barley changed--i'm still getting 25-26 on the freeway--While you're there with he axle out--A GREAT mod would be a mild Stall converter-something in the 2400-2800 range--Again hardly noticeable until you floor it--probably the best mod for the money any A4 can make--I've seen stock engine f-bodies and stock engine C5's gain 1 full second at the track--
Take a look at my profile/sig and see what I have done--My set-up is a bit more aggresssive than you might want- as the idle is lopey-But it is Calif smog legal--My regrets would be to get a larger cam--I errored on the side of passing smog and in hindsight i could have gone slightly bigger and still passed emmisions--
PS : without saying a tune would also required--

 

The car is a 6-speed, the heads I have lined up are take offs from a 2006 GTO, 243 castings, they would only be milling them a bit to clean up and a very mild polish/port nothing crazy.

 

The '02 & above C5 Z06 cams have the same specs.The heads you have are LS2 ,which are essentially a Z06 without the sodium filled ex. valves,still a great head.There is little or no HP becase of the caustic liquid in the valve stems.I had larger valves put in so it was not an issue for me.

Like I said I went the route of a Z06 cam because I abhor the rough idle & that zzzzzzing sound of most aftermarket cams.My car ,with an A4,& 3200 Vig stall, is a great sleeper.It has the manners of a stock C5 but when you pound on it,look out,its a monster.If the stock muffs were on it would sound like a pussycat.

Jeff Hanson of Rush Racing ,who did the vehicle,& has probably done hundreds of LS series engines was very impressed by the cars performance & dyno numbers.He drove it & he thinks with the right tires the car is into the 11's if any car is!If you live anywhere near Schereville In.,give him a call & see what he'd charge you for the work,its near from Lansing Il.Not that I think you being priced for this job is out of the ballpark,but just for the sake of comparison pricing.