LS1 Heads?
 

I have a 99 Coupe the engine is stock. I don't drag or road race. I do like to get on every once in a while. Eventually I plan to upgrade the intake to a ZO-6 intake, LT Headers, and a cam. I'm not looking to build a firebreathing dragon. I am looking to bump the performance to the max within the range of sanity. If I was going to change heads without buying some exotic aftermarket heads what could I do to say a ZO6 set? What part numbers should I be looking for? Should I go with the ZO-6 cam? I'd like the street manners to be good. I'm past the thumpa thumpa cams. I want more of a sleeper. Oh and on the throttle body should I have the stock ported or go with a larger aftermarket?
I am open to your suggestions please give the reasons why you suggest something and please your welcome to dissagree with someone else making a post but lets not flame anyone this is an open discussion that people more knolwedgeable than me can share that knowledge. thus we all learn. Thanks for your consideration.

Id say your best bet for well priced heads is a set of ported 243 heads (z06) as they flow really well and dont cost a fortune. I personally wouldnt go through all the work of installing a cam to just put in a z06 cam due to the minimal gains but thats up to you, you can still get great drivability out of another cam that performs better. Also since you arent looking to go crazy with your build then the stock TB should be fine.
You should be able to make plenty of power with the newer style intake, 243 heads, headers and a cam, if I were to guess I would say you should be able to get north of 400 at the wheels but Im no expert at all.

Before opening up your engine, think about a CAI, LTs and a dyno tune.

That may get you were you want to go.

If you want to re work your LS1 heads maybe this:

http://www.advancedinduction.com/LSX...CGM241Head.php

or a little more:

http://www.advancedinduction.com/LSX...cGMLS1Head.php

look for 243 or 799 heads, they are direct bolt ins and will get you 25-30 hp in their stock form. a cam swap is still going to need gaskets, pushrods etc even if you go with a z06 cam so at best you are going to gain maybe 20ish hp from it and only save maybe a hundred bucks. a texas speed 224R cam will give you great gains even without a head swap and still feel like stock sitting there at idle.

What is a CAI?

Cold air induction such as vara ram or blackwing.

I had AI do my heads and they do great work. But if I was going to spend the time and money I would use 243 or 799 heads

I also have a 99 and have done the basic bolt-ons that I can legally do since I'm in Kalifornia. Check my signature for those. Mine is now making 340 to the wheels and 345 ft/lbs of torque:

http://www.marcmedina.com/c5/ls1dyno.jpg

I was just talking with CompCams and Crane this morning about a cam. Either way I'm looking at something fairly mild for both smog and driveability reasons. The Comp I'm looking at (and currently favor is this one:

http://www.compcams.com/Company/CC/c...csid=1089&sb=2

It's mild enough to still drive very well but significantly bigger than the teeny-weeny .479 lift cam that our 99's come with. I'd consider doing a head swap or head work if it was really worth it. The ported LS1 heads at $1000 have possibilities, but by the time I get them built the way I would want them, I'd probably be better off just getting the AFR's. I'll have to check into that more.

Of all the improvments I've done so far, the Vararam made the biggest single difference. The underdrive pulley and the x-pipe were both a surprise because you could feel the difference - plus it sounds smoother with the x-pipe in place.

Definitely look at a better cat-back system. I replaced my stock system with the Z06 titanium system (called the "ti" system here on the CF) and picked up a little sound, but that was it. When I put the Flowmasters on, it sounded MUCH better without being obnoxious (especially inside the car) and felt stronger too. It was also obvious that the engine felt muchmore free-revving after the muffler change. I did buy used ones that were wuite rusty and both of them have now broken internally. I have a new SLP 31048 stainless system on the way. I'll be interested to see how it compares. http://forums.corvetteforum.com/c5-g...-powahhhh.html

Make sure you get a "real" x-pipe like the Magnaflow one, so one where the pipes just saimese. http://forums.corvetteforum.com/c5-t...ery-happy.html

Video of how the Flowmasters sound (both inside and outside) can be found on YouTube under the same username I use here. Start here: http://www.youtube.com/watch?v=uQialnqMFxs



The Z06 engine is the LS6. The LS6 intake manifold is the same as the LS1 part for the 2001 and later cars - probably why the factory hp rating bumped up 5 hp for the later cars.

http://forums.corvetteforum.com/c5-t...ew-things.html

The underdrive balancer was certainly worth doing too. If you do a cam install, you might as well do this while you're in there. No adverse effects and smoother revving with more power - what's not to like?

That should keep you busy for a while :thumbs:

Except the part about thumping cams , my setup might work for you, I have the stock heads, nice cam and 436 RWHP, LT headers , high flow cats. Now I told england to tune with shake, you might be able to tune some out, I am not sure. If I upgraded the heads I would guess it would run me at least $2500, and I would gain about 40 or so HP , ( Iam guessing, dont know a lot about heads)

http://forums.corvetteforum.com/c5-t...whp-mojo1.html

YES best bang for the buck is to get a set of "take off" Z06 heads from E---b--y and alike---I bought mine for $600 for the pair complete ready to bolt on--from Canada--BRAND NEW !! but 6 years ago-- you can be confident with any Z06 take off head--Most are all low miles anyway ---I don't agree with the 25-30 RWHP gains with headswap alone--On the dyno on my car--LS1 heads to LS6 heads ( no cam) showed gains of only 12-15 RWHP
Now the cam is the key !!! Don't mess with a Z06 cam or the GM hot cam--you'll regret both choices--there are several great cams out there--do some homwork and phone work-- hearing what you want-- a quieter sleeper cam with good power---streetable with no issues I assume--You can safely go to something in the .225 duration range @.050--To avoid having to change springs all the time keep the lift below .575---Most people overlook the LSA---But this is very important as it "generally" defines overlap and idle quality and sound----Most STOCK C5 cams are in the 119-117 range--the LOWER you go the more radical the idle---- 114 to 116 is a sleeper sounding cam- most hi performance street guys choose a 112 as it sounds really cool and the lope is awesome !!
All out race engines on the other hand have LSA's from the 110 to 106 range---a 114 LSA .225 @50 with .550 lift will easily make 35-40 real RWHP---the better the heads--then even maybe more
So heads and cam alone now net you another 50 RWHP not crank--the crank HP would be like 60 making your eng rating at 410---( more than a stock Z06 !!! ) shorty or long tubes headers ---shortys another 10-15 and LT's up to 30 MORE RWHP !!!!!!!!!!
And finally a 99 has the LS1 intake manifold---You need the LS6 intake---The ls1 intake will become the limiting factor on your engine and will LOWER all the expected HP of your mods if you don't chage it to a LS6---PLUS as a direct bolt on worth another 12 RWHP !!!!
Tuning absolutely needed to get all the benefit from these kinds of mods--Sometimes without tuning i will see cars make LESS RWHP if they are NOT tuned after major mods----

Agreed! Mine still hasn't been tuned yet and I'm already running very well - better than I had hoped. I'm only holding off on the tune because I know I want to do the cam and only want to pay for a tune once.