243/799 heads. what cam? ls6 or another?
11-10-2011, 06:02 PM
#1
Launching!
Thread Starter
iTrader: (4)
Join Date: Dec 2010
Location: attleboro, MA
Posts: 260
Likes: 0
Received 0 Likes
on
0 Posts
243/799 heads. what cam? ls6 or another? just as the title says, i dont want anyone to know i did anything. i know i want the 243/799 heads, and i am leaning towards the ls6 cam, but not 100% sold yet. i just want a little more than umph in my 02 ws6, until the single turbo lq4 is finished (couple of years before car will be ready for that.) also what about having the heads milled? i know that raises the compression, and i already only run premium fuel. motor has 106k on it. is it a bad idea to make these changes with that much mileage on the stock bottom end?
thanks in advance for all the help,
Bruce
thanks in advance for all the help,
Bruce
11-10-2011, 06:22 PM
#2
Compression ratio determines what gas octane rating is required for any given engine to prevent detonation. Unless your engine is "high" compression...it does not need "premium gas". That is throwing money out the window that could be put toward go fast engine parts. A engine will NOT make more HP with premium gas than it wil with regular unleaded 85/87 octane. Your engine is tuned to run on the stuff that is listed in your owners manual...anything higher than that is a complete waste.
11-10-2011, 08:37 PM
#3
Launching!
Thread Starter
iTrader: (4)
Join Date: Dec 2010
Location: attleboro, MA
Posts: 260
Likes: 0
Received 0 Likes
on
0 Posts
really? i thought better gas is better for mpg, and all in all just better for your car? hmmm.... roughly $0.35 more per gallon 2 full tanks a week... yikes!! talk about throwing money away....
11-10-2011, 09:47 PM
#4
As far as the octane goes, if you have an LS1 it is really setup to run premium. It will run on regular though, but you won't make as much power because timing will be reduced.
I have 243 heads/valves and cam out of an LS6. It is a very mild setup, but fuel economy stays about the same and there isn't any difference in drivability. I also ran it with the stock stall for a while. I got the cam nearly for free with the assembled heads though. I can't remember what GM's stance on regular in the LS6 was. I am pretty sure it will run on 89 on the low timing table, but I am unsure of 87.
At any rate, my Formula is my only car and at the time I wanted something that would be quicker but be nearly install and forget...
If you want something a lot different then you should probably consider a more aggressive cam than the LS6. If you don't put a lot of miles on your car and depending on what specs you choose you may or may not have to worry about changing the valve springs again before the next setup comes along. As for octane on an aftermarket cam, it will depend on the dynamic compression as well as things like the quench which will depend on what head gasket you use, deck height, heads...
I have 243 heads/valves and cam out of an LS6. It is a very mild setup, but fuel economy stays about the same and there isn't any difference in drivability. I also ran it with the stock stall for a while. I got the cam nearly for free with the assembled heads though. I can't remember what GM's stance on regular in the LS6 was. I am pretty sure it will run on 89 on the low timing table, but I am unsure of 87.
At any rate, my Formula is my only car and at the time I wanted something that would be quicker but be nearly install and forget...
If you want something a lot different then you should probably consider a more aggressive cam than the LS6. If you don't put a lot of miles on your car and depending on what specs you choose you may or may not have to worry about changing the valve springs again before the next setup comes along. As for octane on an aftermarket cam, it will depend on the dynamic compression as well as things like the quench which will depend on what head gasket you use, deck height, heads...
11-11-2011, 11:58 AM
#6
If you are looking for a noticeable power increase I would recommend stepping up a little in cam. You can do something like a 220/220 .581/.581 115 LSA which I would expect to have a very smooth idle but would pick up a decent amount more then the LS6 cam will. If you mill the heads, which I recommend, it would probably be good to keep running premium.
11-11-2011, 12:01 PM
#7
LS1s and above are pretty 'high' compression, and require at the very least 91 octane to run properly. Sure they can run on lower octane, but it loses power.
Depends on how much you raise compression. If it's under 11.0:1 then you should be ok with 91 still as I know plenty of stock GTOs that run 91 only and are fine. Might not be able to increase the timing as much as 93 octane GTOs, but for the stock timing 91 is fine for 10.9:1.
Now if your milled heads get you a higher compresison than 11.0:1 you might have to use 93 all the time if you want to run decent timing.
Depends on how much you raise compression. If it's under 11.0:1 then you should be ok with 91 still as I know plenty of stock GTOs that run 91 only and are fine. Might not be able to increase the timing as much as 93 octane GTOs, but for the stock timing 91 is fine for 10.9:1.
Now if your milled heads get you a higher compresison than 11.0:1 you might have to use 93 all the time if you want to run decent timing.
Trending Topics
11-11-2011, 12:04 PM
#8
Some are answering only as it pertains to making power, not what it will run around town on. They are different and will depend on how you set the timing table as well as the dynamic compression and quench. I agree that if you cam it that you should tune the high octane table for the highest octane you have readily available.
11-12-2011, 04:41 PM
#11
TECH Enthusiast
The most reliable and cheapest route for you is to put your money in the heads. Read some recent posts, there are guys making over 400rwhp with your heads. I went with your heads and did not work them over, but instead put the money into a cam. I would have made the same power for less money and gotten better gas mileage if I had kept my LS6 cam and spent the rest of my money on my 243s.
11-21-2011, 02:49 AM
#13
TECH Enthusiast
Join Date: Jun 2010
Location: Illinois
Posts: 611
Likes: 0
Received 0 Likes
on
0 Posts
i put down 350 to the tires through a stalled auto, stock gears, ls6 cam, 243 heads (untouched), lid, full exhaust. I have a performance products intake and throttle body which I think is holding me back maybe 10whp? The performance over stock seems pretty good, however, I have not taken it back to the track yet...Driveability is perfect, but that has a lot to do with the tune you get. Also gas mileage around town i think i have lost about....2-3 mpg and its about the same on the highway as it was before, possibly a 1-2 mpg drop, but that is also due to the stall. If you are putting another motor in your car that will be turbo'd I would leave what you have and focus your funds on the new build! you figure cam and heads you could probably pick up for 600 if you shop around, and another 500 for a tune (assuming that's all you do). That's $1100 you could put elsewhere....IMO
11-21-2011, 10:39 AM
#14
The owners manual calls for at least 91 Octane. I just did a Top end build with the Z06 cam and intake and i really like it. It is my DD and my gas mileage is the same. I get about 25-26 on the highway going 70-75 mph. My Tach sits at about 2100 rpm's.
