LeMans05C6

Right now i was at 373 with my headers on an LS2. If i go down the path of heads and cam, for road racing so more power under the curve but peak power isn't as important to me as having it in the right place and accessible more often.

If I do get up into the 450 hp range with heads/cam. Hoping i reach that but not sure.

I was thinking I may need a LS7 clutch to hold the power where its supposed to be, just not sure what other parts i should look into while certain things are being done.

The reason i ask on this forum is because road racing is my hobby so not sure what is going to take the wear that track abuse gives a car and i figure this is a good place to ask.

AU N EGL

Very Cool

now do you mean Track days & HPDEs or real racing?

if Racing, NASA or SCCA then one should look at the race rules as to what you can and can not do. and how to conform to a specific race class.



Now really the best modes, may not be HP but in this order:

1. contact patches. brake pads, tires, seats and harnesses
2. cooling, brake cooling, oil, radiator, transmission and diff coolers.
3. then nothing but seat time. lots and lots of seat time

LeMans05C6

Seat time will surely come if i do all this time my car.

HPDE for quite some time i think.

I need to work on a more aggressive alignment and a 2nd set of tires on my other wheels for DOT-Rs at elast.

I have upgraded to solid front rotors and DTC30 pads (only got a weekend on them so no real review yet but they held up well. Front ducts would be nice to help as i think my rotor temps changed all 3 paint colors on the DBA4000s.



*******My wonder is what pieces with that much power will take the most stress under road racing conditions. Diff? Tranny? Clutch? What takes the most stress when Road Racing so i can try and do preventative maintenence to avoid something breaking.

Springs need replaced more frequently depending on the cam, if i stay under .600, maybe 580s they shouldn't need done that often do you think?

I am thinking a streetable cam so staying away from lift over .600, but i would like to get a good amount of power/torque under the curve so i am still learning all the spec numbers.

What about valves or things like that, how long do they last.

AU N EGL

you have a start

DCT30s are aggressive street pads. need to go to DTC60s all around.

Putting in the coolers helps the trans, diff and oiling.

with an aggressive cam or that much HP you may want to think about new springs each winter. But that is up to you and your engine builder. spring duty cycle no matter whos springs wears out quickly

LeMans05C6

Well i have the Z51 so the coolers are there, unless i missed something. In 104 degrees this summer i saw about 280 max and it came down from that quickly with a bit lighter lap.


I think really besides the power just might see about the LS7 clutch since there are some decent deals out there and need something for the power.

tcmc5

Don't be seduced by adding more HP - 370rwhp is plenty to be faster than 99% of the cars you're on track with if you take Tom's advice. Once you've covered those bases, think about upgrading the suspension. HP should be last on the list. For many drivers it tends to be a substitute for driving skill and proper car set up. It also often leads to shortened engine life if costs are important to you.
Resist temptation. You can be very fast with the power you have and have the satisfaction of outrunning higher HP cars.

ace996

If you are not in the expert or instructor group with your HPDE organization, do this first...
Catch a ride with one of the spec-miata or spec-E30 guys, or even the 944s that may be in those groups. Heck, go one more and ask one of the T1 guys with a C5Z to take you out...if they have a passenger seat.
Sit through a whole session in the passenger seat. Then ask them what their hp is.... you will be VERY surprised.

I"m not one to preach, I have a head/cam c5Z...but it was that way when I bought it. 480rwhp...and I don't really go any faster than if I had a stock car. It's not the horsepower of the motor, it's the horsepower that's put down to the ground. T1 guys dont' have an abundance of power, they just use every last horse they can as well as can be done.

For a clutch...I have a McLeod twin and am very happy with it.

Good luck and have fun,
TomK

John Shiels

All of the above and more. First figure you budget then you will have a better idea. More power means many things need replaced more often even the major parts of the car. Diff, tranny, engine and parts of it and on and on.

Timz06

Don't mod your engine unless you are able to fix the car yourself, or have a big bank account! From your other posts, it seems you have other people do the work, so it will add up quickly!

sothpaw2

Definitely you would need a clutch. I think the LS6 clutch is good for maybe 400rwhp and no more. I realize from the other post that you will have everything out, but I think it wise to resist temptation to radically mod for reliability's sake. Tom changes his valve springs once/year and he has a lot of coolers...more power=hotter!!

For the cost and reliablity, you might try just a set of ported heads. Hopefully your cam is ok. Once I did a cam w/my C4, I ended up doing the whole valve train and a new chain etc. The springs only lasted 16,000 street miles.

drivinhard

If you're going to road race, I personally wouldn't put a 56 lb clutch and flywheel in the car

you don't have to run some crazy light unit, but the LS7 clutch is wicked heavy. regardless of engine hp and torque holding capacity, you are going backwards here. there are better options

AU N EGL

Moded engines break quite frequently on road course use.

Stick with the stock engine. Ad a dry sump and bigger oil cooler & radiator.

a Spec III clutch may be more to your liking

HP is Sexy has hell but breaks with out heavy maintenance

Stick with the stock engine until you can out drive the car.

John Shiels

LS6 clutch has worked fine for me on road courses with aluminum flywheel. It is fine for the street too.

briannutter1

I drive my car daily until it snows. I needed more power from my LS6, but want to keep all the streetability that makes the car so enjoyable to drive every day. I sent the heads to TEA, where they installed cut down (2.040 diameter) LS3 valves (very light), stock sodium filled exhausts, CNC ported, Platinum dual springs, and milled the heads to 62cc. They hit 323cfm at .600 with great numbers at .400 and .500 as well. We put some American racing 1 7/8 headers and H pipe on it (big for now, but perfect for the day I build a big short block). Next was the EPS 226/234 113+2 camshaft. We're still breathing through the stock intake system (cut lid), the factory TI exhaust, and standard pulley.

Backstreet Performance in Medina Ohio helped me with the install, tuning, and testing. It made 430/400 and pulls strong to the 7100rpm rev limiter. The idle is louder, but just a bit of lope listening to the exhaust.

We're seeing 92-93 kpa at wot pointing to inlet restriction, so we're putting in a cold air system, fast 102, and I may do something with the exhaust to free it up a little. I'm going to put Random Cats on it to take a bit of bark out of it. I'm going to wrap the headers to reduce valvetrain noise (sewing machine sound). Also going with the Endyn Catch Can to keep oil out of the intake on high-vacuum decel.

At the end of the day, it should make a little over 460whp and 425 ft/lbs. with 92% of stock streetability. At the funday at Nelson Ledges last saturday, it didn't go over 242 oil temps and 185 degrees water temp. The only car that passed me all day was a 800hp p800 Switzer GTR, other than that...I passed everyone in front of me on crap-tastic firestone firehawks.

LeMans05C6

Sounds like you have done most of what I want to do, to your car.

I got some specs on a cam to help with the racing side of things and not peak HP.

Something like 228/232 with .598 lift and 112 or 113 someone pointed me towards with 205cc or 215cc heads to keep the velocity higher so i don't sacrifice low end tq.

LeMans05C6

I still need to see some numbers of what it may take to do what i want to do and decide if stock is the better way to go. Honestly guys I really do understand sticking with stock and just getting it back to normal. The car does have more power than my skill can fully use yet.

Here is my connundrum (not even sure if thats the right word but ill go with it). When a TV you bought new breaks you don't usually go out and find the same one at a good deal and put it back in there, improvements have been made in technology and you want something better. ---- The key for me is you are already going to be spending money on something...If you can afford to why not drop the extra money since some already has to go and upgrade what you have---

Same with my car, my extended warranty i got for things like electrical crap like my seat heater going out (which happened not to long into owning the car) but as soon as I had a tuned i realistically knew the warranty was mostly shot.

Here i may be faced with the charges of replacing the LS2 heads with something close to stock, or depending on what money i spend it may be aftermarket priced anyway.

I already have to eat the labor since the engine is apart, and I could be wrong here, but I figure put better pieces on then came off but nothing to extreme, I don't want a .650 lift racing came that i can't drive every day, but pulling some more power out of this very capable LS2 is quite enticing.

sothpaw2

On the Tv--yes I do actually go back and get the same one if they still sell it. We just did that with a toaster oven.

For your car: Reliability, Reliability, Reliability. The stock stuff has some engineering behind it, albeit mostly for street use. The aftermarket stuff has less. With regard to heads/cam, you'd want to duplicate a proven combination (proven on course by somebody you know does a lot of track days on the same types of track) down to the very last detail. If he has an oil cooler, you have to have one, etc.

I have bad luck w/mods and aftermarket parts. Sometimes it's the install--I need a wheel bearing now because when I had my brake cooling ducts installed (by someone that has done this same kit numerous times) there was not enough strain relief on the wheel speed sensor wiring, which tore off right at the bearing. On top of that, I need to replace the tubing because evidently the stuff from the kit is not long enough and while it was reinforced, it has still torn itself to shreds.

Wicked Weasel

Put a cam in and maybe port the heads. Just watch out you don't want to bump the compression too much otherwise you are looking at running race gas.

probably should add dry sump or accusump while doing that and of course coolers. Radiator with eoc should be top of your list or radiator with separate oil cooler.

Joe_Knesek

I agree with everyones comments above & I'm assuming you have safety & brakes covered. I can tell you first hand that LG Motorsports offers a great head & cam package the following that will produce the hp you are seeking. My LS2 has this package with all the options & drive it daily & attend track days without any issues.

• Your choice of AFR 205 or 225 Heads
• Any G5 'X' Series Camshaft

Optional Items

• Cometic Head Gaskets
• Comp Pushrods
• Comp R Lifters
• ASP Underdrive Pulley
• ARP Head Bolts
• Custom Tune
• TR6 Spark Plugs
• 160% T-Stat
• F.A.S.T. 90mm Intake
• 90mm Throttle Body - Nick Williams

http://www.lgmotorsports.com/catalog...oducts_id=1526

yakisoba

I have to say that were I to replace the engine in my car tomorrow, I'd use the same one. Of course, I'm restricted by TTA in NASA, so it's not much of a choice.

I modded from the ground up, and while maximizing seat time. Tires, suspension, brake pads (and stainless lines and cooling ducts), coolers for oil and trans then headers and a good intake. Then, when the car was no longer a street car, I started taking weight off. That process is still going on. I know plenty of folks who went for big horsies early, and I don't judge.

However, I observe that my bolt on only car has missed just two track days in six years due to mechanical failure: Once for a broken hub (if I had had a spare, I would have missed a single session) and once for a transmission failure (should have driven it anyway; I had fourth gear, lost 2009 regional title because of this). I don't know many C5 drivers with heads/cams/strokers that can say the same.

I will admit that now, I can really say that I'd love some more horsepower/torque for corner exit. I would use it well.