Big Bu Bu

iTrader: (4)

Looking at the tons of aftermaket parts available for the LS motor, I wonder if anyone can chime in as to what is NOT a must have for track days/ road racing engine mods. I've always thought that the super tweaking to shave a couple tenths of an ET or dollars spent to improve your 60' times are really wasted on the road course guys. Having a motor that can operate reliably at the upper range of its power band for a long time and be able to tolerate being on and off the throttle (constant accel/decel) and tolerate heat seemed to be the goal of bulding a stout roadracing engine. So in the interest of following that lead, what are the best mods for the LS motor that can make it reliable and develop power in the useable power range for road racing. Do we need roller rockers and lifters? How carried away can we get on cams and better flowing heads? Are drag racing mods and road racing mods the same? When AFR or Trickflow or Comp or Yella Terra or Jesel or Melling are designing parts, do they have the road race guys in mind? Or do we just benefit from the trickle down? Is there a difference? What is the best valve train config for road racing on an LS motor?

EchoMirage

iTrader: (3)

are you actually racing competitively or just doing track days

SIK02SS

iTrader: (11)

the most reliable setup is stock. a stock untouched motor from GM will be the most reliable motor you run. Even opening it up to balance/blue print a crate engine, you're now on borrowed time. as far as getting the best performance, Heads, cam, valve springs, and high flow oil pump (melling). mods needed also depend on what LSx series engine you have as LS2/3/7's in stock form have an oil issue where in sustained high speed left hand corners causes a severe drop in oil pressure that drops its life considerably.

But if you're talking a full out race motor, then you're talking about a full out ground up build. All forged and light/lightened internals, new crank specc'd out head and cam, etc etc.

I think it works both ways. Drag racing and road racing (nascar included) benefit from each other. Not in the sense in the packages they put together because the engine are completely different, but from materials used and overall design innovations

BruZer28

Looking at your mod’s you already have a nice set up. I road course, HPDE 4 to 5 time a year and found cooling is very important. Oil, power steering and brake cooling is a must! As for motor the cam selection is important. You will want a cam that makes power in the upper RPM range, 4K to 6K. But I’m in no way an expert.

Big Bu Bu

iTrader: (4)

Your advice looks sound. The LS6 in stock form is surprising. My interest is in a car that is fast enough to really challenge someone on a road course, but be tame enough to drive 300-400 miles and back to a track event. My main interest is that I've done about as much I can do with the suspension and brakes without drastically changing the streetability of the car. Except for maybe some heavy duty toe rods for the rear, I'm ready to move on to the engine. My next engine mods which are in process as we speak, are oil and power steering coolers. Maybe an accusump before the end of the year. Frankly when I move on to power mods (LS6), I'm confused over the zillion options. The valve train seems to be a good place to start and it goes along with a cam and head combo. So... are shaft mounted roller rockers better than normal rollers for road racing? Dual springs OK if they come with the new heads or are ovate wire singles better for the track? Can we benefit from an intake mod like a FAST LSx or will a ported 78mm do in the range we perform in? I've spec'ed a cam with Pat G for a track/street car. I guess my concern is that a lot of aftermarket parts are designed for street/roll/drag racing and really high rwhp cars for the street. Look at the project cars on the web sites for some of the well known LSx vendors and you see outrageous dyno monsters and wheel standers. Lots of great expertise and experience is there to be found but I wish there was a vendor that could give some guidance on sensible mods for LSx road/trackday/HPDE enthusiasts. Katech and Lingenfelter come to mind, but they don't offer alot of info about their products.

Big Bu Bu

iTrader: (4)

Track days and solo events.

SIK02SS

iTrader: (11)

I'm definitely not an expert. But racing a C5 in T-1, I have come to find out the crate motors that have been taken apart to build a new "crate" motor at all the best tolerances, balanced/blue printed, etc (everything we can legally do), the motor does not last nearly as long as just a flat out crate from GM.

Most of the valve train stuff is over my head. What I can tell you is a cammed my 2002 Camaro with a Vengeance VRX4, have a Melling oil pump, TEA dual gold valve springs and hardened push rods..my tuner said the VRX4 was a perfect cam for me since I track the car occasionally. The power band is solid from 3k-6200. But during my original cam install I pinched the oil pickup tube o-ring (unknowingly), and went to the track...after a few laps I looked down coming out of an 85mph corner (100 in the corvette ) and at 5500 rpm saw my oil pressure at 15lbs. Car ran okay after I tracked down the o-ring issue, but after getting the tune finished up the o-ring issue caused the premature wearing out of a rod bearing

IMO, if I were you, I'd start with the coolers (if your temps are indeed getting hot enough), a new intake, intake manifold (Fast 90 or 92) and matching TB, and headers. After that, get it tuned and see how you like it. You should have much better throttle response, and the headers will give you a good bump in useable power. If you find later it's still not enough, then look to do head/cam and all necessary supporting mods (new oil pump if you don't already, pushrods, valve springs/retainers), but remember, after the head/cam swap (even with a solid tune) you're pushing the motor much harder which causes it to fail sooner. Probably start using a thicker oil too (we race on 20-50 synthetic). If you track often, it wouldn't be a bad idea to change the factory valve springs yearly or bi-yearly, especially if you find yourself up at redline or on the rev limiter often

Hope this helps a little.

EchoMirage

iTrader: (3)

if youre not racing, you dont need anything else as far as power. concentrate on handling and braking. power wont do you any good if you have to slow down 20mph more in a turn then the other guy.

BobP

iTrader: (1)

+1 on the stock motor. I drive an '01 SS at VIR HDPEs with stock engine and exhaust (still) making about 325 rwhp.

IMO, you'll get more enjoyment per invested dollar with a strong brake set up with race pads and ducted cooling, fat "barely DOT" rubber or slicks, and suspension tweaks. No matter the power you have to slow it down again and again and again without fade and keep it planted. I stay ahead of and pass plenty of cars with more hp.

Ahead of all that, simple seat time will make the biggest difference. I'd say take what you've got now and get on the track. You car will tell you where to start spending $$$. The problem then is that it never stops telling you .

BobP

Big Bu Bu

iTrader: (4)

LOL... that's great. Actually I've been on the track with my present set up. My car can stop quite well for a 3800 lb car and is truly surprising when running with C5s and Lotus's. I've recently went to a twin disk clutch and have removed 40lbs (yes 40!) from the rotating mass of my drivetrain. Without the dual mass set-up it's like a different car. The issue with the V, believe it or not, is getting it out of the corners not putting it in. I'm hoping the ability to spin up the motor quicker will help me with that. Along with that I was thinking about some engine mods that would help get me out of the turns where the lighter cars have an advantage. My friends keep telling me that on the road course it's not how much power you have but where the power is at.

BobP

iTrader: (1)

Ah, good, so you've been out there. Welcome to the obsession. I've seen a couple of CTS out there and they look sharp. Good luck with your plans. I'm ready for more power as well since my brakes and tires can well handle it.

So many mods, so little time....

BobP

EchoMirage

iTrader: (3)

unless youre bogging the motor, which i doubt you are, proper suspension and tires will help you out of the corner, not just more power. if all you do is slap a built motor into a stock suspension, youre going to spin the tires and go nowhere. just track tires alone will increase corner out traction.

Big Bu Bu

iTrader: (4)

I couldn't agree more. If you read my sig I have done the springs, shocks, brakes, rotors, swaybars and brakelines. I also have a great set of Yoko Adan AD08s. I feel I've done some due diligance in that area and I'm ready to do something not to radical to the engine other than the headers and exhaust and tune I already have. I've read your mods from your site. I like the way you've set up your car.

SIK02SS

iTrader: (11)

Don't you instruct with one of the groups out there? Maybe it's someone else I'm thinking of..

Your problem of getting out of the corners comes down to the cars weight. The only way to really fix that is lose more weight (not likely if it's your street car), add more power (less reliable for the long run), or change your gears (what MPG's?). I think putting in lower gears may help you in this case because I doubt at 3800lbs and 380 hp you're getting close to topping the motor out down the straights, so having the lower gears can help you for corner exit and being in the power band or at least closer to it. The hard part is deciding what gears

edit: and I should learn to read, didn't see you already had CAI and headers..a FAST intake and NW throttle body might not hurt, but won't give you huge gains I don't think (maybe searching here will show otherwise?)

Big Bu Bu

iTrader: (4)

The nice thing about the CTS V is that it comes with 3:73 rear end. I'm looking at the last option right now (power). Now don't get me wrong, I believe what you say about weight, but there are some really fast heavy cars out there.
(CTS V2, Nissan GTR, Porsche Panamera, Lexus ISF etc.) The trick is to find a susupension, drive train and power train that will over come the shortcomings of a modern heavy car. With the new Mustangs, Camaros, Pontiac G8s, 3600 -4000 lbs is the norm. And we know these cars have plenty of potential. Just need to figure it out without gutting the car. The Corvette will always be king in my book, but then we're not comparing apples to apples.

crainholio

iTrader: (2)

I'd say the best modification I made was attending driving school. 3 days of Bondurant helped me identify and fix my several recurring errors.

After that, track slicks and high-temp brake pads.

The only engine "modification" I did was using heavier 15W-50 oil based on my observations at Bondurant's school. They were running it in their C5s, zero engine failures since they switched to it at that time. The LS1 likes oil to remain reasonably thick at 280+ engine temps, and my car's DIC was showing me 305degF routinely.

T2-Z28

iTrader: (1)

Either 15W-50 or 20W-50 oil - I've used the Motul 300V with great success.
Ported/polished LS6 oil pump
Heavy duty/double timing chain
ARP rod bolts
Better valve springs/push rods
Power steering cooler (my factory one is still doing fine)
Oil cooler (mine is integrated into a Be Cool radiator)

Other than the above, my LS1 long block is stock and has been working quite well for years on the the road race course.

1fastkingcab

a friend of mine had a 05 CTS V, very cool car on the road course, most can't belive how well such a large car can handle on the track, unlike most of the other posters I have read your sig, and I'd say you covered the brakes & suspension as best as you can, NOBODY has a track only CTS-V thats the point of the car, If you could afford a track only CTS-V you would have a track only Vette and a DD G6 GT but seriously I'd look into a TR224 cam for nice decent power gains across the board and Katech rod bolts to help fortify the bottom end for life above 6K rpm

other than that I don't think a nice set of heads, or your stock 243's ported a little with a FAST intake would hurt.


What did you do to control wheel hop?

Big Bu Bu

iTrader: (4)

Since I don't launch from a dig I don't get any real wheel-hop. The multilink rear end loves grip and does a pretty good job of trying to keep the power down, thus the wheel hop problem. Combine that with sticky tires and your wallet starts bleeding. Urethane motor mounts, trans mount and diff bushing has shored up the drive train so it helps alot. Hendrix axles are the only real cure for street racers. I'm liking Katech more and more since they have plenty of experience with the C5 R racing program. I'm thinking their blue printed oil pump and C5 R chain. I hear they use the GM Caddy racing lifters in alot of their builds even though some people say they fail. Also was thinking about the stage 2 heads they offer. The guys in this thread are offering some good advice suggesting reliability mods verses power mods. I'm going to check out those rod bolts.