bj1888

I purchased a 2001 C5Z a few months ago to replace my E36 M3 track car. Car will be used primarily for HPDE (one weekend a month), with occasional street use (including driving to/from track). Car has 90k on chassis, 30k on engine - PO replaced motor with 405hp LS6 after he managed to suck up water through his intake and kill the original motor (it's an extremely well-documented car, including receipts from dealership for engine swap).

This past weekend I went to Sebring for the Z's maiden track outing, which was a decent shakedown, but confirmed some nagging suspicions about the car/platform. Prep was limited to complete fluid overhaul, cleaning K&N panel filter (PO did zip-tie mod after giving up on the intake that killed the original engine), DRM brake lines, new Centric rotors, Carbotech pads (XP12 front, XP10 rear), and Nitto NT05s on stock Z06 wheels. Car was aligned with factory Z06 setup.

On a relatively mild October day in Florida, I was only able to keep the oil temp below 270F by resorting to short-shifting. Limiting revs to around 4500rpm kept temps to around 265-268F.

My first goal is to improve reliability/longevity of the car by adding a standalone oil cooler (considering locating it either with the Pfadt-style center vent or on the passenger-side of the front impact beam). I need to take out the airbridge and shroud and clean out the radiator and condenser, too. A catch can is also in the works. Second goal is making the car more enjoyable to drive. Not concerned with adding power at this point, just making the car handle and better driving experience (harness bar? seats?)

With those goals in mind, I'm looking for advice on EOC and catch-can/PCV setups for LS6, and secondarily for advice regarding where to start upgrading other areas.

mgarfias

Call DRM and get their Radiator/EOC combo. Its a good radiator, and a well put together kit.

Upgrade the brakes - you can get a wilwood setup fairly inexpensively that uses the stock sized rotors. At 90k i'd be looking at replacing the suspension bushings - I have poly in mine, not real thrilled with it. One of these days I'll get the lathe fired up and make a spherical bearing setup. Seats/harness would be good too, the factory seats blow.

bigmackloud

I've recently done each of the times you mentioned in my 01 C5 (base model LS1). I also did installation videos. Perhaps these will be helpful.

If you decide to do a stand alone oil cooler, I got everything from Improved Racing. They make a nifty adapter block with integrated oil thermostat, which helps the oil heat up properly when street driven. I used a Setrab 625 oil cooler, AN braided lines. I also used RaceFlux heat sheathing over the lines since the lines run very close to my long tube headers, and it also keeps the braided lines from rubbing through things. I fabricated my own bracket, and mounted in front of the ac condenser.

At VIR in Nov and March I was hitting oil temps of 275*. In Sept, ambient temps around 95*, the highest oil temp I saw was 252*. I call that a win.


I have the Elite Engineering catch can and clean side air separator. Easy installation. Excellent products. I believe your LS6 might be slightly different but you'll get the idea.

When I first installed mine, I almost filled the can the first day. It works. Once installed, I recommend cleaning your TB and upper intake tract to clean out in previous oil residue.



For seats I used Corbeau FX1 Pro (driver side, more narrow), and FX1 (passenger, slightly wider). Very happy with the seats for the price paid. The standard FX1 fits but barely, it's a real pita. And I might skip the sliders next time. Fitment is so tight, there's very little forward/backward adjustment, plus no slider means you can get the seat lower. Head clearance is an issue.

For seat mounts I used Marrad Industries seat mounts and sliders. They also incorporate your harness anchor points. They've made some improvements to their seat frames to accomodate some of the issues I discuss in my video. So their newer product is even better.

And I used the Vette Works harness bar. Easy install. Quality product.

Seat install. this is a lengthy video, but it was a lengthy install.

Harness Bar

froggy47

I used the DeWitts, but either will work.

Bad Karma

DeWitt here too, it's a great choice for dual purpose car. I went with their modified C6 lines with pressure bypass in them as well.

I say maintenance and brakes first, then seat. It's not the order I did thing in, but I wish it would have been. The feel of the car is so much better when you aren't trying to keep yourself in the seat.

Dan H.

I am very happy with the DRM track size engine oil cooler setup. I wrestled with oil temps for 2 years and finally solved it with this kit. Before I could easily hit 300 if I wanted to in almost any ambient track temp. I would have to begin short shifting at 8 or 10 minutes into any session. Since adding this cooler setup the highest I've seen is 260 something, money and time (install takes some patience) well spent.

My other reco would be a race seat of some kind. Depending on your size, this can be easy or difficult. I'm more on the big boy side so my install took a lot of test fits. The stock seats are terrible for the track. A nice seat setup allows you to focus on your inputs and not holding yourself in place.

Joshboody

I did standalone oil cooler in front of condenser, but recently went with larger radiator... so the combo would have been best in time and cost. Maybe slightly better cooling with separate though.

JRitt@essex

If you're going to be running hard at Sebring, a quick peek into my crystal ball tells me a brake upgrade will be in your future. Some guys get by with OEM-style discs and a simple pad upgrade like you have already performed. Some guys also waste half of their weekend wrenching on the car and bleeding brake fluid.

Before spending any more money on pads or discs, please check out our range of Essex Designed AP Racing Competition Brake Kits:

Essex/AP Racing C5 Big Brake Kit options

Our brake kits aren't the least expensive on the market, but they are the best. They have the ability to turn a lot of wasted time and aggravation into lower lap times and a pleasant day at the track.

Don't worry too much about rear brake upgrades if you're on a limited budget. Rear race pads and lines will be sufficient unless you go crazy with other upgrades (huge HP, etc.). However, invest in the best front big brake kit you can afford, and it will pay dividends to you for the rest of your ownership of the car. The alternative is to run OEM calipers and discs with the expectation that you'll be constantly throwing pads, disc, brake fluid, and new piston seals at the car. All of the money spent on the OEM parts will be burned up, with very little value retained. The brake kit however will hold a good chunk of it's value over time, and our AP Racing kits typically sell for 60-70% of their original purchase price on the used market.

We've been down this road with a LOT of owners on this forum. 99% of our brake kit customers tell us they wish they had done the brake kit sooner, and that it's by far one of their favorite and most effective track mods.

You can see lots of owner feedback on our blog, including lots of comments from both vette and M3 owners.

I personally owned and tracked an '03 Z06 for a number of years, so I have a very good idea of what works on these cars. We (Essex Parts) are a long-term forum sponsor and have hundreds of owners on this forum running our brake products. We've helped everyone from the weekend warrior to the C7.R's win races and championships. You can feel free to contact me at any time to help you choose the correct package for your car. These videos may be helpful:

FASTFATBOY

https://www.corvetteforum.com/forums...e-learned.html

apex26

Wondering if the oil cooler route is enough so far South. A racing radiator with integrated oil cooler slays the problem. You're going to find your front brakes totally inadequate. As mentioned, the stock seats are marshmallows. I had visions of headers and other cool stuff, but other priorities crop up, so after doing all the above, and little things like catch can, etc, I'm finding the stock bushings deforming too much so this winter looks like suspension attention...

ZedO6

I doubt either aftermarket radiator/EOC will address your oil temp issues for long. I have the DeWitts radiator with EOC and it was a stop gap measure at best, suitable for cool days and light traffic only.

I ended up with a DRM oil cooler and with the aforementioned DeWitts radiator, coolant and oil temps are not an issue. The stock C5 radiator is marginal on the track, especially in traffic.

Brakes:
Even with hoses and spindle ducts, I will offer that any brake upgrade that uses the stock size rotors is a waste of money for an experienced track driver. There are many excellent options for a brake upgrade. I decided on the Wilwood 14.25" Aero6 with slotted rotors with stock rear brakes. I no longer bring spare front rotors to the track and don't have to worry about missed sessions swapping cracked rotors or flipping tapered brake pads. Also gone is the long pedal after 10 mins on the track. With R comp tires the car will brake very deep...lap after lap. OE C5 brakes are a joke for track use.

bj1888

So you're running oil through both a standalone air-cooled EOC and the water-cooled combo radiator/EOC?

ZedO6

No, sorry about that. I'm using the radiator only for coolant and the EOC is unused. The oil cooling chores are handled exclusively by the DRM external cooler.

bj1888

While there's a ton of good information in that thread, the fact that oil coolers aren't mentioned until the end of post #5 (after subjects like "choosing a cam" and "protecting your paint") shows that the thread isn't really structured in a way that helps prioritize what to do first...

ZedO6

Zenak's thread is good reading but I wouldn't call it the ultimate C5 track car build thread. Neither would Zenak I suspect. Good blog on his journey....

jd86L98

Replace your stock seats!

Bill Dearborn

I ran my C5Z for 6 years. The DRM Ron Davis Radiator with built in Engine oil cooler will work great in the car. It is very efficient. In NY State in cooler weather I had trouble keeping the oil temp above 150 degrees if I was driving on the highway. Always remember to add the extra quart of oil above full when doing track duty or autocrossing. I never took out the extra quart.

For front brakes I used the LG G Stop kit which used the Willwood SL6 wide caliper that gave me thicker pads a good selection of Wilwood race pads. The calipers fit under the stock C5Z 17 inch front wheels and worked with stock size rotors. Worked very well except for rotor life. The Wilwood provided kits tend to use the shallower SL6 caliper which doesn't provide the pad depth of the G Stop kit and might require a wheel change.

If you are going to do a lot of track duty you should think about adding transmission and diff coolers as well. I had the GMPP T1 tranny/diff cooler on my car and never had an issue with those items. Basically, the car did street and extensive track duty for 6 years with no failures other than PS rack and pump replacements a couple of times. Adding a much larger aftermarket PS cooler seems to reduce those failures as the system just gets too hot.

The C5 stock seats were designed for lard butts so don't provide a lot of lateral support. If you are using the three point belts using the cinch mode will help hold you in place more than just fastening the belt. To use cinch mode properly run the seat all the way to the rear, put the belts into cinch mode by pulling the lap belt all the way out until it stops. When you hear it ratcheting when you let it start to go back into the take up reel fasten the belt and use your hands to push all the slack into the take up reel. Then run the seat forward until the lap belt feels like it is going to cut your body in two. This will push your butt down into the seat bottom. When the car makes a sudden move from a stop the shoulder belt will also latch. If done right the shoulder belt will be tight enough that it might restrict your breathing if you get out of breath on track. Cinch mode won't keep your upper body from pivoting around the lap belt since the seat doesn't have any lateral support but it is still better than just fastening the belt. There are a bunch of different types of seats you can purchase that will solve the lateral support issue along with different harness bars. The best harness bar would probably be the BK bar.

Bill

mgarfias

I'd add that my RD radiator with integrated oil cooler was used in phoenix. With the 180deg t-stat, even sitting in stop and go traffic in 115+ weather, I wouldn't get above 190. Running hard was never an issue. Now my problem is getting the car up to temp, even in the summers, here in Oregon.

While you're at it, toss in the turn-1 power steering pump with their upgraded pulley. I also did what Bill did, and run the wide SL6R caliper. Rotors are the weak point now, but pads are soooooooooo much cheaper.

froggy47

NASCAR/trucker the air flow as needed. Simple & efficient.