yow

I need input from track enthusiasts with more experience than me. I've done about 10 track days and have just moved to R compound tires and XP20/10 in my nearly stock c5z (GM T1 sway bars, MGW Shifter/box, bolt in roll bar, seats/harnesses, Callaway/Eiback coilovers,...). I had a supercharged c6 that I did all of my HPDEs in, then sold it for this c5z that I just got. I'm building it to be a competent HPDE then TT car. When I bought the car, it had the cheap ACI chin splitter and the not-so-cheap APR GTC-300 rear wing. See pic.

QUESTION: I plan to do about 10 track days at NCM in 2015 as I work towards doing Time Trials in this car in T-2 or T-3(?). Should I keep AERO on this car or should I NOT have aero yet?

I think I know the answer the wiser, older racers will say. If I sold the aero I have now, I'd get another big chunk of change to put towards seat time. If I keep the aero, it will be one more (huge) variable for me to figure out along the way (which would complicate figuring out other variables, e.g. suspension). If I take off the aero and set the car up without it, then I can put it back on later and have lots of fun trying to figure out how it changes things. Ugh. Should it stay or go? Ideally I 'get ready' to do TT over the 10-15 track days in 2015, then start doing TT in 2016.

FWIW, I plan to do a homemade splitter out of ABS and heim jointed supports to add front downforce, if I keep the aero. I'm not sure if I have enough spring rate, so I need to learn about that too!

Hi Volts Z06

While 10 track days is a decent amount of seat time, the fact that you are just starting to run R-comps says that you probably need a little amount of time to acclimate to that change before making other changes. The wing you have is a good unit. The "splitter" is really not much of a splitter at all and I would think you might have a good amount of understeer with this combo. I would take my time with the car the way it is and try to feel it out. If you start finding that you do in fact have a problem with understeer you could always just take the wing off the uprights (very easy to do) and run it that way. Once comfortable you can work on a real splitter that will help balance out the wing. (There is lot involved in putting a REAL splitter on a C5 including strong enough attachment points,proper venting of the hood, etc.) Keep in mind that once you put aero on a car you have two different scenarios- mechanical grip issues at lower speeds and aero grip at high speeds. That's usually a little too much for someone with limited experience to try and figure out right away. I wouldn't sell anything you have already.

Apocolipse

morris

I'm not sure how to answer you as the question is entirely subjective. I am one that believes hey its your money spend it like you want. I am one that doesn't think 10 track days is much at all, HPDE offers a steep learning curve and honestly I wouldn't have been an advocate for R compounds yet either. There is just so much to learn about car control and handling and at least in my case 10 days wasn't enough to really learn what I needed to in order to be safe and achieve good lap times. What is your goal what are you trying to accomplish? What is the car lacking in your opinion? Are you in HPDE 4 yet or still HPDE2? Assuming you haven't moved up to 4 yet, if it were me I would leave the car as it is and learn how to drive faster and safely before I spent more money on stuff that may or may not help me achieve that goal. Does the car handle neutrally or at least in a way that you are comfortable at speed, if so leave it as is, if the current aero setup makes the car unbalanced at speed then pull the wing off. I don't believe that homemade aero parts are a good idea unless you know what you are doing in terms of design and then setup. Balancing Aero isn't as simple as slapping a piece of fiberglass on the front and rear. Since I don't know much about designing aero I would rather buy aero parts that have been designed or tested to work together that way I car eliminate that as a source of potential issues as I begin to tweak stuff. If it were me I would learn the car, learn how to drive better perhaps add cooling ducts, make sure that my oil is cooling properly and just have fun until I am 100% confident and competent in my driving abilities and the cars abilities and safety. Keep in mind that as I stated at the beginning I am a proponent of spending ones money on what makes one happy, it doesn't always have to make sense. In addition you may be a much faster learner than most people including myself so if you are already running in HPDE 4, red or black group then go for it!

yow

I thank each of you for your input. I'm not HPDE 4 yet. I've consistently been placed in the intermediate group, although at some track events they've moved me to advanced to make room. I assume that means some believe I'm competent to be there. I'm not one to have an "I'm fast and I know it" mentality. I'm not fast. I want to be. We're all on a budget of some kind/size. With the amount I can spend this year for seat time, gas, tires, etc. I want to maximize my progress and that of my car's setup. Basically, I want to progress as quickly as possible, learning from the input of others wiser than I am, gleaning from their experience so that I'm not at such a disadvantage because of my inexperience.

I'm not opposed to buying a splitter to add front grip. I've not had this car on track, so I don't know if it will be prone to understeer. I'm going to run square 18x10.50 with 275 NT-01s. My gut says if I have understeer it will be lack of mechanical grip in the slower corners. However, if I have understeer in the faster corners, it will be cheaper to remove the rear wing (or adjust it?) than to buy/build a splitter.

If I bought a splitter, which one would best equalize the downforce front to rear?

morris

I cannot answer that question but what I would do is call Jason at Katech or Anthony at LG and ask them what they recommend for parts both companies actually race corvettes and do wind tunnel testing on their aero products, when I don't know much about a topic I always go with the expert recommendations and neither of those guys will BS you or sell you stuff you don't need or wont work.

One additional thing to consider if you decide that you do not need/want the aero at this point, you could spend the money on more track time either with NCM or with another organization like tracks unlimited or NASA etc.

When you are moved up that's based upon what they see or sometimes just on the number of track days you put down, its not always scientific or objective in my experience. What I would say is how comfortable do you feel in a particular group? Move up when your instructors say it is a good idea and when you feel comfortable doing so. I spent a lot of time in DE2 and then DE3 because I still wasn't super comfortable to moving up to the next group, with the faster and better drivers. With that said I did like driving with better drivers after a certain point because driving with better drivers helped to make me a better driver. My criteria among other things was if I routinely and comfortably pass more cars than pass me then I would move up.

Bad Karma

I would also add Black Dog Speed Shop to that list for aero parts.

Can I ask why you want run 275's all around? I wouldn't want to run a setup that takes rubber away from the rear tires. I can understand it when getting into a class structure for time trials and playing with a balance for power/weight and points deductions, but I've never wanted less rubber under the rear of my car.

The jump to slicks is likely to be a big one, I've been on track for 3 years now and I still haven't made the switch; like said above, you may not want to make that big jump and change a bunch of other stuff on the car at once.

yow

I'm studying up on aero. I'll look into Black Dog.

I went with 275s square because of the cost savings over a 295/305/315. I searched and read here where a lot of guys do it for a number of other reasons. If I went with R6's I'd go with a 295 or 315 (do those fit on 18x10.50?), but they are several hundred dollars more than the 275 NT-01 and don't last as long. I hope to do 10-15 DE days this year and the NT-01s should last at least that long, from what I've read. Then, we'll go up to R6's (which is what I used at my last DE back in May).

Another thought is that if I can learn to be fast and learn car control with 275s, perhaps I'll be that much more capable when getting more tire and stickier R comps. In theory anyway.

ratt_finkel

Lots going on here. Really too much to type out.

To try to generalize, I don't think aero is a bad thing for a novice. And I don't think r-comps are a bad thing for a novice. However, you have to understand that you may lose out on valuable learning experiences of a street-tired, non-aero car.

A good aero package is going to make the car easier to drive. Period. R-comps are going to make the car easier to drive, period. Both will also make the car faster, in the right hands.

Before you go making any significant changes to the car. Try to figure out what you want from the upgrades. And why you want them. What is the end result? Do you want a faster car? More reliable? More predictable? More balanced? Do you want to add front aero and other bits just because?

Answering those questions will help lead you along the right path.

But based on how little you've discussed these items. My suggestion would be to just continue to drive the car as is. Make it safe, make it reliable.

Jeremy Foley

brkntrxn

My recommendation is to remove the splitter and wing and learn the nuances of the car. A C5 with sways, brake pads, Coilovers, seats, amd harnesses is MUCH faster than most people realize. We have the TTA/PTA lap times from 2010-2012 to prove it. By removing the artificial corner grip aids of the aero, it will be easier for YOU to learn car control without the aero saving your bacon.

Don't sell the parts because that wing is functional and it will cost you more to replace it later. Also don't sell the ACI splitter because it can be used as the foundation for a proper functional splitter later on. My splitter setup uses the ACI piece as a spacer and attachment point and it works out very well.

Once your lap times level off in late 2015 or early 2016, then you can put the aero back on and know that you are improving the car and not yourself.

And run the 275 NT01s for now, that tire is a great choice for feedback, longevity, and grip level to learn.

yow

This. I'm convinced that I should remove the aero for now, as well, but not sell. Then, when I get ready to do TT, get bigger R6s and aero. Thank you ALL for your help.

Brkntrxn, do you have photos/diagrams/measurements of your setup? I've searched and found a few pics but nothing really showing how to make the splitter with the ACI as a spacer. I aimed to mock it up and make it from scratch - which I'm now planning to do in 2016 - and would love some input.

zigspeed10

I'll also recommend removing the aero. You sound like some one who wants to learn how to drive and learn car control which is great! So many people just want to put down fast laps or beat their buddy at a track day and don't focus on learning car control.

The only way to really learn car control is to drive at 10/10ths of the available traction. Once you can comfortably drive at the limit you will understand what the car is doing at corner entry, mid corner, and exit, and this can also very from corner to corner/track to track. Now you can dial your car in with sway bar/spring/shock adjustments.

When you get to the point where the car is balanced mechanically you should add aero. That will add another layer of complexity and more tuning to get right. Having aero also raises the limit of traction making it harder for a novice to drive at 10/10ths.

I will also agree with the 275 tire being a good choice. From my experience running 315's on a 10.5 inch wheel takes away a lot of the feel. It becomes harder to feel what the tire is doing. I have been running 275's on 10.5's for years now.

Bad Karma

Here's one way:
https://www.corvetteforum.com/forums...6-build-4.html

Overall that's a great thread you should read from start to finish.

Hat_Trick_Hokie

Yes the 295 Hoosiers will fit on C5Z rear wheels. I just installed a set of scrubs to try out for next season.

chetly

Look into advanced composite products out of Pennsylvania. I believe they are the makers of LG Motorsports aero products. They at are showing LG's car on their product page. They make a lot of bodies for GT-1, WORLD CHALLENGE, etc etc etc