MOTO SCOOB RR

Alright I'm a newb to this forum but no where close to not understanding racing whether it be drag racing and or autox/scca/time attack.

I was currently building my little 98RS (Subaru) GC8 for time attack and talking to my uncle's (who are all very well rounded in the GM world (between Camaros, Nova's, Chevelles, to the F body ls1 Camaros and trans am's along with corevettes) they ventured to get me the knowledge I need to make a jump back into domestics after being with imports for close to 5 years now.

Now where this thread is starting, biggest key is power to weight, which depending on the class you run can either mean a full interior car, to a stripped out and caged, to being able to remove the sound deadening in the car to running lexan glass.

My main thing is obviously there are ways to be able to reduce weight purchasing the correct parts. Hopefully soon i'll be in a 98-02 Trans am that I'd like to build for time attack again utilizing full interior (as I have a daughter 1 year old) but my concern is every build I see, WHERE ARE THE PARTS I'VE COME TO KNOW WITH IMPORTS!?

I see stock wheels with upgraded brakes and a heavy exhaust, or stock body panels.... Where is the weight reduction that doesn't involve the interior?!

My Subaru as tiny as it is, I purchased 18x9.5 Enkei RPF1's... Why you may ask? Only the fact that 18 inch wheels have a more proper contact patch along with little tire flex... ON top of that these wheels only weigh 17lbs!

I know stock c5/6/7 wheels are at least 19-25lbs. but every time I see an upgrade done its on stock wheels.

Another fun fact is lighter the wheel, less rotational mass, meaning the wheels are able to produce less stress on the axles and spin quicker thus causing a little more potential out of the cars movement and nimbleness.


So think of this as a food for thought but I'd like to hear some opinons on why you run what you run and why not go certain "import route" rather than all domestic parts

79_T/A

iTrader: (1)

Because you can get the C5 Z06 wheels 18x10.5 that only weigh 2lbs more than your enkei's, for half the price. Is 8lbs worth 700+ dollars to you? Maybe it is, but I personally feel that money can be better spent elsewhere.

MOTO SCOOB RR

You're missing what is said. For 10.5 wide... what is your contact patch? what are your supporting suspension components? Are you running any adjustable suspension to support the width of the wheel (which is not always needed and actually creates more strain on the diff along with the axles)?

Maybe now you can see my point in reading through the threads and kind of getting a vibe that some people are stuck in the 90's with wider is better and fat tires are the way to go.

I've ran a few of my NA imports only making maybe 140whp with proper weight reduction and suspension and have been able to outrun domestics with twice the power because of knowledge like I'm trying to throw out there.

If building a car cutting costs is never a good thing I'd say 80% of the time it'll hurt what you are trying to accomplish

MOTO SCOOB RR

Also with this, has no one heard of square set ups? Meaning any known good professional shop along with semi/pro racers will always run a square set up to better balance the car and allow the minimization/removal of under/over steer commonly found in staggered set ups. I'm pretty sure you can't run 10.5 wide in the front with out some crazy 2 piece adjustable control arms

79_T/A

iTrader: (1)

Actually you can run a 10.5 inch wheel on the front with no modifications. You could even run 11's no issue. Most everyone in the road racing section here runs a square setup. Doesn't take a genius to figure that out. Most of this "knowledge" you are sharing is common sense. You should probably do some research on what it takes for these cars to work on track. There's plenty on info out there.
Also, regarding the Z06 wheels, I can hardly see how spending hundreds of dollars less for a light, strong, wide wheel that may be a couple of lbs more than the enkei's is cutting corners. But, to each his own.

79_T/A

iTrader: (1)

And another thing, these cars aren't 140hp tiny light imports. What works on a light underpowered car doesn't work on a heavy, overpowered RWD car. But I'm sure you already knew that.

MOTO SCOOB RR

I've read tha majority of the threads and there were very few running a squared set up along with you are still stuck on the width.

Is 10.5 really needed with this 300hp ls1. Or is it more because as you stated "cost". And i'll quote this from another post "Run 315's on 17x11" <-- Really? How is that considered a fast set up with a huge side wall and a fat tire.

Are the OEM wheels forged or cast?

Light imports and heavy over powered cars are the same. Think about it. You just mentioned power to weight ratio in a good retrospect but claimed they are not the same.

You can get coil overs and adjustable suspension along with tubular frames and suspension components and aluminum exhausts/under the hood parts. So how am I confused between the 2?

79_T/A

iTrader: (1)

A few things:

Most people in this section of the forum actually do run a square set up.

Yes, the 10.5 is faster. If the car can use additional front grip, it will be faster. 17x11? Yep, faster too. How do I know? I've done it. Went from a 275/40/17 to a 315/35/17. Same brand and model tire. Guess which one was faster? That's right, the 11.

If you think heavy cars are the same as lighter cars, then this isn't worth arguing. Power to weight has nothing to do with the way a car handles. By your logic, if I added a bunch of power to my car, it would drive like a miata. I have lightened my car, and guess what. Still no miata. My car has suspension components selected and designed to to maximize the cars performance on track. Every component is adjustable. You are making generalized blanket statements here. You might want to take a step back and do some research. Read a few books, search more. There's lots of data on these cars. Plenty of people race these cars.

MOTO SCOOB RR

I want your rationalization along with time sheets to prove please on how a larger tire along with a larger wheel made you "faster"

Bolded statement is false.

What class do you run and what specs are you running. I'd very much like to hear a true logical set up and what you've ran with what you have done with the car.

Also a few things word is that c5/c6 wheels are anywhere from 21-25.5 Lbs. Would prefer exacts not guesstimates. And they were forged so i'll thank myself for providing me with answers.

79_T/A

iTrader: (1)

I put the wider tires on at autocross. My times were lower. Therefore, the car was faster.

But it sounds like you already know everything. No need for our help. If you came on here and truly wanted to learn, you wouldn't be telling everyone here with experience that they are wrong. But, you decided to take a different route.

Have fun.

MOTO SCOOB RR

Time slips? Same course? What class are you running? Same power modifications? Same tread life on tires?


Thank you for proving my point. I'd like a more professional statement from someone who wasn't a weekend warrior.

orthopod

iTrader: (1)

Just a friendly reminder that these guys are very helpful and regularly provide advice based on their actual experiences with our specific cars on the track but that attitude won't get you or anyone else very far on this forum.

MOTO SCOOB RR

I understand that but did you not read everything that was said?

When you say this makes you faster but can't provide sound advice on why, why would you start an argument with no sound facts or improper knowledge?

I don't claim to know it all but when I jump into a trans am I'd like a said sound knowledgeable person to turn to not someone with "I did this and I think I went faster"

I made the thread wanting to see who out there has evolved from knowing only ABC and understands A-Z with these cars.

My only advice and knowledge comes from my Uncles... But they prefer drag racing not time attack.

79_T/A

iTrader: (1)

Same day, same car, same course, same model tire. Class was ESP. 275/40/17 and 315/35/17. The 315's were a bit older, the 275 were fresher. The 315's still provided lower lap times. I dont have time slips. I've never been to any autocross that provides time slips like a drag strip.

You know, your attitude is pretty embarrassing. There are friendly people here who have lots of experience with these cars. Think about it this way: 4th gen F-bodies have been around since 1993. People have been racing these cars in all forms of motorsport for the last 21 years. There aren't many secrets about them anymore. When the knowledgeable people around here respond to your question, its because they have spent time with these particular cars, and they know what works and what doesnt. But you want to reject every piece of good information given to you, while trying to discredit the person providing the information. If thats your M-O, than fine. Go ahead and put narrower tires on your car, if you think its a way to make your car faster then by all means do it. But dont throw negative responses to the people trying to give you answers. I looks foolish. And by the way, I am a weekend warrior. We all are. In fact, you are too. In case you never noticed, so are 99% of people racing these things at tracks around America. It doesn't mean that we have no clue what we are talking about because we dont make a living racing.

thunderstruck507

iTrader: (18)

Very well said IMO.

I can think of a few guys who could tell you a lot about making these cars work, but I would be ashamed to point them towards this thread.

MOTO SCOOB RR

Most tracks do. But I'm not trying to be a dick about any of this in reality. I know I come across like that but I like sound facts.

Subaru's, Z cars, ect have been around for just as long. I've owned a Camaro along with a mustang. I'm not just trying to be like domestic vs imports I'm trying to see as you mentioned "its been around for XX amount of years" but new things are always changing. Wheels, tires, performance, its still growing.

I was seeing who has expanded from the normal or what's already been done. There is always room to expand and make better. Hence why I'm seeing what has been done to improve from the norm and or the me too stuff

MOTO SCOOB RR

Its about thinking outside of the box with sound facts. Plain and simple. If yall don't feel the need because of my said attitude I'm very familiar with time attack forums and SCCA forum only difference is they are running corvettes the majority of the time not F body's

MOTO SCOOB RR

If I'm too left field on this subject and its more customary to go with what's been done and I guess proven let me know. I'll subside from this and continue my research on my own time.

79_T/A

iTrader: (1)

Honest question here: what exactly are you trying to accomplish? By that I mean what aspects of the car's setup are you trying to think outside the box? There isn't some magical wheel and tire setup out there that works any better than what's proven. Want to AX? Can't beat the grip provided by 315's all around. Spend more time on a road course? 275 provides the grip you will need and is lighter. Need more brake clearance? Step up to 18's. as far as uncommon suspension mods, how about replace the panhard rod with a watts link. Or you can lower the panhard to adjust roll center. Changes the attitude of the car completely, and opens up the possibility of running much different spring rates. You can adjust the angle of the rear control arms to change roll steer. There is plenty of things you can do that the average member hasn't done to their car, but in racing circles none of it is new and outside the box. Hate to break it to you, but the aftermarket development for handling-related products for these cars is basically nothing. It's an old platform that not many people race outside a few autocross classes, SCCA A-sedan and NASA's CMC and AI classes. Chances are, most of those out of the box ideas have already been done, there is only so much you can do before you need to re-engineer the whole car. These things have their limitations.

JoeNova

This guy's attitude sucks.

First off:
You have given absolutely zero information on what you need this car to do. You haven't mentioned any classes you have in mind. You haven't given a power-to-weight range you'll need to be in. You haven't given any information other than "I plan to do Time Attack". Then you want to argue that the information you've been given is all wrong? Your attitude is "I'm going to do Time Attack, and not tell you any other information or what I need the car to do, and every piece of advice you try to give me is wrong because of this".

What do you plan to do with the car? Do you plan to race NASA PTC or NASA ST1? There is a titanic difference between those two classes. We cannot possibly give you any sound advice unless you give us some solid information. The only thing we're getting is a poor attitude.

Second:
I'm not even sure how to approach this one. You're saying that a more narrow wheel is better? You're arguing that a larger wheels and tire is heavier, puts excess strain on the drivetrain, and is overall worse? You're absolutely right, I see PLENTY of time attack cars with 6" wide tires. Oh wait no... most of them are running a 3xx wide tire unless they are front wheel drive.

Wider tires provide more grip. You'll be able to brake later, accelerate earlier, and not fly off of a corner and into a wall. Are they a little heavier? Yes. Are you going to lose 6 seconds around a track because your tires are 3 lbs heavier? Absolutely not. If anything you'll be faster from the late braking and earlier accelerating. You'll pull more corner Gs. Are you going to need 315 tires on a AWD Subaru? No, so you need to get that mentality out of your head before you get into a 3800 lb 2WD Trans-Am and try to take a corner on 235 tires.

Also, there is one other thing bothering me. You're asking for proof that the larger/heavier tire made someone faster. You're also putting off the Z06 wheels because they are a couple of pounds heavier than your Enkeis. Then I notice this post in another thread where you claim an 18" Wheel to be better than a 17" Wheel, even if the 18" wheel is a couple of pounds heavier:

https://ls1tech.com/forums/18197189-post11.html

Isn't that a little contradictory?

This makes it all worse:

Huge sidewall? Where exactly did he give a sidewall measurement??? Fat tires are a bad thing? Exactly what are all of the RWD time attack cars running? Most of them run a 285 rear tire because that is what they're limited to. Ultra and Unlimited classes often run even wider tires unless they're running slicks.

Also, you're argument against huge sidewalls is a joke. I take it you've never seen the sidewall on a formula 1 tire? You could hot-press a solid rubber tire onto an 18" Wheel and NEVER see the cornering G's that one of these would pull:



So now lets move onto the next subject:

Power to weight has nothing to do with the way a car handles.

Power to weight has absolutely nothing to do with how the car handles. The bolt statement is true. Power to weight comes into play when the throttle is wide open. This determines acceleration and velocity. You can pull a 1G corner whether your engine has 100 or 1000 HP. Your power has absolutely no factor here. Power to weight plays no role in hard braking into a sharp corner or feathering the throttle into the Apex.

By your logic, a 100 HP 1000 LB car would handle just as poorly as a 1000 HP Veyron with an 3 ton elephant strapped to the roof because they would have the same power to weight ratio. Lighter cars will always handle better, regardless of how much power the heavier car has.


The only reason you're thinking outside of the box is because you are so far from the box that you can't even see what's in it.