Some ideas about my future track car

[SA E30]

Ok, so here it is.

Motor: decieded on a 3.0lt stroker, with ITB's around 292deg camshaft.

Drivetrain: stock except for a 4.11 LSD

Brakes: Tilton Pedal box, with adjustable brake bias... haven't decieded on calipers and discs.

Suspension: Going to go with ones made up here in SA, but not sure of what spring rates, and also not sure of what sway bars.

Body: well it's going to be stripped out, with a full cage going thru the firewall onto the front and rear shock towers. Going to run vented fenders, and hood (prob just tilt the hood up, ala turbo car) , run a fuel cell in the trunk. Big Wing (form follows function) , and of course a a splitter, and more than likely something to help create a venturi affect... maybe something like the Riger or iS spoiler, but bigger and incorporating a splitter.

Wheels : 17" Alpina Reps in 7.5" all around with 225 40 17.


Thats all I've come up with so far... what u guys think and any other suggestions ?

Steve

[matt]

The make and model of tire matters much more than the size.

Before you just go slapping wings on the car, learn something about aerodynamics, or you may do more harm than good. If I wanted to improve the e30s aero, I would add an undertray to the front first.

[JGood]

Sounds like a 16 year old's wish list for a wanna-be track car. None of that stuff makes sense.

The first and only thing you should be concerned with is what you are going to use the car for. What kind of track events, and what size tracks?

Once you figure that out you can decide what you want to do with suspension, and that's the only thing you should really be concerned about first. A ridiculous non-streetable motor isn't going to do any good without a proper suspension setup. Springs and shocks aren't going to do it. You need to look at alignment, bushings, etc...

You don't know which swaybars to go with? Maybe that's because your car isn't even built yet so how do you know if you need more understeer or oversteer?

And why do you have cheap and heavy replica wheels in an oversized diameter wrapped with way to small of a sidewall for racing purpouses? And you fail to mention what tires yo u would use, the single most important thing in racing...

Brake Bias? What makes you think you need to adjust brake bias? Ecspecially when you don't even know what brake setup your going with. You made no mention of larger rotors or multi-piston calipers...

Read man, read. If you actually have the $15,000-$20,000 it would take to properly build that car I hope you do research first instead of puting it together like you have listed....

[Andreas]

Sounds like a 16 year old's wish list for a wanna-be track car. None of that stuff makes sense.

Brake Bias? What makes you think you need to adjust brake bias? Ecspecially when you don't even know what brake setup your going with. You made no mention of larger rotors or multi-piston calipers...

Those are some harsh comments there JGood. My friend SA E30 is basing some of his parts choices on my E30 Track Car, so I suppose one could argue that my car is also a 16 year old's wish list . . .

I will leave SA E30 to defend most of his choices for himself, however I want to make some comments about the adjustable brake bias that you ridicule.





My front brakes




IMO, to have adjustable brake bias can be advantageous no matter what brakes you have. If you are a more experienced driver, you can use your brakes to help you turn into corners. As you approach the corner you brake hard in a straight line, bleeding off almost to the maximum speed you can take the corner, then shortly before turn-in you release the brakes maybe half way (depends on situation), then you turn in while there is still some weight transfer onto the front tyres for more grip, once turned in, release the brakes all the way.

Now playing with brake bias, you could fine tune the rear brakes to induce a minor slide and thereby position the car better for the corner. I've seen this rear-end sliding technique work while observing a professional BMW race team - data logging software showed the undisputable results : half a second faster through the slow speed 180deg corner.

I imagine different tracks could benefit from slightly different setups and this is where adjustable brake bias could be useful.

Also since your not likely to find a big brake kit front AND rear for the E30, your front and rear are very likely going to be mismatched. Adjustable brake bias can help you out in this situation too.

Springs and dampers will affect the car's behaviour under braking via weight transfer. If your car nose-dives under braking due to the suspension setup you cannot really apply too much brake pressure to the rear otherwise they will just lock up. So, different suspension settings for different tracks (or hillclimb on a bumpy surface) might again benefit from adjusting the relative strength of the rear brakes.

The first and only thing you should be concerned with is what you are going to use the car for. What kind of track events, and what size tracks?

He says it is a track car, so that pretty much covers the use. In South Africa we don't have a lot of choice regarding tracks, we enter an event whenever there is an opportunity. We don't have the luxury of ignoring an event just because we don't like the track - otherwise you will have long periods of NO track activity.

So either we build a car that qualifies as a Jack of all Trades or we build a highly adjustable car that can be adapted to whatever we throw at it.

As far as cost is concerned, I have already spent $27,000 on upgrades and expect it to end somewhere between $30-$35K. All areas are being addressed : Engine Power, brakes, downforce, safety, suspension, tyres. Maybe some of my choices will turn out to be bad, only experience will tell.

From your post I'm guessing that you are talking from experience, I would love to hear what you have built and what mistakes you've learned from.

[JGood]

I meant no harm, and now that I re-read it it does sound very harsh. And to be honest I don't speak from experience (not any experience above what you have anyway). The way the mods were listed, it sounded as though he was going to spend alot of money in the wrong places.

I agree 100% that adjustable brake bias can help a fully built track car. In actuality, it can help a stock car with aftermarket pads and rotors. But, for the money he would invest for qaulity parts, and to not be really concerned with tire type or suspesnion components, it seems useless.

I'm sure his intentions are good and the car will end up nicely modified, but the way his post layed out his plans, so much money seems to be directed towards the "little things" that fully built cars use to ajdust and fine tune, while he wasn't concerned with the most important things such as suspension geometry and tires.

And as far as for what purpous, I guess my question is based off of the wheels mainly, why nice replica wheels, and not lightweight, idealy sized racing wheels? Is it doubling as a show car?

I can tell by his signature pic he knows what he's doing and not a "ricer", I guess I was more so commenting on the actuall list. No specifics were givin on the major, important things.

Again, no harm meant, sorry for coming off as arrogant.

[Lance Racing]

Is this car for actual racing, or for general lapping where you are not going wheel-to-wheel with other cars, but just circulating fast around a race track.

How many years of lapping experience do you have? That would help with our comments.

My E30 race car:


cheers,

Lance Richert
#135 Pro-3

[JGood]

Is this car for actual racing, or for general lapping where you are not going wheel-to-wheel with other cars, but just circulating fast around a race track.

How many years of lapping experience do you have? That would help with our comments.


cheers,

Lance Richert
#135 Pro-3

Nice 4-door. Any idea what the weight disadvantage is after the rear doors are stripped out? I weighed mine the other night and was shocked to see I'm still over 2700 lbs with my 4-door.

[Andreas]

Is this car for actual racing, or for general lapping where you are not going wheel-to-wheel with other cars, but just circulating fast around a race track.

How many years of lapping experience do you have? That would help with our comments.
cheers,

Lance Richert
#135 Pro-3

Hi Lance,

good to hear from someone with your experience. Wish we had a E30 racing series in South Africa. SA E30 and I will just be able to attend open days at racetracks to satisfy our need for speed and overtaking in corners is generally NOT allowed. I think there is one series here with some pretty wild cars but I don't know how much crashing & pushing goes on there - must check it out.

Anyway, I would be interested how the advice differs for actual racing versus just circulating fast around a race track.

[SA E30]

Sounds like a 16 year old's wish list for a wanna-be track car. None of that stuff makes sense.

The first and only thing you should be concerned with is what you are going to use the car for. What kind of track events, and what size tracks?

Once you figure that out you can decide what you want to do with suspension, and that's the only thing you should really be concerned about first. A ridiculous non-streetable motor isn't going to do any good without a proper suspension setup. Springs and shocks aren't going to do it. You need to look at alignment, bushings, etc...

You don't know which swaybars to go with? Maybe that's because your car isn't even built yet so how do you know if you need more understeer or oversteer?

And why do you have cheap and heavy replica wheels in an oversized diameter wrapped with way to small of a sidewall for racing purpouses? And you fail to mention what tires yo u would use, the single most important thing in racing...

Brake Bias? What makes you think you need to adjust brake bias? Ecspecially when you don't even know what brake setup your going with. You made no mention of larger rotors or multi-piston calipers...

Read man, read. If you actually have the $15,000-$20,000 it would take to properly build that car I hope you do research first instead of puting it together like you have listed....

Dont underestimate what ppl are willing to spend on a car...

Brake Bias... actually I think it's quite a nice thing to have. As from what I understand it's a great way to get the car coming into the corner the way you would like it... What i'm saying is that if the car is under steering or over steering into the corner with the brake bias, you can help to counter act it to an extent. Calipers and Rotors I haven't decieded on yet, as I'm not sure what. I've got some ideas bouncing around. Was thinkin no less that 300mm discs. With either M850i calipers (but the cast iron) , E46 330i, Nissan 350Z calipers (as I can prob still get them for free, from the Nissan Motorsport South Africa 350z race team) , or Something like Praggia, or Wilwood) ... but I will still research this

Cheap replica wheels, well because over here our selection is very limited on what we can get in a decent size wheel, with the right offset... now I ask. If having a low sidewall is such a bad thing why does BTCC, DTM... WTCC use massive wheels. What I understand is that the smaller the sidewall the less defomation of the sidewall will occur... hence increased responsiveness and driver feedback.

I feel the tyres are pretty much the right size, as with the tyres I'm currently running on my street car (225 50 16) , it breakes traction to easily... so I based my tyre size on somethign a bit larger.

Swaybars... well from looking into them, I see there aren't many choices, u pretty much get 2 diameters and then some with a provision for adjustability... so which says to me that to control the body roll, the car is going to need some seriously high spring rates.

Bushes, will more than likely be Polyurethane... I've done quite a bit of research, and it seems like the only viable option is to import the bushes I need from the states

As for an unstreetable motor... I could have always just gone and dumped a S50B30Euro into the car and said there is enought power in there... but I rather use something I know pretty well.

Thats where I know my most is on the motors... I'm still learning in leaps and bounds when it comes to suspension, area... etc.

As for the aero... It's just things I've been thinkin about that I've seen on race cars (once again ala, DTM, BTCC, JGTC) ... as we dont have to conform to any rules and regs, the bodywork on the car can be as wild as we like, as well as anything else we feel could be modified to better suit what we want to do.

IMO, with every sport there is loads of trial and error... I've spent many an hour in the pits with the Nissan 350Z race team... and watched them spend endless hours, on adjusting the fly by wire throttle, and the brake feel, as well as the brake balance, weight balance... etc. To know this. I take it as something I want to do for the fun of it... nothing else. As I want to enjoy the challenge.

I will take all constructive comments seriously, and I really do appreciate the input.

[erik325i]

Wheels : 17" Alpina Reps in 7.5" all around with 225 40 17.

Good luck finding a lot of tires in this size. The only brand that I know of that makes that size is Nitto.
Very uncommon size.

-Erik

[SA E30]

Oh, sorry... that was a typo... I mean't 225 45 17

[erik325i]

Oh, sorry... that was a typo... I mean't 225 45 17

In that case, there will be plenty of tires to choose from, but good luck getting them not to rub anywhere...

They are a bit taller than stock, and will rub the fenders and quarter panels if you don't have the offset perfect.

I have 215/45-17s which aren't as bad as 225s, but they still rubbed all around. I had to machine about 7mm off of the rear spacers to get them to clear the quarterpanels. I had to roll the front fender lips in to keep the tires from catching the lips.
225s will be even worse.

-Erik

[JGood]

Well, as I said in my second post, all of my opinion's were based on the fact that you left alot of important things out of your original post, making it seem like you were spending money in the wrong place. You said you were unsure of what rotors/pads you were using. Now you mention you want no less then 300mm, which is a huge advantage over stock. It sounds like you've touched on all of the areas that you failed to mention in your first post so all of the "final touches" I was critisizing in my firt post have been justified.

You say you can't hook up with your tires. Size has nothing to do with traction when you don't mention the brand/model. A 196/60/14 Kumho V710 will put a 225/45/17 Kumho Ecsta Supra 712 to shame, not even a competition. You still haven't mentioned what tires you plan on using, and this is one of the most important things for racing, and I know you know this. And with your build I know you have to be planning on running r-comps, but you didn't say you were, so I don't know.

I really wasn't trying to bash you at all, good luck with the build, you have good experience from what it sounds like and should end up with a fast car. Are you using your current car that's in your sig or starting with another e30?

[joshh]

Good luck finding a lot of tires in this size. The only brand that I know of that makes that size is Nitto.
Very uncommon size.

-Erik

I was about to say the same...nice catch on the tire size choice. Even if it was a mistake...

I also agree the tire being used is going to make a huge difference. A 225 race tire is a good choice. If you are going to run a street tire in that size, I believe you will still have traction issues specially with the motor you want.

You're better off going with a 245 40 17 which is a bit smaller than the 225 40 17 plus it will give you better traction. As long (of course) it fits under the fenders. Unless you use a race tire.

[SA E30]

Not sure what a R-comp is... but I've been really interested in the Bridgestone Circuit Semi's (Andreas what was their name ? ) as I noticed that they seem to have quite a nice life on them.

Well, I plan on using std fenders... but seeing as the car is going to be stripped out, I could always roll them out to run on the 245

Ala this car (sorry about the blurry picture)



No, I wont be using the current car... I'm in the process of looking for a clean face lift 2dr (which is quite hard here in South Africa, as almost all our cars came out in 4dr, with exception for the 325iS Evo's, and a few 318, and 325i)

So on that is not bent is what I'm lookin for.

I actually have vey little track (well circuit experience) , I've played a bit on gymkhana's and been 2 1 track day, and lapped a a few times in the Nissan 350z track car. I actually fell in love with circuit driving a when Andreas took me for a ride around a track in his M3 CSL, and since then, I've been planning this track car.