what more can i do for a lighter front end?

[drewbot]

Originally Posted by mokinbird87

Drewbot that is all the alignment spec I have. I`m running on Enkei RC-T4 18x8.5 mounted on Michelin pilot super sports 245/35/18 square. usually run 38psi up front 35 at the rear cold.

As said above, toe and camber do wonders!

Sent from my A0001 using Tapatalk

[mav1178]

Originally Posted by mokinbird87

but then why would car companies focus on weight distribution then? Anyways I admitted it was solely for my butt dyno... Mike@CSG (along with others on this thread) had already mentioned to me it's not as big of a deal as it can be dialed out in many different ways.

no need to get all pissy about it.

you can call my "justification" stupid in person when i see you at the 86 cup.

thanks,

Andy

If you take my comments as me being pissy, I think you need to go back and re-read this entire thread again.

The static weight distribution part is just pure marketing. If you see professional race teams and what they talk about when it comes to car setup, they never talk about this because it's only a minor part of what they are trying to keep secret. Static weight distribution is only useful when you have a car sitting there, not moving.

You're so stuck on the static weight distribution that you're missing one large part of weight distribution: actual weight distribution when you factor in downforce front/rear.

The car's tires, contact patch, and alignment need to consider weight distribution when aero comes into play. You can armchair weights all day but ultimately it may be completely counterproductive given your driving style and habits.

As is already mentioned, work on items you can adjust easily on the car before you go about reducing weight. I think you'll find much better improvements.

-alex

[mokinbird87]

Originally Posted by mav1178

If you take my comments as me being pissy, I think you need to go back and re-read this entire thread again.

The static weight distribution part is just pure marketing. If you see professional race teams and what they talk about when it comes to car setup, they never talk about this because it's only a minor part of what they are trying to keep secret. Static weight distribution is only useful when you have a car sitting there, not moving.

You're so stuck on the static weight distribution that you're missing one large part of weight distribution: actual weight distribution when you factor in downforce front/rear.

The car's tires, contact patch, and alignment need to consider weight distribution when aero comes into play. You can armchair weights all day but ultimately it may be completely counterproductive given your driving style and habits.

As is already mentioned, work on items you can adjust easily on the car before you go about reducing weight. I think you'll find much better improvements.

-alex

thank you. I don't understand why you couldn't have said that the first time. Obviously on the internet we don't see each other's faces so we miss the minute nuances but I was a bit upset and thought you were just trolling the thread. I`ll be at ACS tomorrow with the 86 cup, looking forward to more discussions.

Andy

[mav1178]

Originally Posted by mokinbird87

thank you. I don't understand why you couldn't have said that the first time. Obviously on the internet we don't see each other's faces so we miss the minute nuances but I was a bit upset and thought you were just trolling the thread. I`ll be at ACS tomorrow with the 86 cup, looking forward to more discussions.

I was definitely not trolling... it's just your first post basically said "want lighter front end" but did nothing to address why specifically the front end of the car. Or perhaps the question should've started off as "I want to improve front end handling of the car, here's what I have done A B C D and E... what are my options at this point?"

Weight savings is easily accomplished. Changing weight distribution is better achieved on our cars by moving weight (ballast) around. Weight savings AND improving weight distribution is incredibly hard to do on a lightweight car like ours with not much to take out.

-alex

[solidONE]

^ dude... you guys must be bored. lmao I'll see y'all at Autoclub.

[OkieSnuffBox]

Originally Posted by mav1178

: actual weight distribution when you factor in downforce front/rear.

To be fair, including downforce into that number means the weight distribution changes with speed. So that gets a bit cumbersome to calculate.

Do you have a rolling road wind tunnel with which to test?

[CSG Mike]

Originally Posted by OkieSnuffBox

To be fair, including downforce into that number means the weight distribution changes with speed. So that gets a bit cumbersome to calculate.

Do you have a rolling road wind tunnel with which to test?

No, but it's very easy to calculate out when we have a few knowns (spring rates), and a high speed smooth straight (Auto Club Speedway), where we can get a shot at 100mph, of every car, in basically identical conditions.

Now, we can extrapolate out downforce generated, and force at each corner.

Conveniently, 86CUP runs at ACS tomorrow. What great luck!

[7thgear]

how much downforce is a stock FRS generating though?

[CSG Mike]

Originally Posted by 7thgear

how much downforce is a stock FRS generating though?

That is computed by comparing a photo of the car sitting, vs the car at ACS at 100mph on the front straight. Based on the height change (if any) and the known spring rates....

You get the idea

(A 100% stock car is pretty darn close to zero-lift)

[GSpeed]

Originally Posted by 7thgear

how much downforce is a stock FRS generating though?

Practically zero. If anything, there's a little bit of lift at higher speeds. Here's a plot showing ride height vs. speed at three separate track days.

Green- Stock Suspension, RE71Rs
Orange- Tarmac 2s, lowered 1" with 3/8" of rake
Blue- Same as orange, but with swaybars. Included for reference.



As you can see, there's definitely a tendency for ride height to increase at higher speeds on the stock suspension. By lowering the car and adding a little bit of rake, that tendency has been reduced.

We will be testing the Velox splitter and diffuser in a few weeks to see how much of a different it makes.

[DarkSunrise]

I'm not sure what method C&D used to calculate lift, but they found @ 70mph, a stock BRZ had 25 lbs. lift F / 35 lbs. lift R:

http://media.caranddriver.com/files/...lete-specs.pdf

[OkieSnuffBox]

Originally Posted by CSG Mike

That is computed by comparing a photo of the car sitting, vs the car at ACS at 100mph on the front straight. Based on the height change (if any) and the known spring rates....

You get the idea

(A 100% stock car is pretty darn close to zero-lift)

Originally Posted by PST

Practically zero. If anything, there's a little bit of lift at higher speeds. Here's a plot showing ride height vs. speed at three separate track days.

Green- Stock Suspension, RE71Rs
Orange- Tarmac 2s, lowered 1" with 3/8" of rake
Blue- Same as orange, but with swaybars. Included for reference.



As you can see, there's definitely a tendency for ride height to increase at higher speeds on the stock suspension. By lowering the car and adding a little bit of rake, that tendency has been reduced.

We will be testing the Velox splitter and diffuser in a few weeks to see how much of a different it makes.

That's pretty damn impressive considering how many cars start to get light with speed.

[GSpeed]

Originally Posted by DarkSunrise

I'm not sure what method C&D used to calculate lift, but they found @ 70mph, a stock BRZ had 25 lbs. lift F / 35 lbs. lift R:

http://media.caranddriver.com/files/...lete-specs.pdf

I couldn't resist, I had to calculate that off our data. I took a data dump from a session we ran on stock suspension, and used the spring rates and motion ratios published here:

http://www.ft86club.com/forums/showthread.php?t=26661

Looks like we saw 34 lbs of lift at 70 mph, averaged across the car.



I'm nerding out so hard right now.

Jake

[DarkSunrise]

Originally Posted by PST

I couldn't resist, I had to calculate that off our data. I took a data dump from a session we ran on stock suspension, and used the spring rates and motion ratios published here:

http://www.ft86club.com/forums/showthread.php?t=26661

Looks like we saw 34 lbs of lift at 70 mph, averaged across the car.



I'm nerding out so hard right now.

Jake

Haha I had a feeling you would want to check those numbers across your data.