Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB (https://www.ft86club.com/forums/index.php)
-   Suspension | Chassis | Brakes -- Sponsored by 949 Racing (https://www.ft86club.com/forums/forumdisplay.php?f=59)
-   -   Tightening the Rear (https://www.ft86club.com/forums/showthread.php?t=35965)

scottynoshotty 05-09-2013 01:40 AM

Tightening the Rear
 
So ive gotten a little ways in my FRS build. So far ive dropped around 100 lbs(almost all from the rear), and put some sticky tires on, I have the TRD exhaust and will be putting on the Intake soon. The car drives great, the one thing i'd like to do is keep the rear end in check a little longer, and improve the handling(wouldnt we all?)..Ive been contemplating ways to do this, sway bars..coilovers..a big wing..various aero components, whats the consensus on the best way to keep the rear planted?

Captain Snooze 05-09-2013 06:03 AM

My vote is for coilovers. The benefits of quality coilovers work at all speeds as opposed to high speed for aero.Sway bars (imo) is the last thing you should touch. They are for fine tuning.

See this thread for some aero discussion:
http://www.ft86club.com/forums/showt...highlight=aero

mrk1 05-09-2013 07:19 AM

whiteline rear subframe bushings inserts really keep things in check back there. all those after market suspension componets may be stiffer but they all bolt to the subframe. So if you leave the soft subframe to body mounts alone your not going to get the most from the other parts.

GTB/ZR-1 05-09-2013 07:22 AM

Bigger front bar will help. Also, softer rear springs--or the combination.

LeeMaster 05-09-2013 07:27 AM

50/50 weight distribution is the key.
I believe your stock FRS is 47 in the rear and 53 in the front, and with you taking off most of the weight in the rear, it is probably closer to 45/55 now. Putting some weight in the back will balance out everything and help with traction and braking and cornering.

Sway bars do help out by stiffening up your car when cornering and they can be had at a reasonable price compared to coilovers. Since you are mentioning that you are only looking for steering feel, I say start off with adjustable sway bars front and rear and go from there. I am not really sure what you meant by improving the handling of the rear, are you having too much oversteer or understeer?

deucethemoose 05-09-2013 08:08 AM

All of the above, and put some negative camber in back.

ft_sjo 05-09-2013 08:13 AM

The car only oversteers under acceleration when you go out of your way to make it happen - it also doesn't have enough torque to 'power oversteer' most of the time anyway (crap tyres in the rain doesn't count).

What behaviour exactly do you want? What problem are you trying to fix?

You state "tighten the rear", do you mean get more grip at the rear? Removing compliance from the rear end, in my book "tightening" will reduce grip levels on that axle, and make it understeer less, which may or may not be what you're looking for.

If you're not sure, or think the car oversteers too much, i'd spend your money on some professional driving tuition. You get a lot more result for your money than bolting on the wrong bits.

For the record, i've got a 16mm rear bar on mine, stock front, and it doesn't oversteer. Even though most people on this forum thinks it would, it doesn't. The only way I can get it to oversteer is by driving poorly, like going into a high speed bend at 80+ mph and lifting off the throttle, and even then with LIGHT use of steering you can correct that. That's just poor driving though. If you went into the same bend properly, you can do it faster and not oversteer.

Captain Snooze 05-09-2013 08:18 AM

At the risk of getting off topic.
Quote:

Originally Posted by mrk1 (Post 921726)
So if you leave the soft subframe to body mounts alone your not going to get the most from the other parts.

There are bigger gains to be had with quality dampers. "Soft" is a relative term.
Quote:

Originally Posted by GTB/ZR-1 (Post 921729)
Bigger front bar will help. Also, softer rear springs--or the combination.

This will alter steering, not necessarily a good thing.
Quote:

Originally Posted by LeeMaster (Post 921734)
50/50 weight distribution is the key. Putting some weight in the back will balance out everything and help with traction and braking and cornering.

Why do people keep on repeating this myth? There are much more important factors involved than this static metric. You're suggesting adding weight to improve performance?

LeeMaster 05-09-2013 09:58 AM

Quote:

Originally Posted by Captain Snooze (Post 921781)
At the risk of getting off topic.

Why do people keep on repeating this myth? There are much more important factors involved than this static metric. You're suggesting adding weight to improve performance?

"It's too complicated to make sense, how about I just say lose some more weight up front instead" -LeeMaster

Back to topic....

wparsons 05-09-2013 10:12 AM

What do you mean by keep the rear end in check? Are you getting power oversteer on corner exits?

Racecomp Engineering 05-09-2013 11:05 AM

Quote:

Originally Posted by wparsons (Post 921961)
What do you mean by keep the rear end in check? Are you getting power oversteer on corner exits?

This. What are your goals exactly? Do you have any suspension mods yet?

What kind of tires and what size do you run?

- andy

ayau 05-09-2013 12:11 PM

Adjustable coilovers will offer the most fine tuning as @Captain Snooze mentioned. It's also the most expensive option.

Before you dump your money into parts, get a second opinion on your car. Have someone with more driving experience drive your car and see what they think.

ZDan 05-09-2013 12:31 PM

Quote:

Originally Posted by LeeMaster (Post 921734)
50/50 weight distribution is the key.
I believe your stock FRS is 47 in the rear and 53 in the front, and with you taking off most of the weight in the rear, it is probably closer to 45/55 now. Putting some weight in the back will balance out everything and help with traction and braking and cornering.

No, no, no, no. Add enough weight to the back to give 50/50 and the car will be slower and will not handle as well.

Adding weight to the back will effectively put the outside rear further up the grip/load curve, where you get less additional grip for a given amount of increased load, giving more oversteer (opposite of what OP wants), and less total lateral grip per car weight => lower ultimate cornering g's.

200hp 2800 lb. car and driver split 55/45 (1540/1360 lb.) will beat the snot out of the same car with ballast added to achieve 50/50 (1540/1540 lb, 3080 lb. total) in acceleration, cornering, and braking.

ZDan 05-09-2013 12:32 PM

Quote:

Originally Posted by LeeMaster (Post 921938)
"It's too complicated to make sense, how about I just say lose some more weight up front instead" -LeeMaster
.

Now that would work!


All times are GMT -4. The time now is 01:24 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.


Garage vBulletin Plugins by Drive Thru Online, Inc.