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)
-   Tracking / Autocross / HPDE / Drifting (https://www.ft86club.com/forums/forumdisplay.php?f=39)
-   -   What do I need to change to fix my problem? (https://www.ft86club.com/forums/showthread.php?t=118113)

UFO 04-30-2017 01:10 AM

What do I need to change to fix my problem?
 
I've tracked various cars over the years: a 2003 Evo VIII, a 2005 Evo VIII, a 2001 Porsche 996 C4, and a 2008 Evo X. I was always faster than everyone else in my run group because, well, 300HP and AWD. I used to think I was a pretty good driver but now realise it's not hard to drive a fast car fast!

I've been driving a local track in the FR-S and next weekend will be my 5th time there. I've gone from a lap time of 2:15 to 2:06 and during that transition all I've changed is track time, brake fluid and pads. I'm mostly stock suspension, just have RCE yellow springs and crash bolts with -2.3 camber up front. Also running Enkei RPF-1s 17X9 +35 with 245/40 Hankook R-S3 V2 tyres.

There are at least 2 corners that I feel I could be flat through but the car pushes too much and I have to modulate the throttle. I feel that I need to change something suspension wise but I don't know what. I see so many suspension options but how do I know which option will fix my problems? Will going to coilovers help? Bushings? More camber? Other adjustable suspension components?

I realize this is an insanely ambiguous question but how do I know which suspension part will fix which issue I'm facing?

swarb 04-30-2017 03:44 AM

Play with tire pressures.
Try a different line.
Try different alignment settings. Less toe in rear, more toe out front. More camber up front may help or less in the rear, with a pyrometer it would give you some data.
Have someone more experience sit with you, or sit with someone with the same car.
Whatever you change to make it better, it might make it worse at another part of the course.
You could describe the turn or when/how you experience the issue.

steve99 04-30-2017 08:59 AM

If its understeering you could try a slightly stiffer rear sway bar.


hopefully you might be able to lend one and see, as it might cause you other issues.

strat61caster 04-30-2017 09:44 AM

My suggestion is more camber up front, in my experience the car was happier up at about -3 to -3.2 degrees camber on stock suspension than the -2.5 I started out with after getting camber plates, I'm even higher now but on autocross oriented coilovers.

imo changing other things and buying other parts doesn't make much sense if your tires aren't pointed in the optimal direction, you're just band-aiding the fact that you're not using all of the tire available. Getting tire temperatures will help point you in the right direction but it isn't foolproof and ultimately experimentation will get you where you need to go.

nikitopo 04-30-2017 10:21 AM

Quote:

Originally Posted by UFO (Post 2901443)
I've tracked various cars over the years: a 2003 Evo VIII, a 2005 Evo VIII, a 2001 Porsche 996 C4, and a 2008 Evo X. I was always faster than everyone else in my run group because, well, 300HP and AWD. I used to think I was a pretty good driver but now realise it's not hard to drive a fast car fast!

Exactly, it is much easier to be fast on a powerful and more forgiving (AWD) car.

Quote:

Originally Posted by UFO (Post 2901443)
There are at least 2 corners that I feel I could be flat through but the car pushes too much and I have to modulate the throttle. I feel that I need to change something suspension wise but I don't know what. I see so many suspension options but how do I know which option will fix my problems? Will going to coilovers help? Bushings? More camber? Other adjustable suspension components?

Coilovers will be very helpful to fine dial your car, but don't go on cheap options. Bushings are also very helpful and will give you a more linear suspension feel. The current setup is optimized more for the road.

Sleepless 04-30-2017 12:32 PM

These cars generally oversteer once in a corner so I'm guessing you might be entering the corners too slowly and the making up by accelerating to hard too soon. Try different lines (like double apexing large radius corners) and entering faster with trail braking.

Twinz 04-30-2017 12:38 PM

I recommend having a good instructor/ veteran drive / ride with you through these problem turns first.

Try to nail down if it's the car or the driver that needs to change before you spend a lot of money.

ls1ac 04-30-2017 03:16 PM

As above, 1) good instructor 2) tire pressure. Learn, experience, then change setting, and finally change parts.
These cars are very good out of the box, and can teach a lot about doing most every thing right. Good parts should make you faster but only the clock will tell the truth. Seat of the pants feel is often biased by how much you spent on parts. Change parts only after you think you know what each piece will do then verify it is doing what you thought it would. Changing many parts at once makes it very difficult to find what is doing what.

redlined600 04-30-2017 04:39 PM

Quote:

Originally Posted by Twinz (Post 2901595)
I recommend having a good instructor/ veteran drive / ride with you through these problem turns first.

Try to nail down if it's the car or the driver that needs to change before you spend a lot of money.

THIS. The fact that you dropped 10 seconds on a 2 min course indicates there might be more out there. That doesn't mean you can't tune to your preference but the car might not be the limiting factor at this point.

Imo.
Start with the instructor
Add more front camber
Try a rear sway bar

From there one needs to be sure they have the ability to properly setup the car or have a good relationship with a good shop to set it up.

solort 04-30-2017 04:41 PM

Sounds like you may be entering corner too fast, overheating front tires, too much front tire pressure (should be pretty low with that wheel/tire combo and will go up quickly as tires heat up), too little front camber, or too much rear toe in....

I found my car better balanced with a larger 20mm front bar (adjustible Whiteline with adjustable end links to remove front bar pre load) and the stiffer bar minimized front camber loss by keeping car flatter in corners...

And turn off most nannies with either 6 sec traction control button press, or the all nannies off "pedal dance" so that the car handles as God intended...:)

UFO 04-30-2017 10:47 PM

Thank you everyone for the suggestions. I will have an instructor with me again this weekend, each time I go they want to bump me up but I would rather have the instructor in the car with me as I'm there to learn. I don't have a pyrometer but I do have one of those laser temperature readers which will have to suffice for the time being, I'm running 35ish PSI hot right now.

They're both pretty high speed corners, 90 MPH and 85 MPH mid-corner on each so I'm pretty sure that some of my issues are me. Confidence is building though!

UFO 04-30-2017 10:56 PM

Quote:

Originally Posted by swarb (Post 2901512)
Play with tire pressures.
Try a different line.
Try different alignment settings. Less toe in rear, more toe out front. More camber up front may help or less in the rear, with a pyrometer it would give you some data.
Have someone more experience sit with you, or sit with someone with the same car.
Whatever you change to make it better, it might make it worse at another part of the course.
You could describe the turn or when/how you experience the issue.

Here you go. first corner https://youtu.be/gQqjAQb9PEo?t=833 and second corner https://youtu.be/gQqjAQb9PEo?t=875. First corner is a pretty big lift (no brakes) and mid corner my power steering goes completely dead for a split second and the steering gets super heavy. The car's not tracking out to the edge of the track by itself so I know I could carry more speed through. The only issue is on the gas at corner entry makes me feel like I'm going to be in the grass because the fronts don't turn in the same as they do off the gas. Second corner is the same, on the gas at turn in the car just doesn't want to turn but, again, I know I can carry more speed through the corner.

swarb 05-01-2017 02:32 AM

Quote:

Originally Posted by UFO (Post 2901779)
Here you go. first corner https://youtu.be/gQqjAQb9PEo?t=833 and second corner https://youtu.be/gQqjAQb9PEo?t=875. First corner is a pretty big lift (no brakes) and mid corner my power steering goes completely dead for a split second and the steering gets super heavy. The car's not tracking out to the edge of the track by itself so I know I could carry more speed through. The only issue is on the gas at corner entry makes me feel like I'm going to be in the grass because the fronts don't turn in the same as they do off the gas. Second corner is the same, on the gas at turn in the car just doesn't want to turn but, again, I know I can carry more speed through the corner.

What turn numbers are they called in the video?
So I can look at the line you take before entering the corners.

Guess would be to add more camber in the front for more turn in grip(I see lots of people at -3 up front) and less rear toe in(or close to zero) for more rotation.
What are your alignment settings?
And an adjustable rear sway bar would also help with some rotation. This car does understeer with equal spring rates front and rear. Some people say the car is oversteer prone, but I disagree, they usually have harsh steering inputs and a heavy foot. The camber gain from macpherson strut isn't ideal under compression so the car needs a lot of camber up front.

Ultramaroon 05-01-2017 02:50 AM

Stock geometry is still way understeery. Like strat said, negative camber up front is your friend.

And get yourself a decent oil cooler.

UFO 05-01-2017 02:14 PM

Quote:

Originally Posted by swarb (Post 2901853)
What turn numbers are they called in the video?
So I can look at the line you take before entering the corners.

Guess would be to add more camber in the front for more turn in grip(I see lots of people at -3 up front) and less rear toe in(or close to zero) for more rotation.
What are your alignment settings?
And an adjustable rear sway bar would also help with some rotation. This car does understeer with equal spring rates front and rear. Some people say the car is oversteer prone, but I disagree, they usually have harsh steering inputs and a heavy foot. The camber gain from macpherson strut isn't ideal under compression so the car needs a lot of camber up front.

They are turns 7 & 12. -2.3 up front, I think -1.8 in the back and 0 toe all around. I currently have no way of going to -3 camber, I guess camber plates are next on my shopping list. Thanks for taking the time to reply.

UFO 05-01-2017 02:26 PM

Quote:

Originally Posted by strat61caster (Post 2901557)
My suggestion is more camber up front, in my experience the car was happier up at about -3 to -3.2 degrees camber on stock suspension than the -2.5 I started out with after getting camber plates, I'm even higher now but on autocross oriented coilovers.

imo changing other things and buying other parts doesn't make much sense if your tires aren't pointed in the optimal direction, you're just band-aiding the fact that you're not using all of the tire available. Getting tire temperatures will help point you in the right direction but it isn't foolproof and ultimately experimentation will get you where you need to go.

Thanks, I'm researching camber plates now, what did you run with stock suspension? I was looking at Vorshlag but it looks like they don't have a spring perch for stock applications.

strat61caster 05-01-2017 02:46 PM

Quote:

Originally Posted by UFO (Post 2902096)
Thanks, I'm researching camber plates now, what did you run with stock suspension? I was looking at Vorshlag but it looks like they don't have a spring perch for stock applications.

It's pricey but Raceseng, I spent the extra money because I understood how it was designed and for a reasonable price I could adapt it to any coilover setup I would end up choosing (cheaper in the long run). As a bonus it had almost zero impact to NVH, I still daily on those after 2+ years (currently on custom Bilstein B14's) and almost no problems provided all the hardware is properly secured.

There's also Velox and Racecomp for much cheaper off the top of my head, but I think Racecomp has been out of stock for like a year+

Some googling comes up with a few others, Beatrush, HVT, Hotchkiss, Project Silver, etc.
http://www.ft86club.com/forums/showthread.php?t=113260

And if you want to do it on a budget you may be able to get more camber out of another pair of bolts depending on your current setup. Seems like you have crash bolts in top hole, so the 14mm SPC bolt in the bottom hole may bump up a noticeable enough.

kch 06-19-2017 02:36 PM

Quote:

Originally Posted by UFO (Post 2901779)
First corner is a pretty big lift (no brakes) and mid corner my power steering goes completely dead for a split second and the steering gets super heavy.

That's not the PS dying. That's just how T7 is. When you bottom out on the banking it puts a lot of extra load on the car and steering. You can use that to your advantage and briefly give it more steering input during that moment of extra downforce.

renfield90 06-21-2017 12:47 AM

There is a known power steering issue with these cars actually, under high load it will suddenly cut out on you (have experienced it more than once). There was a software fix for MkII (2017+) to fix it.

OP, for the first turn you mentioned you are ~1.0g and the next turn (slightly slower) you were 1.1g. Obviously taking some liberties with the data since there are longitudinal and lateral components present, but I didn't think you left much on the table for this turn.

For the second turn you were 0.9g, so IMO leaving something on the table there. But I saw elsewhere on the video evidence of the push you described, so I understand where you're coming from.

If I have one piece of advice, it would be to work on your throttle modulation. It's tough for me to judge what you're doing with the throttle currently (more data might help here!) but it may be that you are mashing the gas and overpowering the fronts when a little smoother roll-on might let you find the edge a little better - especially given your background of high HP turbo AWD cars, they reward "stomp and steer" behavior. No, we don't have a lot of horsepower, but if WOT makes you push too much try to find something less than WOT that puts power down without pushing you off line.

That said, IMO you're right about the point where the car's behavior is starting to hold you back. A setup change to increase your confidence when going to the right pedal is going to make you faster. What parts you buy depends on how serious you want to take this, but you could use more spring and an adjustable shock. Sounds like a full coilover setup is in order.

UFO 06-23-2017 11:42 PM

Quote:

Originally Posted by kch (Post 2931411)
That's not the PS dying. That's just how T7 is. When you bottom out on the banking it puts a lot of extra load on the car and steering. You can use that to your advantage and briefly give it more steering input during that moment of extra downforce.

It doesn't feel like extra load but with my limited experience I won't argue. Are you flat through T7? If so, can you share your suspension setup?

cjd 06-23-2017 11:49 PM

Chiming in on PS cutout at inopportune times. It's not uncommon for me during autocross events under high-g cornering with a good bit of steering input.

Also second the recommendation to find more negative camber, and consider coilovers and more spring. Potentially a lot more...

UFO 06-23-2017 11:54 PM

Quote:

Originally Posted by renfield90 (Post 2932469)
There is a known power steering issue with these cars actually, under high load it will suddenly cut out on you (have experienced it more than once). There was a software fix for MkII (2017+) to fix it.

OP, for the first turn you mentioned you are ~1.0g and the next turn (slightly slower) you were 1.1g. Obviously taking some liberties with the data since there are longitudinal and lateral components present, but I didn't think you left much on the table for this turn.

For the second turn you were 0.9g, so IMO leaving something on the table there. But I saw elsewhere on the video evidence of the push you described, so I understand where you're coming from.

If I have one piece of advice, it would be to work on your throttle modulation. It's tough for me to judge what you're doing with the throttle currently (more data might help here!) but it may be that you are mashing the gas and overpowering the fronts when a little smoother roll-on might let you find the edge a little better - especially given your background of high HP turbo AWD cars, they reward "stomp and steer" behavior. No, we don't have a lot of horsepower, but if WOT makes you push too much try to find something less than WOT that puts power down without pushing you off line.

That said, IMO you're right about the point where the car's behavior is starting to hold you back. A setup change to increase your confidence when going to the right pedal is going to make you faster. What parts you buy depends on how serious you want to take this, but you could use more spring and an adjustable shock. Sounds like a full coilover setup is in order.

You are 100% correct with the throttle modulation, every instructor I have had has questioned why I'm on/off the throttle so much and it's because with the AWD cars I would use it to rotate the car, or simply to correct my mistakes. Not much use with the Scion ;). I'm working on it.

I have on order front caster/camber plates and rear adjustable LCAs to give me a better alignment. I'm going to see how that works for me before heading to coilovers but I think you're right and they're probably in my future.

Thanks a bunch for the reply, people like you make this community awesome :).

CatDaddysBBQ 06-26-2017 10:45 AM

I'll add to this:

You can't throw money at a car and expect to never have to lift for a turn.

There is a point where you are just taking the corner too fast, and the solution is to drive better, not throw more money at the car.

I'm not saying this is you, as we don't have nearly enough info to find the exact issue here, but get more seat time in your setup and you'll learn the car and what it needs more. If you try to buy parts every time you go out, you'll never really know what the car is doing, and each time you'll be adjusting your driving to suit the fresh setup instead of learning the car more and becoming a better driver.

If you keep modding away your problems, you won't grow as a driver until you run out of money and then HAVE to just learn to drive quickly on your final setup.

kch 06-26-2017 10:55 AM

Quote:

Originally Posted by UFO (Post 2934431)
It doesn't feel like extra load but with my limited experience I won't argue. Are you flat through T7? If so, can you share your suspension setup?

No, I'm still too chicken to do it flat. I lift a bit and go through around 90mph.

Suspension is RCE T2s, Raceceng cascam, maxxis vr1 255/40/17

Camber -3ish front -1.8r
Toe 0f 0.2r


All times are GMT -4. The time now is 02:38 PM.

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.