AamirCWITR

Hey Guys,

I just finished an HPDE at Moroso in West Palm Beach this weekend. It was a blast. I've been getting better at driving with each event I go to. This means I have been getting faster as well which means harder braking.

Towards the end of my last event and throughout this entire event I noticed that my car gets unsettled when braking at speeds over 100mph setting up for a 40-50mph turn. The steering wheel pulls left and right, and some times, it even feels as if the rear is coming out a bit. The solution appeared to be easing on the brakes slightly and getting back on them, and managing the steering wheel to stay straight, along with breaking earlier. I would have liked to brake later in some of these sections.

I am running a bit of toe out in the front and I know that hard braking increases toe out which can make the car feel darty but I do enjoy the turn-in that my alignment settings give me. The rear toe is zero.

My current setup is Brembo blanks and Axxis Ultimates. The pads and rotors still have about 2 more events left in them. What do you guys think is causing the unsettled feeling I described. Could it just be that my tires, Pilot Sports, are causing this? Will more aggressive brake pads keep the car feeling more settled in these situations? Also, are there more aggressive brake pads that dust LESS than Axxis Ultimates?

My suspension is not stock.

Mods are:

Zeal Super Function S 12/8 Swift Springs
Spoon rear strut bar, OEM front strut bar
J's CF intake, Mugen header, SMSP cat, RM01A exhaust.
Front total toe out 1/8", rear toe 0
Michelin Pilot Sports 215/45-16, 16x7 +45 wheels.

Thanks
Aamir


Modified by AamirCWITR at 11:00 AM 1/29/2007

ninor

This might sound simple, but how about that toe out as a cause?

for pads try this http://www.cobaltfriction.com

97 TYPE-R 312

When you get back in town, we'll talk about getting you a set of GT's.

-Victor

Chris93Si

A stronger set of rear pads will help a lot.

Mugen wing also helped mine feel more stable braking but that's a whole nother can of worms

fso_BamBam

No worries, I had this problem with the car from day one, and it did not go away after 4+ years of tracking. The problem is exactly as you describe it, "unsettled". The rear of the car would become very nervous braking from high speeds.

I eventually got used to it. It would make me nervous from time to time, but once you get to know your and your car's limits and abilities, it all becomes routine.

Some folks recommended that I try Mugen rear TA bushings, and I did get these to put on the car. But then I decided to sell the car, so I never got a chance to actually find out if that would've helped. It's not a very pricey upgrade, so I recommend that you try this before anything else. Good luck!

itr1244

well i think it's pretty normal.

the car's weight distribution ratio is 62/38 and when you're braking all the weight shifts to the front. so you have no weight on the back tires so that makes the back end feel all "unsettled". i guess it will be like 75/25 or less..

i experienced samething especially when i'm braking and turning at the same time. in small tight corners.

and with front toe out. it gives you nice turn in but not stable at highspeeds.

Dave_B

Did you get the infamous "wiggle" in the rear? I noticed this upon hard braking on track. I've heard from a few of the HC guys that you can adjust the toe in the rear from 0 and it helps a bit. You might want to contact one of them.

Also, are you braking in a straight line?

davidnyc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris93Si &raquo;</TD></TR><TR><TD CLASS="quote">A stronger set of rear pads will help a lot.

</TD></TR></TABLE>


Usually a stronger set of rear pads makes it worse. On my ITR I liked SPEC VR's up front and GT's in the rear (Cobalts) on R-compound tires. Still get the wiggle but not that bad.

Is AAmir's car stock?

RTW DC2R

I was getting this feeling at MAM Expo 5 after the long straight. Part of it was due to the track itself, but I was told its also just because of the front toe settings (I was also toe out in the front, 0 in rear). It was a very unsettling feeling until I got used to it. Feels like the rear is skating around all over the place. I was also on worn out stock shocks with H&R springs, so Im curious to see how it feels at VIR with new suspension and alignment settings. I was also on GT Sports in the front, and EBC Greens in the rear.


Modified by RTW DC2R at 8:37 PM 1/29/2007

OG undercover

Loose is fast

But honestly, you can't be that fast if you are on Axxis pads ... or you would melt those ****** right off.

Seems like I'll agree with everyone. car sounds normal.

ZygSpeed

Some stiffer springs all around would probably help.

sander

Make sure to always keep an eye on your Trailing Arm bushings (TA bushings) when your inspecting your car before an event. Bad TA bushings can contribute to this problem as well.

-s

OG undercover

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">Some stiffer springs all around would probably help.</TD></TR></TABLE>

I would have to disagree with that. One reason being that he is still new to track driving and the stock suspension is pretty damm good for most people with less then two years experience. Like I said, the situation sounds normal for the setup he has. Increase the pads performance (upgrade to GT-sports possibly stronger) and the front end will plant it self more and make sure your wheel alignment is on point while keeping a check on the tire wear.
Now as for the *** swinging, that is a good thing when you need to rotate the rear when entering a corner. But that takes time to get the hang of.

Jon D

If only GT Sports were still available

AamirCWITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AwesomeR &raquo;</TD></TR><TR><TD CLASS="quote">I would have to disagree with that. One reason being that he is still new to track driving and the stock suspension is pretty damm good for most people with less then two years experience. Like I said, the situation sounds normal for the setup he has. Increase the pads performance (upgrade to GT-sports possibly stronger) and the front end will plant it self more and make sure your wheel alignment is on point while keeping a check on the tire wear.
Now as for the *** swinging, that is a good thing when you need to rotate the rear when entering a corner. But that takes time to get the hang of.</TD></TR></TABLE>


My suspension is not stock.

Mods are:

Zeal Super Function S 12/8 Swift Springs
Spoon rear strut bar, OEM front strut bar
J's CF intake, Mugen header, SMSP cat, RM01A exhaust.
Front total toe out 1/8", rear toe 0

I am going to try stronger pads in the front. GT sports or Spec VR's.

Why don't you guys recommend stronger pads in the rear?

The speed I was consistently hitting on the straight all afternoon was between 125-130mph in 4th and then slowing to 50mph. My instructor wanted me to keep the on the gas longer and brake later but after feeling what happened when I tried that he mentioned that the next thing I should change are the brake pads/rotors and possibly get SS lines.

My car only oversteers if I get off the throttle or tip into the brakes right before turn in and don't get on the gas. I get a very slight touch of oversteer if I lift during a turn.


Modified by AamirCWITR at 10:41 AM 1/29/2007

OG undercover

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AamirCWITR &raquo;</TD></TR><TR><TD CLASS="quote">
My current setup is... </TD></TR></TABLE>
well now... isn't this interesting. Reading minds is not part of my forte
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AamirCWITR &raquo;</TD></TR><TR><TD CLASS="quote">


My suspension is not stock.

Mods are:

Zeal Super Function S 12/8 Swift Springs
Spoon rear strut bar, OEM front strut bar
J's CF intake, Mugen header, SMSP cat, RM01A exhaust.
Front total toe out 1/8", rear toe 0

I am going to try stronger pads in the front. GT sports or Spec VR's.

Why don't you guys recommend stronger pads in the rear?

The speed I was consistently hitting on the straight all afternoon was between 125-130mph in 4th and then slowing to 50mph. My instructor wanted me to keep the on the gas longer and brake later but after feeling what happened when I tried that he mentioned that the next thing I should change are the brake pads/rotors and possibly get SS lines.

My car only oversteers if I get off the throttle or tip into the brakes right before turn in and don't get on the gas. I get a very slight touch of oversteer if I lift during a turn. </TD></TR></TABLE>
Now we have more to work with
Withholding vital info
Will read this and reply... In due time.

OG undercover

Wow! 125-130 in 4th gear? Do you have something other then the stock ITR trans too?

AamirCWITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AwesomeR &raquo;</TD></TR><TR><TD CLASS="quote">Wow! 125-130 in 4th gear? Do you have something other then the stock ITR trans too?</TD></TR></TABLE>

My speedo probably isn't exactly right, I cant imagine it is since my tach was saying I was revving near 9k, I think fuel cut off is around 8600 which I did hit once or twice. So in actuality I was probably going 123-125 mph. My speedo is also in km/h, a quick glance showed the needle to be right above the small hash mark that said 125mph. It's not as easy to read at speed compared to a USDM cluster

gears 1 2 3 4 5

8400 42 64 92 121 158
8500 42 64 93 123 160
8600 43 65 94 124 162
8700 43 66 95 126 164
8800 44 67 96 127 166
8900 44 68 97 128 168
9000 44 68 99 130 169


Modified by AamirCWITR at 10:54 AM 1/29/2007

SoCal ITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jon D &raquo;</TD></TR><TR><TD CLASS="quote">If only GT Sports were still available </TD></TR></TABLE>

They should be soon, my XR2's are set to ship early-mid February.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AamirCWITR &raquo;</TD></TR><TR><TD CLASS="quote">I am going to try stronger pads in the front. GT sports or Spec VR's.</TD></TR></TABLE>

No dice, they don't make the Spec VR's anymore. Try XR3 or XR2.

AamirCWITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SoCal ITR &raquo;</TD></TR><TR><TD CLASS="quote">They should be soon, my XR2's are set to ship early-mid February.

No dice, they don't make the Spec VR's anymore. Try XR3 or XR2.</TD></TR></TABLE>

Nice, thanks for the info.

davidnyc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AamirCWITR &raquo;</TD></TR><TR><TD CLASS="quote">


Why don't you guys recommend stronger pads in the rear?

Modified by AamirCWITR at 10:41 AM 1/29/2007</TD></TR></TABLE>


Car unweights the rear under braking, better bite in rear = better chance of locking it up (yes, even with ABS) and therefore can spin (I have done this in turn 5 at Summit Point)

AamirCWITR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sander &raquo;</TD></TR><TR><TD CLASS="quote">Make sure to always keep an eye on your Trailing Arm bushings (TA bushings) when your inspecting your car before an event. Bad TA bushings can contribute to this problem as well.

-s</TD></TR></TABLE>

I never knew to look at this, thanks for tip. I will make sure to check that before events.

92TypeR

Stickier tires will help as well. If you are comfortable with stepping up to R-compounds, that will help keep the rear from becoming unsettled, but not eliminate it.

With SpecVR's (f) and GT's (r) + Advan A032's, I still am unsettled braking off the front straight, ~130mph to 65mph, doesn't help that the track surface is rough and uneven.

It scared the hell out of me the first time I went out with the race pads on street tires. I thought I was going to loose it for sure. It is just the nature of the car.

If you become more involved with racing, start doing some relocation and front end weight reduction to even out the distribution. This will also help.

Azcheron

a larger wing would help out a lot actually

more downforce

mstewar

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Azcheron &raquo;</TD></TR><TR><TD CLASS="quote">a larger wing would help out a lot actually

more downforce</TD></TR></TABLE>

it can definitely help.. an adjustable wing is a good start, although it can add more drag, thus slowing you down..

I myself eventually have gone back to OEM rear pads (more pad = worse wiggle), so I definitely agree with those saying NOT to get more aggressive rear pads.. making sure the bushings in the rear are all in good health will help, but most likely not completely solve the issue..

I've just kinda gotten used to it and tinker with the wing.. i've found it to be worse at some tracks than others..