George Knighton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dan GSR &raquo;</TD></TR><TR><TD CLASS="quote">wow, someone giving Matt driving lessons?

lol
come watch him drive, you'll be in awe of what he can do with a car</TD></TR></TABLE>

Talent certainly makes up for a wealth of evils.

The last time I was at Summit Point, Chris Cobetto caught and passed me in the Carousel in our 125 HP Accord race car.

He was turning 1:29's in the 125 HP Accord while I was well into the 1:30's in a 200 HP ITR.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccfries &raquo;</TD></TR><TR><TD CLASS="quote">
Heavier front springs means the front will dip less, but the actual weight transfer is still there.</TD></TR></TABLE>

I just want to make sure everybody understands you're not debunking the idea that heavier front springs will help solve the twitchy-rear problem.

There is still weight transfer, but keeping the front nose higher w/heavier springs (my contact says "at least" 14K) also serves to keep the rear suspension properly planted and aligned, thereby lessening the toe-out phenomenon and also giving you more tread contact and more effective braking in the rear.

The whole thing (evidently) adds up to a less twitchy rear when you go into threshold braking at the end of a long straight where one might reach 130-140 mph.

I'll add a caution that this was part of their overall suspension design theory for the DC2 ITR. If you're going to go w/heavy springs in the front, you will also want more camber on the front, and you might also want one of those big bars in the rear.

Black R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">
I just want to make sure everybody understands you're not debunking the idea that heavier front springs will help solve the twitchy-rear problem.

There is still weight transfer, but keeping the front nose higher w/heavier springs (my contact says "at least" 14K) also serves to keep the rear suspension properly planted and aligned, thereby lessening the toe-out phenomenon and also giving you more tread contact and more effective braking in the rear.

The whole thing (evidently) adds up to a less twitchy rear when you go into threshold braking at the end of a long straight where one might reach 130-140 mph.

I'll add a caution that this was part of their overall suspension design theory for the DC2 ITR. If you're going to go w/heavy springs in the front, you will also want more camber on the front, and you might also want one of those big bars in the rear. </TD></TR></TABLE>


I will add that I was using apexi n1 dampers with the stock springs (16k F, 5k R) on my itr with stock swaybars, decent camber up front, and azenis at little talladega - a somewhat local small road course in AL, which is about a 2.5hr drive from ATL. At the end of a long straight, above 80mph, I would get the tail wag with the dampers on full stiff. I was NOT easy on the brakes - endless NA-R fronts and CC-X rear.....

I will try the mugen trailing arm bushings next.

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">
I will add that I was using apexi n1 dampers with the stock springs (16k F, 5k R) on my itr with stock swaybars</TD></TR></TABLE>

That's a really bizarre setup.

1GreyTeg

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

That's a really bizarre setup.</TD></TR></TABLE>


Ken's kinda a bizzare guy though idn't he?


Maybe it's a typo?

Dr Pooface

I didn't read the whole thread (lazy), but more wing (JDM FEELS) eliminated rear twitch under hard braking for me. I ran 400/600 springs as well, with both the stock wing and the FEELS unit.

.RJ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ausmith &raquo;</TD></TR><TR><TD CLASS="quote">Shock rebound damping (given spring rate and vehicle weight) also has a lot to do with the manner in which this happens. </TD></TR></TABLE>

Ah yes... after installing the Konis, the problem is "better" but still not resolved.

.RJ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">There is still weight transfer, but keeping the front nose higher w/heavier springs (my contact says "at least" 14K)..... you will also want more camber on the front, and you might also want one of those big bars in the rear. </TD></TR></TABLE>

George, you're letting the secret out

Black R

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

That's a really bizarre setup.</TD></TR></TABLE>


Hey, that's what they come with. It's not a typo. It's super soft in the rear that way. But I posted since it was relevant to GK's statement and I don't think that a front-biased setup will overcome the issue at hand.

I have since rearranged them to my liking: 11k F, 16k R and put them on my DM hatch.

rastropovitch

ttt

MattD@Stoptech

quit if f00...that's what the archives/search is for.

Black R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">quit if f00...that's what the archives/search is for.</TD></TR></TABLE>

Fer sherizzle!

BTW, what was the final rates/ suspension components/ etc you ended up with on both of your h1 kaa's?

&lt;--- would like to emulate

MattD@Stoptech

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

Fer sherizzle!

BTW, what was the final rates/ suspension components/ etc you ended up with on both of your h1 kaa's?

&lt;--- would like to emulate</TD></TR></TABLE>

I have multiple race cars?

*checks garage*

nope...still just one POS in there

Zeal S6 (16/18)
Front ITR sway
26mm Mugen Rear
Orijin Motorsports front UCA bushings
Orijin Motorsports front LCA spherical bearings
Mugen RTA bushings

Front camber ~-2.5
Rear camber ~-2 (in process of being dialed in)

Toe = 0 all around

Willard

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">Front ITR sway</TD></TR></TABLE>
why not a smaller one?

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Willard &raquo;</TD></TR><TR><TD CLASS="quote">
why not a smaller one? </TD></TR></TABLE>

I've run without one last season and I needed excessive camber to keep the tires in check.

Willard

smaller one &gt; none.

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Willard &raquo;</TD></TR><TR><TD CLASS="quote">smaller one &gt; none.</TD></TR></TABLE>

true, true, but I dun need more rotation as it stands (I think), I can always control that with less rear camber.

Willard

less rear camber = less grip
there is no such thing as t00 much rotation.

Doctor CorteZ

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

Press in, press out.</TD></TR></TABLE>

:cough: BFH :cough:

MattD@Stoptech

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Willard &raquo;</TD></TR><TR><TD CLASS="quote">less rear camber = less grip
there is no such thing as t00 much rotation. </TD></TR></TABLE>

I'd rather control the rotation with rear camber than with the front bar.

Eventually the car will be set-up even more tail happy but with a wing in back...slow speed rotation, high speed stick.....one of these days.

Spikey

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fso_BamBam &raquo;</TD></TR><TR><TD CLASS="quote">I've managed to deal with this issue for the last 4 years that I've been tracking the car. Basically, if you're entering a turn at high speed and hit the brakes hard, the rear end of the car gets very twitchy. Although I'm somewhat used to it, I'd really like to find a way to either eliminate the nervous back end, or at least reduce it somewhat.

I think this year was the worst, maybe because I'm starting to really push the car hard. My friend Chris who drove the car several times also noticed this. I've thought of several things, I'll share them, but mostly I'd like some feedback here, and maybe over the winter, I can address the issue in time for the '05 track season.


1. More wing: Well, there's only one choice here, the Mugen adjustable wing. But at $1000 (wing + paint) it's a very costly option. I'm not even sure that this would help all that much under hard braking, but maybe the additional downforce would keep the car more planted on high speed corners. So, this may not be a solution at all.

2. Rear tower bar: Several choices here, including JDM and Mugen bars. Cost is under $300, but is it going to make a meaningful difference? The ITR's chassis is already solid, so again, I'm not sure if this will help with the nervous rear end under hard braking.

3. Thicker sway bar: Another low-cost option. Main purpose here would be to introduce a bit more oversteer, and my driving style would be OK with that. But are you also stiffening the rear, so the rear stays planted under threshold braking?

Did I miss anything? Is there even a solution to this issue? There has to be, I've watched the Realtime ITRs for years. And those guys, the racers who go 10/10s, they don't seem to have this problem. So if anyone knows what to do, let me know. I've got all winter to take care of it.
</TD></TR></TABLE>

referring to turns 2 and 8 at Pacific?

Doctor CorteZ

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

slow speed rotation, high speed stick.....one of these days.</TD></TR></TABLE>

x 100.

Black R

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

I have multiple race cars? </TD></TR></TABLE>

I was referring to the following:

'03 49 H1
'04 7 H1

fso_BamBam

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

referring to turns 2 and 8 at Pacific?</TD></TR></TABLE>

heh, is it that obvious? Clearly, I'm not the only one who's dealt with this.

I think there's some good advice on this thread. Mugen TAs on the way, and work on braking technique next Spring. Sounds pretty good to me.