BRNGT4

I am slowly progressing on setup and have been able to move in the right direction with lap times all the while keeping the setup very street friendly. So during this weekends track day I installed RSS rear toe links (Thanks BGB Motorsports!). What this allowed me to do is increase rear camber and still being able to get the rear toe in the required range. So first let me list all the mods and adjustments I have made to the car and then some feedback on how it felt on track and backed up by AIM Solo data.


Mods so far in the order they were made:
Increased rear win angle and removed front aero dams
Rear Sway bar moved to full stiff
Switched from Cup2's to Dunlops
Lowered the car (three full turns on the adjusters)
Front camber 2 degrees
Rear camber 1.75 degrees (1.45")
Front toe 0
Rear toe 9" toe in per wheel
Added 15mm spacers per side on the front


This setup looks visually appealing in that the front tire is no longer leaning into the fender and is more flush. It is also a comfortable setup to drive on the street with no rubbing or wandering/tracking. The car felt very stable on track and the data shows that in most corners I can carry better speed. I believe that this setup is about 0.5seconds quicker per lap than the previous setup (reason I was not faster than before is this track day they had cones on top of the apexes for new drivers and those cones are right on top of my racing line). Anyways I do have to say that I like this setup and will continue to build on it. My only negative comment is that it brought back some of the understeer which went away with the previous setup. I also noticed that the front tire is not wearing all the way to the triangle mark as with the previous setup which maybe tells that 2 degrees front is too much???


Here are my alignment numbers if anyone is interested.

mrd_spy

I find cup 2 much better than dunlops ! could never get stable temp in dunlops and they go off after 2 laps.

what was your last set up as I hate understeer and now you have more !

also you state in most corners you were faster not all corners ,

interesting, I am not sure what I am going to go for.

def more wing sounds bad from the people I have spoken too, slower speeds and more understeer.

Bardman

What colour is that - looks brown?

ChrisF

Definitely agree that the cups are better.

Check front fender and liners regularly. I found rub on track with hard cornering.

Maybe try a little toe out in front.

ExMB

Based on other pictures I've seen on here that have more camber and more aggressive offset wheels or spacers I find it hard to believe that this pic represents the spacer install.

bhk1004

Confused. You say a certain alignment and your sheet that you posted has a different alignment.

jphughan

So to get past 1.5 camber while maintaining toe within spec on the rear, are toe links the only option, or can you alternatively use shims to achieve the target setup? I may end up buying a set of RSS shims to get more camber up front, which would in turn require being able to get more camber in the rear to maintain the desired camber stagger, and I want to make sure I buy what I need but not buy things that I don't.

Also, are there any guidelines to toe link installation? I remember reading posts about people who heard weird noises and felt weird things that turned out to be the result of improperly installed aftermarket toe links.

jphughan

No, you're just not converting between degrees with decimals and degrees with minutes.

ExMB

While there is a camber/toe relationship you cannot correct toe on these cars via shims. You might be able to achieve your camber goal and NOT have to buy new toe links by lowering your car.

On what car? Did the shop know what they were doing? Was it the correct toe link for the application? Etc.

bhk1004

Woops. Ignore the noobie

jphughan

Ok, right now I can hit the desired toe with -1.5 camber in the rear, which of course isn't surprising since that's the factory spec. I was asking if shims would allow me to just add more camber than -1.5 without upsetting my current toe setting, but it sounds like they won't. Good to know.


On this car. I think it may have been USCTrojanGT3 and I seem to remember at least one other, but I'm not sure anymore.

katmeho

What tire temps are you getting? Outside/middle/inner temps will give you a lot of feedback on track and driver inputs vs. setup. Wear could be pressure related.

katmeho

Also, which track?

BRNGT4

I agree the Cup2's have a larger operating window but when you get the dunlops to proper temps they are without a doubt good for 0.5-1.5 seconds depending on track. The dunlops like cold pressures of 24/28 and once up to temp we adjust them so they are 28/33 hot. This gives amazing grip and the tires dont go off. The previous setup was no spacers, 1.75deg(1.45")Front camber, 1.5deg(1.30") rear camber, 0 front toe, and 10" rear toe in. Everything else the same. I mentioned i was slower in some corners because during this particular event they had guidance cones placed on the apex of turns. I usually ride the curbs and since the cones were there i couldn't hence slower in some corners. I am very confident though that this setup is in the right direction. I have an event on the 20th and i hope to confirm this finding there.

Guards Red

Thanks for the heads up will be checking fenders and liners! I didnt want to go with toe out on the front because i use the car fairly frequently on the street and want a setup that is streetable and track worthy. I believe this setup i found is ideal for both.

It does have a 15mm spacer per side on the front. Will take pics and post after work.

BRNGT4

I am surprised you were able to get -1.5deg rear camber while staying within the oem 10"+-2". On 3 of the GT4's i have seen here we could not achieve the -1.5deg oem setting even when lowered. I had no problem with the toe link install. The RSS toe links are good quality and fit and finish is great.

Although i own a pyro and we do use it for our race cars i've never gotten around to checking tire temps on my GT4 which i use for track days. You could be right in that wear is pressure related though i am trying to set the fastest laps and not concerned much about tire longevity and these pressures give the highest amount of grip. The Dunlops have a zone that when they are in are close to Hoosiers, the Cup2 can never achieve this level of grip. Track is Bahrain International Circuit on either the inner loop or the GP configuration.