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Discussion Starter #1
Hi Guys,
I've building my track MR2 for a while now and today the cars seems more or less ready for racing weekend (this weekend) but as I go deeper into details (not only from from posts on Spyderchat) the more concerned I am. The main spec as of today is:
K20 swap with 281hp
quaife sequential 5speed gearbox
rollcage, bucket seat etc
Powertrix coilovers currently 4/6k
Superpro rear swaybar
17/8 front rim + 210/610/17 yokohama slick
17/9 rear rim + 230/610/17 yokohama slick
and few other minor improvements

Already had few hours on the track and first impressions are ok but as for now it is not much quicker than my other racetrack car (CTR EP3). Obviously reserves are mostly on my side as I need to get more confident in a rwd car but the car itself is quite unpredictable and almost undriveable in the wet.
Did a lot of research but as said before, the more I read the more confused I become, so to start with few questions:
1) what spring rate F/R do you recommend? Japanese racers suggest soft front (5-8k) and stiff rear (12-16k) but I've read opinions saying otherwise.
2) stiff swaybar only on the rear axle? Japanese guys say front should be soft and rear stiff as otherwise the car is too dangerous. From my understanding the stiffer the rear the bigger the tendency to oversteer but on the other hand that makes the front more precise. What do you think?
3) OEM brake setup with EBC bluestuff front and Yellowstuff rear and ABS seemed ok but pads wear very quickly and after few hot laps some fade occured. I have all the necessary parts for front BBK swap (Clio 3 brembo calipers, Ferodo ds 2.11 pads, 305mm rotors, brackets), do you think that swapping to that is a good idea? Won't it ruin the balance?
4) what about alignments? Again, Japanese racers suggest -3 camber front and -5 on the rear. I only tried -3 front and -2 rear.

Will hugely appreciate opinions from you guys, especially those who have practical experience with that.

Cheers!
 

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I was hoping to see your post answered at some point.
I will have the same questions before Spring track season opens up in 2020 at COTA.
Drove a friends Radical car around it and was instantly hooked.
 

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You need way more data before you can really discuss setup. Driving style also plays a part in a cars setup as well as the type of track and track surface.

Usually the point of having a softer front is to keep the nose down in the corner to prevent understeer. This usually also needs high shock rebound rates to jack the front down. It mainly works on high speed corners and needs rear aero such as a big wing to compensate. It doesn't really work in slow speed corners (autoX) and causes understeer.

EBC is not a track pad, period. Carbotech xp10 is probably your best bet. If not sure ask the manufacturer for coefficient of friction and temperature data. If they dont' have it then it's not a track pad.

You need tire temperature data and track datalogging to really do a proper setup on a real track car.

Do a track day. Make one or two changes and repeat. Keep detailed notes.Every car is going to be different.
 

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I can tell you that the Tein S coilovers with stock OEM rear Bar and adjustable front bar (3/4" holow) is nicely balanced and not so stiff that it isn't streetable on my K20 Spyder
 

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I was hoping to see your post answered at some point.
I will have the same questions before Spring track season opens up in 2020 at COTA.
Drove a friends Radical car around it and was instantly hooked.
COTA you say... That's in my neck of the woods... Or about as close to close as we get in Tx...
 

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I was hoping to see your post answered at some point.
I will have the same questions before Spring track season opens up in 2020 at COTA.
Drove a friends Radical car around it and was instantly hooked.
COTA you say... That's in my neck of the woods... Or about as close to close as we get in Tx...
Awesome to hear there are some other Spyders near the Austin area! I picked up mine a couple months ago and this will be my first AutoX season with the car so I am extremely excited!

I don't have too much to say to the original post other than there is an awesome sticky posted in the main "Autocross, Racing and Motorsports" forum that I'd recommend looking through! I am working on improving my handling and will post my results/thoughts but @silversprint is right, all cars will react different so it's best to log your results/thoughts yourself and make adjustments from there
 
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