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Discussion Starter · #1 ·
Finally got to a track that I had some times on.

All times are with a hot lapper. Many laps were with traffic so I only averaged those that were either in the time trial portion or clean. Track conditions and temps were extremely similar.

Consistent Mods for both sessions:
Kooks Headers, RT Cats, Vararam, DRM ducts and SS pistons, Carbotech XP9 and Panther plus pads, Rear rollcage.
Alignment - -1.5 front and -1.1 rear with 1/8 toe out Fr and 1/16 in rear.

Mods recently done:
Penske SA with Guy Ankey valving. Set at 19/11 rebound.
Toyo RA1's - unshaved - 275/40/17 and 305/35/18 run at 40/38psi hot based on past experience.
Lowered and Cross Weighted - 10mm all around and cross weighted with 7lbs.
Alignment- Same toe as before but actually -.3 less negative camber up front (I wanted more but they couldn't get it)

Track: VIR South
1.6 miles very tight and many elevation changes. Only run once before so assume 1/2 second just from learning track a little more.

Before:
1:20-1:22 avg. with a best of 1:20:1
Under braking way to much nose dive and car felt very unstable. Poor turn-in ability but car felt neutral in overall handling. Power oversteer could be easily induced as this was a slow speed course in parts.

After Mods:
1:18-1:19avg. with a best of 1:17:3
Car now had more obvious understeer alhtough not bad. Under braking was much improved. A high speed turn though felt like I went through slower and I think I did looking at mph etc.. Was harder to get throttle oversteer and seemed to plant butt a lot better and earlier.

My Interpretation:
So with everything on a short course it appears to be at least 2 seconds quicker (assume part of my gain was knowing the track a little better).
My guess is tires were worth 1/2 of that and the shocks the other part with some wild card being the cross weighting.

Hope this helps folks , who like me, are always curious exactly what you will get.

Will really have good comparison on long track next time I do full course VIR
:thumb:
 

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Good write up. Thanks.

Interesting that your impression of the Penske shock change is similar to my impression of the 02 to 04 shock change- the rear seems to stay planted much better.

Regarding the corner balancing, I'm reminded of the first time I met Heinrocket when he told me one of the biggest improvements they got on his T-1 car was from corner balancing.

Randy Pobst drove my car and was also a passenger while I drove at a VIR DE last year and his only comment afterwards was to get a aset of RA-1's. I was on new T1-S's. What was your inpression of the RA-1's, specifically. I hear they are a big-time improvement over OEM.

:D
 

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Thanks for the information. When are you planning to go back to VIR? Who do you normally run with? I ran the Grand Course about a month ago with the BMW club. 4.2 miles and 33 turns... absolutely amazing track! I would like to run the Full Course later in the year, but I don't see anything yet I can make.

Kirk
 

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Discussion Starter · #4 ·
I normally run with NASA, THSCC, or SCCA Solo1 these days. Occassionally I will run with Audi or BMW.

The Toyo's are good but make no mistake they are not a real race tire like a hoosier. So expect mild improvement, a litle better traction, no miracles.
 

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Glad to see all the changes moved your times in the right direction.

With the big change in tires, the rest will probably be tough to quantify. Probably the seat of the pants impressions are the best method for the shocks and corner balancing in your case.
 
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