What JSpeed said. Only the 245 base tire was the typo. His clarifying email still said that I can use sport brakes.

I didn't trust my spare diff when I went to swap it in last weekend. I stayed in TTD, and managed a class win both days. Free purple crack, sweet.

Sorta related. This is a customers car, recently completed by TC Design in Campbell, CA. This particular car had it's engine provided by Trackspeed Engineering. Diff, wheels, clutch and several other bits from us, including the tub. The owner has a second car with an engine, wheels, Xidas from us.

The bare tub started life here with the intent of building an T25 E3 specific car. We had the tub dipped to remove paint, sealant etc. TC Design seam welded, caged for us late 2012. My intent was to run a fuel cell in the pax floor with 2" filler on the RR fender just under the B pillar. Not having to run around the other side of the car would save about 6s per stop. The special jug would dump 5g in about 6s. All in all we would drop our usual 40s 10g stop down to about 18s stationary. Beyond the time saved, the CoG and PMI would both be improved by this change. Mounts built into the cage for the carbon skin top. The box you see in the OEM tank area was repurposed as a bin to hold other stuff, such as a battery, alternator, fire bottle, etc. I'm not sure if it got used in this customers build.

We ended up running Crusher in E1 (and won) two E3's and an E2 car. This tub "Bubbles" never got built. A customer called early this year for parts going into national level PTE car. He bought the bare tub from us, we shipped it back to TC and here is the result.

Since it is not our car, I'm not able to answer too many questions about it. From the pics you can see it has an NB1 engine, USDM intake manifold, header and sway bars, no aero so do the math on class config

PTE pron

https://cimg1.ibsrv.net/gimg/www.mia...b4f20237b.jpg?

https://cimg4.ibsrv.net/gimg/www.mia...66ec1a5a5.jpg?

https://cimg6.ibsrv.net/gimg/www.mia...1b0a8b608.jpg?

https://cimg8.ibsrv.net/gimg/www.mia...486035e5b.jpg?

https://cimg0.ibsrv.net/gimg/www.mia...ac01aa4f2.jpg?

https://cimg2.ibsrv.net/gimg/www.mia...540165842.jpg?

https://cimg4.ibsrv.net/gimg/www.mia...b30fe8f9f.jpg?

Super sexy. How do you like the MCS? Why not Xidas?

"Since it is not our car, I'm not able to answer too many questions about it. "

TC is an MCS dealer and worked with them for a long time. He has put Xidas on a few other builds there though.

Ah. Though TC was just cage stuff. Makes sense.

Trackspeed radiator in this application seems like big-time overkill and unnecessary weight in a not-so-good place. ??

Beautiful car though. I dig the metallic interpretation on 949 Orange -- the first combat scar will be painful.

I think the burnt orange is coincidence. Not our car.

TSE rad works. Yes a fair bit heavier than some other options but I'm guessing that was the option offered when the engine was being built. FWIW, our revised crossflows are on a boat, due here next month. Not availablel when this car went together.

What about going from S7 to SM7?
I am kind of in the same boat, looking at options.

The new 205/50 Rival S and RE71R are awfully fast. :party:

Faster than say... SM7s with three or four sessions on them?

Million dollar question. From the little data I've gathered, fresh RE71-R's and Rival-S are only about 1-1.5s off R7's on a 2 minute course. So about as fast as an RR. Yes, stupid fast. 1.5g on street tires w/o aero fast. That's at full tread but that condition is not persistent should you avail yourself of their grip for more than about an hour.

So pretty much as fast as SM7s.

Has Greg given them a point value yet? I'd guess he is waiting until after nationals.

Hold up! Where's the data on sm7s being that much slower than r7s? I missed it......

Per the rules, they are a 200tw DOT-legal tire, so they are +2.

Below the tire points list:

Per the rules, they are actually +30 at this point in time.

Bringing this back up, I'm extremely curious. This would directly effect my tire budgeting

I don't have real data, just putting together internet conjecture. Here is what Dragoo had to say about the SM7.

What I've read on the R7 is that it is a faster than the R6 tire once you change your setup to match it.

Direct comparisons of the SM7 and R7 are going to be difficult to find since PTE is likely the only place that is meaningful.

Ya, SM7 is just as fast as R7. just use it because its cheaper ;)

Direct personal experience in controlled A/B testing? Where did you get that info? Great news if it's verifiable.