Cam questions...
The only other mods I want to do are LT headers.
Thunder Racing TRx V.2 - 242/248 .608/.612 110lsa +2
Piston to Valve clearance
When going with a cam of this size, piston to valve clearance becomes more of a concern. Both of these cams are well within the spec of allowable clearance with stock heads and stock shortblock. They are, however, on the tight side of the spec, but definitely something that can be used with the proper attention being paid to the install (intake centerline) and valvetrain selection.
The cams have the following PtV with a stock cylinder head (stock valves, stock valvejob, no milling), '98/'99 GM graphite gasket (.053", compressed), stock shortblock (pistons .007" above deck), and a 108* intake centerline:
V.2: Intake .070", Exhaust .090"
For those that feel that this is too tight and are uncomfortable with this clearance, we do offer the ISKY flycutting tool which will make valve reliefs in your stock pistons. The heads do need to be removed to perform this task, so be prepared to purchase new gaskets and bolts. You can notch the pistons with the motor still in the car. You can also just select a smaller camshaft and not have to worry about any of this.
The pistons in my car are not notched and I have had no problems with any PtV.
Valvetrain
We recommend either the Comp 921s or Crane 144832 dual springs due to the aggressive nature of this cam. Thunder Racing 7.400" hardended pushrods are needed as well.
Tuning and Driveability
Tuning is going to be an absolute must with either of these cams to get the idle and driveability sorted out. Once the tuning is taken care of, for a cam of this size, it drives pretty well. Still, this cam is not for the faint of heart. It was designed for those looking for a cam that makes very impressive power with stock heads. It can be used in a daily driver if you don't mind the driving characteristics of a large cam. For those looking to drive this cam everyday, I would recommend a complete tuning session, gears (4:10s or steeper in a M6), and a loose converter in an A4 car.
From my limited street time with the V.2, it really is quite driveable. I just put 25 miles on the car in the last hour with the Hooker catback installed and it is much better now with some additional tuning Geoff did.
We will be spending a full day early next week taking care of the final driveability tuning. It is 10x better than what it was with the stock tuning.
Rest assured, this only the beginning of the new camshafts Thunder Racing will be offering. The V.3 is already in the works.
If anyone has any specific questions regarding this cam, post here or sent me an email (jason99ta@hotmail.com). I'll be more than happy to help you as best as possible.
Jason
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but i'd get a TC before the cam anyway, theres nothing worse with an a4 then a mismatched combo. i've ridden in a few and they feel slow as ****.


. Would be pretty fun turning everyone's head with the huge lopes though 
