Guidance on Tremec purchase from those who have one and are running SC's.

[benzopyrene]

Been contemplating putting a tremec magnum XL in my 2011 GT for a while. The only thing really holding me back at this point is deciding which one to get. the 2.66 or 2.97. Currently I have 4.1 gears in my car, and engine is stock except for CAI. Getting ready to install ARH catted long tubes with my current borla setup and kooks side pipes. My plans for this car are to put on a twin screw SC at some point in time in the next year, forged internals, lower compression , new cams...other engine work will follow...with the current goal to be somewhere around 7-800 HP....that might change. The kicker is this is still my daily driver, and probably will be for another year. Anyway, any advice would be greatly appreciated. I did all the gear calculators with different gears and what not....but I think now Im just more confused and thought I would see what some of you guys who are running these XL's with SC's are doing. I have read a bunch of the previous posts about the magnum xl which had me leaning towards the 2.97, but JPC recommended the 2.66 ( but I didnt get a good explanation why this might be better for my goals...which might be my fault because I may not have put all of them in my email) , so I thought I'd throw it back out there and see what you guys thought! Cheers!

 

[DTL]

I run the 2.66 Mangum with a Paxton. I'm in the process of switching my 3.73 gears for 4.10s. It could probably tolerate 4.56s with that first gear ratio, but I don't want to go overboard. I chose the closer ratio (2.66) spacing, and had Liberty put the shorter OD cluster (.80 5th) in it, to have a very close ratio box all the way up. For a centrifugal style blower like mine, I like it very much. A PD blower like a Whipple or Roush could probably tolerate the wider spacing of the 2.97 box, but that first gear is LOW. It'd probably be a tire fryer. I like the way I went (2.66 first with .80 5th) and would definitely do it again. With the 4.10s and some more boost, I should have it dialed in about perfect.

 

[Eric@jpc]

2.66 works good on a PD blower since it makes so much torque.

I generally recommend the 2.97s for paxton/procharged cars because they need RPM to make boost. i think the 4.10 would be solid gear for that combo. it may feel a bit slugish untill you put the blower on tho. It would work better on the motor with like a 4.56