ET is all about traction. period. You can go about it in two ways. Get a set of sticky tires, or run your slippery street tires, and do whatever it takes to make a lot more HP to try and make up the difference after launch.
You'll notice Grannynational when to the low 13's but look at his mods. See what I mean.
Or just run more fuel and more air and more intercooling.
Dump more weight.
I'd be closer to the low 13s with traction and being able to launch with more than 1-2psi of boost. But, whatever. I am still turning 104mph with extra gear, short tires, and a tight non-L/U convertor.
What was your mph in your sig times? Your car just needs to be tuned.
10 years ago I went [email protected] on 93 octane. My mods were 200 cam, open dump, Hoosiers on 17 psi. Later after adding a TA49, ATR DP/WG and bluetops, I went [email protected] on 93 on old radials with boost control problems through the mufflers. Did nothing to it at the track but lift the hood. If you want to run fast on radials, practice alot at the track on radials! The last time I ran on radials it went 12[email protected] on 13 psi.