Estimate my 1/4-mile time!::: (also, what's next)


New Member
Oct 30, 2003
I've done some searching, but I haven't found anyone with my exact combo. I'll find out in the spring, but I've got lots of friends wondering! Any help is appreciated.

'86 GN, 93k miles. Stock: turbo, IC, exhaust manifolds, rebuilt stock posi with factory gears.

36-lb bluetop injectors, Terry Houston 3" dp with dump, Walbro 340 hotwired, billet adjustable FPR, adjustable wastegate rod, Turbo Tweak 93-octane chip, Scanmaster, lightweight Centerline Telstar wheels (15x6 front with 205/70-15s, 15x8 rear with G60-15 McCreary dirt cheater slicks, like Sportsman Pros), Hooker exhaust, Red Stripe 2500 lockup torque converter, rebuilt 200-4R transmission with shift kit. I think that's it. 93 octane fuel, about 18 psi boost, until I get a race chip. Assume decent track conditions and air.

Estimates? ***EDIT: I'd also like to know approx trap speed....

Also, what should be my next mod(s) (besides race fuel/chip/more boost)? Turbo upgrade? IC upgrade? Need to know what the 'next step' should be.

Becareful running 18psi with 93 octane through the 1/4 (knock)
If you were to run some xylene mix you might bust a high 12 if you could get a good 60 ft.
Do you have a knock guage or scanmaster?

alky system
Large neck innercooler
box lower control arms
Originally posted by ES1

Do you have a knock guage or scanmaster?

My Scanmaster is listed above. I haven't used it yet - the car is parked. If I can't get away with 18psi, I'll run 17 or 16 or whatever.

It'll be tough running much faster than 103-104 without knock unless you add some octane.
Look at UNGN's time slips.
It is very good information.
You also need to read about his launch technique.
ive got about your exact combo. my times are in my sig. with about 21 psi. on 110 octane
and thrasher 108 chip
Thanks jetmech! Very useful.

So it sounds like to run anywhere in the 12s I will need:

a) Alky setup (not my 1st choice)

or b) Race chip and race fuel and lotsa boost (crappy on the street though - $5.99/gal fuel is no fun)

Trouble is, I spend a lot of time on a local Mustang/F-body site and I want to run the bolt-on LS1/pre-03 Cobra guys, who run 13-flat at 107-108 all day. I will have the time, but not the mph to beat them from a roll.

Eh. We'll see. Keep the info coming!

Thanks again,
It doesn't take a lot of race gas to run 107-108, it just takes some to stave off the knock on the 2-3 shift.

Two to three gallons of leaded 116 to a tank of 93 with a good 100 octane chip and 18 psi of booost should allow easy 108 mph 1/4 mile speeds.