Benchrace this?

Dauntless

1990 740 Turbo wagon. Stock except for 15G at 14psi, IPD Turbo cam, 3" downpipe and cat to 2.5" exhaust, 225/55R16 Pirelli P7s on the back.

Best run so far at the drags has been:

60: 2.191

330: 6.172

1/8: 9.537

MPH: 73.43

1000: 12.430

1/4: 14.896

MPH: 91.43

Next time I'd like to improve on this. I needed a full tank and spare tyre still in to help traction with the stock open diff, and it hits the rev limiter in 1st if I haven't given it enough time to cool down between runs. I'm thinking PowerTrax No-Slip in a 4.10 ratio diff, a decent ATF cooler, maybe the accumulator mod? Also thinking I'll get a wideband soon, and maybe turn up the boost a little more. I'll need it for later when MS happens anyway.

From what I've been hearing, that's a low trap speed for that ET?

Thoughts? I'd like to see a 14.6 next time if that's reasonable.

egads (she/her)

Good atf fluid and filter change? Not really an expert, but I know that this basic stuff makes a big difference with autos.

Dauntless

Oh yeah, I'll be doing that too. Forgot to mention it.

Dauntless

Oh, and I'll remove the wiper motors. Won't provide any benefit, but they're annoying me.

Vee_Que

How many RPMs are you leaving the line at? What tyres are you running and what pressures? I'd say it's at the limit judging by the MPH what RPMS is it at going through the traps as well?

I'd bet that if you do the oil and filter for the transmission and dot he accumulator mod while you're there, you will have a dead box within 10,000km's I'd be saving for a built AW71L or manual box. My preference is the auto if drag racing.

Also, were many other cars losing too much traction off the line that other nights they wouldn't have? Did you do the small burnout once going through the water too?

Dauntless

Not sure what RPM, was getting decent traction at about 10-11 psi though. Tyres at 28 psi. Not sure what RPM at the end of track. Why do you think the box would die if I service it and do the accumulator mod? Are you saying don't do the mod? Or don't service it?

Traction was much better on the car than last time, due to more weight over the rear. I'd think on a warmer night I could reliably launch at full boost. With a locker I should be able to remove the extra 50+ kg from the back of the car and still launch hard. Yep, had to do pretty big burnouts to get some temperature into the tyres. AWD cars were struggling off the line.

Vee_Que

Yep. Track was to cold for good launches. I say about the box because I have gone through to many boxes that were half worn out to start with. It will be fine with the mod. And a service is essential anyway. Locker will help but the mph seems low.

Dauntless

Nah, I got good launches. Trap speed was exactly the same as when I ran 15.0 last year. I think maybe I'll just service the auto, fit a better cooler and leave it at that.