I just ran some that were (30 amp #'s) 480's low 1.18's this weekend in 19 touring car.
I ran the atlas 19 turns since that's what I tune. I built 2 motors one with 767's and one with XXX brushes.
I ran the same setup on the car with the same ratio all day to compare between 3300's and the 3800 IB's. Both the 3300 and 3800 batteries were low 1.18 batteries... The GP 3300's were deadshorted...
The track was VERY technical and the longest straight was maybe 30-40 feet into sweeping corners etc. So I was off and on the trigger a lot...
Round 1 My fastest lap was a 10.106 on lap 9 and my last lap was a 10.552
(3300 batteries and Atlas 19 with 767's 1st run on motor) (I believe the motor/battery fell off at the end it was definately several tenths slower the last few laps) I had 36 seconds left at 30 amps
Round 2 My fastest lap was a 9.918 on lap 24 and my last lap was a 10.176
(3800 batteres and Atlas 19 with 767's 2nd run same motor as first round) (the motor/battery didn't seem to fall off at all) I had 120 seconds left at 30 amps
Round 3 My fastest lap was a 9.890 on lap 14 and my last lap was 10.493 however my next to last lap was a 9.893 so I don't attribute the last lap to the battery falling off just traffic.
(3300 batteries and Atlas 19 with XXX brushes 1st run) (battery/motor did not feel like it fell off at all) I had 48 seconds left at 30 amps
Main My fastest lap was a 9.804 on the 2nd lap... now this main was a hackfest and I ended up breaking so I don't have the data I would like on this run... The 9.804 lap wasn't a perfect lap as I was pushing hard to break away from the pack... I believe I could have gone faster with a couple clean laps... only made 10 laps and let's just say they weren't "clean"
(3800 batteries and Atlas 19 with XXX brushes 2nd run) can't give a run time estimate I broke too early...
I purposely ran the 2nd run with the motors on the 3800 runs to give the advantage to the 3300's if possible. That way if the 3800's seemed better that would take the motor out of the equation...
As a quick note... I ran two warm up laps before each run to heat up the tires... track was a little slick...
Here is what I get out of the info... from round 1 and 2... The 3800's were faster and didn't drop off at all.. 2 tenths advantage.
Now after switching to the XXX brushed 19... that motor had more power and didn't fall off as bad towards the end of the runs.
In the 3rd round I picked up 28 hundredths or .028 seconds... virtually nothing but I feel the motor was stronger... (3300's didn't fall off)
In the main although I didn't finish, I picked up almost a tenth (.086) of a second from the 3rd round with the 3800's. This wasn't on a perfect lap (or as close as I get to one) i.e. hitting all the apex etc. and I didn't get a really good lap in due to traffic etc.
I'd say that in the main with the 3800's I could have gotten an even faster time, but it was still almost a tenth of a lap advantage.
Now I'm by no means a perfect driver, but I've won in our region numerous times and missed the A in sportsman 19 at snowbirds by about a second. So my times should be consistent enough to draw a conclusion from.
To me, the 3800's were faster on the track and on the race results. Not by much, but they definately did not give up anything to the 3300's.
The 3800's never fell off at all and seemed very consistent throughout the runs.
Hope that helps