4.10 Gears ET times suggestions

MUSTANGGT06 · 07-03-2009, 05:05 PM

I installed 4.10 FRPP gears and have not improved my ET's. I have a 06 Gt with an automatic transmission. The last time I ran the at the drag with my old 3.31 gears was about 2 yrs ago and approx 40k less miles. My times where between 2.1-2.3 from 0-60 ft. and 9.1-9.3 in the 1/8th. I took it out for the first time yesterday withthe new gears and I am still running the same times. The only thing that is different are the tires sizes, 275-50-17 with old gears to 255-50-17 with new gears. Also, I took my Magnaflows off and had the car straight piped. It sounds good, but will it cause that much in the ET's. My brother said that the 0-60 ft times are terrible and I should be picking up any where from 2/10th to 5/10th with the new gears.

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blackmustang285 · 07-03-2009, 06:35 PM

How were the temps for the old runs compared to the new run?

acarzt · 07-03-2009, 06:44 PM

you're running smaller tires, so that is going to have an effect. The DA could be worse this time out. Do you have the time and date of your old times?

stealth_GT · 07-04-2009, 04:08 AM

I am assuming you have a new tune with the new tires?

How are you launching?? I can get a solid 2.1 with a 'decent' launch consitently, and sometimes a 2.0. I usually do a mini burn out in the water box ( which is unavoidable at my track!) stage, power brake HARD, ride the gas a little when launching then give it hell...

I HATED the 4.10s at first, but if you launch it just right they are awesome. They are very unforgiving and can spin out, lurching the rear sideways if you are not careful. You have some fat tires so you 'should' have better traction off the line. The only thing that would be effecting it would be a speedo miscalibration/tune or your gears are lower now (4.01?)

Z06 Killer · 07-04-2009, 05:28 AM

try a good tune up

MUSTANGGT06 · 07-04-2009, 10:03 AM

I installed a diablo sport 93 octane tune with a C&L cold intake street firm shift tune. I had this on before I put the new 4.10 gears on. When I installed the new gears, I went back into the the tune and modified it for the new gear set up. Do you think that I need to get a custom tune at a dyno shop.

08GT4U · 07-04-2009, 10:28 AM

you need a little back pressure in your exhaust.a straight pipe might have you loosing some botton power.2nd you need to get it tuned by a tuner.i saw a drop of 2tenth in the 1/8 by switching to 4.10.another thing you need to consider is weather,this time a year if you are in a hot place you are gonna loose about 2 to 3 thenths.humidity places a big factor in time as well.i ran 8.75 in december in 60 degree weather with bbk intake and 4.10s.yesterday i went to the track and with c&l racer intake,4.10s,cmdp and o/r x pipe i ran 8.75 as well but in 90 degree weather with like 60 humidity.

Big50 · 07-04-2009, 11:00 AM

Like stated before the weather conditions could have been different. Second, what are 60' times? It's sounds like they are pretty bad. You need to get some drag radials to see the benefit of the 4.10's. There probably won't be an improvement in your et's until you get some. Also, your car did put on 40,000 miles since last time.

acarzt · 07-04-2009, 01:11 PM

I forgot about the mention of straight pipes... Do you still have an H pipe or an X pipe? Or did you go straight back from each header with no kind of cross over? Cuz if you did that... you're gonna lose some power... you need to put an H or X in there.

MUSTANGGT06 · 07-04-2009, 02:46 PM

I've been starting out by just leaving the car in drive and power braking at the launch at approx. 2000 rpm. The diablo sport tune seems to do a good job shifting automacially. However, my brother said that I need to start out in 1st gear(not in drive) with an automatic and manuel shift at about 6000 rpm thru 2nd and 3rd. He said that I don't need to be in overdrive when I finish the 1/8th and should be in 3rd gear when I cross the finish. He stated that the 4.6 engines really like to rev and if for some reason I red-lined, the rev limiter would kick in. Does anyone know if the diablo sport tune turns off the rev limiter and would it be ok.