I post this every now and then to see what the newer victims have to say.

A friend of mine who works at Roush mentioned that gears don't seem to help the ET as much as earlier cars (probably b/c of a more broad power peak) but they do make the car feel faster.

I'd like to see a few before/after ET's, all else equal to see if this holds up.

 

I just got mine last week, 3.73 in my auto. Might be going back to the track this week, if so I'll post my times.
I average 13.7/8 with my best being 13.6 so far, hoping they help me get at least 13.5 average

 

is your car stock except for the gears??

 

unfortunatly no, I have the K&N and Bamachips tunes. A friend of mine who has a stock 06 Manual GT was able to pull off a 13.6 100% stock, so that kind of makes me mad, thats why I had to get the gears to help me out a little more. With the auto I'm alot more consistant though, he sometimes hits 14's and such, where as I have yet to get a run over 13.9. I do also have the subs in the trunk as well as weigh 230 so I'm sure those don't help the best.

 

Ok.
Here are my timeslip with and without my 4.10 gear.

2005 GT Auto, Mods : Steeda CAI, Steeda UDP, BamaChip 94 Race Tune, Street Tire (not even drag radial) Corsa Exhaust.

Last year with my stock gear :

2.027/8.490/13.121@107.753

Last Week end with the 4.10
1.949/8.405/13.121@107.922

Yeah after 1/8 my car doesn't push anymore.
Don't know where it come from. peharps the gear.
So my gear help me at start until 1/8 but doesn't help on 1/4.

For my 1/8->1/4 if you look at with a manual 2005 kinda stange :
The manual mod :
Steeda CAI,
UDP
94 Tune
Stock Tire.
Off Road Pro chamber hpipe.
American Thunder Catback.
Stock Gear.

Me / GT Manual / Difference.
1.960 / 2.065 / 0.105
8.477 / 8.746 / 0.269
13.250 / 13.495 / 0.245

2nd run
1.997 / 2.069 / 0.072
8.511 / 8.808 / 0.297
13.307 / 13.576 / 0.269

 

4.10's in my manual have done nothing for my ET. All other things equal before and after, ET is a fraction slower, but trap speed is up one or two mph.

I think that if I switch from a 28 inch tall tire to a 26 inch tall tire I'll be able to get into 4th well before the finish line. As it is right now, I'm redlining 3rd with about 100 ft to go. At this point shifting to 4th is too time consuming, riding it out in third is quicker.

 

Yeah, my launches are as consitant as the weather, always changing. When I got the 13.6 stock, I was redlining at about 6100 to 6200 in in 3rd gear. I tried other runs shifting to 4th gear but like nonsensez9 said, it was a waste of time.

Now I have a new C&L Racer Intake and Brenspeed Tune. I'm hoping now I can get the revs and speed up quicker to take advantage of 4th gear sooner. We'll see maybe tonight. dekujala, I hope you can make it!

 

Well with the gear change, I didn't even best my best time before. I was getting 13.7 all night, where as mot250 with just the CAI and tune got 13.4

 

4.10's in my auto haven't done much for my ET either, but it's fun to drive on the street.

 

Maybe your K&N is too restrictive since you can technically run it without a tune...

 

This is an excellent thread. Imediately it is counter-intuitive. Because you would immediately think 4.10 would beat 3.73 or 3.55 in the 1/4 mile.

4.10 is great for launching and 60ft times, but if it adds an extra shift for the 1/4 mile, it can be costly.

I think we need to see more data, before we can say this myth is busted.

 

Actually the myth was busted long ago... But it's not a waste IMO. After all having fun is what it's really all about, and I love the way the powerband has shifted on my car. Now I'd be a little ****ed if I got slower, but I stayed the same just like enitalp. I'll probably see a little drop once I get M/T ET Streets for the track. It's a 26" tire versus the 28" monsters I have on my car for the street. With my tall street tires, my effecvtive final drive ratio is a 3.92.