Recommendation On Gear?

[Batmobile5_0]

Finally got my car to the local 1/4 mile. The prep was crap unfortunately but I did get an idea of what my car runs. With a 1.8 60' the car ran 11.5 @ 117 mph. In the interest of running a lower time, I'd like to know what you guys recommend for gearing. The car has 3.31 gear now so I was high in 4th gear, I'll be setting up the gears myself. What ratio would you guys recommend? I am leaning towards 4.30 because of my 28" tire and also it puts me around 6000 rpm in 5th.

 

[skwerl]

The MT82 is geared super low. 5th is your 1:1 gear, not 4th. I have 3:55 gears and it's geared too low IMO. I have no idea what you expect to get out of 4.30 gears other than having to shift twice to get past the 60' mark.

 

[Rob72]

With 3.73's, the stock plenum and 26" Brembo wheels and tires I was maxing out 4th going through the traps. I now have a 28" DR and I feel a noticeable loss out of the hole. I haven't went to the track with those tires so I don't have any slips to back it up. That being said I'd try to find a gear that maxes out 4th without going into 5th with your 28 inchers. Not certain but it seems like a 3.90 would probably work best. I'm interested in what others have to say as well. I plan on doing gears at some point too if I stick with these tires.

 

[Batmobile5_0]

With my current gear set up I am going through the trap at 117mph and according to my calculations will do about 135mph in 4th @ 7200 rpm. With 3.73 I'll top out at about 120mph in 4th. While 11.5@117 was my best ET my best MPH was 11.6@120. I figure with the 4.30's I'll be in 5th gear passing the trap at about 120mph and 6200 rpm which is right in the power band. I am wondering if anyone has tried this combo.

 

[Grabber Blue 5.0]

With 3.90's and a 28" tire you should be able to run it out in 4th gear. Anymore and you'll be shifting into 5th. The less shifting you can do with that MT82 the better lol.

 

[justinsstang]

You don't want to be in 5th. IMO keep your 28" tires, keep your 3.31s, go FI and it will be perfect. I have 3.73s and I want to get rid of them for 3.31s, I'm going twins very soon though.

 

[Five Oh Brian]

My '11 GT was an MT-82 Brembo Package car with factory 3.73's. On 28" tall drag radials, I just couldn't get it to launch well (seemed to bog too frequently, so it was very inconsistent). I was able to cross the traps in 4th gear. Car typically ran 12.20's @ 115+ in the 1/4 mile.

I swapped in 4.56's to get the launch fixed. I picked 4.56's to make sure that I would make full use of 5th gear since I knew I'd have an extra shift to contend with. The 4.56's made the car super easy to launch well, and do it consistently and predictably. My short times improved, but the extra shift (into 5th gear) offset the short times, so the 1/4 mile #'s didn't improve at all. However, it was much easier to launch & run consistently, so it was more enjoyable.

 

[Batmobile5_0]

My '11 GT was an MT-82 Brembo Package car with factory 3.73's. On 28" tall drag radials, I just couldn't get it to launch well (seemed to bog too frequently, so it was very inconsistent). I was able to cross the traps in 4th gear. Car typically ran 12.20's @ 115+ in the 1/4 mile.

I swapped in 4.56's to get the launch fixed. I picked 4.56's to make sure that I would make full use of 5th gear since I knew I'd have an extra shift to contend with. The 4.56's made the car super easy to launch well, and do it consistently and predictably. My short times improved, but the extra shift (into 5th gear) offset the short times, so the 1/4 mile #'s didn't improve at all. However, it was much easier to launch & run consistently, so it was more enjoyable.

You don't want to be in 5th. IMO keep your 28" tires, keep your 3.31s, go FI and it will be perfect. I have 3.73s and I want to get rid of them for 3.31s, I'm going twins very soon though.

It seems like the 3.31 gear is perfect for my set up. At my local 1/8th mile which is prepped better my car on motor 60' 1.7 on 100% stock suspension with a 5500 rpm launch. I was just hoping for better 60' times. The more I think about it, the more sense it makes to keep the 3.31 gear.

 

[Boaisy]

I've heard of more people going from 3.73 to 3.31 than the other way around, and it is usually after they start adding on the power mods. At my track, depending on the launch, I'll sometimes find my self needing to shift to 5th right at the end of the 1/4 mile on street tires. Best I have run is about a 12.6 with a crappy 60'.

 

[sh4rkbayte]

There are some calculators out there that will tell you exactly what rpm and mph you'll cross the stripe at. I'm just not sure what speed I would be trapping with my setup. Anyone have an idea what a 150 shot coyote should trap or estimated rwhp of a coyote on 150 dry shot (MT82)? It's the missing piece of the gear puzzle for me. I have 3.73s now and know it will be too much. Just split between 3.55 and 3.31.

 

[Boaisy]

I think the previous owner had that much in my car, before he traded, and he ran low 12's high 11's. Not sure if it was on street tires or radials. I know for sure it wasn't slicks because all he bought was 2 extra Brembo wheels for the rear.

 

[sh4rkbayte]

I think the previous owner had that much in my car, before he traded, and he ran low 12's high 11's. Not sure if it was on street tires or radials. I know for sure it wasn't slicks because all he bought was 2 extra Brembo wheels for the rear.

He was spraying on 3.73s? I have a friend that was running 10.89 with 3.55s, but said was topping out 4th. I ran 12.7 on 27" street tires with 3.73s stock and hit rev limiter about 50ft before the stripe. A 28" tire would help some as well as raising the rev limiter, but adding spray is going to really mess that up. I just don't know what trap speed or est. rwhp to expect with a 150 shot. My goal this season is 11.0-11.2 with a 150 shot and slicks on the MT82. Just trying to put the right combination of gears and tire size out back to maximize effectiveness.

 

[Boaisy]

My setup (info. on the MPG link in sig), before the Vorshlag Street-Pro, was running 12.6's on Hankook Noble 2's. N/A and about a 2.0 60'. This was running down the right lane, of course. I can't hook the left lane for shit at MIR.

Even before half of my parts were thrown in, I would find myself topping 4th just before the line.

 

[sh4rkbayte]

My setup (info. on the MPG link in sig), before the Vorshlag Street-Pro, was running 12.6's on Hankook Noble 2's. N/A and about a 2.0 60'. This was running down the right lane, of course. I can't hook the left lane for shit at MIR.

Even before half of my parts were thrown in, I would find myself topping 4th just before the line.

So you think 3.55s or 3.31s for nitrous? I don't want to go too low, but don't want to go too high and have to swap again.

 

[Boaisy]

That would be a question someone else would have to answer. I've never used spray personally, and don't plan to. I can only go off of what the previous owner had done, and/or what he said his plans were.

However, when he traded in the car that I own now, he had bought a 13 auto with a Brembo package. His plans were to put a twin turbo system in it, and I believe he said he was going to run 3.55s in it (if that helps your decision any). The plans never came to be when he had to trade the 13 in because of a 2nd kid coming. He only got as far as putting in the F.I. Aluminator in it.

 

[sh4rkbayte]

Hmm. I'll have to check the 6R80 gearing again vs MT82. I wanna say the 6R80 is longer. All I know is I have NO 1st or 2nd gear N/A with 3.73s, just smoke and noise.