Which Atlas?

highrolrcustoms · Jun 30, 2014

So im currently running a Np203/dana 300 doubler. Works great for crawling but feel im lacking in strenght with the 300, ground clearance with the 203, and length of the combo. If i read right the np203 has a low of 2.0:1 and the 300 has a low range of 2.42:1. So when im in double low my final ratio is 4.42:1. Correct? I wanna go ahead and swap over to an atlas but not sure if i have enough motor for a 3:1 case. Plans are to have about 400hp by next season. I really like the crawl ratio of the doubler but affraid if i go with a 4.3:1 atlas it will hold me back when i need alot of wheel speed on hill climbs and things. Currently running a v8, turbo 350 tranny, 1 tons with 456 gears and 42,s. Once 42s are worn out i will be moving to 43" stickys. So which atlas do i buy? Or even look at a atlas 4 speed to.give me more options?

TBItoy · Jun 30, 2014

Re: Re: Which Atlas?

Doubled down you're at 4.84,

Run a 4.3 atlas, and build a motor that will let you pull 3rd gear low ?

Can you currently hit the rev limiter 3rd in double low on big climbs?

I'm assuming you have a th350?

highrolrcustoms · Jun 30, 2014

Yes th350. And yes at rush this weekend i was in double low hitting rev limiter on some of the climbs

TBItoy · Jun 30, 2014

Re: Re: Re: Which Atlas?

highrolrcustoms said:
Yes th350. And yes at rush this weekend i was in double low hitting rev limiter on some of the climbs

3.8 atlas might work for you?

Nothing will replace the selection of a 4 speed atlas though... Especially if you actually rock crawl and don't just throttle everything

I am accustomed to the 4speed Toyota case setup (duals with 4.7 rear case),

kmcminn · Jun 30, 2014

I prefer Rand McNally.

GONOVRIT · Jun 30, 2014

If a 4spd atlas is an option do it. You would never regret it. I sold one earlier this yr that would have been perfect for you.

highrolrcustoms · Jun 30, 2014

I always miss the good stuff for sale. Lol. One question on the atlas 4 speed.....with the extra gears does it have the same strength as the 2 speed atlas?

Mortalis5509 · Jul 1, 2014

highrolrcustoms said:
I always miss the good stuff for sale. Lol. One question on the atlas 4 speed.....with the extra gears does it have the same strength as the 2 speed atlas?

Yes. I have and there are options for days.

yankster · Jul 1, 2014

Bombshell has 43s, a 3.0 with 5.13 gears and 400 hp. It's hits the rev limiter in 3rd pretty quick. Also it tries to shift into 2nd when crawling. I think with 400 hp a 3.0, 3000 stall and 4.56 is the perfect combo to trail ride and haul ass.

gubni · Jul 1, 2014

NP203 is 1.96 and Dana 300 is 2.62. To get the final ratio multiply them. 1.96x2.62 = 5.13 When in double low you are essentially 5:1 ratio.

gubni · Jul 1, 2014

To get your final drive ratio - 2.62 first gear and 4.56 in axles x 5.13 transfer case is 61.29 to 1. Then add some for torque converter slip. I've heard anywhere from multiplication of 1.5 to 2.

highrolrcustoms · Jul 1, 2014

My main concern is transfer case gearing... turbo 350 isn't changing and neither is axle ratio. Just don't wanna spend $2500 on a atlas just to install it and realize I should have went with a different ratio transfer case.

zayne2427 · Jul 1, 2014

I went through this a few months back. I am running 39 Reds and 4.10 in axles with a Turbo'd lightly built 4.3 v6, th350 trans with a 3900 stall to help the turbo spool. I broke the gears out of my toyota 4.7 case my last trip out. After reading a bunch of these threads i bought a 3.8 atlas to go in mine. Haven't got it installed yet. Will update with performance

BUG-E J · Jul 1, 2014

yankster said:
Bombshell has 43s, a 3.0 with 5.13 gears and 400 hp. It's hits the rev limiter in 3rd pretty quick. Also it tries to shift into 2nd when crawling. I think with 400 hp a 3.0, 3000 stall and 4.56 is the perfect combo to trail ride and haul ass.

This is close to what I'm shooting for. After I get my engine tuned I should be 350hp 2500 stall 3.0 and 4.56's. As bad as it runs right now the gear ratios feel real good.

Mortalis5509 · Jul 1, 2014

Re:

I have a built 5.3, th350, 5.13, and atlas 4. I have 1:1, 2.73:1, 3.8:1, 10 something. I can move quickly or do some dumb crawling.

2400 stall that matches my cam on 40" treps

matth_85 · Jul 1, 2014

My last buggy was 450HP approx., TH 350 3K stall (10" convertor), 3:1 case, 4:10 gears, 42" Iroks. It got it done in 3:1. The 5:1 option was way too much, you got no wheel speed there.

My first convertor was a 2200 stall and it left a lot to be desired.

My current buggy has a stock 5.3, full size convertor 2000 stall, 3.8 atlas, 4:88's, and 39" Krawlers. It leaves a lot to be desired. Gearing is plenty but needs more convertor IMO. Or motor, or both.

yankster · Jul 1, 2014

BUG-E J said:
This is close to what I'm shooting for. After I get my engine tuned I should be 350hp 2500 stall 3.0 and 4.56's. As bad as it runs right now the gear ratios feel real good.

Started out with a 2500 stall. It pushed through the brakes pretty hard in low range. 3000 was much better. 3500 would have been perfect.