Outer Limits 4x4 Board

G'day Guys, I'm entering a new phase with the Cruiser and changing a heap of things so it's more suited to the Aust4/U4 style of racing. This means i am going to go with a LS1 and Auto. I am a complete novice with autos so I need a bit of help. I have access to a free th400 which I would have built by someone recommended to me up here in Mackay. It would be fully manualised and good for up to 800hp, this is according to the bloke building the autos, so strength shouldn't be an issue.The thing I don't like about this setup is that it is fully manualised, if doing a long race I'd like to be able to put it in drive and just put the foot down, but it is not really doable with the th400 and still have it work well.

The other option is to run the 4L60E, I haven't been able to get in contact with the auto builder to talk about it with him but I'd like some other opinions/experience as well. I've done a bit of google and talking to a mate and this set up could offer me the ability to leave the standard shift kit in the transmission and play with it electronically to make it shift harder? This would leave me with the option of also just chucking it in drive for longer races. The other good thing about this box is the gearing, 1st gear is 3.06:1 (th400 is 2.48) an it also has overdrive, which would be nice. My only concern is in regards to the strength of the 4L60E, could it cope with 300ish HP, 37" tyres and extended periods of racing without too much work? Maybe a rebuild, some good clutches and a big cooler?

Cheers,

Rob

Plenty of guys in the states running big hp thru a 4l60e.

I just went thru this recently and went the 4l60e as I wanted the 4 gears for low as well as hi.
You can get lower gears for the th400 if you wanted to go that way.

Running manual is good cos if you need to stand on the skinny at any point (say heat up tires on rocks) it won't shift!
Changing the gears whilst racing isn't a hard thing to do and gives you more control.

My opinion anyway

Have you had much use with it since you put it in buggy?

Buggy is only in build stage ATM. Output shaft is going in now.

Oh righto. The gearing is not a major issue, I have 4:1 transfer gears so that should be fine with the auto. It's be good to have setup so I could hold it in a gear for sections if I wanted to but I'd also like to just put it into drive and go.

I beg to differ, not many run the 4L60e as it is weak in the scheme of things & 1st is not low enough. More run the 4L80 as it has bigger gear sets & much stronger box. T400 is a better option with shorter setup, can be built stronger & being manualised is a benefit (like Evan said).
I have a 4L60e that I will swap you for the T400 if you like !!


brooksy

Thanks Brooksy, I managed to get hold of Phil (the auto builder). He said that the 4L60E will cost much more to build and be less reliable, so I'm inclined to go with his opinion as he seems to have a good reputation amongst the drag race community. I had a good chat with someone off outers today and gave me some good advice and insight into it but I think I will go with the Th400 seeing how I already have it. My crawl ratio will be about 97:1 with the th400 (2.48x4.0x4.88 and then times that by 2 for the auto) so that should be fine for when I need it in Aust4/ winch comps, might be a little tall for rock crawling but I should manage.

I have blown up several really big dollar well built 4L60s with LS1 level power. We had to put 300M everything to make it live and it needs a rebuild every race. Painful. Also you either need a stock computer or a standalone computer which is an extra complication. There are a few cars over here with 4L60 but anyone building one now is living in the past. We have learned the hard way they just aren't up for it, even with medium horsepower. Also if you build around a 4L60 it will be very hard to retrofit in the future - impossible in my case.

400s and 4L80s are bigger but easier to build at a cheaper price.

4:1 is REALLY low. You'll be running at the top of low range in the rocks and having to work the atlas. I spent weeks on a gear calculator working out the maths to make it all work - http://www.grimmjeeper.com/gears.html" onclick="window.open(this.href);return false;

You need to understand the terrain you will be racing on and think about what is a workable top speed in low and top speed in high. Do all your calculations for gear ratio.

Also I still manually shift my 4L60 to get extra punch into and out of corners. It is configured so when in 1 it only uses 1st, 2 it uses 2nd. 3rd it will computer shift 1, 2 and 3 and then in drive it will computer shift all gears. I often find I am shifting mostly between 2nd and 3rd. Leaving it in drive even with all the shift points re mapped makes the car lazy.

Thanks for your input Ben. I'm pretty certain I'm going to stick with the th400, a 4L80E would be nice but it's out of my budget.

What about the 6l80e? Brand new in box for under 3k. Paddle shift! Can't manualise them though - at least as far as I know. Although you can tap up / tap down

I think that might be getting a bit technical for the home built rig... haha

napsta wrote:There are a few cars over here with 4L60 but anyone building one now is living in the past.

We are only just getting ultra4 style events. They are 11km laps!

We are already many years behind! In rigs, races and harshness!

Come back to winch challenge you pussy

Who me?

bru21 wrote:What about the 6l80e? Brand new in box for under 3k. Paddle shift! Can't manualise them though - at least as far as I know. Although you can tap up / tap down

A few guys in the USA have tried them but have got rid of them as they are too long & ratios are too close so you are forever changing gears when not needed. Also for $3K only gets you stock internals although still stronger than most built 4L60's.
Not enough aftermarket support here either.



brooksy