zim Posted September 25, 2012 Share Posted September 25, 2012 Evening, So based on personal experience - can an LSE range rover ZF 4hp22 automatic gearbox handle 400bhp and 500ft lb of torque ? I'll admit that i have a heavy right foot and that i'll be spinning big wheels on big axles ! Only to be used offroad for challenging. Dave W - what gearbox have you got on your LS1 ? Although from memory, you run landrover axles successfully, so i think we have a different driving style Nige - what did you find out in your quest. I do have an early p38, which i'll use the torque converter from as these are bigger afaik ??? I'm also lead to believe the lse had a tinkered with hp22 compared to the 3.9 rrc ? I don't really wish to use the 4hp24 out of my p38 as i'll have to run a compushift. No yank gearbox suggestions please 4l80 etc (although i'd love a 6l80e ). G Quote Link to comment Share on other sites More sharing options...
Steve Hiatt Posted September 25, 2012 Share Posted September 25, 2012 No yank gearbox suggestions please 4l80 etc (although i'd love a 6l80e ). Then I'll make this an observation rather than a suggestion. Most yank boxes are built or regularly modified to take that sort of power for breakfast, the older ones are simple and the parts cost peanuts. The opposite applies to the ZF. Also, with Yank stuff the higher rated torque converters tend to be smaller not larger in my experience. Quote Link to comment Share on other sites More sharing options...
BIG DAN T Posted September 25, 2012 Share Posted September 25, 2012 No it can't. We used to kill them with a mildly tuned 4.6 in a comp safari motor. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 25, 2012 Share Posted September 25, 2012 Be worth asking Ashcroft, they build their 'monster box' if you have the cash, to spec, it still seems a bit too much to be putting through the poor little thing in all honesty. I don't think the P38 boxes are hugely stronger either, plus as you say compushift etc becomes a nightmare... Quote Link to comment Share on other sites More sharing options...
iomlt Posted September 25, 2012 Share Posted September 25, 2012 why not just put the internals of the hp 24 into the hp 22 box? 400bhp is alot and i'm guessing the torque is alot more? the lse box is an uprated hp22, good for 200hp all day long like the 4.2 kicked out. i'm guessing they can take alitle more with good cooling.. but if your a bit of an animal off-road then something alittle beefier is going to be needed especially with your hp and torque figures. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted September 25, 2012 Share Posted September 25, 2012 Dave has, I think the 4L80E box behind his LS motor Quote Link to comment Share on other sites More sharing options...
Daan Posted September 25, 2012 Share Posted September 25, 2012 I wouldn't even run that kind of power through a jank box, because it wont last. How many yank boxes has bathtub cooked so far? not many miles done I reckon. How many horses have you got now and is it giving problems? Given how easy it was to break a CV (I saw a you tube clip of you doing a special stage with a cv), I would ask myself if more power is the priority. Hate to be the miserable old boy... Daan Quote Link to comment Share on other sites More sharing options...
Dave W Posted September 25, 2012 Share Posted September 25, 2012 I am fairly gentle on the loud pedal and do have some mechanical sympathy when I drive generally. I have corkscrewed a rear propshaft though so I do have my moments. I run Land Rover axles with Ashcroft internals and ARB diffs. Other than bending a rear axle (more due to a heavy landing than the power throughput) the only transmission part I've broken since 2007 was a rear propshaft. When I had the 3.9 V6 I went through, approximately, a ZF 4 speed every 2 years and I've yet to be convinced that the ZF HP22 is capable of handling much more than a standard RV8. Much like the RV8 engine though if you throw enough money at it I'm sure it could be beefed up enough. The main thing with any auto box is cooling though and all the ZF failures I had were primarily due to them being cooked. On my LS1 I have, as suggested, a 4L80E box that is rated at 1000BHP IIRC and cost a fraction of what it would cost to get a ZF box to a similar spec at the time. Having said that the USD/GBP conversion rate isn't what it was then. I have the "Bionic 80" shown on this page... http://www.transmiss...r.net/4l80e.htm 5 years on and it's never missed a shift or stuck in gear. Quote Link to comment Share on other sites More sharing options...
Dave W Posted September 25, 2012 Share Posted September 25, 2012 Oh, it's also worth having an interlock/warning on the diff lock switch if you have an LT230. Running the box without diff lock engaged off road WILL kill the centre diff, usually in around 10 minutes. I've done it twice so far Quote Link to comment Share on other sites More sharing options...
zim Posted September 26, 2012 Author Share Posted September 26, 2012 I wouldn't even run that kind of power through a jank box, because it wont last. How many yank boxes has bathtub cooked so far? not many miles done I reckon. How many horses have you got now and is it giving problems? Given how easy it was to break a CV (I saw a you tube clip of you doing a special stage with a cv), I would ask myself if more power is the priority. Hate to be the miserable old boy... Daan Point taken, at the moment i'm running about 200 ish i think. It's a tinkered with 4.2. No problems at all touch wood. On my next one i won't be running landrover axles. Dave - thanks for the reply. Have you got an lt230 bolted to your 4l80e ? Do you reckon you could bolt a 4.80e to an rv8 ? How good were the torqueflight 727's ? Cheers G Quote Link to comment Share on other sites More sharing options...
Steve Hiatt Posted September 26, 2012 Share Posted September 26, 2012 The 727 was popular with safari racers and a number still run them. The Rover derived boxes are not as strong as the big block versions and you'd need to do a fair bit of research as to whether the numerous available uprated parts would fit. The flexplates are rare now too but they can be made if you were struggling. I've been running a modified TH350 for six years, the only failure was that I snapped the input shaft. It was about £100 for a 300m shaft. problem solved. I've rebuilt it once and the bits were less than £200 delivered, including some hard parts. Quote Link to comment Share on other sites More sharing options...
Dave W Posted September 26, 2012 Share Posted September 26, 2012 Dave - thanks for the reply. Have you got an lt230 bolted to your 4l80e ? Do you reckon you could bolt a 4.80e to an rv8 ? Yes, I'm running an LT230 on the back of the 4L80E although if I were using different axles with a central rear diff I'd be using an Atlas transfer box. As well as being a stronger transfer box it would make for a much shorter transmission length allowing the engine to go further back. The only real danger might come if you get a bit carried away with it in 2WD, be great fun on the road but your rear axle might not thank you for it It should be possible to fit the 4L80E to the RV8, the TransmissionCenter guys that I linked to know their stuff and would probably be able to supply a gearbox with the correct bell housing and cover - I'm sure some of the Yank engines still use the same bolt pattern as the RV8. They shipped my box out via air freight, with them arranging it from the US it was a LOT cheaper than it would have been for me to arrange shipping from this end. Quote Link to comment Share on other sites More sharing options...
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