Captainbilos Posted August 29, 2002 Share Posted August 29, 2002 Can anyone tell me what is the maximun (safe) bhp you can put through a marina live axle, with and without LSD. Catherham told me that 125bhp was about the most it could handle without the fear of breaking it - is this true? Cheers Paul Link to comment Share on other sites More sharing options...
New Barbie Posted August 29, 2002 Share Posted August 29, 2002 I'm sure I've read of people with nearer 180bhp without too many problems. Given Caterham no longer sell anything but the de dion setup, they are unlikely to be very positive on the subject. Link to comment Share on other sites More sharing options...
Mike Bees Posted August 29, 2002 Share Posted August 29, 2002 It isn't that simple... There were quite a few breakages on the Academy cars with only 100bhp and wooden tyres. Mike Link to comment Share on other sites More sharing options...
Casbar Posted August 29, 2002 Share Posted August 29, 2002 My car's 140 bhp at the wheels and the axle is fine. But there again, I don't do a lot of track work and I'm running Yoko 21s as opposed to something more sticky. Link to comment Share on other sites More sharing options...
TIM 5O Posted August 29, 2002 Share Posted August 29, 2002 Casbar are you running that 140 on a standard marina axle 🤔 Link to comment Share on other sites More sharing options...
groutledge Posted August 29, 2002 Share Posted August 29, 2002 Accepted max is 155Bhp which is what I was running but my halfshaft still broke. I think tyres have a bigger effect on longevity. I had a load of trouble with wheel bearings etc so I had them shimmed in the end which solve the problem The wheel parted company whilst using ACB10s on track. I've gone ford now. Graham Link to comment Share on other sites More sharing options...
cskip Posted August 29, 2002 Share Posted August 29, 2002 Graham, Was the Ford upgrade painless? How much did it cost? Skip. X-flow and proud - Can you fit Sat Nav in a Seven? Link to comment Share on other sites More sharing options...
Captainbilos Posted August 30, 2002 Author Share Posted August 30, 2002 What about the rear break disk conversion used on the Fireblade, has anyone gone down this route? Is it worth doing or would the Ford axle be a better bet. Link to comment Share on other sites More sharing options...
Dave H Posted August 30, 2002 Share Posted August 30, 2002 I think to quote a max power is rather a simplistic approach. As has already been said, cars with 100bhp have had problems, and some with significantly more have been OK. Much depends on how you drive. Are you brutal with the right foot, slamming the power through the drive chain, or are you mechanically sympathetic, because it will make a difference. Crude example - If you snatch a piece of thread, you can break it, apply the tension gradually, and it will take more to break it. Drive smoothly and you can put more through it for longer. Advice I received from James Whiting. Repair it first time you break it, replace it with a Ford. Dave H Link to comment Share on other sites More sharing options...
Martin H Posted August 30, 2002 Share Posted August 30, 2002 Just a note on the Academy/Graduate cars - yes, a number have failed (mainly broken half-shafts), but I think its true to say that fitting uprated half-shafts has significantly reduced the problems, and a large number of people have had no problems at all. My car's in its second year of Grads after a year of Academy with no hint of a rear axle problem. I'm sure that mechanical sympathy is relevant however, as there are some who have had multiple failures. Link to comment Share on other sites More sharing options...
groutledge Posted August 30, 2002 Share Posted August 30, 2002 Cskip the engine upgrade was easy ( RK an Chris at the 7 workshop did it fo me ). It's not cheap though I think realistically including drysump, mapped iginition and the fitting etc you looking between £3.5 and £5k, and it will still need a rebuild every now and again if you do a lot of track work like I do. It's been 100% reliable since the build this time last year. As an asside the main reason for the rebuild ( it was already 155bhp spec ) was that engine was on it's last legs. and I had a Spa track to get to so I needed a quick job hence staying the Xflow. If there had been less of a rush I would have put zetec in and gone for a throw away motor instead of one that needs £1k rebuilds every year or two. Rogers work is beyond reproach though so it's up to you, a Xfow suits the car well as the lower torque compared to a zetec helps on track. Also I was worrried about my Ital axle self destrcuting with the higher torque or Zetec ( which it did anyway). As for axles the disc brake kit only supports the bearing which can also be achieved by shimming. The main problem seems to be that there is a weakspot where the shaft tapers into the hub, that combined with having to put big torque setting on the hub nut seems to be asking for it. My shafts where the uprated ones, lessthan a year old and where not tack weld which I belive casued a lot of the failures in the Academy even using happy shopper tyres. Go for the ford the shaft and hub are much tougher and a one piece affair. I have one now and SPC modified it to Ital spacing but I have ford studs which are much heftier than the Ital studs. The wheels ( wellers ) still fit fine. I would personally never trust an Ital axle they are ****e there I've said now Graham Link to comment Share on other sites More sharing options...
Casbar Posted August 31, 2002 Share Posted August 31, 2002 Tim 50, yes mine is a standard Ital axle. There has been various threads on how to make the half shafts stronger, but the two methods seem to be, spot weld the bearings for go for the shimming option. Each has its followers. SPC use the spot weld method and supply all the half shafts and axles for Caterham and the Fireblade kits. Apparently, when Caterham had the uprated half shafts made, they used exactly the same pattern as the original ones, so in theory there is no difference, except they are new. As stated before, its more to do with how the cars are driven and how sticky the tyres are. Although if you are looking for big power, over 180 bhp, then the answer is either a De-dion or Ford axle. Although I believe the Ford axle is heavier than the Ital one. Link to comment Share on other sites More sharing options...
Captainbilos Posted September 4, 2002 Author Share Posted September 4, 2002 Thanks for your replies, it seems that the ford axle might be the way forward. Graham, can you give me an idea of how much the Ford axle conversion cost and let me have SPC's contact details. Cheers Paul Link to comment Share on other sites More sharing options...
Tonycaterham Posted September 4, 2002 Share Posted September 4, 2002 Paul, There are several threads on converting to a Ford axle, a route I went down earlier this year. You can save a lot of money if you do it yourself and can devote time to sourcing parts. My conversion cost about £800 including a new LSD (£560) after selling off old parts/axle. Remember to allow for converting to Ford PCD from Ital and do not forget the front hubs as well. Should be able to source wheels through blatchat and sell your old ones through same. Tony 😬 Link to comment Share on other sites More sharing options...
cdg Posted September 4, 2002 Share Posted September 4, 2002 Mallock racing do a conversion which allows you to keep the BMC diff. (which is very lightweight) but use Ford planet gears and Ford Quaife halfshafts. Hillclimb Supersports Mallocks use this arrangement to good effect, and they generally run all steel 180+bhp X-Flows. Conversely, they also do High-Spec BMC shafts (Quaife I believe) for about £140 per shaft. Give them a ring on 01604 863504/863569 Chris. Link to comment Share on other sites More sharing options...
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