Hi all,

           Sorry to have been off line for a while, but I'm still waiting for an internet account with the new job (which is manic) so have had little time available for contributing to the forum.   I could do with a little help/advice if anyone knows of any suitable companies that can rebuild and modify automatic gearboxes.   For those that remember from earlier posts, I'm co-driving an offroad racer, based on a spaceframe powered by a 2.5litre BMW turbo diesel (from a 3-series BMW), mid-mounted, running at 1.5bar boost and mated to a standard ZF auto box from a Range Rover.   The latter half of this season has been very successful, culminating in outright wins against opposition with much larger engines (i.e. 5.7 litre Chevy V8 powered stuff).   Piccy of the beastie in action below.

          Now that the season is finished and we are in the winter rebuild time, we are aiming to sort out the gearbox.   It is being used effectively as a manual by shifting 1-2-3-4 rather than using the standard "leave it in drive" position.   This has worked well and we are aiming to get the box re-valved so that the change is quicker and the stall rate on torque converter raised so that we can keep out of low revs turbo lag territory.   The other issue is that only first, second and third are much use as gears, as third is the 1:1 ratio and fourth is an overdrive ratio of 0.72:1, so it is pretty much zero use in accelerating     Not knowing too much about the internal magic of an automatic gearbox, I don't know whether it is feasible, or if parts are available, to change ratios such that fourth becomes the top 1:1 ratio instead of third and then space the other ratios to give us a nice even power band.

       Basic question in all of this really is does anyone know enough to be able to advise and/or know of a good company that not only rebuilds and but also modifies automatic gearboxes?   all the best and ta,

Mark

I know nothing...as ever.

But try a post on the Technical forum at www.honestjohn.co.uk. There's all kinds of levels of skill and contacts there. A bloke called Aprilia might know of someone, I think that's his line.

Based near Huntingdon, but travel within reason isn't a problem.   Thanks for the leads, I've followed up a couple of them and I'll see what I get back from them.   Quaife would be lovely, but they do tend to be massively expensive and manual.   One of the main reasons we are using an automatic is that it helps cushion the drivetrain - over the course of last season, we had no broken drivshafts or diffs, which compared to the competition was unique.   Plus my dirver only has two pedals to worry about.....

Mark

Hi Guys,

            Sorry not to have posted earlier, but work has been pretty manic and a lot of the festive break has been taken up with fettling the spaceframe ready for next season.   Thanks for the advice, which gave us some very useful pointers and contacts (who gave us useful info) and, in the case of one firm in Birmingham, got the job of converting the  torque converter to a higher stall setting, so that drive will come in at the point that the turbo starts kicking in - should help us no end out of slow corners.   Should get the converter back in a week or so, then we can start building back up to try it out.   One little thing that we did find out was that keeping the kickdown cable connected is still v. important.   Ours was disconnected, as we reasoned that because we were using the box as a manual shifter, the kickdown wasn't necessary.   Well, apparently the first inch or so of cable movement before the "click" when it kicks down actually regulates the pressure within the gearbox according to the throttle position - this would explain why the gearbox pressure gauge swings wildy between about 20 and 120 psi.   So for anyone out there with a kit car or the like who thought like us that the kickdown cable wasn't important, think again.....

Oh, and on the basis that the good Mr Brown will probably read this, no, I haven't fitted a V8 to the MGA yet, but I am most of the way through converting it to run with an early MGB gearbox, fitted with a close-ratio gear set and overdrive - should be on the road at the end of next weekend

All the best for now,

Mark

Look! I keep telling you, a V8 won't fit in the engine bay! Even if it did, it'd strip the crownwheel and pinion in a nanosecond. Now, a diesel transit engine is a different matter, though whether or not I'd choose and adjustable backstop diaphragm is a moot point.

Indeed we do have the technology..... and that technology has seen plenty of over the last couple of weeks on the gearbox region of the chassis and on the transmission tunnel, along with the gearbox bell-housing, followed up with MIG and TIG weldeing.   Its the gearbox from an early MGB, so retains the smaller input shaft and the non-synchro first gear like the MGA's original gearbox and, after a small mod to the starter motor mount slots straight onto the MGA engine.

A V8 has been dropped into an MGA, twice to my knowledge.  In the early 60s, one of the club racers transplanted a Daimler 250 V8 engine and gearbox into an MGA and, more recently, Warren Marsh fittefd a Rover SDI V8 plus gearbox into one.   In the latter case, however, this was at considerable expense and some extreme mods to the chassis, suspension, brakes, bodywork etc.    All the best for now,

Mark

Steve - sorry hit post before typing on the last one.   Never heard of an adjustable modulator, and I'm pretty sure that the ZF box we use doesn't have one - what the heck does it fit in line with?

Mark

Now there's an engine  
I remember a few of these hemi engines running on nitromethane at Santa Pod in the 70's and 80's.