DHSE Chip vs Gearbox

jamesblake said:

I dunno anything technical, but I plugged in my PSI Box on Saturday and the car is totally different......some good some bad....

Better mpg +9mpg (As per computer, not yet measured)

Feels more spritely, easier to pull off etc

Doesn't hunt around gears all the time

Some gear changes are now hard, as in can feel them through the car

bit of black smoke on hard throttle (expected)

Is it really any better, or just a placebo effect

Anyways, think i'm going unplug it and stick to slow and smooth.....can't afford new gearbox/clutch thing/any sort of breakdown that results in money/pain!!

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TCubed said:

The thing I still don't quite understand is how the increased torque from the engine maps to the various gears. As in, 4th high will have very little torque while 1st low's will be colossal. Is it therefore just the lower gears (and low range) which are at risk, and if so, are they only so if forced to undergo harsh acceleration?
(I'm a chemist, not a physicist!)

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jt_armstrong said:

See what you started..

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wammers said:

How do you get a 9 mpg better consumption and black smoke? Only way to increase power is to increase fuel. You don't get owt for nowt. Not in this world.

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jamesblake said:

It's only an indicated 9mpg and that was on a run. 17mpg up to 26mpg.
A day or so round town it indicating 23's.

Still gonna take it out thou after reading through this post!

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jamesblake said:

It's only an indicated 9mpg and that was on a run. 17mpg up to 26mpg.
A day or so round town it indicating 23's.

Still gonna take it out thou after reading through this post!

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Clarky130 said:

Many people seem to use these for years though... Do they generally report gearbox issues after fitting them?

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Datatek said:

That will to some extent depend on driving style and mileage covered. If you up the power the temptation will always be there to use the extra power without perhaps even realising it. If you use the extra power it will stress the box at every gear shift. In my case I started to get the revs flaring on 1st to second and second to third gear shifts. Removing the power box improved things, adding Lucas Transmission Fix cured it for the moment. It's mostly diesels that have trouble with the box, it's much more reliable on the petrols, but then of course the engine is the problem
Unless I can fit a ZF4HP24 I won't be looking at upping the power again.

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jamesmartin said:

i would imagine yours would have been sticky shuttle valev or free wheel clutch,they do become less effective with deposits building up (extra power would show up earlier and more often )cleaning them can put them back to goog condition, ive done quite a few ,oil conditioner couldnt help a clutch pack or epicyclic unit

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Clarky130 said:

James, that's exactly the symptoms I have - quite bad 'flaring' when changing between 3rd & 4th. Sometimes it'll 'flare' all the way to the redline if I have my foot down far enough. A bottle of Lucas Tranny Fix did nothing for it - what's the solution? Hopefully not a full rebuild....

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Clarky130 said:

Changed oil but not filter - filter had been done not so long ago. Oil is nice and pink, clean with no crap in it, and doesn't smell burnt.

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Clarky130 said:

Occasionally when it has a really bad flare, the box will go into limp mode and I will get 'GEARBOX FAULT' on the dash on shutdown - buy that's only happened 2 or 3 times. Jamesblake kindly read my fault codes last weekend with his nanocom, I'll wait for him to email them to me and post up the gearbox ones.

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jamesblake said:

Paul, might be a day or so on that, walking home tonight as Oil Cooler Pipe situation has turned into Oil Rad Situation! And the Nanocom is is the car! Doh!

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