xud v hdi gearbox

[n0v0s]

I'd like to hear the opinions from people who have tried the xuds with a hdi gearbox fitted. Do you recommend it?

Mainly interested in what you think of the longer 2/3 gear lag compared to the xud box. I can't decide as i find the xud box annoyingly long already. But the hdi box with its longer FD would give higher speeds per rpm so would this be worth the extra laggier feel. It would ultimately take longer for a 'bigger' turbo to spool up and so could also be a disadvantage with non oem turbos. But for outright mpg on motorway runs (80% of my driving) - it would appear to drop 500 rpms over the xud box.. mmmh... discuss!

[mark_airey]

its essentially the same box, apart from the FD being 500 rmp lower as you say, fist is never too long, how can you find first too long hock: its the shortest, most pointless gear in the world "oh, the car has started to move, time to change up" 2nd gear launches at 5k FTW, (probably not good for the clutch mind but meh)

then you have the gap between 2nd & 3rd which is interesting on the HDi box at times, up hills when 3rd is high geared and 2nd is revving the bollocks off it, other than that its fine, as you say, much better for the MPG's if you do a lot of motorway and it doesn't run out of puff as quick as with the DT box.

I like the HDi box on the XUD engine but I also know that a lot of people don't, for day to day driving I find it fine, oh and as far as overtaking and lag..........change down, its not hard to fix that.........hehe

[n0v0s]

what you on about mark?

Haha, i should re-read what i type! First is just dumb. But the spacing between 1/2 is shit..as 1st is so shit.

I'm probs gna replace my clutch anyway.. This 2nd gear launch you speak of... :think: heh

[strictly_perv]

If you want a close, hard reving box go for a 205 diesel box. Not good on motorways though!

[THE_Liam]

To0 be honest, most of the tuned diesel boys reckon 2nd gear launches are faster...

I've driven one, and I thought it was great. Far more relaxing on a cruise and it seems to keep you on boost longer, and the extra resistance of the higher gear helps increase exhaust pressure to spool the turbo. I'd do it

[Ruan]

Can't stand HDi boxes.

Way too long, you're always trying to keep the turbo spooled on gear changes, a HDi box every time drops you off boost and you've NEVER got the right gear for the situation...

3rd is ALWAYS too tall, and you know if you go for 2nd you'll end up with your face smeared on the windscreen it's such a sharp downchange, the gap between 2nd and 3rd is so badly accentuated. The change between 3rd and 4th is what the change between 2nd and 3rd should be like - the only way to reduce this is by using a DT box, or as strictly points out, a 205DT box...

I think both me, Darren, Dave, and James are of the same opinion...

[chippyba]

This is a interesting topic as I'm fed up of reving the bollocks out of engine at 70/80 mph will a hdi box drop my revs basically

[Ruan]

Yes, Hdi box drops your revs by around 400-500rpm on the motorway.

Rather than 2750 at 70mph, you're doing more lke 2250-2350...

[Anton]

Dtub 2900rpm at 70
Hdi 2450rpm at 70

[Ruan]

There you go ^^ ;

Though I'll admit I thought a DT box revved lower than that at 70, could have sworn it was more like 2750... There might be slight differences, admittedly mine originally is actually a Xantia DT box... I know the DHX Xantias/406s have a slightly different box.

[Anton]

I've had 2 306's and now a ZX. I do lots of miles, around 30k a year and I prefer the hdi box.

It makes 1st and 2nd more useable but you do struggle to keep on boost in 3rd.
On a T2 at 20psi in a hdi box I've had genuine 120mph+.

however if you are going for a big turbo a hdi box makes it hard work for everyday driving. I have Joes T25'd, 11mm frankenpump with a hdi box and it's not an easy every day drive.

My daily is my ZX and that with 195 50 15's sits at 70 at about 2550 and is literally the best of both worlds.

[CJ_Derv]

Really interesting topic this guys keep the opionions flowing and i can decide what to do lol.

CJ

[Anton]

What size tyres you running Ruan?

[Ruan]

195/50/15 - so slightly smaller than standard, but like feck am I paying for 55s and suffering with sidewall flex.

[Anton]

Lol doing around 66-67 then when speedo reads 70.

Apart from that 55's just look gash

[Ruan]

Well, that's what I dont understand...

My speedo is WORRYINGLY accurate for a 15 year old French shitter! At 70mph indicated my GPS fluctuates between 69 and 70... Which don't get me wrong, is a total fluke...

[Anton]

Haha that's weird! Your xantia box must be different.

I was told the ZX uses the same boxes as 306's, erm no they don't.

My zx was doing 71 whilst reading at 70.

[chippyba]

Is the hdi a straight bolt on box or do u have to modify it

[Ruan]

Just need to swap the clutch fork back to the XUD one and put the clutch cable brackets on - all bolt on though, no modification required.

[psamk1]

And about the GTI-6 gearbox on DT?
I know that is a wrong thing to do but there is some way to change the FD, like swapping differentials or something...?
That would be very interesting

[Ben Jay]

And about the GTI-6 gearbox on DT?
I know that is a wrong thing to do but there is some way to change the FD, like swapping differentials or something...?
That would be very interesting

that would be too much effort for little gain i think. also i think the main gears are too short so swapping the final drives wouldnt work

[Dave]

I think this is personal opinion really... and depends on how your engine is setup... I still prefer the long box with big turbo because of my driving style, and I do alot of miles, plus I doubt it will ever go on a track... with a low down torquey turbo its better, but with massive late spooler a long box isnt the best although I like the wait in contrast for lag... my 2p

[Ruan]

GTi6 box is way too short.

You're talking almost 3250rpm at 60mph...

You can't even hit 100mph with one on, you'll hit the governor. And don't worry, I've taken the effort of taking one apart, you can't put in a bigger final drive without a lot of modification to it...