Turbo Replacement

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mrbump
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Turbo Replacement

Post by mrbump »

Is there an easily swappable turbo that is slightly larger than the kkk or garret that is fitted to the td zx engine? EG something that has the same manifold/exhaust mountings but that is larger or employs a larger compressor wheel?
I was wondering if the hdi turbos were any larger or designed to supply more pressure? Like the VW (cough) 1.9 engines that have different turbos for the 130 and 150bhp variants. Usually specific turbos come from a 'family' of turbos that utilise the same exhaust housing (with varied internals) and have different compressor wheels/housings to suit the application, so, I thought there might be one for my zx to get it to supply cold air at >18psi. ([}:)]eg loads of boost!![}:)])
Anyone know if this is possible?
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AndersDK
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Post by AndersDK »

I suggest you fit a bullet-proof safeguard between engine and firewall - to protect you from your poor ZX engine shooting you down with flying bits [}:)]
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Post by ddahaa »

I had read somewhere on the internet that the BX TD turbo gives an upgrade on the ZX, but this is only what I read so I would check first!!!
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mrbump
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Post by mrbump »

i see further investigation is called for.
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Post by Guru Meditation »

I was under the impression that the turbo attached to a stock td zx either the garett or the kkk unit could both be tweaked (adjust waste gate) to provide more boost than the engine can handle anyway ie the engine can be tuned to it's maximum mechanical limit without changing the turbo.
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Post by AndersDK »

" .... to provide more boost than the engine can handle anyway ie the engine can be tuned to it's maximum mechanical limit without changing the turbo. "
- exactly.
Of course if the engine is never driven to extremes with this extra boost - it won't just blast up your face.
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Post by neilsxm »

hi mrbump
i don't know of any off the shelf turbo's that fit straight on
but you can have your own turbo made into a hybrid at a cost
and out of experience the standard turbo will go up to around 25psi before going into surge(which destroys it) but the problem is that it becomes inefficent after about 18psi so you need a really big intercooler
the problem with a really big intercooler is
price
space to fit it
a big intercooler increases lag
another way to decrease inlet charge temp which is the real gain in perfomance on a diesel
is water injection
also a massive increase in horsepower is nitrous injection
also you can inject propane with the diesel aswell as an increase in power you also get a good increase in fuel economy
--hth--
--neil--
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mrbump
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Post by mrbump »

Neilsxm - thanks for the reply, I realised that the standard units are only good for around 18psi, at which point the efficiency drop off and heat build up are larger than the benefit of any extra air. The golf race car tdi and the seat tdi racers (which might be in btcc next year) use very high amounts of boost (2.53 bar) to get more power. It is becoming more and more common to see deisel cars that run high levels of boost straight from the factory to acheive these figures. How else does the gtipd150 make its power? Small increase in power from PD system, Lots of extra fuel, and higher boost from a larger turbo running 1.95 BAR!!
I am rebuilding a 1.9td engine at the moment, and I am getting the block o-ringed to help the HG survive and then I hope to run a bit more boost on the ZX. I am just mounting the normal intercooler at the front of the car, no water spray and I will see on a rolling road how far it can go safely (with temps, lambda etc).
Cheers!
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Post by sooty »

Most likely they are 16v or 20v and use injectors with a multi-spray nozzle.
Which by using 4 or 5 valves per cylinder gets more air in and then by using multi-spray nozzles you get more fuel and finer mist to burn quicker which then equals more power, without greatly increasing the boost much more the our 1.9td citroens at 18.5lbs/sqin.
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Post by mrbump »

18.5psi = 1.2BAR
1.95 BAR = 28.665psi
Not much of an increase then..... only 62%!!
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Post by mrbump »

sorry, forgot to mention that the 150bhp model of the VW tdi is also only 2 valves per cylinder. Only main difference is the PD system (high pressure direct injection) That is mainly focused on cleaning up emmisions rather than power increase.
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Post by Gavin1 »

There was guy on the old bx forum who changed his KKK on a Bx for Volvo 2.5 td turbo with a little modifcation! He also lowered the compression ratio and fitted a bomb proof head gasket.
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Post by sooty »

Why not shoe horn the VV engine into your car then, it will probably be cheaper and easier, rather spend money on cosworth style modifications 'O-ringed block', if you want 150bhp.
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Post by mrbump »

Sooty-
I dont want a VW engine in my nice citroen thats why!
Fitting a turbo that is more efficient at producing slightly higher levels of sustained pressure (at a lower temperature) is not a crazy idea! I have changed turbos on different cars before (or rather just the compressor wheels) to get the effect I want. You get slightly more lag, but cooler and more stable boost, plus the potential to run more. I only really want to try and get something like 130bhp from the engine without spending a fortune.
The o-ring block is not anywhere near a 'racing' modification, the cost of getting the block machined to accept the rings (which are made form normal copper wire) was £45 last time. They just sit in little grooves around each cylinder and get squashed when you torque the head down. This gives you a much nicer bite around the cylinder edge, and can help contain high cylinder pressures better.
There must be a similar turbo out there that uses the mountings (and maybe exhaust housing) of the garret/kkk units on the td engines, but a larger compressor???????
What about the 2.1 xantia?
Gavin1 - do you know if the same guy is on this board? Is the Volvo turbo also a kkk or garrett unit?
Cheers
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IanD
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Post by IanD »

Mr Bump,
I've owned Cossies in various stages of tune over the past 4 years & it's very true what you say about using bigger turbo's at a lower boost being better than cranking up the boost on the standard turbo [:D]
I am getting out of the cossie game this year & going for cheap & reliable motoring (due to it being impossible to save for a house whilst owning a cossie!! [:(]) in the form of a ZX or 306 TD & will be tweaking it slightly [;)]
I "believe" that the cossie Garrett T3 turbo fits the ZX/306 TD engine with little modification.
Best person to speak to about tuning though is either Stu or Kenny at Motorsport Development's in Blackpool (01253 508400)........they know LOADS about tuning diesels (& Cossies [;)] )
HTH
Cheers,
Ian
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