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To adjust overboost on an LPT engine is the same as on a full Turbo. You need to adjust the linkage rod between the Turbo wastegate and the actuator. This is done by loosening the locking nut (at Turbo end) and rotating the linkage rod the correct way (not sure which way off hand, but the rod needs to be wound OUT from turbo unit to increase boost).

BUT the actual max over-BOOST limit is preset within the ECU. An LPT with intercooler (i.e. post 1993 9000's) are set at approx 4.5 BAR, and I am informed that the ECU will limit overboost to 5.5Bar to 6Bar.

So the wastegate linkage can only be adjusted to increase Max Boost to approx 5.5Bar before overboost cut off will occur on hard accelleration, and the power will be cut temporarily by the ECU.

Full Turbo ECU's have higher overboost settings of around 1 Bar, but I am not familiar enough to be more specific,.
 

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Roger that Paul D ! On a serious note, the point you are making is that there is little point in screwing any more from the turbo fitted to a typical LPT machine because the ECU is going to limit the boost to approx 0.6 Bar.I pressume this would also be the case if you fitted a bleed valve...from what I understand from other threads on this, a bleed valve may not be compatable with the plumbing on a LPT. It would seem then that the only way forward is to buy in modified software which doesn't start become a spoil sport until say 1.0 Bar of boost. The Hirsch stuff looks nice but is a tad expensive.
I get the feeling that us LPT people probably have the most to gain from turbo tweeking but must put up with spending money on overpriced software. Sounds familiar doesn't it ?
 

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I get the feeling that us LPT people probably have the most to gain from turbo tweeking but must put up with spending money on overpriced software.

Depends on your point of view. Given that an LPT was cheaper in the first place I don't really think it is an issue.

In fact, the Abbott Racing chargecooler upgrade to the classic 900 lpt gave performance just beyond the T16S.

You could go and buy a brand new LPT, have the chargecoller fitted and still have change left over from the cost of a 900T16S.

Of course, if you did not purchase the vehicle new then you have saved even more by not paying for the depreciation on the vehicle.

Sometimes you need to look beyond the "cost price" of an upgrade and see what it delivers in the context of the vehicle you have, and your budget.

/john
 

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Hi john, I think what you are saying is that you pays yer money and takes yer choice. In these days were the free lunch is extinct I have to agree with you.

I think it is obvious though that the 2.0 LPT is essentialy a detuned engine which can produce a 40% power increase with a plug & play upgrade as sanctioned by SAAB.

Unfortunatly this particular lunch comes in at a rather expensive £900. I still say thats a lot of money for a load of re-arranged ones & noughts.

To answer mutungi's original question forget about playing with wastegate thingies either remortgage for an approved ECU upgrade or trade your LPT against a full turbo !

PS Is it true that the Italians got a free half lunch. ?
 

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Paul R, yes I agree with your summary of my comments on the 2nd.

The most cost effective ECU upgrade I have been quoted was by Abbot Racing, at approx £480 (1 year ago!), which gave 200BHP as I recollect.

Yes, the Italian version of the LPT was set at 185BHP, and some 900's have this engine outside of Italy I understand.

I guestimate that a simple tweek of the wastegate linkage to just below ECU max boost cut off (e.g. 0.59ish Bar) plus straight-through pipe (CAT back, preferably stainless) plus K&N (or the new filters advertised by Elkparts) will take the 150BHP up to around 175BHP to 180BHP. This is based upon a variety of feedback specialists have given me. Not alot of extra oommph for the money, but a bonus if the parts need changing and you decide for the very best!

I'll be going for an elkpart filter (JR??)at my next service. £30 odd quid and never needs replacing, (although should be cleaned), and TUV rated as most efficient filter ever.
 

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I've had the 'Hirsch' sales pitch and it's convincing (9-3 LPT). Engines are basically the same whether LPT or HPT - only difference is in management system I understand.
I will upgrade but my choice is to go with one of the Scandanavian companies - probably Nordic.
Their upgrade gives same output as Hirsch's but at half the cost.
In my view it's a bit like getting your food from Waitrose or from Asda.
 

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I'll be going for an elkpart filter (JR??)at my next service. £30 odd quid and never needs replacing, (although should be cleaned), and TUV rated as most efficient filter ever.


I stuck the JR Filter on my 1991 900s lpt at my last service a few weeks ago. Not for the ooomph, because you don't get this just by changing the air filter, but for similar reasons given above. Nice little burble from the exhaust on the overrun, too ;-)

/john
 
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