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Date: Tue, 02 Nov 2004 16:34:01 GMT
From: Retro Bob <nothingherenospamcom>
Subject: Re: Manual Boost Control Valve Kick --why?

On Sun, 31 Oct 2004 16:55:34 GMT, Paul Halliday <> wrote: >As a general matter, increasing the power of a car beyond the specification >of the manufacturer is at the owner's risk. The main points of failure due >to increasing power on turbo cars in general are cracked pistons; and on >SAABs, the gearbox. I agree. However, I think the Saab motor ha shown it's ability to take a couple more pounds of boost than the ECU provides. The stock 185hp NG900 was 11lbs, I think a properly tuned MBC pushes it to 14 and then you hit fuel cut off. Certainly if you push it to 22lbs you are in the danger zone but Saab themselves now push the motors at least a bit with their own upgrades and just general HP increases. It's also worth noting that a *properly tuned* MBC tends to give you boost faster (particularly in 1st & 2nd gear) and _holds_ that boost at higher levels longer - but does not typically _increase_ the boost level itself very much. However, your point about the gearbox is well taken. The 230HP Viggen has gearbox issues. Lastly, the same gearbox & other wear/abuse issues are present with an ECU upgrade too... and the ECU's often boost even higher. >Certainly the NG900 and the 9000 tuners seem to champion MBCs for power >increases - perhaps the DI setup was not that advanced, but I think T5 and >above SAABs should go the ECU route, rather than MBC - the ECUs are doing >too much to negate their functionality with an MBC. It's like taking a >microwave oven and lighting a fire underneath it :) The ECU is always preferred, but at least 15x the cost too. >The Abbott tuning equipment is of a very high standard (and so it should be >for the price!!!) and I know that the stage upgrades are sold as kits - you >get an ECU chip, but ECU setups of a certain power upwards are sold with >exhaust upgrades and air intake upgrades. Likewise, the Speedparts kits. If >the car in question has an Abbott upgrade in place, ditch the MBC!!! Simple. >NG900s and early 9-3s do benefit from an improved intercooler and that in >itself will give a good power boost. The kit is a good idea... but at least Abbott will sell you just an ECU. That's not really a good thing. >Oh, as for hitting the fuel cut off switch ... >Well, erm ... (Looks both ways) ... that's the first thing classic 900 >tuners bypass :P Yeah, I've heard :-) I think it's actually a nice feature in an NG900 in that even if you mess up the MBC setup, the ECU stops you from doing something _really_ stupid. Of course, it's worth noting that some ECU tuners not only reprogram the boost curve but also raise the cut off to allow higher boost... again the ECU upgrade can actually cause more significant wear issues. With the MBC at least you know you are not exceeding the stock limit Saab engineers dialed in for max boost. Bob

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