[microcat36]

just wondering! while having a scout around a saab breakers today noticed a intercooler, now would this make any diff to a 9000i engine,i know it lowers the air temp for the turbo engines, cooler air = denser air= more power but is this the case on a atmo engine as well

 

[billj]

Cooler air is better air for a non-turbo too. However, the air arrives at the air filter at ambient temperature. The best an intercooler could hope to do is cool the air to ambient temperature. Since there is nothing to cause the air temperature to rise, requiring the air to be cooled again, you wouldn't see any difference. It is the compression of the incoming air in the turbo that causes the temperature rise on a turbo engine and makes intercooling advantageous.

However, if you could come across a device that cools the air below ambient, you might see some advantage. Such devices have been tried, but none was ever fitted to a standard Saab.

 

[wrighar]

Correct answer.

Now, how about adding water injection to a 9000i?

Ever notice how a diesel car or turbo petrol car runs much better in the wet?

Andrew

 

[Aero]

I am not right in saying that even normally aspirated engines run better in the wet?

Certainly my 1980 Mini was noticeably more responsive in the wet (with a corresponding drop in fuel economy).

 

[ms08]

My understanding is that all engines benefit from running in the rain (unless you run a Mini when all the rain goes straight into the distributor ) - from what I have been told the air has a greater density - more air/more fuel more power - what about an extra washer nozzle just in front of the air intake?

 

[Border Raider DK]

LocoSaab - must try this out next time the CD's on the dyno

 

[billj]

I remember Car Mechanics magazine testing a water injection device in the 1980s. They tried it on a Vauxhall Astra and the effect was to make the air filter so soggy it was sucked into the engine

. Sounds as if that particular device was badly engineered. I suspect they would have had better results had they managed to find a device intended to inject after the filter.

I'm sure a modern device could do better.

 

[john]

Originally posted by Aero:
[qb]I am not right in saying that even normally aspirated engines run better in the wet?

Certainly my 1980 Mini was noticeably more responsive in the wet [/qb][/b]

My experience of driving a Mini through fog was that it cut out at every junction due to the moisture getting into the distributor which was located immediately behind the grille

 

[MartinR]

I am not right in saying that even normally aspirated engines run better in the wet[/b]

Surely the engine is experiencing a minor amount of water injection due to the vapour in the air?

 

[Border Raider DK]

Seriously Chaps, there are some freebies here, in the form of increased efficiency.

BillJ - before I go into the Heath Robinson overdrive mode

, don't you think the injector should be downstream of the air mass metering? Any ideas if Aquamist have tried this kind of thing on a n/a engine?

David (Warming up the dyno)

 

[Border Raider DK]

Hmmmmm

Aquamist FAQ 16. "I have a normally aspirated car, would water injection help me to obtain more power?
No, in general. Unless you decided to increase the compression ratio, more advance ignition or run lower fuel grade than recommended by the manufacturer."

And: FAQ 22. Is water injection really necessary or it is just a new gimmick?
Well, yes and no. For the old fashioned traditional engine tuners with fixed ideas and blinkered outlook, water injection is regarded as an utter nonsense and a complete waste of time. Engines are designed to consume FUEL and not WATER.

On the other side of the coin, engineers such as Sir Harry Ricardo (1930s) and bunch of aeronautic engineers (German, English and American) during the WWII (1940s) has found the positive side of injecting water into their supercharged fighter-plane engines. So the traditional has begun, Formula 1 engines (1980s) used it. SAAB 9-5 supplied as an OE part and now World Rally cars use it (1995 onwards). We leave you to decide ...

Looks fun though:- Aquamist mappable system

David

 

[Aero]

Originally posted by /john:
[qb]My experience of driving a Mini through fog was that it cut out at every junction due to the moisture getting into the distributor which was located immediately behind the grille  

 [/qb][/b]

I got one of those plastic covers too keep most of the water off the distributor. I only ever had a problem with this when there was persistent, excessive spray off the road.

When the air was moist (ahem) my mini seemed more lively and responsive.

 

[rob.storer]

I also fitted a cover to my mini, it was yellow and made by marigold

 

[ms08]

 I got one of those plastic covers too keep most of the water off the distributor  [/b]

Yes - I think BMC finally caught on and my 1969 Cooper had a plastic plate screwed to the crossmember in front of the distributor to stop this. I also have a feeling that I have heard or read somewhere that water injection is used to cool things down a bit in high hp engines to prevent detonation which might cause failure.

 

[billj]

Originally posted by Border Raider DK:
[qb]don't you think the injector should be downstream of the air mass metering?[/qb][/b]

Absolutely, but the Astra they fitted it to was carburetted, so had no AMM.

 

[Aero]

Originally posted by RobS:
[qb]I also fitted a cover to my mini, it was yellow and made by marigold    [/qb][/b]

To your mini what?

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