Switchable Turbo?

[RobM77]

A friend of mine has just bought a Nissan 200SX S13 and asked me an interesting question earlier on today. He asked if it was possible to disable the turbo with a switch. He doesn't always need the boost and the subsequence decrease in fuel economy.

I haven't got a clue, thus this post

Could this be done with some sort of electrically actuated clutch between the impellor and compressor? I don't understand how turbos work very well, so I may need this explaining as well!

thanks.

[RobM77]

Andrew Noakes said:

Fitting some sort of clutch between turbine and compressor would be complicated and expensive, and would probably add to the inertia of the assembly giving you massive turbo lag. The most cost-effective way of keeping the turbo off boost is to keep the revs down and use high gears.

Thanks.

Andrew Noakes said:

Begs the question, why buy a turbocharged sports coupe in the first place?

He loves the power, but just not all the time as it is a little hard on the wallet! Apparently the turbo comes in at 3,000rpm; which makes accelerating without using the turbo an arduous task as the engine's way off it's peak torque and efficiency.

[RobM77]

stevieturbo said:

Some crazy ideas popping up here.. How much money do some people intend to spend to TRY and save a few pennys worth of fuel ?? Turbo cars are generally very efficient, and more so that n/a car for what they give power wise. The most sensible option would be a proper mappable ecu. At least that way you can have more power, and better efficiency. But even that will cost hundreds of pounds, if not over a thousand. Unlesss you do high miles, you will be a while saving that back. If its turbocharged, just enjoy it. Isnt that why you bought it ?

To be honest, that is a fair comment. Doing 10,000 miles a year, even going from 20 to 30mpg only saves £500 a year. I expect that we're talking more about going from 20 to 25mpg to be honest, so £250 a year saving. It was an interesting theoretical question though I think some driver adjustment of the turbo sounds like an interesting idea - worth pursueing bearing the costs and savings in mind.

I've given my friend a link to this thread, and he says "thanks for all the comments"!