Turbo internals

[DaveSakky135]

is it possible to upgrade the internals of th stock turbos, and with the right tuning make it work?

[DBFIU]

I am guessing the only way to do that is to actually bore out the compressor inlet and turbine exit housings and use larger impellers and turbines. This would be costly and would require some R&D, which is what is going on right now with a few small companies out there.

just slapping a different compressor in there wont make a huge gain, you need to change the overall dimensions of the impeller to flow more air, hence the machining of the housing. Costly but it can be done.

[Lester]

Ummm....No.

[BrokenVert]

Originally Posted by Lester

Ummm....No.

Agreed. These little things arent like engine blocks. You cant just bore em out.

The tolerances in a turbo are extremely tight, if you mess up in desgin or machining by a fraction of an inch it could theoretically explode once it reaches full boost.

[DaveSakky135]

thanks guys, i was wondering because i bought a used set of N54 turbos on ebay for pretty cheap. they only had like 17k on them.

[jeremyc74]

Anything's possible with enough cash, but the return just isn't going to be worth it. There have been a couple of tuners who've tried modifying the stock housings and adding larger wheels, but it doesn't seem to have worked out very well because we haven't heard a lot from them recently.

I'm not sure if they had issues with them, or just couldn't get enough additional power out of them to make it worthwhile.

[plasar]

If you've got 2 extra turbos from eBay, you should be thinking "quad-turbo" 170i... now that's laggerriffic!

[DaveSakky135]

ahah good shit man.

[DBFIU]

Originally Posted by BrokenVert

Agreed. These little things arent like engine blocks. You cant just bore em out.

The tolerances in a turbo are extremely tight, if you mess up in desgin or machining by a fraction of an inch it could theoretically explode once it reaches full boost.

Well I used the term 'bore them out' to make it simple to understand that you need to change the overall internal dimensions to accomodate new rotating machinery. It is a lot more involved than just boring out, but that is the term I used to help him understand.

To take the stock housing and make it 'flow more' you need to increase the overall internal dimensions to fit bigger rotating components. Volute dimensions, discharge, inlet, bearing speed and load, all have to be considered when using a housing designed for one turbine/compressor combo with another. You cant just slap new guts in there and expect it to work, although people have done such things in the past with other types of housing combinations, it doesnt always work.

Also, the compressor and turbine combination you use will be greatly affected by the volute dimensions. And BMW (mitsubishi actually) did a very good job of matching them perfectly for our combination, sticking bigger components in there without changing the internal dimensions will lower the system efficiency of the turbocharger (heat up the air more) if the dimensions are not optimized for the new combo.

If you want more details I can explain further, but I didnt want to get into it since there are already companies out there experimenting with it.

Sorry if that wasnt clear. But there is no need for the snooty remarks by Lester.