Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: Lum on April 06, 2007, 07:35:17 PM

Title: 2 blow off or not?
Post by: Lum on April 06, 2007, 07:35:17 PM
Not sure whether i should run a BOV or not an my new single turbo set up?
It is a garrett GT35R turbo! Seems to be various opinions on this subject so was wondering what other people are doing?
Will my turbo be able to handle running with no BOV?
Title: 2 blow off or not?
Post by: Fish on April 06, 2007, 07:59:12 PM
Yes you should run one, otherwise you will damage the turbo. Running without one will cause an excess buildup in pressure which will stall the turbo, which isnt good.

Fish
Title: 2 blow off or not?
Post by: Papercup on April 12, 2007, 05:25:56 PM
My engine was built by WGT and converted to single turbo at the same time and they didn\'t fit one.
 
I took it to Re:Worx last month and they said it was fine not to run one on it.
 
My friend works for a firm that prepare 600hp rallycross cars and they don\'t run them on anything, including their own cars.
 
Modern turbos can live without them just fine, especially ball-bearing ones. So i am told.
 
Ask the experts, i guess....
 
Personally i think BOVs sound chavvy in the extreme (loud hissy ones, at least) and i love the noise of not having one, the chirping noise. That\'s just me though.
Title: 2 blow off or not?
Post by: strange_days_uk on April 12, 2007, 05:31:35 PM
do you want the risk of compressor surge ??

fit one, they are cheap and fun and safety devices.

I don\'t see how you could get away with not running one...  :xconfused

p.s - time to change your sig..
Title: 2 blow off or not?
Post by: memski on April 12, 2007, 08:14:40 PM
No problem on big turbos, I\'m keeping one off mine for as long as it\'s running under a bar of boost. Let ye olde bov debate commence...
Title: 2 blow off or not?
Post by: n4bes on April 12, 2007, 08:19:00 PM
I have a t304s single and no bov, I have a greddy type R waiting in the wings tho..............don\'t really want to fit it as the chirp is cool off the external wastegate.

I await the outcome of this debate............................
Title: 2 blow off or not?
Post by: strange_days_uk on April 12, 2007, 08:45:02 PM
get a mod to add a poll option !!
Title: 2 blow off or not?
Post by: nikp on April 13, 2007, 08:10:55 AM
Quote from: n4besI have a t304s single and no bov, I have a greddy type R waiting in the wings tho..............don\'t really want to fit it as the chirp is cool off the external wastegate.

Just to clarify that the chirp does not come off the wastegate, but is the turbo stalling and running backwards.
Title: 2 blow off or not?
Post by: Papercup on April 13, 2007, 08:21:19 AM
Quote from: nikpJust to clarify that the chirp does not come off the wastegate, but is the turbo stalling and running backwards.

The sound is pressurised charge being forced back into the vanes of the turbo and them \'cutting\' it. Not sure it stops, and i doubt it runs backwards? Its running at 200,000 rpm or something daft. Mine changes gear with no lag whatsoever but still makes the noise; if it had to stop, go backwards and start again it\'d be laggy? This is a guess though; i don\'t know for sure.
 
Its the advances in turbo manufacture and materials that make it possible to run without a BOV. Yes, years ago it was a bad thing but the world has moved on.