I made a couple flanges to block off one half of my 1.0 A/R split turbine housing on my twin turbo setup. Worked great - much faster spool-up and made more boost. Worth a try if your turbine housing is too big.

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Wow, what kind of turbos are you using?

 

Twin T04B

Here is a plot of 3rd gear WOT acceleration boost v's psi. The boost comes in soooo much faster with the 0.5 A/R. And the waste gate actualy has to do some work now.

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What's with the drop?

 

The pressure in the intake drops when you close the throttle. Too much traffic on the test track to keep it wide open in 3rd for long.

 

Ah, I see

 

What kind of computer do you have? Never seen a graph like that. Thats cool that it works but it must have some serious Back pressure.


Jeremy

 

Zeitronix into Excel. And yes the back pressure must be up, but its faster so I am happy with this $0.00 mod. Also it sounds different, exhaust noise is much quieter but when you get into boost is howls when the turbo spools up. I like it.
Another plot, same data but boost v's rpm for a 3rd gear WOT. SOTP difference is impressive.

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damn, I wouldn't have guessed that'd work so well - thanks for sharing

 

Holy Crap!.. Believe it or not, this, IMO, is a major development.
There was some talk of this earlier, and I was on the side it would never, ever work. I can not believe it worked so well
Now many of the very large diesel turbines may be useful to us, making it cheaper to use these very large turbine housings..

 

http://www.speedshopthagard.com/projects/280Z_Turbo/index.html

this guy put a valve on his. Same idea though. i wonder what that does to the boost map.

 

thats intresting... you could slowly open the valve with RPM. but i would use something a little beefier

 

I'd use something beefier as well. It'd probably be rather tricky to get the clearances right, that shaft will go through a bunch of expansion from ambient temps to 1400*F. I'd imagine you'd have a bit of exhaust leak tick as it warms up. Perhaps a 50mm wastegate set to .5psi below your max boost would do the trick.

 

Variable vane technology, I love it. You could activate the the solenoid with WOT and then release it with something like a shift light output when you know you'd be spooled. Excellent. It'd be just like an electric cutout.
issuez

 

Glad you tried that. I too thought it would not help much, but WOW. Big singles may work better with this mod. Are you blocking off the one next to turbo or next to downpipe? Does it make a difference on which side?

Wonder how we could make a smilar design for an open tang housing? Any ideas?

 

I'm blocking side the closest to the down pipe - thats all I have tried but I think they are reasonably symetrical (both 0.5 A/R). You could not do this for an open tang housing - sorry.

I like your ideas duplox and traction for a valve rather than just a blanked off flange. Either a solenoid opening a butterfly valve or a big wastegate should work well. I would use a pressure switch to actuate the solenoid, say close at 0 psi then open at 11psi, for a WG set to 12 psi. This mod would help big singles spool up aswell (if they have split housings).

 

Even better. While it's probably been done before in some way or another, great job introducing it to the rest of us.
issuez

 

very similar idea to the variable vane turbo by Aerodyne. Is the housing split all the way through or just at the opening?

I would have never thought it would help either. I just realized, you have twin turbos each with 1.00 exhaust housing A/R's?? damn, i'll bet it spools up fast now with twin .50 A/R's.

 

What's funny is that a $200 solenoid and pressure switch could (within reason) eliminate the need for a transbrake because of the boost response. This changes the game entirely. Now a 302 reasonably can spool a 88-90mm turbo on the street and still be completely driveable.
issuez

 

Does anyone here not think this is HUGE news?
I mean, think about it. How many new, exciting ideas come out on turbos nowadays? Not very many, and if it is new, it's proably just some tweaks and small changes. This could really impact the use of so many turbos that we currently couldn't use, or now we can make more user friendly. I find this just amazing.