Quickspool Valve.

[Rolls]

I explained it. I'll try and do it slower/clearer - even though you almost answered your own question.

When anyone who has half a clue upgrades their turbo, they retune their car to suit - right? So if you are going to have a setup which alternates between a bigger or smaller turbo and there is no way the ECU knows exactly which point in the transation the flapper is at, what tune should it use?

How do all the sequential factory turbo setups know which turbo is on and when? You can do it.

The people who binned their turbos on mazda were series 6 onwards people cause the twin turbos had lots of issues, the older S4/S5 units are still used by a lot of people.

[Rolls]

http://forums.hybrid..._1

interesting results from someone who made his own

http://www.supraforu...265#post7419265

some more here, with valve open, valve closed and valve moving

looks like it kills top end quite a bit, probably better off just getting a smaller turbo

Edited February 17, 2011 by Rolls

[Lithium]

My opinion too, definitely the safest bet.

[rockabilly]

hi guys, thanks for the interest in this thread, good reading. i have sent my .96 t4 twin scroll rear housing to the states now for this mod to be done, mine wont be on the road till mid april for testing as i have a couple of jobs i am doing right now on the car. another reason i chose this one over the sp one is there is no spindle in the exhaust flow path, when the gate is in the centre postion the turbo will be as before, its only when the gate is swung over the flow is forced onto one scroll, the guy modding the housings has done back pressure testing with good results, you can decide at what boost pressure you want the gate to swing too.also if it does not work i only have to buy a rear housing, save me cutting a 6boost manifold to bits which i would need to do with the sp one..bernie uk

price wise. it cost about 630 us dollars plus postage. iknow its not cheap but may save me time in going twins..lol imagine having 800bhp and boost from 3000,full boost buy 4000rpm.lol

if he can get a gt4202 to spool to 1.6 bat by 4700 on a mitsi 3000gto then i am impressed.

[rockabilly]

update guys, housing been sorted, just waiting for it coming home..

[Lithium]

I hope its really stout, I'd hate for something to go through the turbine - but that has potential to work really really well. Nice, look forward to results!

[discopotato03]

I see this as a bit of a curiosity and it is mildly interesting but it raises a few points .

1) If you want a turbo engine to start boosting earlier why use a GT42 based turbocharger .

2) RWD platform so traction limited , why chase power beyond traction ?

3) We all know biggest is often far from bestest so why encourage people to supersize turbos in the first place ?

I think a properly proportioned TS twin gate system would work better overall because its not part time limiting the exhaust throughput so the engines tune could be better in the mid range .

I get the feeling that that car would be a handfull to drive and difficult to modulate power in the real world .

I also think turbos of that size on a 3L based engine are getting a bit wild and really dyno comp/dyno queen material .

Ultimately a properly designed twin integral gate twin scroll turbocharger with light weight internals is a better bet and EFR appear to have gone that way .

Just need "TS T3" flanged versions to keep the bolt up brigade happy .

A .

[Lithium]

1) If you want a turbo engine to start boosting earlier why use a GT42 based turbocharger .

Because they might not make GT42 based power, I'm guessing. The rest of the questions are irrelevant imho as he clearly already has that sized turbo, and must be happy with everything about it but the spool.

Rockabilly has a GTR, so your point doesn't relate to him

[rockabilly]

so fair points.

i had a etm manifold and a gt35r fitted before with a 1.06 rear. but the motor was just to much for it,. we ran it at 2.2 bar but it could not produce enough air. the engine is designed to be as responsive as possible but have 800bhp @ the fly.. the car is awesome to drive and the turbo sounds superb. it just needed about 500-800rpm quicker spool. if you use the gt35r at 2.2 bar then when you get to 7300rpm its out of puff and dies. the dyno showed this. yes its an awesome turbo but imho too small for me.we do quite often get the chance to stretch the cars motor upto 8000rpm in 5th..lol

p.s some say why rev to 7300 when the power will be there in the next gear. until you have driven a responsive 30 with a gt40 (gt4088r,gt4094r,gt4202r)based roller bearing turbo at 1.8 bar boost and 8000rpm, you have never lived...lol

[Lithium]

How is this coming along? Any ETA on test drives/tuning results?

[rockabilly]

update guys, got the housing back, wont be until may when i get it up and running, will update when i get it done....

[Lithium]

Awesome, looking forward to hearing how it goes

[rockabilly]

update cars still in bits, just doing some subframe bushes and undersealing at the rear, will update guys dont worry.lol

[rockabilly]

update guys..

hi guys, been a while sorry, funds have been very tight so no dyno..

anyway as jon says above. this is a superb bit of kit.

below are the graphs. the boost graph on its own is the motor before the gate.and the dastek one is yesterday.

now because the valve should only work to around 4k we only mapped upto that intially. we found that alot more air volume was entering the engine and it was very lean. so we added fuel. you can see the difference. the issue was the gate would not open. i am in touch with the guy in america who designed this.we manually fed the actuator and as jon says it took 2.5 bar to switch it over then the motor suddenly would not pull so we aborted to investigate further.

on the dastek graph bottom right. the red line is the pressure the turbo is making in psi,the small yellow line on the same graph bottom left corner is when i manaully added pressure to the gate as the motor increased in rpm. as we got to 2000rpm in added pressure to the gate and by 3000 rpm the gate opened and the motor did not like it at all so we shut down hence the sudden drop.

with this set up your twin scroll manifold is not touched from std.

if we can find a way of switching the gate open then i suspect what you will end up with is the responce of a very small turbo and the power of a very large turbo.

will keep you guys updated when i know more.

here are the graphs.

also if you look at the dastek graph bottom left. this is boost. the red line was leaving the valve shut. you can see the power drops at 5000 rpm. this is because the rear is in effect a .48 and too small at that rpm. also you can see it makes 1.2 bar from 3100 rpm. this is insane for a gt4094r . the blue line underneath is when we t,ed into the actuator line to measure the pressure .

[rockabilly]

p.s jon was my mapper, sorry pasted from mlr forum thread and wont let me alter the post

[hypergear]

Interesting bit of gear. I've also made a prototype with the similar sort of swing valve, the problem I've found is the exhaust manifold pressure on the flapper valve was too strong for the actuator to engage, which it never opens. But there are ways around it.

[scotty nm35]

I designed a unit also, using a 7psi turbo actuator to switch over. I havent tried making it yet but I came to a similar conclusion, the gate would need clearance so there was no pressure differential.

Perhaps drilling an 8mm hole through the flapper would help or filing the sides a bit to let some of the flow enter the other port of the rear housing still?

[ARTZ]

my BT50 has this standard...runs 16 psi standard too....probably irrelevant...

[luke gtr]

Very interesting stuff.

I like the idea very much, but think you would need a pretty strong actuator to open the flap with the pressure/flow from the exhaust on it.

Maybe lengthen the actuator rod for better leverage?

Will be paying close attention to all the follow ups.

Thanks to those trying for the insight, for future modders...

[rockabilly]

cheers guys, my initial thoughts were a longer arm on the flap, but then we may struggle with travel length of the actuator arm.

a stronger actuator would not work as the turbo is only producing 1.2 bar of pressure , so a 3 bar actuator would never open..

when the guy comes bacvk to me i will post up his thoughts..