Which Twin Scroll Turbo for a 930

[vas930]

Any news on this system, Brian?

[RarlyL8]

The engine is (still) being rebuilt so no data yet.
I am very curious to see how quickly the setup can build boost and maintain it. These same headers on a stock engine with a K27-7200 and my muffler show threshold boost at 1700rpm and full (stock) boost at 2400rpm. This is on a flat road in top gear. If the twin scroll can reduce the distance from threshold to full boost it will be an animal!

[vas930]

Sounds awesome, Brian.
Thanks for the reply.

[Tippy]

In the drag world, Precision is popular.

Regarding T3, I would think that would be too small since normally, you run a larger A/R with a twin vs the single scroll.

I would assume you'd want a T4 to not choke off top end horsepower.

[CaptainCalf]

[AskewRSR]

So. How did these systems turn out?

[CaptainCalf]

I went with the GT3582R turbo with Brian's twin scroll headers but it's not done yet. Maybe in the next few weeks I'll get it fired up:
The Beautiful Puzzle: 1987 3.3L 930 EFI Build

[Rich Buckner]

Brian,

Here is my twin scroll set up. I have a T4 turbine with a .58 Aspect Ration. It pulls like a Mack truck for 2000 rpm all the way up to 6500. I specified what I wanted with Brian at Comp Turbo. It is a T3/T4 hybrid with the ceramic ball bearing cartridge. The headers were also of my design and I had a local fabrication shop (Maxwell Industries) modify my Zuc-Z headers.

The engine actually needs a higher aspect ratio (its EFI), but for a CSI system, it would work exceptionally well. Here are some photos

[img]

http://forums.pelicanparts.com/uploads20/IMG003791329944078.jpg[/img]

[Beetspeed]

Originally Posted by Rich Buckner

It looks like you didn't keep the both individual wastegate pipes separated all the way to the wastegate valve head?
If you didn't, the whole twin scroll system is pretty much wasted (no pun intended) to a single scroll system. I would really advise to weld in a divider wall in the WG 'uppipe'. It should stick out a bit and just not touch the wastegate valve head. The closer the wall is to the WG valvehead the better; even better are just twin wastegates (stating the obvious here) but still

[Rich Buckner]

Well, here are some cold hard facts about this design:

486 Rear Wheel HP
.2 BAR at 2000 RPM
.7 BAR at 2500 RPM
1.0 bar at 3000 RPM

Instants throttle response with no (and I mean NONE) over boost issues.

It drives like a normally aspirated car on steroids.

The best of both worlds and then some.

[Beetspeed]

Originally Posted by Rich Buckner

Well, here are some cold hard facts about this design:

486 Rear Wheel HP
.2 BAR at 2000 RPM
.7 BAR at 2500 RPM
1.0 bar at 3000 RPM

Instants throttle response with no (and I mean NONE) over boost issues.

It drives like a normally aspirated car on steroids.

The best of both worlds and then some.

It drives awesome, no doubt. Exhaust system looks very nice too. Doesn't mean it couldn't be improved upon.
Just trying to help you develop an even better exhaust system, thats all and thats what forums are all about right? If you don't agree with my statement about what a twin-srcoll system is, lets discuss.

Imo, its just the nature of twin-scroll to keep exhaust gasses from both banks seperated. The reduction of reversion is where the extra spool and respons comes from. Your set-up of the single wastegate doesn't completely do that atm for all boost situations, but could be 'easily' adapted if for instance you cut the last piece of wastegate pipe open and weld a wall in there.

Trust me, I do have the best of intentions mate

[CaptainCalf]

Originally Posted by Beetspeed

It drives awesome, no doubt. Exhaust system looks very nice too. Doesn't mean it couldn't be improved upon.
Just trying to help you develop an even better exhaust system, thats all and thats what forums are all about right? If you don't agree with my statement about what a twin-srcoll system is, lets discuss.

Imo, its just the nature of twin-scroll to keep exhaust gasses from both banks seperated. The reduction of reversion is where the extra spool and respons comes from. Your set-up of the single wastegate doesn't completely do that atm for all boost situations, but could be 'easily' adapted if for instance you cut the last piece of wastegate pipe open and weld a wall in there.

Trust me, I do have the best of intentions mate

+1...something like these Rarlyl8 twin wastegate headers might help:

[RarlyL8]

To have a true divided twin scroll system each bank must be completely separated. The significance in affect this has on performance depends on all other parameters of the build such as turbo size and design. The purpose behind the design of my headers was to utilize the affect of tuned primaries to both increase lower RPM torque and to send coordinated pulse signals to each side of the twin scroll turbo which will increase mid range RPM torque and HP. The extent that this tuned flow is disturbed by a common waste gate manifold I do not know as both designs have not been tested back to back with the waste gate manifold design being the only change. I do know that both waste gate manifold designs will completely eliminate boost creep / overboost as the angles are very good and signals are taken from both banks.

[JakobM]

Great to hear... now you are talking real Twin scroll setup RarlyL8. That is how it should be!! Every 19 out of 20 suppliers show their true knowledge when mess up the divied pulsing in one common WG piping... and call it twin scroll. Puls energy is lost, and back pressure won again...they only have the bling bling sales text headings left on the price shield.
Every thing must be 100% divided, and using one WG means a WG collector with a collector wall as far as goes up under the WG-valve. However, when on boost, and WG valve is open you still suffer from some backpressure over cam overlab...the size of backpressure depends on WG-valve diameter, angles etc. Two wastegates has the advantage that it holds the back pressure divided ALSO on boost. It does matters on ignition timing and to some extend minor influence on choosing cam/static CR due to cam limitations on duration and thus higher actual dynamic CR from same static CR. The problem is not having the boost the problem/challenge is to get rid of the boost you dont need. Ideal you divide and split your pipe flow angle 50%/50% to turbo and WG. Or primarely to WG secondly to Turbo.

I can ensure you that MasterPower from Brazil, a ISO9001 company (which I happens to be the main distributor of in my country ... now you know where I stand), has a very advanced available programme for small twin scroll application racing turbos (and of course bigger models). It goes down to application with bullseye effeciency arround 280-300hp for the smalles twin Scroll T3 turbo (this one Turbo 150-(300)-480hk Twin Scroll + Antisurge | POWERPAGE if you see brown lines on turbine that is copper grease). I proberly have between 2-5 different twin scroll housings for each turbo. We only carry Twin scroll housing from 300hp and upwards.

Master Power has just released all new racing programme with billet wheels, new innovated journal bearings (yes, journal...no ball bearing thanks) AND compressor maps. Very few suppliers has compressor maps on their wheels...why ... because it cost an "irak war" to do the wheel product developements and innovations based on actual mapped flow. Garrett and Borg Warner, turbonetics has it...oh and MP now. Many other $$$ ball/grease bearing turbos dont have it.

I have some drift car teams running on 3rd seson with various MP turbo...2 supras, 2 skylines and 1 BMW all 6 cylinders. None of them changed turbo in any sesons. If any turbo can resist multible and multible hours of drifting years out they can resist anything you through at it. I have not had even one warranty issue, not even from tractor pulling. We also have many interesting "non-official" customer 1:1 comparison on $$$ 58mm, 62mm + .... single scroll ball bearing turbos vs. MP TS. *And gues why MP TS turbo setup get 800-1500 rpm earlier spoolup. It is all physics and development.

Anyway here is my link Turboladere | POWERPAGE with the current turbos (the new line not yet visuable) forget the language .. read the wheel size mm A/R and pictures. The new racing/bearing/billet line is in stock within a month, however all the compressor maps, pictures availble if interested. I can make you a suggested setup on the new MP racing line T3 or T4 twin scroll flange platform from 300-650hp, from hereon +650 hp T4 Twin Scroll flange setup. You will be in for a happy surprice on power, backpressure, spoolup and price. I could also give you some suggestion on second runner pipe diameter after each 3 cyl bank collector. Many forget this last diameter importance on the manifold setup. PM me if interested. Otherwise this is just my 10 cent TS input to consider when doing puls energy and back pressure manifold engineering....and chosing turbo

Anyway, great with finally a true TS manifold with single WG. Looking much forward to see it ... show the WG collector :-)

Thanks
Jakob

[JakobM]

Originally Posted by CaptainCalf

+1...something like these Rarlyl8 twin wastegate headers might help:

Awsome TS setup!! If space would alowe it, the WG's would in an ideal world be heading in same direction as second runner after 3 cyl merge bank. However space dont allow it. Garage TS porn..!

[CaptainCalf]

Originally Posted by JakobM

Awsome TS setup!! If space would alowe it, the WG's would in an ideal world be heading in same direction as second runner after 3 cyl merge bank. However space dont allow it. Garage TS porn..!

Thanks! The Garrett GT3582R twin scroll ran outta blow at around 400 whp with my setup, so we are going with a bigger Bullseye 66mm turbo. Our plan is to make more torque then horsepower with a torque goal of 500 ft-lbs at the wheels and this new turbo with triple compression technology should help

[xbmwguy]

hey calf the bullseye is great dmatera is using one i think but my garret gt40 was putting down torque #s in the 5s at 12 lbs of boost. and that was twin scroll holcombe headers

[CaptainCalf]

Originally Posted by xbmwguy

hey calf the bullseye is great dmatera is using one i think but my garret gt40 was putting down torque #s in the 5s at 12 lbs of boost. and that was twin scroll holcombe headers

Very nice! If I didn't already have all the hard piping done for the smaller turbo the GT40 would surely be on deck. The footprint of the Bullseye is close to the smaller GT35, so we're gonna test it first in an effort to just bolt it on and go...

[TurboKraft]

Originally Posted by CaptainCalf

Thanks! The Garrett GT3582R twin scroll ran outta blow at around 400 whp with my setup...

At what boost pressure? We rarely see lower than 475whp from a GT35R, and usually more like 520whp from a 3.3L.

[CaptainCalf]

Originally Posted by TurboKraft

At what boost pressure? We rarely see lower than 475whp from a GT35R, and usually more like 520whp from a 3.3L.

Hello Chris

Yes, I agree the GT3582R twin scroll turbo could make that kinda whp and would be all Brian would need for his CIS application. We ran it up to around 1.2bar on the dyno when we realized that boost leaks in some of our silicone joints and restricted flow from the GSF IC prolly limited the turbo from reaching it's max whp numbers. At that point we decided to replace both the IC with a larger unit and the silicone joints with hard pipe then try it again, but while were had the GT35R off we decided to go bigger...it's a slippery slope my friend