Not necessarily..depends on the collector size and length.If you don´t use a common collector,then the 2-1 collectors should be the appropriate size,to minimize pulses and backpressure.I´m not saying that is the case with your system,just speaking out generally.I´can´t remember where,but I saw a collector that someone made from a Burns collector,it was a 4-1 system with a 4-1 collector that then divided into 2 rectangular pipes to the twin scroll flange.As far as heat retention and minimizing back pressure,I think that would be pretty effective.

Ah, yes, that would work too, but it does mean you are keeping all 4 primaries seperate untill at the divided turbine flange and only then merge 2 into 1, twice. Its still a twin scroll header then, only you keep 4 primaries all the way untill the turbine, resulting in much longer primary lengths, thus reducing spool time imo.
My turbo location is already rather far away, so I will do anything fysically possible to keep pipe lengths to a minimum, hence this construction/lay-out ;)

Yeah,I hear ya Wally - space is a big problem.I´m hoping my GT3071R will fit in your old location.I won´t find out until I have the engine in the car.Hopefully my case will finally be back on friday so I can put it together.I will be putting the car together this winter -finally.

Winter time is the best for car projects!

Yeah,finding time and motivation can be tough.Thanks to threads like this it keeps the fire going.So if my car never gets finished it´s Wally´s fault for not posting enough videos and pics :lmao:

Wally we need more videos, pictures, everything you have to keep us going!!!!!!!!!!!

Haha! well, not spectaculair news, but some small steps are sometimes needed as well to complete a job.
So, I now finally have the oil feed for the Borg turbo complete :)
This was quite a hassle. Why? see for yourself:

http://i174.photobucket.com/albums/w...1.jpg~original

http://i174.photobucket.com/albums/w...2.jpg~original

Left to right: 1/4" NPT is the thread size into the turbo, so I needed a 1/4" NPT to 1/8"NPT adapter, 1/8"NPT male to 1/8"NPT with 0.165" restrictor (1.5mm), 1/8"NPT to inverted flare female connection and M10x1.0 inner thread, M10x1.0 male and inverted flare 'copper' 5mm (~3/16") brake line.
This connects then to a goodyear braided oil line (with M10x1.0 ends) that feeds of the oil pressure connection on the engine case (with a 'T' for a oil pressure sensor)

Next job will be the oil drainage adapter, which will have to be made from scratch (from hi-grade alu) for my -12 line... (all adapters for sale are -10...)

Why the 1.5mm restrictor?

Folder! This is almost like a masters class.

1.5mm or AN3 line feed.
Its prescription from Airwerks Borg-Warner. Same as large frame Garrett non-ball bearing turbo's ;)

Learn something new everyday! So this one isn´t ball bearing either?

Nope, no ball-bearing. Would have loved to have that in there as well though, but these models just don't come with them.
The twin-scroll should provide the quicker spooling. When tuned right (header sizes), these spool as 'fast' as a Garrett 35R does with a little more hp under the curve, but for less then 2/3 the Garrett BB price tag ;)

If you have the same spooling time as with the old turbo but more power and ability to keep the boost level in the high rpm aswell, then it was worth it imo.The BB turbos are nice,but like you said so much more expensive.You would have to ask yourself if the advantages of the BB outweigh the price tag.

This turbo is NOT a logical 'upgrade' for this engine!
I am sure spool is much later now, as this is a TOO large of a turbo for this engine/application. A comparable BB turbo of this size would also have later spool, but like I said before: this turbo was NOT ment for this engine, but a much larger one ;)
Still I am very curieus what this will do on this 2.2 engine as I have so much data on this engine already.

Only if you look at a drag racing application, this turbo could do well if the cam could support the flow/rpm. For pure drag racing, the cam is not optimal either though..

As always, its a big compromise as it is.
It is tempting to completely disassemble the engine and do a cam swap, just to give it drag racing caracteristics and really let it rip at the strip :rolleyes:
Not for now anyways, I have a hard time thinking how to install this turbo as it is ;)

When is enough?
 

:(
Hi Walter, I have noted your up-grades and congrats. Question, when is enough on your current engine, before you have a major failure? You have done very well, I'd hate to see you engine let loose:(.

So Walter, if I am reading between the lines correctly...you´re planning on a larger engine?

I hear you! But that is also the nature of me: I'd like to improve untill I think there is no gain to be had. And imo there are still loads of thinks to improve upon and the type 4 case is much stronger than 400 hp. Swedish lunatics (and I mean this in a kind way :D) have gone 600+ on the type 4 casing with a drag-race-only engine, so I think there are possibilties to extend that to track-driving with a little less hp, but for longer duration ;)

The car itself is still very drivable too. Its not scary when you step on it, so also because the handling can handle it, I think more power is possible.
If I can keep it 'in tune' (and I am getting rather well at this, even if I say so myself), there is no reason it should break with more hp, although I am getting more and more surprised the alu cylinders keep up :)

Another thing to consider: this (much) bigger turbo is more gentle on the engine at comparable boost then the smaller turbo was due to lesser backpressure...
So more power at less stress for the engine! How can you pass up on that? :D

Of course! But that will take a while as its a lot of $$. The stroker crank however has already been 'heat treated', a forged (stock 914) flywheel seems to be able to be used for 228mm enlargement and a set of 'virgin' 914 2.0 heads is in storage for some time already to get the 'treatment' once funds are available :D
After all, the current engine was only made from left overs of the 2,7 carnage and therefore not 'all i can be'...

Sounds good! I think the heads you have now will do just fine.Or are planning with bigger valves and welded ports,etc.? You could sell your current engine,that would give you enough money for the next build.I´m sure you would find a buyer for it.

;)I agree: the current heads flow well, even with just 0,500" valve lift. The 'new' set would be about the same, but with a tiny bit more porting, maybe Be-seats and upgraded valve train package. They would have a little more beef left in the heads as I would start with virgin heads and like a bit more CR, so they would get a little better in all aspects. Then a cam with more lift and you have more potential. At least thats my thinking.

I don't think I want to sell the current engine as I can use lots of its parts from it and I am VERY curieus how its looks on the inside. Only if I can see what it looks like will I be able to judge how well certain solutions have worked out.
But thats all in the far future due to $$ needed ;)

I wanted more "beef" on the exhaust ports,since that is a weakspot imo.That´s why I chose the CU heads.They have a thick chamber and enough room for big valves.The square ports allow a better seal at the header.I´m also curious what your motor looks like inside,mainly the cam and lifters.The crank and rods will be fine I´m sure and should show little wear.I´m anxiuos to see what size engine you will build.

Walter, in regards to more cam, how about a set of Pauter ratio rockers in the mean time. I believe that would allow a sort of more cam/results for a short investment. And later you can still use the ratio rocker in your next build?

I have DLC'd the tool steel lifters from Thorsten, so the lifters are the least of my worries ;)
Personally I would like to see how the pistons are wrt skirts in relation to the clearance they had and of course the head seal ;)

That would give too much lift with this cam... its a fine balance ;)

Hello Wally
I like your combination of short stroke and large bore in your engine. And it seems to be very realibly, you have realy succeeded.
I have read your thread but I cant find what valve size you use in your heads? I could have missed something....

// Anders

Its 46x40mm ;)

Slowly but surely the new parts for the new intake and exhaust side are coming together:

http://i174.photobucket.com/albums/w...turbo003-1.jpg

http://i174.photobucket.com/albums/w...erturbo004.jpg

Changing the springs to CB650:
http://i174.photobucket.com/albums/w...erturbo005.jpg

The double Berg springs had 3 saisons on them and were VERY much down on spring pressure, so this was/is a good thing to do either way.

Nice one Wally! Did you put rope inside the cylinder to hold the valve or did you use air pressure?

Great idea with the jubilee clips, that would made it much easier for me if I had thought of that!

I used air pressure Paul. Killed an old compression measuring device for that a few years ago :o

The Berg double springs were about 35% down on spring pressure :eek:

Check your springs after about 2 years of driving I'd say...

Anyways, back tp building the twin scroll header:
Trial fitting:

http://i174.photobucket.com/albums/w...derbouw017.jpg

http://i174.photobucket.com/albums/w...derbouw022.jpg

Impressive, as always! How will you route the oil return line, with the turbo that low?

Welcome to the board Frix!

Oil return will run as it was before with the former turbo as its about as high or low as the other one was ;)

Looks great Walter !

Well thought out, and looks like the turbo was meant to fit there.
:cool:

Did you end up revising the down strut / cup brace ?

Sandeep

Thanks; well, I have removed it for now as it didn't fit at all anymore with the air intake in the way. I have not come up with another alternative then brace it through the firewall onto a cage support point in the rear...
Oh well, first have to finanlize the install completely with WG before I do anything drastic.

I also wanted to redo the piece of 2" pipe just after the intercooler (2,5" exit) and the T-split. The individual 2" pieces to the pressure hats can easily remain 2" imo, but making the intermediate bend from 2,5" just seems more logical:

http://i174.photobucket.com/albums/w...0.jpg~original

Wally,
Check this divided housing fabrication.
http://www.honda-tech.com/showthread.php?t=2880250

Wicked nice welding for sure! Subies/Evo's and Honda's use the twin-scroll set-up a lot.
You're reading ricer forums now? :lmao:
j/k its a good thing to broadthen (sp?) our minds and apply new (although usually very old) tech to our engines/cars ;-)

You too!

...always know what you´re enemy is doing...:D

I agree! :D

Walter, what's with Your 1200 turbo engine and will you have thread here on GL forums about build? That downsizing stuff is very popular now :cheers:

I dunno if that would be a good idea, its not really in the spirit of max performance, though I am very exited about the project it myself tbh ;). Its slow progress too as it all costs still a lot, even if its type 1.

Meanwhile, some progress on installing/trial fitting the Tial wastegate, trying to outsmart the system by just using one WG by dividing the uppipe ;)
Divided pipe is now visible, of course needs to be shortenend and connected to both up pipes to turbine.
http://i174.photobucket.com/albums/w...6.jpg~original

http://i174.photobucket.com/albums/w...1.jpg~original

New wider pipe to the intercooler fits well too now, almost straight shot from the turbo :)
http://i174.photobucket.com/albums/w...5.jpg~original