[raamaudio]

Turbo manifold porting underway
This might not do much for the stock turbo power band except cause it to spool a bit faster but it is sure going to help with a GT25 or GTX, etc...turbo upgrade.

I tried to get some good pics of the rough casting, ridges, etc....but just could not get good enough lighting and focus inside as so dark. I cleaned it out and still no luck so you just have to take my word on this, it needs done!

Still a work in progress and the results are much more impressive than my pictures show.



Two middle ports to show the difference in opening them up a bit and cleaning up the flow. I am looking at getting a flexible shaft so I can do the whole inside as well, I have a flexible color camera I will use to see if I can get better pics and do a good job deeper inside.



Outlet was worse than it seems in this picture.



Better now, I am testing different bits, etc, to get things smoothed up as possible.

When porting there are a few rules to doing it right, these are the simplest but very important ones.

1) always leave enough material to not weaken the part
2) always match precisely from port to port if you an ensure no offset when bolted up.
3) #2 is tough to do so an easier way it to ensure the outlet is smaller than what it feeds into and even if no lined up there is not direct flow blockage
4) match the port volume as close as you can, in this case not possible with the inner to outer ports being so different but do the best you can.
5) CLEAN it out completely before reinstall

 

[wash]

Could you trace the flange? And compare the gasket to the ports on both the head and manifold?

I want to make a header but can't really afford down time on my daily driver or justify buying a manifold.

I tried getting Finsport or something to sell me a flange, I never heard back from them.

 

[raamaudio]

It is so easy to just open up the receiving ports larger than the ones feeding them I am just doing that, it helps with reversion as well so a good way to go actually in NA but in a turbo I do not know if it matters as long as no restrictions.

I looked inside the plastic intake side of the turbo and it has a little ridge in it, had in my case, soon that is as will smooth that out. I might clean up the aluminum after that if needed but not going to get carried away as not planning to run this turbo much, not even running the car until all these parts are done and tuned.

 

[raamaudio]

Latest improvements

I had forgotten to match the manifold gasket to the manifold, I had done it on the head and it looked good but as you will see below, there was enough offset that the exhaust flow could easily of hit the edge of the intake port.

Stock end port.

Other end port already opened up but not checked to see if centered over the head port.

Fully opened up to the edge of the gasket. Of course the head port is a fair amount smaller but the gasket fits nicely centered on them, this will ensure the cleanest flow into the manifold and also helps prevent revision when the the outlet port is smaller than the inlet port.

As noted here or elsewhere, I am only port matching or stepping as in this case and cleaning up the rouge interior of the manifold, it will not be enlarged a great degree by doing this work in order to ensure it spools the turbo sooner.

It will still flow more and allow more top end power will enhancing lower end power when I put on a bigger turbo.

 

[wash]

That looks like a steel shim gasket with round ports and you say the cylinder head ports are well centered.

Could you measure the cylinder head port I.D. ?

I need to chose a pipe/tube size.

I can order a gasket and make a flange from that.

Thanks.

 

[raamaudio]

The ports are not perfectly smooth inside so I took several measurements, 1.135" was the largest I found.

I have 8 new SS weld els(I forgot how to spell it, been nearly 6 years since used any) that have thicker walls, measure 1.95" on the outside, 1.65" on the inside, probably to big for this engine and turbo size needed, I guess I need to list them for sale.

I also have some good 3/8" SS plate.

I still might build a manifold if all else goes well, if you do this would you consider making me the flange(s)?

Or, if not to costly, a manifold?

Thanks
Rick

 

[raamaudio]

I would consider selling my well ported manifold to a member to help them out

 

[wash]

I was talking to a friend about CNC plasma cutting 3/8" flanges, I would probably just do the perimeter then lay out the holes to drill on a mill for accuracy.

At this point its a long term plan but it would make sense to gang up several flanges to machine at once, maybe 5?

Those ports are smaller than I expected, I was thinking 1.25" schedule 10 pipe would fit but now I need to look up the ID of 1" pipe.

I think I know the routing I need for a twin scroll manifold but clearance to the block and firewall have to be designed in.

As for making a header, maybe. Like the flange, if I get set up for one, making 3-4 might be the smart move but everything I read suggests that thermal expansion can crack manifolds if they are not designed properly. If I made a few they would all be untested prototypes.

I've been trying to find a reference about how much a mandrel bend will move at 1,300° or so but there doesn't seem to be a calculator or even anecdotal evidence of if the bend opens up or closes when heated.

I might have to make a test piece and add a propane burner to do the heating.

 

[raamaudio]

It can get quite complicated!

I really only need a bit larger turbo and the stock ported manifold to be just fine and most likely trouble free so I have to keep reminding myself of that

 

[wash]

If I make a manifold its going to be for a twin scroll EFR 6258...

It looks like 1 3/8" tube with 0.120" wall will match the ports just about perfectly and leave enough meat to port match if there is any misalignment. I kind of like that because 1 3/8" is a common roll cage diameter, lots of people have dies for that size.

 

[raamaudio]

It sounds like you mean to have the tubes bent instead of using SS elbows, which is cool but I am not sure you can find somebody with the dies to make such tight radius bends. I have a tubing bender I used for roll cages and can do 180 degree bends but only in 1.75" tubing and the radius is quite large compared to what I would want to make in a turbo manifold.

We were able to bend a few sections, moderate angles, of smaller tubing buy cutting out a filler section of 1.75" to line the dies but doubt it would work for a very long bend.

 

[raamaudio]

Since that turbo in single scroll is rated up to 440HP how would it work in a single scroll(if I wanted to use it on a stock ported manifold) with the rest of the supporting mods and keep the boost down as really only need around 275WHP, 300 is probably overkill....?

Any ideas on a less costly turbo than it or the GT25, X, series that would do what I want, a nice wide powerband that is easy to use on the street, very little or no lag but big enough to move the air without to much heat added, not to hard to mount to this engine.....?????

I have not been able to dig up the info on the turbo I had on my 1.8 Matrix tuned to 250WHP but it had power all the time and never a heat issue.

Thanks

 

[raamaudio]

I looked a couple of days ago or so but must of entered a better search parameter, the 6258 looks pretty dang impressive even in single scroll....which I am sure I want to stay with.

I did build a hybrid single WG, twin scroll, manifold once, I still have it with the DP, WG, BOV, IC, exhaust, all never used, turbo on it is a GT3076R

 

[wash]

The header design in my head will require some tight bends and some with a larger radius.

Hopefully I can bend the larger radius stuff, use butt weld 90s for the tight bends and connect the two with Burns style double slip joints.

 

[raamaudio]

You do more than most have done that is easy to see and more than I have in this area, by far, I might be 62 and a bit opinionated but I also am open to learn as there is a thousand more times info out there than my brain can store away and find again when I need it

 

[wash]

I started seriously looking at the EFR when I was waiting to get my Fiesta. Then I went to SEMA and got to see the EFRs along with the competition.

Since the compressor doesn't change, I think the twin scroll 6258 should have the same potential but I think that 440 HP is what you can see on a bigger motor like a 2.3 or small V6. On a 1.6 with 24 psi boost and a 7,000 rpm rev limit it seems more like 350 HP is reasonable (determined by match not) but may require race gas.

The twin scroll should just minimize lag, spool quicker and maybe give a hair more top end due to the larger ar ratio.

After SEMA I went to the closest BW turbo retailer: Track Speed Engineering who makes some really fast turbo Miatas. They had gone through a progression of turbos in Miatas and settled on the EFR series using some of the bigger ones on dedicated track car builds on the Miata 1.8.

TSE's basic setup uses the single scroll 6258 and they say it spools faster than a gt28 or maybe a gt25 (I don't recall), with better flow for more power.

Miatas don't have direct injection but they do have variable valve timing. The VVT certainly helps with spool but I think DI might help even more if an anti-lag feature can be implemented to spray fuel in to the cylinder during the exhaust stroke. Long story short I believe a twin scroll on our 1.6 will spool quicker than a single scroll on the Miata 1.8 with only a slight power disadvantage.

As for how much I've done, a little bit of many things and a lot of a few things. This is my first turbocharged car but I've studied a lot...

 

[raamaudio]

Back in 1960-62 or so when I started building model cars with fuel lines, spark plug cables, etc....then super fast slot cars with my hand wound and balanced motors, then real cars....

You have done a great deal of research and posting some very solid information for just starting out with boosted engines!

 

[raamaudio]

I built a hybrid twin scroll manifold for a GT3076R, single divided port for the WG that was separated right up to the face of the valve

 

[thekilowattkid]

What about after gasket match having the manifold extrude honed?

Sent from my HTC6500LVW using Tapatalk

 

[raamaudio]

I looked into that and extrude honing is the ultimate I know of but I was able to do the majority of the manifold by hand for just the cost of a few consumables. The little bit I could not reach would have a pretty small gain and cost $500 or so, better ways to spend the money, only all out race cars with big budgets and a set of rules that require a stock manifold but allow it would have any gain worth considering.

Thanks
Rick