Twin Seq. Dry sumping for beginners :D

[jaistanley]

The way I can think of doing it would be to vary the wastegates, not the boosted charge. Two wastegates for turbo 2 (big one) and none for the little one. Of the two wastegates for the big one I'd plumb one to the exhaust and one to the little turbo.

Low rpm/boost the wastetgate with the little turbo would be open allowing the small tubo to spool (so will the big one a tiny bit but the lighter, less restrictive small one will boost properly due to the pressure difference). When this reaches it's max boost it's 'feed wastegate' would close till the pressure levels out. The big turbo has then got more pressure and will begin to boost too.. When this eraches max, the second wastegate will open controlling pressure to the while system to level the boost out.

This way you need no flap to the turbos on the charge side as both turbos will be boosting, just at different ammounts at different times.

I hope this makes sense without a diagram or anything.

Jai

[Turbo-Brown]

Certainly interested in piccies and sketches if people are willing to post them up

Gonna have to look at materials, I know a guy with Titanium available but that's gonna be very expensive. Stainless is an option as it has a melting point in excess of 1550degrees C, it's just a case of ensuring it has a decent chance to dump heat when the flaps are partially open.

I'm not that far behind by the sounds of it Ben, I've got the twin turbos and six throttles already running, just not got the laughing gas

[Turbo-Brown]

Awesome, had a quote of £140+Vat to clean and bore a two litre block to 84mm. Doesn't sound unreasonable to me

[bootyman]

Cant wait to see it. It should be interesting to see what problems you encounter and the end result when it's finally done! How much do you reckon it will set you back roughly?

[Turbo-Brown]

Well, I've racked up the sum total of £305 on turbos so far, not sure on the price of the Ireland Engineering bits yet as I'll have to pay import duty

Manifolds should be around the £250 mark.

Got the engine management.

Gonna need a new clutch for this one I suspect, and head gasket although I might go for a wire ring job on the block and just use normal HGs.

Will keep tabs on how much it all costs this time too

[Ant]

Alex, you are insane dude, like your style

Jai has a good plan, using two external gates, one to the small holset with the W/gate vent pipe feeding the bigger blower the bypass stream.

alternative is a split setup, use two pulses on the small turbo, and 4 on the bigger unit to achieve the same goal.

be like having a 1 litre engine with small turbo, and a 2 litre with a bigger unit

Hmm, brain is now in overdrive

[WillG]

whats wrong with mine , i like the 2 pulse and 4 pulse idea tho , i got quoted £120 + vat for wire rings alex

[Ant]

whats wrong with mine

Its not in my engine bay yet, thats what

PM replied to BTW.

[Speedtouch]

I'm sorry, but 2.5 litres with twin turbos is no match for this setup: http://www.barris.com/gallery_cars/Nove ... auler.html

[Turbo-Brown]

Don't think we'll know the rights and wrongs until I build and try one

I'd like to have all exhaust gas available to either on turbo or the other (or a combination) to keep spool times to a minimum so it needs all 2.8 litres pointing at the HX27 under light loads etc and vice versa.

Should be fun in the wet

[Simon13]

Alex where are you taking your block to be bored? There's Roe engineering in Fleet on the Kings Road. They will do a good job. My dad is in a similar line of work and has known them for years. Quoted me £30 per bore as there is quite alot to come out.

Make sure you give them the pistons for a perfect fit!

[Turbo-Brown]

Yeah, I used Roe's when I rebuilt the last engine.

Mike there is the man, really helpful and enthusiastic. I was recommended them by a mate who used to build race engines for pre-war classics, Invictors and the like. Glad they're still going, must be something of a dying art as less and less people are willing to get their hands dirty these days!

I got the quote from QEP though but I'll have to see nearer the time as they're in Sussex which is a fair ol' trek.

[gcorky]

nice one m8,hope all goes well but im puzzled why people post to say "your not the first and your car is no match"etc...... it will be well engineered and thought out ....like your style m8

o.t did you progress on drain flanges?

[Speedtouch]

Hey, I'll have you know I rebuilt an MG Midget engine once - still running to this day!

[tee]

Alex, if you need I have alot of literature for the BMW sequential turbo diesel lump. If you want to have alook at it give me a call and we can meet up. It may give you some ideas and already made parts you could use. Just a thought. Plus I want to talk to you about this stroker kit

[Turbo-Brown]

That'd be wicked Tee if you can spare the time

I see you're becoming power hungry too

o.t did you progress on drain flanges?

Sorry dude, I've not had a chance to sort them yet, I'm waiting on an order to make a set of throttle bodies though which should come through this week or the next so I'll get the materials in for the drains when I order up materials for them if that's alright?

[gcorky]

That'd be wicked Tee if you can spare the time

I see you're becoming power hungry too

o.t did you progress on drain flanges?

Sorry dude, I've not had a chance to sort them yet, I'm waiting on an order to make a set of throttle bodies though which should come through this week or the next so I'll get the materials in for the drains when I order up materials for them if that's alright?

no sweat m8-appreciated

[Nelly]

I've seen 2x E30's now with twin's on and i must say they look the nuts - one is nearing the end of it's build and the other one - well - frigging monster!!!!!!!!!!!

[Turbo-Brown]

Ooh, got any details Nelly?

They members on here? Glad I'm not the only one with turbo greed!

[dips346]

Ooh, got any details Nelly?

They members on here? Glad I'm not the only one with turbo greed!

maybe ,was waiting to finish fully first

[Turbo-Brown]

Sweeeet!

Confirmation that an butterfly valve in the inlet system will work:



I'm willing to bet that the exhaust from the upper turbo vents to the inducer of the larger one although can't quite make it out in the pic. Infact you can see that the flow to the large turbo is simply stopped by a big valve.

Perhaps the principals of 6 into 2 should be replicated instead of the twin 6branch I'd envisaged.

Gonna have to cad this one up properly me thinks, none of this trial and error fitting! (this time)

[Turbo-Brown]

Ooh, got any details Nelly?

They members on here? Glad I'm not the only one with turbo greed!

maybe ,was waiting to finish fully first

Crikey, twin parallel or sequential Dips?

[dips346]

Ooh, got any details Nelly?

They members on here? Glad I'm not the only one with turbo greed!

maybe ,was waiting to finish fully first

Crikey, twin parallel or sequential Dips?

twin parallel

[Nelly]

I'm bound to a promise so unfortunatly can't release details but i can say you'll be pleasantly suprised

[Turbo-Brown]

Aah go on, spill the beans Dips!

Would I be right in thinking that if you were to go sequential, you'd perhaps have needed four turbos?

[dips346]

Aah go on, spill the beans Dips!

Would I be right in thinking that if you were to go sequential, you'd perhaps have needed four turbos?

lol..no its not the v12 but a m20 heavyly built soon the pics will be up,not till we finish it and my mate says so

[Turbo-Brown]

EDIT> this was in response to another post which has since been deleted and not you Dips!

Hokey doke, could we not hear anything more on the subject in this thread please

[bootyman]

Sorry mate. Just answering a statement that's all. Regardless of how many twin turbos there already is, i'm sure you'll do a good job

[Turbo-Brown]

Nay worries, wish I shared your confidence in my abilities

[bootyman]

Mate i pretend to design Oil Rigs for a living and they somehow stay afloat, so i'm sure you can do it. Besides you wont know unless you try and you've done it before havent you?

[Turbo-Brown]

The last one was twin parallel which is relatively simple as both turbos are the same size, to it's just like turbocharging two little engines in isolation, albeit that they both draw air from the same source.

This one's gonna be a twin sequential which means having various valves in the intake and exhaust streams diverting flows at the right moment.

If it works, the engine'll be a monster with torque eeeeeeeeverywhere

[bootyman]

TORQUE! The magic word that everyone misses out when they tlk about power cause they are all too bussy throwing bulls@it BHP claimed figures around. Certainly have my interest in this and i'm much more into styling than power

[Turbo-Brown]

EDIT> Oh blimey, people have been deleting posts left right and centre


Oooh, there's some handy piccies on realoem too, even down to a vague setout of the vacuum system.

Seems odd they'd use vacuum to control things rather than positive air pressure, afterall there'll be positive pressure for more of the time that things like actuators need controlling than vacuum.

Hmmmmmmm.

[gareth]

good god man, you move one step further towards insane at every post!!!

keep up the good work!!!!

[Turbo-Brown]

Well, I've gathered up the turbos and modelled them in a 3D CAD package (don't all laugh at the compressor housing of the H1C!)

And have spent countless hours trying to figure out a way to get them both in with the requisite divertor valve in place. Think I've cracked it from a packaging point of view (I made up some 1:1 paper mockups and they seem to fit in) although the pipework could still use some smoothing I'm sure.

Not shown (cos I've not drawn it yet) is the pipe that runs from the exducer of the HX27 to the far side of the divertor valve, although that's what the big target shaped thing is there to mount.

Your thoughts and comments appreciated