Twin Seq. Dry sumping for beginners :D

[jkarran]

It's tricky to see what's going on here but as far as I can tell the top (H1C?) is a split pulse turbo fed from all 6 ex ports (front 3 to rear of turbo, rear 3 to front?) via some kind of series shutoff valve.

The H1C appears to need an external wastegate which isn't shown yet right?

The smaller H27C appears also to be split pulse driven front 3 to rear of turbo and rear 3 to front of turbo. It appears to have an integral wastegate judging from the exducer port shape.

Presumably you plan to route all the H27Cs exhaust (either via its wastegate or turbine) directly into the H1Cs turbine (how? not shown yet I presume) behind the shutoff valve controlling flow into the H1C.

Sounds like a plan to me

Out of interest, have you just done the front 3 ex ports to rear of turbos and vica versa for the rear 3 to simplify the fabrication?

Would the H27C spool up faster if it were allowed to vent straight into the exhaust via a butterfly valve that would close as the H1Cs opened? Of course the downside is the larger turbo is not kept spinning constantly. Worth a thought but I suspect your idea is the best one.

A very lightly sprung flap valve (held closed by H27C boost + spring) in the air side to prevent boost from the small turbo escaping out the large turbo would automatically flow air from the H1C when it gets spooled up without any need for complicated actuators.

jk

[stuartgallafant]

this project sounds amazing!!

but im SO confused!!!

[sam325is]

that is how I thought the manifold would want to be, looks good, would still prefer a valve/wastegate over butterfly and actuator type thing i think.

WillG

[dazleeds]

this project sounds amazing!!

but im SO confused!!!

i'll second that

Damn you turbo boys are good

keep up the work lads, truly inspirational

[Dan318-is]

alex, what 3d cad pacakge are you using? Looks like solid works from here

those drawing are pretty sweet mate!

[Turbo-Brown]

Pretty much spot on Jkarran.

The HX27 does have an integral WG, but that's going to be permanently closed with the boost control for that turbo being taken care of by the poppet valves in that block shown in the piccies. That way, anything not being used by the HX27 is starting to spool the H1C.

The exhaust gas from the HX is to be diverted downstream of the poppet valves so at some point, all gas from the engine must pass through the H1C.

The H1C will indeed need an external WG

The rear 3 ports feed the front of the block and vice-versa as you say, just for ease of fabrication, although I might change that, but it'd make the fabrication of the log for cyls 1-3 more complicated.

I think the HX would spool quicker if it could vent straight to atmos, but that might dull the H1C and also introduce another valve into the hot side which I'm keen to avoid.

I can't really take any credit for the design as it's essentially a re-packaged copy of the BMW system pictured above so I'll probably knock off the air system too.

Dan, yeah, it's SolidWorks. We've got a licence at work that I'm playing with / learning to use which is kinda fun

[jkarran]

So that's the small HX27 drawing air through the H1C at low rpm and bypassed (though still spinning) at higher rpm? That's a good idea, the draw through the H1C compressor will help it spool up (at the expense of some performance from the smaller turbo perhaps?).

Vent the wastegate to atmosphere side exit, you know you want to It'd sound mental

Nice plan

[Dan318-is]

sounds cool mate, who do you work for?

im using catia at the moment, cost £500,000 per license for a company piece of piss to use though!

your cad skills are impressive!

[Turbo-Brown]

Yeah, it's a kind of "all roads lead to H1C" thing, with all inlet air having to pass through the big'un on it's way in, and all exhaust passing through it on it's way out.

I work for a little company called GK Design Contracts (www.gkdc.co.uk) as a Project Designer drawing building envelopey type things.

Think SW costs about £4000 for the basic version, slight difference in price

[Dan318-is]

yeah solid works is still very good though; its not too basic; its what a started on; then used Autocad for a bit which is stupidly complex. i thing the home version of catia is £22,000 its so easy to use its untrue though;

think im going to have to pop round when im home agian and have a look at some of this alex

best of luck

[Turbo-Brown]

Our bread'n'butter's ACAD, if you have a look on our site in the examples of 3D stuff for the Ascot Weighing in Room, I did all that in ACAD 3D. It was a nightmare! Took me and another guy almost 6 months to disassemble the 3D model and detail up all the components so it could be made. Only got one bit wrong too which was kind of amasing!

You're welcome to pop over mate, although all I've got at the moment is two turbos and a drawing

[gareth]

looks like you're getting on fairly well with solid works! i've never used it personally but have heard good things about it. i made the transition from autocad-LT to solid edge when i last switched jobs nice package to work with we also have a program called EasyCad which is the "new version" according to the manual, in this release it will work in windows 3.1, not DOS!!! the software dude at work has modified it heavily to work on XP! not too hard though, it only takes up 800k on the single floppy disk! that's the downside of working for a company with a 35 year history and only one design engineer. in the 6 years i've been there, i've managed to get 5 - 10% of the old drawings onto solid edge. over half of our drawings are still hand drawn!

[Turbo-Brown]

Wowzers, 800k for an entire CAD thing is mad!

I remember our first home PC. You could have DOS and ONE other application on the hard disk at any one time. If you wanted a different program, you needed to delete the one you weren't using and load the new one on!

I also remember using TurboCAD a bit later on....that was, um, crap.

Anyway, I'm thinking about changing the design for the umpteenth time to more closely resemble BMW's own effort.

The more I think about it, the more I think I don't need the split pulse system as the little turbo should eliminate lag completely so rapid spooling of the big one isn't such an issue as it'd be if it were on it's own.

Making the switch to log would certainly make packaging and fabrication a whole lot simpler!

[jkarran]

Could you not stick with split pulse AND a simple log manifold like Toby's albeit with the turbos more central on the engine (between cyl 3 and 4), one above and one below as in you're initial plan. Would be easier to fabricate than a tubular one and needn't flow badly.

If you have split pulse turbos you might as well use them

You're going to have a hell of a lot of stuff down the side of the engine what with the valve assembly, HX27 exducer pipe and the external wastegate/actuator + all the air plumbing. LHD shell?

Anyone ever tried Bently Microstation? We had a trial at work for a bit, the photo realistic rendering was cool but the actual drawing process was pretty tricky. More importantly it was too much money for my boss to cope with, back to AutoCad LT for me

jk

[Turbo-Brown]

Unfortunately, the bigun needs to be situated forward of the gap between 3 & 4, otherwise I could keep the split pulse and run log (titter) as you say.

Gonna have to keep the bigun where it is which is with it's trailing edge in line with cyl 3 in order to clear the bodywork.

I'm not adverse to redesigning all this again. I've been down so many dead ends already as far as packaging is concerned

[Turbo-Brown]

Well, here's the log style manifold:



It was just SO much easier to package like that!

The valve is more compact and the routing of the HX exhaust gas to the H1C inducer will be considerably easier now, as will adding in the external WG for the H1C.

I'm quite excited about this design, it seems the neatest and easiest to manufacture. I'm just a little worried about it's ability to flow for decent power.

What do people think?

Cheers!

Alex

[maxfield]

This will be awesome!

And good CAD work

[Turbo-Brown]

It'll be awesome....if it works

Cheers Max

[Andy335Touring]

I think you have to get up to wacky racer power levels before the log will be restrictive ?

Good old E30 rear suspension is a bigger restriction to big power

[WillG]

it could flow fine, look at the log i made and see how it works out for ant if hes uses it, it is a very similar design, i got my idea from the TCD log where it gets slightly bigger on each branch, i made the the log section larger each time a branch joined it, think it was 1 1/4" single branch then 1 1/2" when 2 joined togther and then 2" where they all join by collector, I worked out the cross section of pipe and with firing order it should flow just as much as a tube but with less volume so might even be more responsive, the only downside to the log is the gas has tighter bends to follow so it might slow gas down abit more but then as its got less distance to travel to turbo it should even out. It will be intresting to see the valve and will probly work out fine, if it doesnt i think you could still package 2 wastegates in the place of the valve and use them to same effect.

[jkarran]

That looks like it'll flow fine especially if you flare the collector part of the rear three out a bit to increase volume a touch toward the H1C. The front part looks like you already have.

Are you planning to use engine valves in your valve assembly? If so, are you planning to cool them? As you are no doubt aware, exhaust valves in an engine are seated for a lot of the time so give their heat up quite readily via their seats and guides to the oil/coolant in the head. These will be exposed to the full heat of the exhaust with very little oportunity to cool themselves especially on a track where you'll be at full throttle with them unseated quite a lot. It'll be even worse if you wrap the manifold. Just a thought, wouldn't do fot the turbo to ingest a molten valve head

jk

[Turbo-Brown]

The valve's is similar to a normal WG poppet, only longer (kind of oblong in shape). I've drawn it at 4mm thick (S/S) and it has a generous heat flow path into it's spindle and when it's fully open can reject heat to the manifold wall.

I do expect to have to replace it every so often though.

I'm not fantastically keen on wrapping manifolds so that shouldn't be a problem

[jkarran]

Ah good idea, I hadn't thought about opening it against another 'seat'. Sounds like you have it all in hand. Impressive project

jk

[Turbo-Brown]

Awesome, my new purpley wastegate's arrived.

Mmmmmm, generic and non-branded

[e30_Turbo]

Awesome, my new purpley wastegate's arrived.

Mmmmmm, generic and non-branded

What did you go for Alex? 50mm

And ALL the info I can find on manifold design have said the same thing, for F/I it isn't an issue, just no leaks!

Mark.

[Turbo-Brown]

Yeah, it's a 50mm jobbie. Didn't come with any different springs unfortunately but sure we can turn something up from somewhere.

Just gotta get my hands on it and model it up in the CAD thing (had it delivered to a mate's)

[e30_Turbo]

Cool. Toby's is 50mm too, aren't you going to use the ECU to control boost anyway? That way the springs only used as a fail safe.

And have you seen this:

[Turbo-Brown]

I've seen that kind of thing on those Tractor-Pull type things.

At some point around the crossover, my system will be working like that, with the large turbo feeding compressed air to the smaller one.

It's quite cool as it allows you to multiply the pressure ratio of the turbo that's being fed, so if it could supply 1bar (PR=2) absolute max and you fed it 2 bar, you'd get 4 bar out (I think)

[jkarran]

And have you seen this:

Diesel dragster

[Turbo-Brown]

Hmmm, only just realised that Derv engine is an I6

Anyway, in other news, I've just been out to the red car (whose engine I stripped of pretty much everything yesterday) to have a poke and prod / trial fit of some bits.

Sadly, those bits are only made from paper but it's cheaper than metal!

So, looks like a cossie 2wd IC will fit on top of the rocker cover which I'm really pleased about as it's a big step towards my new chargecooler setup.

Looks like quite high flowing bilge pumps can be had for about £25-£30 so the pump shouldn't be expensive either

Also looks like my new design of throttle bodies fits in neatly too (this is the paper bit), gives me much longer runners than I've currently got, moves the injectors away from the head and clears the servo better. The also include some sealed ball bearings this time so the boost shouldn't be an issue (not that it is currently mind)

Just itching to get on with it all now!

[Turbo-Brown]

Here's a question for ya:

Turbos do quite an effective job of silencing an engine so you can fit straight through silencers and not make people's ears bleed.

Now if one turbo is a reasonable silencer, would two turbos be a really good silencer?

What I'm getting at is, could I get away without any form of silencing do people reckon? All of the exhaust must travel through both the little turbo and the larger one at light loads, and once the throttle's burried I ain't too bothered about the noise.

Your thoughts appreciated

[Gunni]

Depends on exhaust size.
Wich I´m assuming will be "3 straight trough?
If so I think at light loads there isn´t going to be an issue but of course at WOT and high load
the exhaust tone will pass the larger turbine easier and make more noise.

Another question :
Does the exhaust note come trough the wastege or the turbine wheel at load

[E30_1JZGTE]

Here's a question for ya:

Turbos do quite an effective job of silencing an engine so you can fit straight through silencers and not make people's ears bleed.

Now if one turbo is a reasonable silencer, would two turbos be a really good silencer?

What I'm getting at is, could I get away without any form of silencing do people reckon? All of the exhaust must travel through both the little turbo and the larger one at light loads, and once the throttle's burried I ain't too bothered about the noise.

Your thoughts appreciated

Hey mate on my twin turbo set up the enigine sounded nice and strong on idle and when i took it for an engineers report as required in Australia, the turbo's played a massive part in silencing the bugger.

They test it on idle, then 4400rpm which gave a decible reading of 84db's.

So my car passed with 1 resonator and 1 big muffler on the rear.

Good luck with yours.

[Turbo-Brown]

Well, I've taken a million years to get this far with my current project (all for someone else unfortunately) but it's almost done so let the ordering of bits for the twin sequential begin!

Gonna order some pipe bends to start making the manifold tomorrow as it occurs to me that I don't have time to swap the engines between Brown and Pink at the moment (I know how to choose car colours!) but the bare engine's still in Pink so I can trial hang bits and make sure everything fits.

Will post pics as and when so you can all laugh at my TIG welding

[karaokebykris]

Ah the eternal "Do I stick it in the pink or brown" dilemma.......