Tuning a compound charged car with megasquirt?
 

Hey guys. A lot of guys told me to check out this forum. Never thought I had to until I hit a roadblock. Yes I am a bit of a noob but I am here to learn from you guys.

The car
1990 Volvo 740
16v motor with a Holset H1c
Megasquirt n spark(EDIS)

My car is mid build at the moment. I have had "builders block" with my latest issue. My turbo is a Holset H1c. It has a 21cm exhaust housing on it. Big, too big. Some people use the block off plate to block one scroll. Some people perfected it further and allowed the other side of the scroll to open once boost hits(learned that here ;)).

Well I bought a M62 blower hoping to use that to spool the turbo. Is it the best idea? No. I could buy a better sized turbo, or block a scroll, or to be completely lag free use a blower. BUT I am doing this partly to be different. I have become determined to use this 21cm housing.

Now from what I understand an o2 sensor is affected by the amount of oxygen that passes by it. If I blow clean atmosphere air into my turbine, and out my exhaust, will this throw my AFR readings off? I have NOT tuned much before. I am a noob. But believe me, there is not much to read about tuning a compound charged car.

This has been done before. How so? Best choice? Thanks for the help.

Re: Tuning a compound charged car with megasquirt?
 

you are gonna blow the outlet air from your blower through the turbine in addition to the exhaust, yeah hope that works out for ya :1

Re: Tuning a compound charged car with megasquirt?
 

reversion and pressure difference owns :S

Re: Tuning a compound charged car with megasquirt?
 

You know more than me. Like I said, how is my idea wrong and how would I fix it? Blow through the compressor housing? Will the holset have issues drawing through a blower?

I have never got to see this setup. Probably never will due to the rarity. We talked on the Volvo board about TT. A small stock T3 and a holset. Nobody really knew, but it was assumed the holset would have a hell of a time making boost through a T3.

Re: Tuning a compound charged car with megasquirt?
 

I could tell you what I was going to do.

But then you'd have the car I want. With the setup I want.

So no.

Re: Tuning a compound charged car with megasquirt?
 

spill the beans amigo :8
come on...

Re: Tuning a compound charged car with megasquirt?
 

for one thing what you said is not doable, learn the correct terms for what you want to do and then get back to us, i think you want to run a twin charged setup. it has been done befor and is done on like all detroit 2 stroke diesels.
learn what a turbine is, what you said is you want to have your blower running into the hotside of the turbo? what?

Re: Tuning a compound charged car with megasquirt?
 

You can do that as well.

But I would run a smaller turbo and a bigger turbo on the same manifold. Smaller turbo spools until it becomes a restriction, by which point the larger turbo is already moving and that will keep it going all the way to the top.

Only problem I can see is the added heat from the smaller turbo still flowing some amount of air, but the majority of the charge would take the path of least resistance.

Re: Tuning a compound charged car with megasquirt?
 

Its got nothing to do with knowing the lingo man. I knew what I said. If you read what I said, you would have understood that. Again, I asked if the added oxygen in the exhaust would throw my O2 sensor for a loop. O2 sensors are effected by the passing oxygen in the exhaust. By added clean atmosphere air to the exhaust, is that going to throw off my AFRs.

I meant what I said. If you don't know the answer to my ----, just sit back and read along with me. Don't hate on me. ::)

wafflesincars come on man help me out. PM me if that helps lol.

Re: Tuning a compound charged car with megasquirt?
 

Exhaust leaks are notorious for ------- up your o2 sensor reading,ect. I would'nt run an m62. 50% compressor efficiency and weaksause. If I was looking for low end power with some room up top, I would phase in a larger turbo from a smaller one with some sort of wastgate/flapper device than run that.

Re: Tuning a compound charged car with megasquirt?
 

The goal is to use the blower to get the holset moving. This is why a smaller turbo running until the big turbo spools isn't what I need. The smaller turbo, in my idea, would spool the larger turbo. I chose the M62 because it is smaller. The M90 is too much. I am just trying to spool a turbo, not feed the motor.

If feeding through the coldside would the blower be a constriction worth mentioning?

Re: Tuning a compound charged car with megasquirt?
 

You can do what you're saying, and have that compressed charge fed into the intake as well, but as soon as the larger snail makes boost it's going to outflow that small turbine.

Reversion.

Why isn't a small + large what you need?

Re: Tuning a compound charged car with megasquirt?
 

I'd twin charge it before I tried using the M62 for only spooling the turbo.

Let the added exhaust gasses and heat from the blower feeding the engine spool it.

Re: Tuning a compound charged car with megasquirt?
 

it is not what I need because I already bought the blower. So far my best bet is to blow the blower through the cold side but I am worried about the holset being restricted by it. Any thoughts on that?

Re: Tuning a compound charged car with megasquirt?
 

Strapping a roots onto your car is a HUGE project in and of itself, much less making the turbo fit and a bypass for when the turbo spools up.

Your best no-nonsense solution is to talk to Jaymez (pronouced James) at Diesel Injection Service in Ohio about what turbine housings you could buy that would spool your Holset. There are probably dozens of knowledgable people out there, but I know from experience Jaymez will take time to answer your questions and will get back to you if he needs to look up some interchange information.

Re: Tuning a compound charged car with megasquirt?
 

JD that would work though wouldn't it?

Having a small turbo and a larger turbo on the same manifold, and by the time the smaller turbo becomes a restriction the larger turbo is spooled up?

Re: Tuning a compound charged car with megasquirt?
 

ok

Re: Tuning a compound charged car with megasquirt?
 

ok

Re: Tuning a compound charged car with megasquirt?
 

Super chargers suck, most TT setups suck, but a clever American company that makes a LOT of gearboxs came up with this a year or so ago :

https://s50.photobucket.com/albums/f.../twinturbo.jpg

If the lag and spool characteristics of my holset continue to piss me off after I plumb and tune it properly I'll be building that on my ute. It's much like what waffler described above really, but it's actually running on a bunch of bmw and ford engines right now and works brilliantly ;-)

Fred.

Re: Tuning a compound charged car with megasquirt?
 

Re: Tuning a compound charged car with megasquirt?
 

think about it blackman, the large one would act as a wastegate, never allowing the little one to spool. (think pressure difference)
however, if flappers/valves are involved, then it will work. (like a sequential twin turbo rx7 or 2jz (same size turbos))

ok



fred, is that the setup on the new 3.0l turbo diesel in the x5 (and others) ?
which fords? euro diesels? jags?

dan.

Re: Tuning a compound charged car with megasquirt?
 

Waste gate is more free flowing than a turbine, I assume it would bleed off some pressure but it's not going to act exactly like a wastegate because the gas still has to work it's way around the turbine. Unless you have a piss poor motor displacement wise there is going to be some back pressure.

Flappers would round it out to work much more efficiently.

Re: Tuning a compound charged car with megasquirt?
 

That company is approx. 15 miles from my house lol. I have a friend on the research team that tests newer designed turbos using that specific setup. Pretty cool stuff.

Re: Tuning a compound charged car with megasquirt?
 

Not all of the bmw diesels use them, but some do, and the ford is the f350 maybe? not 100% sure, and don't care at all. I just care that I can build such a setup and have 20psi from 2k to 8k seamlessly :-)

The check valve is the key thing. NONE of the other TT setups are any good IMO. This though... aside from being a bit large/heavy/complex is absolutely brilliant IMO.

SOMEONE BUILD ONE SO I CAN OGLE AT IT!!!!!!!!!

I'd have built one already if I wasn't stuck 11000 miles from my MIG :-(

Fred.

Re: Tuning a compound charged car with megasquirt?
 

You can ogle the ass end of my car if I build it.

Re: Tuning a compound charged car with megasquirt?
 

whats so hard about running compound turbos. no need for any flap valves in a dual exhaust manifold. the 2 turbo setups on all the diesel trucks are compound. small turbo on the manifold, with the exhaust from it spooling the big turbo. by the time the small one runs outta spool, the wastegate on it opens and the big one keeps spoolin.
http://www.4btswaps.com/forum/attach...4&d=1181210907

Re: Tuning a compound charged car with megasquirt?
 

Oh and the 21cm housing is worthless on that turbo. throw it away and get a wastegated 12cm from an hx35 holset, or at least a 16 non-wastegated.

Re: Tuning a compound charged car with megasquirt?
 

Please do, I'd love to see it work!

Nothing's hard about it, but you want the wastegate on the small one to be huge for low restriction (I'm thinking 60mm vband) and you want to bypass the small turbos compressor when it stops flowing or you are choking the big turbo hard out...

The borg warner system is a beautiful thing indeed. Standard compound turbocharging is ugly.

Fred.

Re: Tuning a compound charged car with megasquirt?
 

explain, but it still works...































lol smashed, i like beerssssssssssssssss

Re: Tuning a compound charged car with megasquirt?
 

It still works on diesels where IAT doesn't matter a damn. It's ugly because it's not efficient everywhere. It's ugly for lowish boost 20 - 30psi because it's designed to increase the total pressure output of the system. Finally, for a gas engine, it's ugly because both turbos need to be large and you may as well just have one on there for any semi reasonable pressure.

The borg is beautiful because you get to put an _under_ sized turbo and an _over_sized turbo on the engine and get the best of both worlds with no compromise besides weight and complexity. The best solutions are often the most simple.

Fred.

Re: Tuning a compound charged car with megasquirt?
 

Compound compresses the charge twice, we're talking about a sequential setup that doesn't suck ass.

Re: Tuning a compound charged car with megasquirt?
 

Exactly, it's only compound in the lower rpm area when the large turbo doesn't restrict the small one and does need pre-spooling to be smooth when being transitioned into. Once the big one comes up to speed the small one gets totally bypassed and everything is efficient and lovely. 2k - 7k 20psi+ FTW.

Re: Tuning a compound charged car with megasquirt?
 

The biggest reason this is not a viable solution for a gasoline powered vehicle is the PR's that it produces. It is easy to get 60psi out of that setup, and not uncommon to run 100psi+ As well as was mentioned it still only works over a very narrow power band. As even a full pulling cummins diesel still at most only turns 6000rpm and the boost threshold in that setup would be about 1500 - 1800rpm with use able boost not until 2200 - 2500rpm. Leaving you with a power band of about 3500rpm, or about the same as stock. In a street setup they can extend this power band a bit, but at the sacrifice of peak hp numbers.

Re: Tuning a compound charged car with megasquirt?
 

Why would you connect the blower's output to the hotside of all things. That's retarded.

In a twincharged system you would run that to the COLD side of the turbo, thus helping to spin it quicker (you do know how a turbo works, right?).

The boosted charge (containing a much higher volume of air than aspirated) after the turbo then goes to the combustion chamber, where it comes out as as a much higher quantity of exhaust gases (-> pressure) that also help spin the turbo quicker.

:8

Re: Tuning a compound charged car with megasquirt?
 

truth, problem solved. Ford 2.3 guys have made 500hp with the 12cm housing and it spools up quick to boot.