Why wouldn't this work? Turbos in series
 

I am trying to find a good reason not to try this:

http://www.geocities.com/cheaptrixra...equentials.jpg

I have been running a few of the IHI's on ew4/d15a3s for a while now and i know they are spooled by 2.5k and push great up to about 12psi (after that they just overheat the air).

I am running a t3/t4 now and it isnt spooled until a little after 4k but it could make 20+psi all day long.

I'm thinking the boost from the little turbo would create more exhaust to spin the big turbo so that both are on good boost by 3k. This seems like it would work well for 11-13psi of boost and eliminate my need for expensive nitrous oxide to spool the turbo.

I think it would start to cause problems if I turned the boost up past 14psi or so because the little turbo would be overworked and make the air so hot it would not be efficient. I will address that problem later unless someone tells me this is stupid now (with a good reason).

Any advice or comments or questions would be appreciated.

-Tony

Re: Why wouldn't this work? Turbos in series
 

only problem I'd see is the oil lines for the IHI turbo. It would be really low.

Re: Why wouldn't this work? Turbos in series
 

i meant to add a note to ignore the physical positioning in the picture. the drawing is only to illustrate the routing of the exhaust and intake pipes... the turbos would actually be mounted almost side by side (no oil drainage problems).

-tony

Re: Why wouldn't this work? Turbos in series
 

What's going to prevent reversion of the intake pressure when the larger turbo isn't spinning fast enough to keep the pressure in the intake?

Air, water, and electricity will flow towards the path of least resistance. I'd fear that the larger turbo will be leaking out boost prior to it's spooling up to speed.

This can also cause the smaller turbo to overspin during these conditions as well.


Just a thought,


Wink

Re: Why wouldn't this work? Turbos in series
 

that smaller turbo would just be a bottleneck. Real Sequential twins usually have some kind of air doors to isolate each turbos exhaust flow and charge air

Re: Why wouldn't this work? Turbos in series
 

I know they do stuff like this on pulling trucks/tractors.

Re: Why wouldn't this work? Turbos in series
 

I think once the T3/T4 gets spooled it will overspool the lil IHI.

Re: Why wouldn't this work? Turbos in series
 

cause i made the chart wrong

http://memimage.cardomain.net/member...7_359_full.jpg

Re: Why wouldn't this work? Turbos in series
 

The second drawing is more of what I had in mind. The intercooler would have to kick ass because the charge temps would be quite high.

Re: Why wouldn't this work? Turbos in series
 

When the smaller turbo spools, the air will be forced into you intake mani and probably back out through the bigger turbo. When the larger turbo finally spools the higher boost will probably put a decent amount of back pressure on the smaller turbo and maybe even cause it to flutter or over spool. You need some kind of proportioning valve as someone said ealier. Maybe some way to redirect air flow depending on what rpm or boost your seeing. Just a like a turbo/supercharger application.

Re: Why wouldn't this work? Turbos in series
 

http://www.geocities.com/cheaptrixra...rbo_piping.jpg

how about this then; i know it is getting complicated, but so are factory sequentials. the small turbo would be allowed to free spin while the larger turbo makes boost without being forced in the opposite direction. the exhaust could be vented after the big turbo at whatever psi i want the little turbo to make (i guess the vauum line should connect to the pipe after the little turbo... oops). and the charge air could bypass the little turbo via a wastegate used on the charge pipes. the first wastegate would actually control my max boost setting from the large turbo.

and the intercooler will be circulating with ice water so it will kick as much ass as an intercooler possibly can.

thanks for the response so far everyone,
-tony

Re: Why wouldn't this work? Turbos in series
 

IMO the best way to do it... but i think its a little over the top for such a small motor. a large turbo is better off spooled due to high rpms/compression proper ignition timeing and AFR's and the heads ability to flow.

http://img91.imageshack.us/img91/5894/myversion5rl.jpg

Re: Why wouldn't this work? Turbos in series
 

I would go with the first setup. use a one way valve on both charge pipe. and an electronic exhaust cut out in between both exhaust side so exhaust from the bigger turbo can go directly into the DP once it start to spool.

Re: Why wouldn't this work? Turbos in series
 

just run nitrous+t3/t4. screw all of that nonsince

Re: Why wouldn't this work? Turbos in series
 

Newbies.
Study how sequential turbocharging works. It requires lots of control valves and electronic control too.

Re: Why wouldn't this work? Turbos in series
 

Yup.

Actually, you can stack turbos like the diesel boys do, but gas engines usually don't like the charge temps or mutant boost figures.

None of the diagrams shown are how the diesel guys stack turbos, tho... :3

Re: Why wouldn't this work? Turbos in series
 

I think that is a great idea but out of ease of installation, wouldn't it be better to run one of those variable exhaust turbos you find on the newer audi's? It would give you the spool up time of an IHI and then once the pressure is high enough the exhaust fins adjust to resemble more like a bigger turbo. Just like the one found here:

https://www.homemadeturbo.com/forum/...?topic=57479.0

I would really like to see someone have one of these installed and running. Don't get me wrong, I think you have a great idea on your hands and it is something very different but simply out of ease of installation this can be a great alternative.

EJ O0

Re: Why wouldn't this work? Turbos in series
 

i think banks turbo system has a similar setup for diesel. a sequential would be nice if it had some type of gating system to regulate flow from one turbo to the other depending on engine speed

Re: Why wouldn't this work? Turbos in series
 

Correct. They also use two different sized turbos as well. Here's my old Volvo project that got started but sadly never made it into the car:
http://img89.imageshack.us/img89/365...project9xe.jpg

Re: Why wouldn't this work? Turbos in series
 

Yeah the diesel systems are different, they're used to run high boost figures not normally possible with a single centrifugal compressor. (100psi ish)

Re: Why wouldn't this work? Turbos in series
 

exactly just think of when you hear a rig you usually hear the turbos over anything and when they blowoff they sound like 4 turbos releasiing pressure=mad psi

Re: Why wouldn't this work? Turbos in series
 

how do you plan on controlling the boost to the little turbo because you're only going to be running on the exhaust that goes through the bigger turbo.....i would recirculate the WG dump into the piping BEFORE the littler turbo in order to give it full potential to boost..........

Re: Why wouldn't this work? Turbos in series
 

one thing...after seeing your pics of your choices....

1. Put the big turbo up top on the manifold
2. Use the exhaust from the big one and the recirc dump to spool the smaller one
3. Put the compressed air from the smaller turbo into the compressor side of the larger one

The reason is you're going to want the big turbo to have the access to the most exhaust as you can, so you're going to want it right on the manifold and let the littler one take the leftovers because its not going to take as long to spool it. Use the compressed air to feed the bigger one in order to reduce the amount of work the bigger turbo has to do. The only problem i see is that you're going to pull ONLY as much air as the little turbo will supply and once you're out of its efficiency range, then you're going to be eating a lot of hot air and possibly not enough air for the big turbos liking.......

Re: Why wouldn't this work? Turbos in series
 

lame waste of time.

Re: Why wouldn't this work? Turbos in series
 

^^ Probably because it doesn't take a T3T4E 57 trim that long to spool anyway..........its a fun idea and would be kinda cool....practical....maybe

Re: Why wouldn't this work? Turbos in series
 

It is completely un necessary to run 2 turbos on a 1.5 liter motor

Re: Why wouldn't this work? Turbos in series
 

it does on my 1.5l 12 valve motor. no boost until 4k and full boost isnt until 5k or so. not soon enough to get a good launch without electronics or nitrous.

-tony

Re: Why wouldn't this work? Turbos in series
 

Diesel's usually don't have BOV's. That BOV noise your hearing is the air brakes.

Re: Why wouldn't this work? Turbos in series
 

No that noise you're hearing on the tractor pullers is the compressor chatter. When the accelerator is released, the flow of exhaust pretty much stops. With high pressure in the charge pipes you are going to get surge when you stop the exhaust flow.

Re: Why wouldn't this work? Turbos in series
 

Id hate to ruin this little party but the thought of a sequential turbo'd 1.5L just sounds like overkill. why dont you just supercharge/turbo the damn thing and call it a night..? just a thought

Re: Why wouldn't this work? Turbos in series
 

^^Or with the money you'd be spending to do any of these ideas, get a different engine like a GSR or B16........just a thought......

Re: Why wouldn't this work? Turbos in series
 

or get a burly motor like mine... ;D