sequential turbo
 

Here's the plan: 14b or t25 attached to the exhaus manifold, dp and wg pipe into a t4.

Here are the problems: space is going to be as hard to get as the chick in my avatar, the 14b is going to be restrictive as heck (yes, I said heck) going into the t4.

here are my proposed solutions: do my best with space, get a different radiator for sure. maybe just have a huge solenoid that is either always open or always closed for the small turbo wg, that way when I get to the boost I want out of the little one the big one will be ready and I can just dump all exhaust gas into it.

the car: 88 civic hatch dx red (for speed)
the motor: B18A bottom end, built with forged rods and pistons and posted sleeves; B16A top end.

any input? so far I've been told by one person that this will not work (they put it in nice terms though), and I've talked to 2 people that said it was going to be a challenge.

Re:sequential turbo
 

Dear god it will NEVER work. Sequential is IMPOSSIBLE to get it to function correctly. simply impossible. Also you can't connect a turbo to a downpipe.

Re:sequential turbo
 

why no turbo to dp action? the pipe coming out of the small turbo will only be 6 inches to a foot, not really a dp. I know I'll probabably have to support the big turbo, I'll just put a brace on the block.

Re:sequential turbo
 

Hey kyle...

You'll also have to run your charge piping through both turbos..

I have no experience on this but, It seems like the t4 will just take over when the exhaust pressure reaches a high enough level.

Restriction from the smaller turbo does seem like it would create a problem.

Can't you play around with two turbos that are more closely related in size? May be that have different trims or rotor sizes to get the different boost threshold.

Edit: After reading what whitey wrote, you may not be able to get enough flow to make the primary turbo spool.

Re:sequential turbo
 

How do you think the flow is going to be? Trust me I thought of a sequential twin and the best way would be to build a custom manifold with multiple wastegates to change the exhaust flow from one turbo to the other. The vaccum system is complicated as hell to get it to function correctly. You'll also need valves in the charge pipes to prevent the massive pressure loss through the non spooling turbo

Re:sequential turbo
 

I trust you Whitey....It's a head scratcher for sure.

How do the factory sequential systems work?

Re:sequential turbo
 

they work like that: http://homepage.ntlworld.com/peter.b...ips/turbos.htm

I didn't even finish reading that, I got bored. ya, I'll have to have butterfly valves in the 2 seperate charge pipes before they come together. Or what they do on semi trucks is they just put one charge pipe into the intake of the second turbo and double compress the air or something like that.

Re:sequential turbo
 

They use a series of multiple valves and ---- with miles upon miles of vaccum lines. The RX-7's had problems with their sequential setup that they run so much better when you rip them off. The theory of it is a good one, it would take alot of research and money to get it to run right.

Re:sequential turbo
 

Kyle, you don't need sequential turbos to impress the girl in your avitar.

One BIG one will do fine I'm sure.

Re:sequential turbo
 

alright, I just read that article, it was shorter than I thought. I'm going to have to have a few valves to prevent gas reversion. It talked about a one way reid valve in the charge pipes, I need to figure out how to make one, it sounds like a good idea.

Re:sequential turbo
 

Check into the reed valves that two stroke motocross bikes use.

Might be adaptable in some way.

Edit: May be rob some of the parts off some one's RX7 system that they took off.

Re:sequential turbo
 

oh but I do. I can tell her: my car has sequential turbos, just like some supras. and her panties will drop right there because she drives a supra.

Re:sequential turbo
 

But you see...Women want what they don't already have.

Re:sequential turbo
 

She'll be more impressed if your car was faster than the Supra, but she's probably in the car with the guy who actually has the Supra ;)

Re:sequential turbo
 

http://www.cardomain.com/memberpage/472959

if some dude really owns the supra I'll just beat him down, I'm crazy like that.

Re:sequential turbo
 

Why don't you use the sequential system off an RX7, I think it would be a lot easier.

Or you could spend WAAAAY to much time and resources to build your own, it would be cool tho. Seriously if you do, you need to completely bypass the 14b once the T3 is spooled. This is going to be a pain in the ass for you.

Re:sequential turbo
 

i dont see the advantage really when you could get a nicely sized t3 or t3/t4 that would spool fine and boost/flow way more than you would need most likely

Re:sequential turbo
 

There were alot of problems with the RX-7 Twin turbos

Here's the sequential setup off a Supra

https://i18.ebayimg.com/01/i/01/34/87/b6_1.JPG

Re:sequential turbo
 

wtf is with all the negativity? I'll have about a year to figure this thing out, it should work by then.

where did you get that pic? any more? I'll draw up my plan on paint next time I'm on a computer. I'll see you guys on monday.

Re:sequential turbo
 

Woah, completely forget what I said about it being impossible, this is very possible and seems like it could work. I'm going to start doing some reseach, I'll let you know what I come up with and we'll get this thing figured out.

Also, I got that pic off of Ebay

P.S Sorry for the negativity I didn't want to sound like a douchebag, but I still believe you can't attach a turbo to the downpipe of another one

Re:sequential turbo
 

alright, twin turbo man will help kyle become sequential turbo boy. We will fight crime.

I found a map sensor on the shelf in my automotive class, and since I don't fully understand a reid or rotary valve I think I'll use the map sensor idea. It was kind of like a trap door. I've got to go, I'll be back in 15 and in 30 I'll have my plan drawn up in paint.

Re:sequential turbo
 

http://www.newbieforces.com/files/sequential.jpg

that's the basic plan. I didn't draw the bypass for from the mani to the big turbo, but you can pretend it's there.

Re:sequential turbo
 

Don't connect the downpipe to the downpipe of another. A custom manifold is necessary. You need 2 actuators, one in the manifold and one after the one turbo in the charge pipe.

Re:sequential turbo
 

I understand the charge pipe one, that's where I was going to put that maf trap door one, I don't know what you're saying with the other one. which turbo will the manifold one block? my plan is to use the ac bracket holes on the block to make a bracket to support the second turbo, and have a one way valve in the exhaust before the second turbo and after the first, in the dp of the first so to say.

for future reference we'll call the smaller first turbo t1 and the bigger second turbo t2.

Re:sequential turbo
 

Answer these questions:

1. Are you connecting t2 to the downpipe of t1?

2. How are you going to regulate the exhaust flow from one turbo to the other?

3. Do you think a MAF trap door will stop 4 to 8psi? Remember if boost is pushing past the seal and spinning the turbo thats not in use, it will be spinning the wrong way and when it is finally in use the change in direction will kill the bearings.

4. What size turbos are you going to use?

5. What motor is this going on?

Re:sequential turbo
 

Kyle, I'm about six months ahead of you. I'll post pics and a write up when I'm done. :-*

Re:sequential turbo
 

Just post pics of how you did your manifold and what actuators your using. Unless your cheating and just bought an RX-7 setup

Re:sequential turbo
 

he's either joking or holding out on his hmt brothers, I think it's the first one

1. Are you connecting t2 to the downpipe of t1?
yes, with a bracket to support t2 so nothing breaks off

2. How are you going to regulate the exhaust flow from one turbo to the other?
some sort of bypass valve before t1 to go into t2, still need to figure out how, and a wg in front of t2

3. Do you think a MAF trap door will stop 4 to 8psi? Remember if boost is pushing past the seal and spinning the turbo thats not in use, it will be spinning the wrong way and when it is finally in use the change in direction will kill the bearings.
I hope it will stop alot of psi, do you have any better suggestions? I could make a nice seat for the door and a high temp rubber seal

4. What size turbos are you going to use?
t1=either 14b or t25 t2=t4

5. What motor is this going on?
LS/VTEC forged rods and pistons pinned sleeves (not yet built, waiting on block and lots of money; the block is coming from bambooseven and the money is coming from magic)

Re:sequential turbo
 

he's either joking or holding out on his hmt brothers, I think it's the first one

Im being a bitch, I'll show you all when its done.

Re:sequential turbo
 

since that's going to be never just show me your progress so far. there is a quote function, I just neglected to use it due to the complexity of my reply.

Re:sequential turbo
 

I figured out how a reid vavle works today, I was getting confused because the picture in the book I was looking at sucked. It's just a flap. anybody have any real-life pictures of them? I can't figure out how to hinge it, maybe just use thin metal?

Re:sequential turbo
 

sounds nifty but with sucha built motor planned why not just run a nice sized t3/t4....originality is cool but think its going limit performance.

Re:sequential turbo
 

You mean like reed valves out of a 2 stroke? I have carbon fiber ones in my Banshee.

Re:sequential turbo
 

ya, like in a 2 stroke. is your banshee a bike?

hotrex, you just don't want my car to be soo much cooler than yours. this isn't just about originality, it's about the power band.

Re:sequential turbo
 

A Yamaha Banshee is a 4-wheeler. 350cc 2stroke twin cylinder. (107mph top speed) Hotrex is right, don't go crazy with dumping lots of money into this thing. I mean I spent under $350 on mine and it was only going on a d-series. You have to be prepared that it might not work and you have to throw it in the trash.

Re:sequential turbo
 

I'm already crazy on this thing. I've decided that I'm going to go with the 2 air filter design so that t1 isn't restricting t2 and so I can pull off both my headlights and put air filters in them when I drag race. There are only 3 things I need to figure out before the planning stages are done:
-how to do the bypass into t2
-where I'm going to put it inside the engine bay
-how I'm going to make the anti reversion vavles.

whitey, what is your idea with a custom manifold so that I don't have a turbo attached to a dp of another one? could you put your paint skills into action for me?

Re:sequential turbo
 

what im saying is your feeding a 14b then a t3 60/03? your still gonna need a big turbo to push the cfm

Re:sequential turbo
 

no, the 14b feeds a t4, I don't know what ar yet, still don't have either of them. what do you mean? the 14b is for fast response, once it hits 6 psi then the t4 takes over and whoops some ass.

Re:sequential turbo
 

Are you saying that you want the 14b to not have anymore exhaust? It sounds like to want to have the exhaust flow switch from one to another, not sequentially.

After thinking about this one for a few days, it really isn't that hard, The only things that has me thinking is the amount of CFM you can flow through one wastegate. I think you might need to look at two wastegates to feed the T4. This is where the math comes into play...

Re:sequential turbo
 

I'm trying to figure out how I can get some sort of bypass worked out with a big hole to go from teh mani to the t4. It may not be supra sequential, but it's sequential by definition since one turbo follows the next. the t4 is getting exhaust all the time, it's the 14b that gets cut off.