Hey guys, i saw this being discussed in another thread & was excited because it has been on my mind for a while. I am working on getting the parts together to turbo my neon and have orderd the parts from 10secgoal to make a cutom turbo header/manifold. I was going to build a side mount manifold and mount the turbo over the trans. Basically a side mount style manifold that you see on different honda's etc. On neons, the exhaust ports are on the rear of the head, facing the firewall with not much clearence for anything larger than t3 based turbos.

Now I am thinking that since I am using a twin scroll .94 t4 exhaust housing (gt40/82 turbo) on a 2.2 liter (9000 max rpm, 700hp goal) that I should take advantage of the twin scroll housing. I called precision about using a smaller turbine housing, but they think the larger housing will work well with my combo. So, with some help from my brother we were able to move the engine forward to gain clearence for the turbo in between the engine & the firewall. With that being said, I would like to now make a equal length tubular manifold the splits the exhaust pulses between the scrolls on the turbo. What would be the correct way to do route each cyl? The firing order is 1-3-4-2. Do I put 1+4 & 2+3 together? I have tried to think this through but I can't seem to grasp the concept.

Any insight anyone can provide me with will be much appreciated.

*edited for typos

 

In 4 bangers with 1-3-4-2 firing order, complementary cylinders should be grouped together. 1 with 4 to one scroll and 2 with 3 to the other one. (Equal length)


On a side note, I have seen some Neons using the Avenger-Eclipse head on top of their 420a blocks, something like this:


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Or even like this...


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get dustin to send you a picture of what he does inside his collecters...

have a dit of a talk to him about tube size too
there is alittle bit of info around on this subject

 

"In 4 bangers with 1-3-4-2 firing order, complementary cylinders should be grouped together. 1 with 4 to one scroll and 2 with 3 to the other one. (Equal length)"

Typically an expansion "bellows" is used on #4 and #1 to allow some movement of the pipes. If you do not provide for the movement you will crack, even very good, stainless pipes at the common merge point of the transition to one side of the twin scroll. Thick
header flanges (1/2") and slots in the flange (except for one bolt) are normally used too.

Tom Vaught

 

I actually ordered a collector from him so I will get to check it out in a few days. I decided to with 1 5/8" primary tubing and a 2.5" collector. Do you think I would be better of using the merge collector before the turbo than splitting the primary tubes to the seperate scrolls on the turbine?

 

auto or manual ?

 

Manual.

 

I am also going to keep the nitrous on the car incase I need to help get things moving.

 

soo u got antilag ???

 

I have a 2 step with timing control.

 

cool
ur 3/4 's won the deal..

 

3/4's? Sorry man I'm not following...lol

 

your 3/4's there to getting it spooled up
just need the tuning to finish it off
doesn't sound very hard to get the deal working

 

I am thinking about injecting straight meth as well to help keep the motor together with higher boost levels. I am sure I will be looking you up when it is all together for input.

 

Any idea where I can find bellows that can hold up to the head/pressure?

Thanks

 

Thanks for the input. I am actually using a SOHC head on this setup..one of the many things that make my combo unique. The head is the "magnum" head that was used on second generation ACR & R/T neons that has been heavily worked over and also has larger valves. The avenger head is a great Idea and what I will do if I ever move to a dohc setup, I love the extra room of having the exahsut on the front of the egine.

 

I have been mulling the theory of this for a while. A friend of mine is doing a buildup on his corvette with twin turbos with split scrolls. We are going to do 4-2 headers that alternate the firing cylinders on each side of the scrolls of the turbo. This is done on 6 cylinder diesels all day long so there is no reason why it wont work on a 6 cylinder gas. The headers will be the same size primary from the header flange to the turbine inlet flange. The only issue we are looking at on this setup is that a pipe needs to be ran from each side of the header and merged together prior to the wastegate so it vents exhaust from all 4 cylinders instead of just 2. I am hoping the design allows us to have the maximum levels of preturbine exhaust velocity by never letting the cross section increase. We hope alternating the pulses from one side of the housing to the other helps with low speed spool.

 

I have been thinking about wastegate placement more today...isn't a balance tube going to defeat the purpose of splitting the pulses in the first place? How is this usually done? I am not going to use a collector at all, I'm going to run the primary tubes right to the turbo flange and square the ends unless you guys think otherwise...

 

nah, i know nothing...

 

if you go that direction, run a large waste gate run the tube from each pulse and have them join at the v band on the gate
u will not get much 'leakage' of gas thru the small gap near the valve face itself.
ive seen it done of ca 18's and sr 20's