96-98 Custom Centri Discharge Tube

[greasy]

I am picking up a centri kit and going down a path less followed. I had a couple of questions for you guys. I am going to be running a non-intercooled blow thru setup with BOV and meth. Since that is the case, I was going to fab up a custom discharge tube.

I was planning on running a 45 degree 4" to 3" reduction silicone coupler right off of the TB in to a straight piece of pipe welded into a cut 180 bend back into the head unit. I understand that I will probably have to modify the angle of the coupler to locate the straight portion appropriately. I am doing this to give me the longest run of straight pipe and produce the best laminar airflow possible for the blow thru MAF.

Do you foresee any issues with running an angled couple off of the TB in a boosted application?

Will the 3"/3.5" fit under the hood if it is running over the valve cover just adjacent to the strut tower? The strut tower brace is not on the car.

Should I use 3.5" or 3" pipe for my discharge tube? This is going to be a setup on about 10 lbs. right now, with plans to boost more in a couple of years.

I am going to run a Vortech Race BOV very close to the head unit, before the bend into the straight portion of the tube where the MAF is located. Will this BOV cause any issue affecting air flow?

I was hoping somebody might have experience with this and I am just spitballing ideas since my car is in storage right now. Thanks for the help!

 

[amoosenamedhank]

With the distance of the piping and more important the angles you're dealing with, I think you're going to cause yourself more headaches than it's worth going Blow Thru.

That and I've never seen an oval to round silicone coupling in a 45°..... I'm not sure how that's going to work.

 

[greasy]

I hear ya and the draw thru option is not out the window.

With the plans of going bigger down the road, I would rather just work my way through it now because draw thru has its limitations. The fab up does not seem like that big of deal to accomplish.

 

[amoosenamedhank]

Well I still don't know where you'd get a coupler like that... physically making the tube isn't going to be the issue. Have enough straight section before the MAF is going to be your biggest problem.

 

[greasy]

Here is the coupler....

Bending Reducer

When I actually get the car out of storage to my place and have the kit, I can see if this is actually feasible. I think I will at minimum be able to get 4-5" before & after the MAF.

 

[amoosenamedhank]

How is that going to fit on the cobra's oval throttle body?

 

[procharged 99]

Well I still don't know where you'd get a coupler like that... physically making the tube isn't going to be the issue. Have enough straight section before the MAF is going to be your biggest problem.

+1 I don't see a way how your going to make this work, to short of distance to many bends.

 

[greasy]

It is silicone and pliable. Why wouldn't it fit?

 

[greasy]

+1 I don't see a way how your going to make this work, to short of distance to many bends.

How much straight pipe is needed pre and post MAF in your opinion?

 

[amoosenamedhank]

How much straight pipe is needed pre and post MAF in your opinion?

There are a lot of opinions out there on this... and I think which MAF sensor you're using may make a difference. I've seen people recommend 3-4x the diameter before and up to 2x after.

You may also need to place a section of honeycomb in there with how violent your turn is going to be.

 

[greasy]

That sounds like some good advice and I have been entertaining the idea of a honeycomb. I was thinking of going with the Pro-M Slot or VMP HPX 05 Slot MAF. Any other recommendations?

I appreciate you guys poking holes in this. Even if this fails miserably, it will not cost much to switch back to a draw thru setup. I want to try and make it work though.

 

[greasy]

This sounds promising......

100mm Maf kickin my Butt!!! - HP Tuners Bulletin Board

 

[SpittingCobra]

Helomech74 and a few others have their tube leading to the throttle body as you described. Only issue I think might be that the throttle body is 4.5" or another odd size IIRC.. Saw some discussion about it and the coupler was difficult to source..


And no offense to the other posters in the thread but this is nothing new.. Even the Hellion turbo kit is built the same way with a coupler from oval to round.. That's a ridiculous idea to think it's not possible!

 

[greasy]

Helomech74 and a few others have their tube leading to the throttle body as you described. Only issue I think might be that the throttle body is 4.5" or another odd size IIRC.. Saw some discussion about it and the coupler was difficult to source..


And no offense to the other posters in the thread but this is nothing new.. Even the Hellion turbo kit is built the same way with a coupler from oval to round.. That's a ridiculous idea to think it's not possible!

Thanks bud, I think I recall seeing that the TB was 4.25" in diameter in that thread in my tons of research. I know that website that I posted the link to with the coupler has a 4.5" to 3" 45 degree reducer. The 4.25" one may be a little more difficult to source.

 

[SpittingCobra]

Thanks bud, I think I recall seeing that the TB was 4.25" in diameter in that thread in my tons of research. I know that website that I posted the link to with the coupler has a 4.5" to 3" 45 degree reducer. The 4.25" one may be a little more difficult to source.

Stalked his threads and looks like he asked the question before he sourced his piece but nobody gave him an answer.. hm..

http://www.svtperformance.com/forums/blower-bistro-74/484093-need-info-coupler-size.html


I think you're right though, think it is 4.25"..

I know for a fact Hellion Turbo kit comes with one. See if they'll sell you a coupler.

 

[greasy]

I found a thread on the Corral that said the outside diameter of the stock TB was 4.5" and Treadstone sells the 4.5" to 3" straight coupler. Looks like I will use a 45 degree bend tube instead of the coupler, it is probably for the best anyway.

 

[amoosenamedhank]

And no offense to the other posters in the thread but this is nothing new.. Even the Hellion turbo kit is built the same way with a coupler from oval to round.. That's a ridiculous idea to think it's not possible!

I guess I wasn't very clear, I meant the 4" circular coupler wasn't going to fit around the cobra's oval throttle body.

I've never seen a 4.5" to 3" 45° reducer coupling. Your idea with a straight coupling and a curved pipe will most likely be your only option.

 

[SpittingCobra]

I guess I wasn't very clear, I meant the 4" circular coupler wasn't going to fit around the cobra's oval throttle body.

I've never seen a 4.5" to 3" 45° reducer coupling. Your idea with a straight coupling and a curved pipe will most likely be your only option.

^This is still a confusing statement.^

ANY silicone coupler that is the proper diameter to fit the throttle body WILL fit. And also will be ROUND before you clamp it on your TB.

Silicone couplers are simply a length of silicone hose..

It's not hard rubber like JLT uses with their CAI kits..

 

[SVTPete83]

Just go draw through and do this...